FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt...

290
ISRS 2005 International Congress and Exhibition 11-15 September - Brussels, Belgium www.isrs2005.com 2 0 0 5 , I S R S i n B r u s s e l s ISRS thanks the Magritte Foundation for its support Under the High Patronage of Her Majesty the Queen Fabiola of Belgium 7 th International Stereotactic Radiosurgery Society Congress A multidisciplinary artistry for the brain and the body FINAL PROGRAM AND BOOK OF ABSTRACTS

Transcript of FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt...

Page 1: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

ISRS 2005International Congress and Exhibition 11-15 September - Brussels, Belgium

© A

DAG

P, P

aris

200

5

www.isrs2005.com2005, ISRS in Bruss

els

ISRS

than

ks th

e M

agrit

te F

ound

atio

n fo

r its

sup

port

Under the High Patronage of Her Majesty the Queen Fabiola of Belgium

7th International Stereotactic Radiosurgery Society Congress

A multidisciplinary artistry for the brain and the body

FINAL PROGRAM AND

BOOK OF ABSTRACTS

Page 2: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Congress VenueThe ISRS 2005 congress and exhibition take place in the heart of the businessand commercial district of Brussels, place Rogier. The 2nd and 3rd floor of theSheraton hotel have exclusively been reserved for the ISRS 2005.

Address Sheraton Hotel Brussels3, Place Rogier • B-1210 BrusselsPhone : +32.2.224.31.11 • Fax : +32.2.203.34.56Website : www.sheraton.com/brussels

ISRS 2005 Floorplan

Ground Floor Welcome and registration desks

1st Floor Speakers slide center : room Tempo

2nd Floor

3rd Floor

, International Congress and Events OrganizersOrganized by

Page 3: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Table of Contents

FINAL PROGRAM

Congress Program Overview 4

Welcome Messages 8

ISRS 2005 Committees & Organisers 10

The ISRS Society 12

Registration Information 13Registration Desks 13On-site Registration 14Registration fees include 15

Congress information & services 16Book of abstracts 16Accreditation 16Awards 16Badges 16Bags Contents 16Cancellation 17Catering 17Certificate of Attendance 17Cloakroom 17Disabled Persons 18Display Areas 18Disclaimer 18Dress Code 18First Aid 18Hotels 18Internet Area & Wi-fi 18Language 19Lost and Found 19Lottery 19Meeting Rooms 19Meeting Point 20Messages 20Parking 20Personal Insurance 20Photocopy & Fax 20Press 20Security 21Smoking 21Special Needs 21Vouchers 21

Scientific Program 22Introduction 22Scientific Sessions Descriptions 22Slide Center & Oral Presenters Guidelines 23Poster Presenters Guidelines 24Disclaimer & Guest Editor 25Daily Scientific Program 26

Sunday Sept. 11, 2005 26Monday Sept. 12, 2005 27Tuesday Sept. 13, 2005 49Wednesday Sept. 14, 2005 57Thursday Sept. 15, 2005 79

Exhibition 87Description 87Floorplan & List of Exhibitors 88

Sponsors & Exhibitors Activities 90

Congress Social Program 97Opening Ceremony & Welcome Reception 97Gala Dinner & Concert of Toots Thielemans 97

Tours & Accompanying Persons Program 99

About Brussels 102

Area Map 106

BOOK OF ABSTRACTS

Oral Presentations Abstracts 107Posters Abstracts 201Sponsored Sessions Abstracts 285

Copyright: ISRS 2005, Brussels, August 2005The information and statements herein are believed to be reliable, but arenot to be construed as a warranty or representation for which the authorsassume legal responsibility. No part of the editorial content may be trans-lated, transcribed or reproduced in any way without prior written permis-sion from ISRS 2005.

03

Page 4: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Congress Program Overview

04

Monday 12/09/05Sunday 11/09/0507h00 - 18h00

07h00 - 17h30

08h30 - 18h00

10h00 - 17h30

07h30 - 08h30

08h45 - 10h00

10h00 - 10h30

10h30 - 11h30

REGISTRATION DESKS

SLIDE CENTER - Tempo

EXHIBITION

REGISTRATION DESKS

SLIDE CENTER - Tempo

EXHIBITION

POSTER VIEWING - Holbein/Turner/Foyer

BS1 - RembrandtFramelessStrategies

COFFEE BREAK & EXHIBITION

BS2 - PermekeCombined

Approaches

BS3 - WillumsenRadiosurgical

Pathology of BrainTumors and

ExperimentalBackground

P1 - POSTER SESSION - Holbein/Turner/FoyerGeneral, Extracranial Radiosurgery,Vestibular

Schwannomas, Arteriovenous Malformations, Metastases,Gliomas, Radiobiology, Medical Imaging, Proton Therapy

P1-1 to P1-70

11h30 - 12h30

12h30 - 14h00

OS1 - NationLarge

ArteriovenousMalformations

PRE-CONGRESS SYMPOSIUM & LUNCH *

Permeke/RembrandtOrganised by Accuray

Pioneering Techniques in CyberKnifeRadiosurgery

* Registration required

OPENING CEREMONYNation

Welcome Session The EU

Competitiveness and the Socio-economic

Challenges ofRadiosurgery

WELCOME RECEPTION& OFFICIAL OPENING OF THE EXHIBITION

13h00 - 13h45

14h00 - 15h00

15h00 - 16h00

16h00 - 16h30

16h30 - 17h30

11h00 - 17h00

14h00 - 18h00

16h30 - 20h00

12h30 - 16h30

17h00 - 18h00

18h00 - 20h00

OS2Permeke/Rembrandt

Radiobiology

OS3 - WillumsenGliomas

COFFEE BREAK & EXHIBITION

LUNCH & EXHIBITION Supported by BrainLAB

SPONSORED SEMINAR, by BrainLAB - NationNovalis for Functional Neurosurgery

OS4 - NationVestibular Schwannomas 1

OS5 - Permeke/RembrandtLung Tumors 1

OS6 - Nation Vestibular Schwannomas 2

OS7 - Permeke/RembrandtLung Tumors 2

OS8 - NationVestibular Schwannomas 3

FREE EVENING

OS9 - Permeke/RembrandtOther Tumors

PS1 - NationConformity & Selectivity, Lung Cancer,

Craniopharyngiomas, Spinal Metastases

Page 5: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

05

07h00 - 13h00

07h00 - 12h30

08h30 - 13h00

10h00 - 12h30

07h30 - 08h30

08h45 - 10h00

10h00 - 10h30

10h30 - 11h30

11h30 - 12h30

12h30 - 14h00

Tuesday 13/09/05REGISTRATION DESKS

SLIDE CENTER - Tempo

EXHIBITION

POSTER VIEWING - Holbein/Turner/Foyer

BS4 - Rembrandt What Risk of Cancerogenesis

in Radiotherapy and Radiosurgery?

COFFEE BREAK & EXHIBITION

BS5 - PermekeRadiosurgery for

Arteriovenous Malformations

BS6 - WillumsenPhysics – New Technologies

OS13 - NationBrain Metastases 2

FREE EVENING

OS14 - Permeke/RembrandtMeningiomas 2

OS15 - WillumsenPhysics – Leakage

OS10 - NationBrain Metastases 1

OS11 - Permeke/RembrandtMeningiomas 1

OS12 - WillumsenPhysics – General

PS2 - NationData Blitz Update 1 Extracranial RadiosurgeryData Blitz Update 2 Vestibular Schwannomas

Brain metastases

FREEAFTERNOON

ISRS Board Meeting - Mezzo

Page 6: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Congress Program Overview

Wednesday 14/09/0507h00 - 18h00

07h00 - 17h30

08h30 - 18h00

10h00 - 17h30

07h30 - 08h30

08h45 - 10h00

10h00 - 10h30

10h30 - 11h30

06

REGISTRATION DESKS

SLIDE CENTER - Tempo

EXHIBITION

POSTER VIEWING - Holbein/Turner/Foyer

BS7 - RembrandtEpilepsy

COFFEE BREAK & EXHIBITION - Offered by BioScan & Dixi medical

COFFEE BREAK & EXHIBITION

BS8 - PermekeBrain Metastases

BS9 - WillumsenPhysics - Quality Assurance

P2 - POSTER SESSION - Holbein/Turner/FoyerPhysics, Molecular Imaging, Meningiomas, Functional Radiosurgery,

Spinal Radiosurgery, Pituitary TumorsP2-1 TO P2-68

11h30 - 12h30

12h30 - 14h00

OS16 - NationFunctional Radiosurgery 1

13h00 - 13h45SPONSORED SEMINAR, by Medtronic - Nation

The Complementary Role of Intra Operative MRI and Radiosurgery

14h00 - 15h00OS19 - Nation

Functional Radiosurgery 2OS20 - Permeke/Rembrandt

Physics – News

15h00 - 16h00OS21 - Nation

Functional – Trigeminal Neuralgia 1

16h00 - 16h30

ISRS Business Meeting - Nation (for Society Members only)17h30 - 18h00

OS22 - Permeke/RembrandtPhysics – Quality Assurance

16h30 - 17h30

19h30 - 23h00

OS23 - NationFunctional – Trigeminal Neuralgia 2

GALA DINNER Plaza Theater - Théâtre Le PlazaConcert of Toots Thielemans

OS24 - Permeke/RembrandtSpine

OS17 - Permeke/RembrandtImaging Arteriovenous

Malformations

OS18 - WillumsenExtracranial Radiosurgery 1

PS3 - NationData Blitz Update 3 Brain Metastases

Data Blitz Update 4 PhysicsComparative Technologies

LUNCH & EXHIBITION - Supported by Medtronic

Page 7: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

07

07h00 - 13h30

07h00 - 12h30

08h30 - 14h00

10h00 - 12h30

07h30 - 08h30

08h45 - 10h00

10h00 - 10h30

10h30 - 11h30

11h30 - 12h30

12h30 - 13h30

Thursday 15/09/05REGISTRATION DESKS

SLIDE CENTER - Tempo

EXHIBITION

POSTER VIEWING - Holbein/Turner/Foyer

BS10 - RembrandtSpinal Stereotactic

Radiotherapy

COFFEE BREAK & EXHIBITION

BS11 - PermekeVestibular Schwannomas

Hearing Preservation

BS12 - WillumsenPituitary Tumors :

Radiosurgery or Radiotherapy?

OS28 - NationArteriovenous

Malformations 2

OS29 - Permeke/RembrandtExtracranial Radiosurgery 2

OS30 - WillumsenImaging 2

OS25 - NationArteriovenous

Malformations 1

OS26 - Permeke/RembrandtPituitary &

Craniopharyngiomas

OS27 - WillumsenMOLECULAR IMAGING - PET

PS3 - NationData Blitz Update 5 Functional Radiosurgery

Data Blitz Update 6 Spinal RadiosurgeryCombined Strategies, Trigeminal Neuralgia, Cancerogenesis

CLOSING SESSION - NationFabrikant Lecture, Young Neurosurgeon Award, Best Poster Award,

Lottery, Closing Speaches

CONGRESS AREAS

Meeting room Nation : 2nd floor

Meeting rooms Rembrandt, Permeke, Willumsen : 3rd floor

Slide center Tempo : 1st floor

Exhibition & catering area : 2nd floor

Posters areas Holbein, Turner, Foyer : 3rd floor

SESSIONS CODES

PS: Plenary session

OS: Oral Session

P: Poster session

BS: Breakfast seminar

Page 8: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

08

Welcome Messages

A word from the Local Organising Committee of the ISRS 2005

Welcome to our ISRS 2005 Scientific Congress !

We are proud to welcome you to the 7th International Stereotactic Radiosurgery SocietyCongress, under the High Patronage of Her Majesty the Queen Fabiola of Belgium.

Welcome to Brussels, our city

We are pleased to offer you as a setting for the congress, the city of Brussels with its specialarchitectural charm and culinary specialties. But Brussels is not only that, it offers muchmore opportunities in term of social activity and has a tradition in hosting guests from allover the world. Moreover, it is a pleasure to welcome you in the year when Belgium iscelebrating its 175th anniversary.

Welcome among the multidisciplinary attendants

The unique multidisciplinary environment will allow you to meet attendees from variouscountries and to elevate and share your knowledge in the perpetually evolving field ofRadiosurgery.

Thank you

Special thanks to Prof. Jean Régis, Chairman of the scientific committee and to its membersthat have put together such a strong and well-balanced program covering scientificbreakthroughs and key developments in the major fields of our activity.

Also, this diversified program was made possible by the many proposals for topics, lectures,speakers and posters covering a wide range of topics in cranial and extracranial pathologies,radiology, new technologies, physics, …

The ISRS 2005 congress would not have been possible without the support of the sponsorsand the exhibitors, warmly recognized in this program and during the entire congress.

Your very attendance is of the greatest importance: thank you for being here in Brussels anddemonstrating the value of communicating ideas in the field of Radiosurgery.

The congress is all yours !

Yours sincerely,

On behalf of the local organising and host committee

Professor Marc LevivierChairman of the CongressErasme Hospital, Brussels

Professor Jacques BrotchiHonorary Chairman

Erasme Hospital, Brussels

Professor Dirk VerellenCo-ChairmanAZ VUB, Brussels

Professor Paul Van Houtte Co-Chairman

Bordet Institute, Brussels

Page 9: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

09

A word from the President of the ISRS

On behalf of the organising committee and leadership of the International StereotacticRadiosurgery Society, we welcome you to the 2005 meeting !

The venue for scientific interaction is superb and we know that you will enjoy all thatBrussels has to offer.

The scientific program committee under Prof. Jean Régis and with the helpful contributionof David Wikler, has put together a program that will emphasize both brain and bodyradiosurgery, stereotactic imaging, new technologies, and fractionation approaches. Somuch is happening in our field, and this meeting will be a superb opportunity to evaluateclinical outcomes and new concepts.

I would like to thank the meeting committee under Prof. Marc Levivier and Prof. JacquesBrotchi, who have worked so hard to plan, develop, and administrate this meeting.

The meeting received a record number of innovative abstracts and authors of acceptedabstracts are invited to submit formal manuscripts for consideration towards publication inRadiosurgery, the ISRS journal.

Take time to visit the exhibits and explore new technologies. If you are not an ISRS member,visit the registration area and obtain information on membership. On behalf of the ISRSboard of directors, we welcome you to Belgium.

Douglas Kondziolka, M.D.ISRS PresidentPittsburgh, USA

Welcome Messages

Page 10: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

10

ISRS 2005 Committees & Organisers

ISRS 2005 Local Organising Committee

Marc Levivier Jacques BrotchiChairman of the congress Honorary ChairmanNeurosurgery NeurosurgeryErasme Hospital, Brussels Erasme Hospital, Brussels

Paul Van Houtte Dirk VerellenCo-Chairman Co-ChairmanRadiation Oncology Radiation OncologyBordet Institute, Brussels AZ VUB, Brussels

Nicolas Massager Danielle BalériauxTreasurer Medical ImagingNeurosurgery Erasme Hospital, BrusselsErasme Hospital, Brussels

Gyorgy Szeifert Jean D'HaensNeurosurgery Erasme Hospital, Neurosurgery Brussels and National Institute AZ VUB, Brusselsof Neurosurgery, Budapest

Stéphane Simon Medical PhysicsBordet Institute, Brussels

ISRS 2005 Scientific Committee

Radiation Oncology Medical Imaging

Rita Enghenhart-Cabillic Wan-Yuo GuoMarburg, Germany Taipei, Taiwan

John C. Flickinger David Wikler, SecretarisPittsburgh, PA, USA Brussels, Belgium

Minesh P. MehtaMadison, WI, USA

Neurosurgery Medical Physics

Seiji Fukuoka Frank J. BovaSapporo, Japan Gainesville, FL, USA

Roberto Martinez Ingmar LaxMadrid, Spain Stockholm, Sweden

Jean Régis, PresidentMarseille, France

Page 11: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

11

ISRS 2005 Committees & Organisers

Scientific Secretariat

Local Organising Committee Scientific Committee

Professor Marc Levivier Professor Jean RégisChair of the Congress Chairman of the Scientific CommitteeU.L.B. - Hôpital Erasme Service de NeurochirurgieNeurosurgery and Gamma Knife Center Fonctionnelle et Stéréotaxiquec/o ISRS 2005 Hôpital d'adulte de la Timone808, route de Lennik 264 bvd Saint Pierre1070 Brussels, Belgium 13385 Marseille Cedex 05, FrancePhone: +32 (0) 2/555 82 50 Phone: +33 (0) 4/91 38 65 62Fax: +32 (0) 2/555 82 51 Fax: +33 (0) 4/91 38 70 56E-mail: [email protected] E-mail: [email protected]

Professional Congress Organiser

The official Professional Congress Organiser (PCO) appointed by the local organisingcommittee of the ISRS 2005 to ensure the successful efficient administration of allnonscientific aspects of the congress is:

ICEOInternational Congress and Event Organisers122 avenue de l'Atlantique1150 Brussels, BelgiumPhone: +32 (0) 2/779 59 59Fax: +32 (0) 2/779 59 60E-mail: [email protected] & [email protected]: www.iceo.be

You can find the team members of ICEO at the registration desks at the ground floor or inthe congress venue (light blue lanyards & badge), they will be pleased to help you !

Page 12: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

12

The ISRS Society

About the ISRSThe International Stereotactic Radiosurgery Society was founded in 1991. It was organizedto promote the development of the field of stereotactic radiosurgery as follows: • by encouraging mutual fellowship, goodwill and scientific collaboration between all

physicians and scientists actively involved in the field of stereotactic radiosurgery; • by elevating and sustaining the education of all involved in radiosurgery; • by establishing and promoting high standards for the treatment of patients with radio-

surgery; • and by encouraging the accurate reporting of the results of radiosurgery. Members of the International Stereotactic Radiosurgery Society - mostly neurosurgeons,radiation oncologists and medical physicists - convene every two years to share clinical andscientific progress in radiosurgery.

Visit our website : www.intlsrs.org

OfficersDouglas Kondziolka Robert Smee Roberto SpiegelmannPresident Vice-President TreasurerUSA Australia Israel

Board MembersRita Engenhart-Cabillic, MD David Larson, MD, PhDJohn Buatti, MD Mike McDermott, MDFrank Bova, PhD Masaaki Yamamoto, MD

John Sun, MD

ISRS Congress 2007The 2007 ISRS Congress, the 8th anniversary of the biennial congress, will be held in SanFrancisco, USA. This congress will include not to be missed scientific sessions and posterson all aspects in the field of stereotactic radiosurgery. There will be extensive exhibits aswell as opportunities for meeting colleagues and experts from the world at large. San Francisco is considered by many to be the most beautiful and interesting of Americancities. Plan now to be a part of this hallmark event !More information will be available soon on the ISRS website www.intlsrs.org

ISRS Board MeetingTuesday Sept. 12, 2005, 12h30-14h00, meeting room Mezzo (1st floor)

ISRS Business Meeting (for Society members only)Wednesday Sept. 13, 2005, 17h30-18h00, room Nation (2nd floor)

Page 13: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

13

Registration Information

Registration Desks

The team will be pleased to help you with all queries regarding registration, congress mate-rials, hotel bookings, social arrangements, congress program and excursions. Do not hesitate if there is any way in which we can make your stay more enjoyable.

Location Ground Floor of the Sheraton hotel

Opening hours Sunday Sept. 11, 2005 11h00 - 17h00Monday Sept. 12, 2005 07h00 - 18h00Tuesday Sept. 13, 2005 07h00 - 13h00Wednesday Sept. 14, 2005 07h00 - 18h00Thursday Sept. 15, 2005 07h00 - 14h00

Services desks available

Pre-registeredFor participants (members, non-members, one-day, scientific presenters, students, sessionchairs & accompanying persons) who have already registered at the congress and paid theirregistration fee.

Payments & on-site registrationFor all type of participants who register and pay their registration fee on-site, for partici-pants already registered who still have a balance to settle.

Sponsors & exhibitorsFor sponsors and exhibitors (company staff members).

Hotels, social events & tours• For any hotel information through the congress organiser ICEO (bookings made in

advance or on-site requests - subject to availability).• For tours through the congress organiser ICEO (bookings made in advance or on-site

requests - subject to availability). • For any information in relation to the official congress social events (bookings made in

advance or on-site requests - subject to availability).Payments for these activities will be performed from the payment & on-site registrationdesk.

PressFor journalists, registrations, press material or any other related information.

Tourist informationA representative of the Brussels tourist office is available for any question you may haveabout your host city.

Page 14: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

14

Registration Information

On-site Registration

On-site registration will start on Sunday September 11th, 2005.

0n-site registration fees

Type of participants or event FeesMembers 600Non-members 700Medical students and assistants 300Accompanying persons 100One-day registration 250Exhibitors 350Gala dinner 90

The above fees are in EURO (€), Belgian VAT (21%) included.

Payments

Payments are accepted only in EURO (€), by credit cards (Visa, Master/Eurocard andAmerican Express, exclusively) or cash.Checks, personal checks or money orders are not accepted.

Specific requirements

Students and assistantsFee available for medical students and assistants up to 28 years old at the time of congress.Document from department head to certify student status as well as a copy of the ID cardwith the complete registration form are required.

Non membersIf you are not listed on the ISRS membership list, the organisers reserve the right to applythe non-member registration fee.

Page 15: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

15

Registration Information

Registration Fees Include

Parti

cipat

ion

and

adm

issio

n to

the

scie

ntifi

c se

ssio

ns

Cong

ress

bag

and

con

gres

s do

cum

enta

tion

Badg

e

Fina

l pro

gram

and

abs

tract

s bo

ok

Mor

ning

cof

fee

brea

ks o

n 4

days

Afte

rnoo

n co

ffee

brea

ks o

n M

onda

y an

d W

edne

sday

Spon

sore

d lu

nche

s on

Mon

day

and

Wed

nesd

ay

Open

ing

cere

mon

y &

wal

king

rece

ptio

n

Acce

ss to

the

post

ers

sess

ions

& a

reas

Acce

ss to

the

exhi

bitio

n

Certi

ficat

e of

atte

ndan

ce

Poss

ibili

ty to

rese

rve

socia

l eve

nts

and

tour

s

a a a a a a a a a a a a

Mem

bers

,no

n-m

embe

rs,

med

ical s

tude

nts

and

assis

tant

s

aUp

onav

aila

bilit

y

a

aUp

onav

aila

bilit

y

a a a a a a a

Exhi

bito

rs

a a a a a a a

Acco

mpa

nyin

g pe

rson

s

a(o

ne d

ay)

a a a

a(o

ne d

ay)

a(o

ne d

ay)

a(o

ne d

ay)

a(o

ne d

ay)

a(o

ne d

ay)

a(o

ne d

ay)

a

One-

day

regi

stra

nts

For o

n-sit

e re

gist

ratio

ns, e

xhib

itors

and

one

-day

regi

stra

tion

the

full

cong

ress

doc

umen

tatio

n, th

e fin

al p

rogr

am &

boo

k of

abs

tract

san

d th

e co

ngre

ss b

ags

are

subj

ect t

o av

aila

bilit

y.

Page 16: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

16

Book of AbstractsThe abstracts are printed and listed in this final program. They are also available on-linethrough the website www.isrs2005.com.

AccreditationThe ISRS Congress 2005 has applied for Belgian accreditation from INAMI/RIZIV (Institutnational d'assurance maladie-invalidité / Rijksfonds voor verzekering tegen ziekte en inva-liditeit) to establish the congress as a Belgian CME activity.

For more information regarding the credits, please contact the scientific secretariat at theslide center.

AwardsFabrikant, Young Neurosurgeon and Best Poster Awardees will be recognized and celebratedduring the closing session, planned on Thursday September 15, 2005 at 12h30.

BadgesName badges are used as passes. Admission into the congress venue (slide center, whole2nd and 3rd floors) is strictly restricted to registered participants wearing their badge. You arealso kindly requested to wear your badge during the official congress social events.

Exhibitors and accompanying persons are not entitled to enter in the conference rooms.

If the badge is lost, please go to the registration desk. Lost badges can be replaced at a costof 10 € per badge.

The following badge colors are used at the congress :

Transparent: Delegates (members, non-members, on-site, students)White: Accompanying personsYellow: One dayRed: Scientific presenters (oral and posters)Blue: Sponsors and exhibitorsBlack: Staff and organisers

Bags ContentsThe congress bag for delegates includes: the final program and book of abstracts, anotepad, a pen, documentation from the congress major sponsors, companies bag inserts,a city map and documentation about Brussels.

Congress Information & Services

Page 17: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

17

The documentation for accompanying persons includes: touristic information, map ofBrussels, a notepad and documentation about the social program and the tours.

Please note that for on-site registrations, one-day registration and exhibitors, there is noguarantee of availability of the full congress documents and bags.

CancellationA refund of the registration fee will be given after the congress minus a 20% administrativecharge, provided that a written notification has been sent to the organising secretariat nolater than 30th June 2005.

No refunds will be given for cancellations after June 30th, 2005.

Reimbursements will be made after the congress.

CateringRegistered delegates have free access to the congress catering area organized, in the exhi-bition (2nd floor).

Coffee breaks

10h00-10h30 Monday Sept. 12, 2005Tuesday Sept. 13, 2005Wednesday Sept. 14, 2005Thursday Sept. 15, 2005

16h00-16h30 Monday Sept. 12, 2005Wednesday Sept. 14, 2005

Lunches

12h30-14h00 Monday Sept. 12, 2005Wednesday Sept. 14, 2005

Certificates of AttendanceCertificates of attendance can be collected at the registration desks as of WednesdaySeptember 14, 2005 (during the desks opening hours).

CloakroomA cloakroom is at your disposal on the 2nd floor during the congress opening hours.Please note that the organisers of the ISRS 2005 congress deny any responsibility in case oflosses and/or theft.

Congress Information & Services

Page 18: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

18

Disabled PersonsLifts can be used by participants to access all floors of the Sheraton hotel. For specialrequests, please contact the team at your disposal at the registration desks.

Display AreasDisplay areas are situated on the ground floor and on the 2nd floor.

DisclaimerThe ISRS 2005 congress and/or its agent have the right for any reason beyond their controlto alter or cancel, without prior notice, the congress or any of the arrangements, timetables,plans or other items relating directly or indirectly to the congress. ISRS 2005 congress and or its agent shall not, subject as after-mentioned, be liable for anyloss, damage, expenditure or inconvenience caused as a result of such alternation or can-cellation.

Dress CodeThe dress code during the congress is business casual. The gala dinner dress code is business attire.

First AidFor any medical assistance or emergency service, please contact immediately the registra-tion desks (ground floor).

HotelsMost of the participants to the ISRS 2005 congress are accommodated in hotels near thecongress venue in the center of the city. For further information regarding your hotel boo-king or availabilities, please come at the hotels, social events & tours desk (ground floor).

Internet Area & Wi-fiThe ISRS 2005 internet area is at your disposal on the left side of exhibition entrance (2nd floor).To avoid long lines or waiting time, users are kindly required to limit the use of the work-station to 15 minutes per connection.

Congress Information & Services

Page 19: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

19

In the Sheraton hotel, Wi-fi services cover the first floor as well as the restaurant of the hotel.More information regarding Wi-fi services is available from the Sheraton hotel receptions.

LanguageThe official language of the ISRS 2005 congress is English. No simultaneous translation isprovided in the conference rooms.

Lost and FoundFor lost and/or found items, please contact the registration desk (ground floor).

LotteryAs published on the website at the time of the second announcement, delegates who havebeen visiting and registering on the website, www.isrs2005.com, before 31 March 2005,have a chance of being reimbursed of their registration fee. The winner drawing will beorganized on Thursday September 14, 2005 during the closing session. The winner will beinformed through the message board (2nd floor) on the same day as well as by email.

Meeting RoomsThe ISRS 2005 congress scientific sessions and all related activities are exclusively held inthe meeting rooms of the Sheraton Hotel.

The sessions are organized in the following meeting rooms :

Plenary sessions Nation (2nd floor)

Oral sessions Nation (2nd floor)Permeke - Rembrandt (3rd floor)Willumsem (3rd floor)

Breakfast seminars Rembrandt (3rd floor) Permeke (3rd floor)Willumsem (3rd floor)

Poster sessions Holbein (3rd floor) Turner (3rd floor)Foyer (3rd floor)

See maps on the inside front cover for the exact location of these meeting rooms.

Wireless microphones are at your disposal in each meeting room. Participants wishing to take part in discussions should raise their hand to be acknowledged by the chairs of thesession and go to the nearest microphone.

Cellular phones should be switched off and video or tape recording is not permitted.

Congress Information & Services

Page 20: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

20

Meeting PointThe ISRS 2005 Congress meeting point is situated in the registration area (ground floor).

MessagesDelegates have the opportunity to let messages to other participants at the message boardon the 2nd floor, near the lift and stairs. You can pick up your message there.

ParkingThe Sheraton does not have a private parking.The nearest underground parkings are the Rogier parking or the Manhattan parkings (samebuilding as the congress venue).The Manhattan Parking is open 24h/24h. For one hour the fare is 2 €. The whole day at theISRS Congress, which is around 10 hours, will cost you around 13,50 €.The Rogier parking is open from Monday to Saturday form 7h00 to 23h30, closed on Sunday.For one hour the fare is 2,10 €. Between 9h00 and 24h00 parking time, the price is 13,80 €. Both parkings are equipped with automatic cash machine and credit card facilities.Also, many public parkings can be found in the surroundings.

Personal InsuranceAll participants should carry the proper travel and health insurance. The ISRS 2005 congresscannot accept liability for any accidents or injuries that may occur at the congress.

Photocopy & FaxA business center, where you can make photocopies and send fax is situated in front of thehotel reception desk (ground floor).

PressPre-registered or on-site registrant journalists are invited to go at the press desk (groundfloor) to collect the press materials.A press conference is organized at the congress venue on Thursday September 15, 2005.More information is available from the press desk.

Congress Information & Services

Page 21: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

21

SecurityAccess within the congress floors during the congress hours is controlled by the security ofthe ISRS 2005 Congress and it is limited to the participants wearing the congress badges. The Sheraton surveillance agents will ensure the general security of the hotel’s guests. Theexhibition area will be locked during the night.Every reasonable precaution is taken in terms of safety and security. However, as in all majorcities and public areas, people should take special care of their personal belongings. Theresponsibilities of the ISRS 2005 are limited.

SmokingFor health and security reasons and as a courtesy to non-smoking participants, you are notallowed to smoke on the 2nd and 3rd floor of the Sheraton Hotel, as well as in the restaurantof the hotel. However the hotel lobby on the ground floor remains a smoking area.

Special NeedsFor any special needs or dietary requests please contact the on-site registration desks(ground floor). Special requirements for vegetarians or other diets can be arranged uponrequest.

VouchersVouchers for pre-registered delegates to the gala dinner or tours are distributed togetherwith their badge.

Congress Information & Services

Page 22: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

22

Introduction

The day by day scientific program is organized along calendar days in the following pages.The overview chart is on the inside back cover, at the beginning of this program. Thisdetailed day by day program contains all information regarding day, time, session type, session number, meeting room, session title, chairmen, speakers and abstracts titles.

The book of abstracts is published at the end of this final program. It includes acceptedpapers, listed in the chronological order of their presentation.

Numbering of abstracts

The abstracts have been numbered by session. Poster session abstracts have been groupedaccording to the poster session to which they relate.

Scientific Sessions Descriptions

BS / Breakfast seminars

Parallel breakfast seminars are taking place on the 3rd floor, in the rooms Permeke,Rembrandt and Willumsen on :

Monday Sept. 12, 2005 07h30 - 08h30Tuesday Sept. 13, 2005 07h30 - 08h30Wednesday Sept. 14, 2005 07h30 - 08h30Thursday Sept. 15, 2005 07h30 - 08h30

A light continental breakfast is served in the respective meeting rooms to the attendees ofthese sessions.

PS / Plenary sessions

Plenary sessions are all organized on the 2nd floor, in the meeting room Nation. They last1h15 and are held by renowned experts on :

Monday Sept. 12, 2005 08h45 - 10h00Tuesday Sept. 13, 2005 08h45 - 10h00Wednesday Sept. 14, 2005 08h45 - 10h00Thursday Sept. 15, 2005 08h45 - 10h00

OS / Oral Sessions

Oral sessions are located on the 2nd and 3rd floor, in the rooms Nation, Permeke, Rembrandtand Willumsen and will take place on :

Monday Sept. 12, 2005 11h30 - 12h3014h00 - 15h0015h00 - 16h0016h30 - 17h30

Scientific Program

Page 23: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

23

Tuesday Sept. 13, 2005 10h30 - 11h3011h30 - 12h30

Wednesday Sept. 14, 2005 11h30 - 12h3014h00 - 15h0015h00 - 16h0016h30 - 17h30

Thursday Sept. 15, 2005 10h30 - 11h3011h30 - 12h30

Poster Viewing

Posters are displayed on the 3rd floor, in the rooms Turner, Holbein and Foyer as follows :

Monday Sept. 12, 2005 10h00 - 17h30 Poster Session P1Tuesday Sept. 13, 2005 10h00 - 12h30 Poster Session P1Wednesday Sept. 14, 2005 10h00 - 17h30 Poster Session P2Thursday Sept. 15, 2005 10h00 - 12h30 Poster Session P2

P / Poster Sessions

During the following sessions organized in the poster areas on the third floor, you are ableto meet the authors of the posters as well as some of the co-authors.

A poster board with a position number for identification purposes is at the entrance of theposter rooms. Moreover, an ICEO team member will be there to assist you.

P1 Monday Sept. 12, 2005 10h30 - 11h30Topics: GENERAL, EXTRACRANIAL RADIOSURGERY, VESTIBULAR SCHWANNOMAS,ARTERIOVENOUS MALFORMATIONS, METASTASES, GLIOMAS, RADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY

P2 Wednesday Sept. 14, 2005 10h30 - 11h30Topics: PHYSICS, MOLECULAR IMAGING, MENINGIOMAS, FUNCTIONAL, RADIOSURGERY, SPINAL RADIOSURGERY, PITUITARY TUMORS

Slide Center & Oral Presenters Guidelines

Slide center opening hours

Sunday Sept. 11, 2005 14h00 - 18h00Monday Sept. 12, 2005 07h00 - 17h30Tuesday Sept. 13, 2005 07h00 - 12h30Wednesday Sept. 14, 2005 07h00 - 17h30Thursday Sept. 15, 2005 07h00 - 12h30

Scientific Program

Page 24: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

24

Location

The slide center is located on the 1st floor, room Tempo for the arrangement and preview ofpresentations. A representative of the scientific secretariat will also be at your disposal inthis room.

Guidelines

All presentations should be downloaded at the slide center for distribution to the conferencerooms. It is not allowed to bring your presentations directly to the technical assistants in themeeting rooms.

Speakers are requested to be present in their presentation room 10 minutes before the startof the session.

The presentations run with PowerPoint only.

The technical equipment and software in the Slide Center is both PC and MAC compatible.

In order to avoid any delay, speakers are kindly requested to hand in their presentation onan electronic support (CD-ROM, USB key, DVD, zip disc, floppy disk or folder) at the slidecenter at least two hours prior to their session. If your session starts early in the morning,please bring the presentation by 17h30 the day before (by 12h30 on Tuesday if your ses-sion is on Wednesday).

If you have any questions, please contact the team of technicians at your disposal in the pre-view room.

Equipment in the meeting rooms

All meeting rooms are equipped with a data projector and a computer. A technician isplanned in each meeting room.Speakers do not need to bring their own laptop.

Poster Presenters Guidelines

At least one of the authors must be present during the entire poster session for which youare scheduled. We encourage you to come with many of your co-authors.

Awards

During all poster sessions the scientific committee members will circulate and discuss postersubjects in order to select candidates for Poster Awards. Be prepared to discuss all aspectsof your work.

Size and font

The poster should be no larger than 90 cm (wide) by 150 cm (tall). As a courtesy to all posterpresenters we ask the poster presenter to respect this size limit. A font size that is easily readable from a distance of up to two meters should be used.

Scientific Program

Page 25: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

25

Posters setup

Posters must be mounted on the first day of your presentation (according to the topic),between 07h30 and 09h30 in the morning. They must remain displayed until the end of your poster session (the 2nd day).Presenters should ensure that the poster is displayed on the correct poster board, accordingto the position number communicated. Please note that the provided stickers are the only method of mounting allowed in order notto damage the panels. Any damage will be charged to the poster presenter/author. Nothingshould be written or painted on the poster boards.

Poster presenter help desk

During the mantling time, an ICEO team member will be there to assist you with your posterboard position and to provide you with poster stickers.

Dismantling

The presenters are requested to take the poster down at the end of the 2nd day of theirposter presentation. If the poster is not removed by the end of the poster viewing slots itwill be taken down by the congress staff. The congress cannot accept liability for lost anddamaged posters.

Disclaimer & Guest Editor

Disclaimer on the published scientific information

This program and book of abstracts have been produced using the author-supplied copy,received by August 27, 2005. Every effort has been made to faithfully reproduce theabstracts as submitted.

Editing has been restricted to some corrections of spelling and style where appropriate. ISRS2005 assume no responsibility for any claims, instructions, methods or information con-tained in the abstracts and title: it is recommended that these are verified independently.Subscription cancellations may have been received after the publishing date. Therefore,some change may occur in the scientific program, on-site, or in the posters numbering. Missing numbers indicate abstracts either not submitted in time for publication, or thosesubsequently withdrawn.

Guest editor and contact

The scientific program and book of abstracts have been organized and edited by thePresident and Secretaris of the scientific committee, Prof. Jean Regis and Ir. David Wikler,respectively . For any inquiries regarding published scientific information or for any other questions thatarise after acceptance of a paper, please contact them by e-mail or inquire the scientific deskat the time of the congress, located in the speakers slide center.

Scientific Program

Page 26: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

26

Daily Scientific Program

Sunday 11/09/05

PRE-CONGRESS SYMPOSIUM & LUNCH * 12h30 - 16h30

Organized by Accuray RoomPIONEERING TECHNIQUES IN CYBERKNIFE RADIOSURGERY Permeke & RembrandtChairmen: Marc, Levivier; Berndt, Wowra; Peter, Levendag

Technology Innovations for Accurate Full Body Radiosurgery

Intracranial Indications

Spinal Indications

Soft Tissue Indications

Special welcome desk organized from 12h00 (distribution of the complete program of the session and bagdes)

Lunch planned for all attendees in the meeting room, from 12h30

* registration required

OPENING CEREMONY 17h00 - 18h00

THE EU COMPETITIVENESS AND THE SOCIO-ECONOMIC Room NationCHALLENGES OF RADIOSURGERYSpecial guest speaker: Philippe Busquin (European Deputy and former Commissioner forResearch at the European Commission)

Scientific ProgramSu

nday

11/0

9/05

Page 27: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

27

Scientific Program

Monday 12/09/05

Breakfast seminars 7h30 - 8h30

FRAMELESS STRATEGIES BS1Room Rembrandt

Frame-based versus frameless strategies BS1-1Ingmar, Lax

Frame-based versus frameless radiosurgery : accuracy issues BS1-2David, Wikler

Novalis system – What future for frameless strategies? BS1-3Antonio, DeSalles

COMBINED APPROACHES BS2Room Permeke

Combined strategies for large skull base meningiomas BS2-1Seiji, Fukuoka

Rationale for combined micro- and radio-surgical approaches BS2-2in the management of vestibular schwannomas and skull base meningiomasPierre-Hugues, Roche

Neurosurgical image guidance in partial tumor removal BS2-3for radiosurgeryMarc, Levivier

RADIOSURGICAL PATHOLOGY OF BRAIN TUMORS BS3AND EXPERIMENTAL BACKGROUND Room Willumsen

Radiosurgery: is it an immune stimulating weapon BS3-1in brain tumor neurosurgery?Gyorgy, Szeifert

How do brain tumors respond to radiosurgery? BS3-2Dave S, Atteberry

Brain vascular changes induced by radiosurgery in a rat model BS3-3José, Lorenzoni

Monday

12/09/05

Page 28: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

PLENARY SESSION 8h45 - 10h00

CONFORMITY & SELECTIVITY, LUNG CANCER, PS1CRANIOPHARYNGIOMAS, SPINAL METASTASES Room NationChairman: Marc, Levivier

Enhanced conformality and selectivity using robotic radiosurgery PS1-1L. Dade, Lunsford (1); Douglas, Kondziolka (1); Ajay, Niranjan (2); John C, Flickinger (1); Ann H., Maitz (3) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of PittsburghMedical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Image GuidedNeurosurgery Pittsburgh, USA

Stereotactic radiotherapy for patients with inoperable PS1-2early stage lung cancer. A retrospective studyPia, Baumann (1); Lars, Ekberg (2); Ulf, Isaksson (3); Karl-Axel, Johansson (4); Ingmar, Lax (1); Rolf, Lewensohn(1); Jan, Nyman (4); Suzanne, Rehn-Eriksson (5); Lena, Wittgren (2); Signe, Friesland (1) (1) Karolinska Institutet - Department of Oncology; (2) Malmö University Hospital - Department of Oncologyand Hospital Physics; (3) Karolinska Institutet - Department of Neurosurgery; (4) Sahlgrenska UniversityHospital - Departments of Hospital Physics and Oncology; (5) Uppsala University Hospital - Departments ofHospital Physics and Oncology Stockholm, Sweden

Quality of life after stereotactic radiotherapy for stage I PS1-3non-small cell lung cancer (NSCLC) Frank J., Lagerwaard (1); Ylanga G., van der Geld (1); Ben J., Slotman (1); Suresh, Senan (1) (1) VU Medical Center Amsterdam - Department of Radiation Oncology Amsterdam, The Netherlands

Role of radiosurgery in the multimodality management PS1-4of craniopharyngiomasAjay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); John C, Flickinger (3)(1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center- Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA

Image-Guided radiosurgery of single spinal metastasis PS1-5 Samuel, Ryu (1); Jack, Rock (2); Jian-Yue, Jin (3); Marilyn, Gates (2); Benjamin, Movsas (4); Jae Ho, Kim (5) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery; (3) Henry Ford Hospital- Radiation Oncology; (4) Henry Ford Hospital - Radiation Oncology; (5) Henry Ford Hospital - Division ofRadiation Oncology Detroit, USA

28

Mon

day

12/0

9/05

Page 29: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

29

POSTER SESSION 10h30 - 11h30

GENERAL, EXTRACRANIAL RADIOSURGERY, P1VESTIBULAR SCHWANNOMAS, ARTERIOVENOUS Room Holbein,MALFORMATIONS, METASTASES, GLIOMAS, Turner & FoyerRADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY

Clinical and radiobiological advantages of stereotactic light ion beam radiation therapy for large intracranial arteriovenous malformations P1-1Bahram, Andisheh (1); Bengt, Lind (1); Mohammadali, Bitaraf (2); Panayiotis, Mavroidis (1); Anders, Brahme (1) (1) Karolinska Institutet - Department of Medical Radiation Physics; (2) Iran Medical Science Of University, AliAsghar Hospital - Iran Gamma Knife Center Stockholm, Sweden

Gamma knife radiosurgery for cerebral arteriovenous malformation P1-2Maheep Singh, Gaur (1) (1) VIMHANS Complex - Department of Gamma Knife Radiosurgery New Delhi, India

Management and outcomes of hemorrhage for cerebral arteriovenous malformations treated with radiosurgery P1-3 Tomoyuki, Kouga (1); Keisuke, Maruyama (1); Masahiro, Shin (1); Hiroki, Kurita (2); Nobutaka, Kawahara (1);Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) Kyorin University Hospital - Department ofNeurosurgery Tokyo, Japan

Follow-up to cure of intracranial arteriovenous malformations after gamma knife radiosurgery P1-4 Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA

Fractionated stereotactic radiosurgery for large intracranial arteriovenous malformations P1-5 Shaan, Raza (1); Quoc-Anh, Thai (1); Salma, Jabbour (2); Gustavo, Pradilla (1); Lawrence, Kleinberg (3);Moody, Wharam (3); Daniele, Rigamonti (1) (1) Johns Hopkins University School of Medicine - Department of Neurosurgery; (2) The Johns HopkinsUniversity School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences Baltimore, USA

Scientific ProgramM

onday12/09/05

Page 30: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

30

Scientific Program

Fractionated stereotactic radiotherapy in residual or recurrent nasopharyngeal carcinoma P1-6 Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1);Putipun, Puataweepong (1); Ladawan, Narkwong (1); Jiraporn, Laothamatas (1); Boonchu, Kulapraditharom(2); Veerasak, Theerapancharoen (3); Ekaphop, Sirachainan (4); Pornpan, Yongvithisatid (1); Prasert,Assavaprathuangkul (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - ENT; (3) Ramathibodi Hospital Mahidol University - Department of Surgery; (4) RamathibodiHospital Mahidol University - Medicine Bangkok, Thailand

Linac radiosurgery in extracerebral head and neck lesions P1-7Miron, Sramka (1); Augustin, Durkovsky (2); Arpad, Viola (3); Yaroslav, Parpaley (1); Peter, Strmen (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Departmentof Radiology; (3) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (4) ComeniusUniversity hospital - Department of ophtalmology Bratislava, Slovakia

Endocavitary irradiation of glioma cysts with 90-Yttrium colloid solution P1-9 Arpad, Viola (1); Jeno, Julow (1); Balint, Katalin (2); Istvan, Nyary (3) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute ofNeurosurgery, Budapest, Hungary - Department of Pathology; (3) National Institute of Neurosurgery,Budapest, Hungary - Department of Neurosurgery Budapest, Hungary

Specific nurse attendance during routine Leksell Gama Knife radiosurgery in children P1-10Elisabeth, Rioz Galvez (1); Benoit, Pirotte (2); Patricia, Palacio (1); Arlette, Dewil (1); Philippe, David (3); Daniel,Devriendt (4); Françoise, Desmedt (5); Michel, Baurain (6); Jacques, Brotchi (2); Marc, Levivier (7) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme -Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Centre Gamme Knife; (6) HôpitalErasme - Anaesthesiology Brussels, Belgium

Gamma knife radiosurgery in pediatric population. Early Mexican experience P1-11 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, De Anda Ponce de Leon (1); Miguel, PerezPastenes (1); Juan, Ortiz Retana (1); Manuel, Martinez Lopez (1); Josue, Estrada (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Mexico, Mexico

Mon

day

12/0

9/05

Page 31: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

31

Scientific Program

Stereotactic radiosurgery for benign brain tumors - A single institution experience P1-12 George, Pissakas (1); V, Georgolopoulou (2); M, Kalogeridou (3); E, Andriotis (4); K, Doukaki (3); S, Kosmidou(3); S, Mourgela (5); G, Arhontakis (7); E, Pappas (2); V, Kouloulias (6); I, Kouvaris (10); A, Sotiropoulou (3) (1) ALEXANDRA Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3)St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Radiology; (5) St.Savvas Hospital -Neurosurgery; (6) University of Athens - Radiation Oncology Athens, Greece

Gamma knife radiosurgery for skull base tumors - Complications and outcome P1-13 Sujoy, Sanyal (1); Sandeep, Vaishya (2); Aditya, Gupta (2); S S, Kale (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of MedicalSciences - Neurosurgery Department Calcutta, India

Image guided micro radiosurgery for brain tumors to avoid underlining dysfunction of the surrounding vital structure: technical note P1-16 Motohiro, Hayashi (1); Jean, Regis (2); Taku, Ochiai (1); Koutaro, Nakaya (1); Mikhail, Chernov (1); Masahiro,Izawa (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service deNeurochirurgie Tokyo, Japan

Preliminary experience with MMLC at the INNN in Mexico City. 804 patients treated in a singular facility P1-17Miguel Angel, Celis-Lopez (1); Jose, Suarez-Campos (1); Sergio, Moreno (1); Leopoldo, Herrera (1); Jose M,Larraga (1); Amanda, Garcia G (1); Mariana, Hernandez B (1) (1) National Institute of Neurology and Neurosurgery - Radioneurosurgery Mexico City, Mexico

The use of tissue equivalent Super Stuff Bolus (TM) material to treat skull metastases with gamma knife radiosurgery P1-18 Lilyana, Angelov (1); Gennady, Neyman (2); Gene H, Barnett (3); Betty, Jamison (4); John H., Suh (5); Lilyana,Angelov (6) (1) Cleveland Clinic Foundation - Department of Neurosurgery; (2) Cleveland Clinic Foundation - Departmentof Radiation Oncology; (3) Cleveland Clinic Foundation - Brain Tumor Institute; (4) Cleveland ClinicFoundation - Brain Tumor Institute; (5) Cleveland Clinic Foundation - Gamma Knife Center; (6) Cleveland ClinicFoundation - Brain Tumor Institute Cleveland, USA

Monday

12/09/05

Page 32: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

32

Scientific Program

Magnetic resonance image distortion: a phantom study with varying parameters for stereotactic radiosurgery P1-19 Sawwanee, Asavaphatiboon (1); Ladawan, Worapruekjaru (2); Jiraporn, Laothamatas (2); Pornpan,Yongvithisatid (2); Wiboon, Suriyajakyuthana (2); Lojana, Tuntiyatorn (2); Mantana, Dhanachai (2) (1) Ramathibodi Hospital Mahidol University - Radiology; (2) Ramathibodi Hospital Mahidol University -Department of Radiology Bangkok, Thailand

The use of T2 weighted MRI for post gamma knife follow-ups P1-20 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong

Effects of fiducial marker defects in image registration P1-21 Hyun-Tai, Chung (1); Dong Gyu, Kim (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

The impact of different ways of image definition on the z-position of the target P1-22 Andreas, Mack (1); Stefan, Scheib (2); Marcus, Rieker (3); Dirk, Weltz (4); Robert, Wolff (5); Hans-Jürg, Kreiner(6); Volker, Seifert (7); Heinz, D., Böttcher (8) (1) Gamma Knife Center Frankfurt - Medical Physics; (2) Klinik im Park - Medical Radiation Physics; (3) PTGR-GmbH - Software Development; (4) PTGR-GmbH - Software Development; (5) Gamma Knife Center Frankfurt- Neurosurgery; (6) GKS-GmbH - Management; (7) Johann Wolfgang Goethe University - Neurosurgery; (8)Johann Wolfgang Goethe University - Radiotherapy Frankfurt, Germany

Hypofractionated stereotactic radiotherapy for lung tumors P1-23Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Rolf, Sauer (1); Oliver, Ganslandt (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology Erlangen, Germany

Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose to the organs at risk: a treatment planning study compared to 3-D radiotherapy P1-24 Jean-Briac, Prévost (1); Joost, Nuyttens (2); John, Praag (1) (1) Erasmus MC-Daniel den Hoed Cancer Center - Radiation Oncology; (2) Erasmus MC - Radiotherapy Rotterdam, The Netherlands

Mon

day

12/0

9/05

Page 33: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

33

Scientific Program

The combined stereotactic procedures for cystic cerebral metastatic tumors: A possible pitfall in ‘one day double procedures’ P1-25In-Young, Kim (1); Jung, Shin (2); Tae-Young, Jung (1); sam-Suk, Kang (1) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department ofNeurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea

The benefit of Gama Knife radiosurgery in the treatment of thalamic and brainstem metastases P1-26Wolfgang, Kreil (1); Verena, Weigl (1); Josef, Luggin (1); Sandro, Eustacchio (1); Georg, Papaefthymiou (1);Oskar, Schröttner (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria

Clinical impact of high-resolution MRI on stereotactic radiosurgery for patients with brain metastases P1-27 Julian, Perks (1); William, Hall (1); Conrad, Pappas (1); James, Boggan (2); Robin, Stern (1); John, Hartman (3);Claus, Yang (1); Richard, Latchaw (6); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation Oncology; (2) U.C. Davis - Neurosurgery; (3) U.C. Davis - Radiology Sacramento, USA

Evaluation of prognostic factors in patients affected by brain metastases from lung cancer treated with gamma knife radiosurgery P1-28 Piero, Picozzi (1); Alberto, Franzin (2); Silvia, Snider (2); Francesca, Marchesi (3); Luca, Attuati (2); Antonella,Del Vecchio (1); Vanessa, Gregorc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele- Neurosurgery Department; (3) Ospedale San Raffaele - Department of Oncology Milano, Italy

Linac based sterotactic radiosurgery (SRS) of brain metasases - 10 years experience P1-29 Martin, Chorvath (1); Martina, Skoknova (2); Yaroslav, Parpaley (2); Augustin, Durkovsky (3); Miron, Sramka(2); Juraj, Steno (4); Elena, Boljesikova (1) (1) St. Elisabeth Cancer Institute - Department of Radiotherapy; (2) St. Elisabeth Cancer Institute -Department of Radiosurgery; (3) St. Elisabeth Cancer Institute - Department of Radiology; (4) Faculty Hospitalof the Comenius University - Department of Neurosurgery Bratislava, Slovakia

Gamma knife radiosurgery for brain metastasis. Analysis of survival and prognostic factors P1-30 Alberto, Franzin (1); Piero, Picozzi (1); Silvia, Snider (2); Camillo, Ferrari Da Passano (1); Lorenzo, Gioia (1);Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department; (2) Ospedale San Raffaele - Stereotactic Neurosurgery& Gamma Knife Department Milano, Italy

Monday

12/09/05

Page 34: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

34

Scientific Program

Stereotactic drainage and gamma knife radiosurgery of cystic brain metastasis P1-31Alberto, Franzin (1); Micol, Valle (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department Milano, Italy

Recurrent metastases following whole brain irradiation: hope for patients in RPA class III? P1-32 Markus, Gross (1); Steffi, Pracht (2); Klaus, Hamm (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Helios-Kliniken Erfurt - Department ofstereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy andRadiooncology Department Marburg, Germany

Gamma knife radiosurgery for the cavernous sinus metastases and invasion P1-33 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Masaki, Yoshimura (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

Fatal intratumoral hemorrhage immediately after gamma knife radiosurgery for brain metastasis: Case report P1-34Masahiro, Izawa (1); Mikhail, Chernov (1); Motohiro, Hayashi (1); Yuichi, Kubota (1); Hidetoshi, Kasuya (1);Tomokatsu, Hori (1) (1) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan

Gamma knife radiosurgery for metastatic alveolar soft part sarcoma : a case report P1-35 Jang, Jae-Won (1); In-Young, Kim (1); Jung, Shin (2) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department ofNeurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea

Radiosurgery for the treatment of brain stem metastases: relationship between clinical status and survival P1-36José, Lorenzoni (1); Daniel, Devriendt (2); Nicolas, Massager (3); Françoise, Desmedt (1); Stéphane, Simon (4);Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme -Neurochirurgie; (4) Institut J. Bordet - Physique Brussels, Belgium

Stereotactic irradiation (STI) boost for multiple brain metastases P1-37 Hisato, Nagano (1); Takashi, Shuto (2); Yuji, Nakayama (2); Inomori, Shigeo (2) (1) Yokohama Rosai Hospital - Radiationoncology; (2) Yokohama Rosai Hospital - Neurosugery Yokohama Kanagawa, Japan

Mon

day

12/0

9/05

Page 35: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

35

Scientific Program

Localized therapy for limited metastatic disease to the brain: A Phase II study of surgery, stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) in favorable patients P1-38Lucien, Nedzi (1); John Wilson, Walsh (2); Roy, Weiner (3); Bryan R., Payne (4); Ellen, Zakris (1); Robert,Sanford (5); Timothy, Pearman (6); Paul, Rosel (7); Raja, Mudad (3); Anna, Hall (8); Judy, Weber (9) (1) Tulane University - Radiation Oncology; (2) Tulane University Medical Center - Department ofNeurosurgery; (3) Tulane University - Department of Hematology/Oncology; (4) LSU School of Medicine atNew Orleans - Department of Neurosurgery; (5) Tulane University - Radiation Oncology; (6) Tulane University- Psychology; (7) Tulane University - Radiology; (8) Tulane University Hospital and Clinic - Radiation Oncology;(9) New Orleans Regional Gamma Knife Center - Nursing New Orleans, USA

Gamma knife (GK) radiosurgery for small brain metastases P1-39 Ouzi, Nissim (1); Daniel, Devriendt (2); Nicolas, Massager (3); Philippe, David (4); Françoise, Desmedt (1);Olivier, Coussaert (1); Stéphane, Simon (5); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme -Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Physique Brussels, Belgium

Fractionated gamma knife radiotherapy for huge metastatic tumor P1-40 Ushikubo, Osamu (1) (1) Kasai cardiology and neurosurgery hospital - neurosurgey Tokyo, Japan

Stereotactic radiosurgery boost for metastatic brain tumors receiving WBRT P1-41 George, Pissakas (1); V, Georgolopoulou (2); K, Doukaki (3); S, Mourgela (4); E, Andriotis (5); M, Kalogeridou(3); S, Kosmidou (3); G, Arhontakis (4); E, Pappas (2); I, Kouvaris (6); A, Sotiropoulou (3) (1) Alexandra Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3)St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Neurosurgery; (5) St.Savvas Hospital -Radiology; (6) University of Athens - Radiation Oncology Athens, Greece

Stereotactic irradiation for metastatic brain tumors from hepatocellular carcinoma P1-42 Masao, Tago (1); Kenshiro, Shiraishi (1); Keiichi, Nakagawa (1); Keisuke, Maruyama (2); Hiroki, Kurita (3);Masahiro, Shin (4); Atsuro, Terahara (4); Shunsuke, Kawamoto (5); Kuni, Ohtomo (1) (1) University of Tokyo Hospital - Department of Radiology; (2) University of Tokyo Hospital - Department ofNeurosurgery; (3) Kyorin University Hospital - Department of Neurosurgery; (4) Toho University OmoriHospital - Department of Radiology; (5) Dokkyo University School of Medicine - Department of Neurosurgery Tokyo, Japan

Monday

12/09/05

Page 36: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Radiosurgical treatment of “radioresistant” cerebral metastases P1-43Charles, Valery (1) (1) Hopital de la Pitie-Salpetriere - Service de neurochirurgie Paris, France

Repeated in-situ recurrence of brain metastases after radiosurgery and resection: dural contact as a risk factor P1-44 Dirk, Van Den Berge (1); Guy, Soete (1); Christine, Collen (2); Recai, Ates (3); Katrijn, Van Rompaey (4); Jean,D'Haens (4); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ-VUB - Radiotherapy; (3) AZ VUB - Neurochirurgie Brussels, Belgium

Paradigm shift in management of patients with multiple brain metastases: From whole brain radiotherapy to gamma knife radiosurgery P1-45 Masaaki, Yamamoto (1); Bierta, Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Repeated radiosurgery for local recurrences of brain metastases after gamma knife radiosurgery P1-46 Kazuhiro, Yamanaka (1); Yoshiyasu, Iwai (1); Yasuhiro, Matsusaka (1); Kazuhito, Nakamura (1); Toshihiro,Yasui (1); Masaki, Komiyama (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

Gamma knife radiosurgery for large volume brain metastases: Acceptable volume response rate with marginal increase in toxicity P1-47C.P., Yu (1); Joel Y. C., Cheung (1); Josie F. K., Chan (2); Samuel, Leung (3); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Center; (2) Canossa Hospital - Gamma Knife Center; (3) Queen ElizabethHospital - Department of Neurosurgery Hong Kong, Hong Kong

A comparison of Whole Brain Radiation Therapy (WBRT) and radiosurgery (RS) for the treatment of brain metastases: If the volume is prognostic factor influencing survival ? P1-48Edyta, Wolny (1); Aleksandra, Grzadiel (2); Andrzj, Tukiendorf (3); Leszek, Miscyk (1)(1) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Radiotherapy Department; (2) Center ofOncology-MSC Memorial Institute Branch in Gliwice - Treatment Planning Department; (3) TechnicalUniversity of Opole - Mechanical FacultyGliwice, Poland

36

Mon

day

12/0

9/05

Page 37: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Gamma knife radiosurgery for skull base chordomas: What is an adequate dose level? P1-49 Marc, Goldman (1); Georg, Noren (1); Stephen C., Saris (1); Carla, Bradford (1); Melissa, Remis (1) (1) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA

Stereotactic radiosurgery in the management of glomus jugulare tumors P1-50Francisco, Mascarenhas (1); A, Gonçalves Ferreira (2); H, Carvalho (3); M, Santos (4); A, Almeida (5); M, Vacas(6); M, Sá da Costa (7); S, Germano (8) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal- Neurosurgery Dpt; (3) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (4) Hospital de SantaMaria- Lisboa-Portugal - Radiotherapy Dpt; (5) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt; (6)Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (7) Hospital de Santa Maria- Lisboa-Portugal -Radiotherapy Dpt; (8) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt Lisboa, Portugal

Dramatic short term response of tumors of the pineal region to the gamma knife radiosurgery P1-51 Mazdak, Alikhani (1); Mohammad Ali, Bitaraf (1) (1) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Tehran, Iran

Cyberknife radiosurgery in recurrent head and neck cancer P1-52 Seong Yul, Yoo (1)(1) Radiation Oncology DepartmentSeoul, South Korea

Radiosurgery for glomus jugulare: late results P1-53Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil

Early experience with a cyberknife stereotactic radiosurgical program P1-54Michael, Schulder (1); Brian, Beyerl (1); Richard Hodosh (1); Edward, Zampella (1); Elsbieta, Masur (1); LouisDchwartz (1)(1) New Jersey Medical School, Newark NJ, Overlook Hospital, Summit NJNewark, USA

37

Monday

12/09/05

Page 38: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Final design, integration and testing of the dedicated proton SRS/SRT beamline at the NPTC P1-55 Marc R, Bussiere (1); Isaac, Mendelson (1); Hanne, Kooy (1); Jay, Flanz (1); Miles, Wagner (1); Bernie, Gotchalk(2); Paul, Chapman (3); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Harvard University - PhysicsDepartment; (3) Massachusetts General Hospital - Pediatric Neurosurgery Department Boston, USA

Three year radiosurgery experience at the Northeast Proton Therapy Center P1-56 Marc R, Bussiere (1); Hanne, Kooy (1); Paul, Chapman (2); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Massachusetts General Hospital- Pediatric Neurosurgery Department Boston, USA

History of proton beam radiosurgery P1-57 Mehryar, Mashouf (1); Elham, Bidabadi (2) (1) Guilan university of medical sciences - Department of neurosurgery; (2) Guilan university of medical sci-ences - Pediatric neurology Rasht, IRAN

Radiosurgery damage probability in target volume. - A proposal for a biological response model P1-58 Vinicio, Toledo-Buenrostro (1); Gabriel, Rodriguez-Hernandez (2) (1) Hospital San Javier - Radiation Oncology; (2) Hospital San Javier - Medical Physics and Radiation Protection Guadalajara, Mexico

Distal region cephalothorax map of Crayfish Procambarus clarkii. Magnetic resonance atlas for experimental gamma radiosurgery P1-59 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, Ponce de Leon (1); M.P., Torres Garcia (2);J.L., Bortolini Rosales (3); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); E, Muñoz Mancilla (5); Miguel,Perez Pastenes (1); JA., Viccon Pale (7) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico -Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) MetropolitanAutonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico

38

Mon

day

12/0

9/05

Page 39: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Distal region cephalothorax map of Crayfish Procambarus clarkii. Cerebroid ganglion and adjacent structures histological map: basic model for gamma radiosurgery P1-60 Ramiro, Del Valle (1); Daniel Salvador, Ruiz Gonzalez (1); Salvador, De Anda Ponce de Leon (1); Miguel, PerezPastenes (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); E, Muñoz Mancilla (6); Manuel, Martinez Lopez(1); L., Mendoza Vargas (4); JA., Viccon Pale (9); Juan, Ortiz Retana (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico -Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) MetropolitanAutonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico

Modulation of dose rate effects to minimize normal neural tissue toxicity while maximizing tumor control probability P1-61 Steven, Howard (1); James, Welch (1); Ian, Robbins (2); Wolfgang, Tome (1) (1) University of Wisconsin Medical School - Human Oncology Department; (2) University of WisconsinMedical School - Medical Oncology Madison, USA

Vascular changes in the rat middle cerebral artery after gamma knife irradiation (preliminary results) P1-62José, Lorenzoni (1); Gyorgy, Szeifert (2); Isabelle, Salmon (3); Françoise, Desmedt (1); Jacques, Brotchi (4);Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) National Institute of Neurosurgery - Department ofNeurosurgery; (3) Hôpital Erasme - Department of Pathology; (4) Hôpital Erasme - Neurochirurgie Brussels, Belgium

Comparison of late radiobiological effect of the brachytherapy and LINAC radiosurgery modalities on the normal brain tissue P1-63 Arpad, Viola (1); Jeno, Julow (1); Tibor, Major (2) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Oncologyand Radiation Therapy, Budapest, Hungary - Department of Radiation Therapy Budapest, Hungary

Treatment of acoustic neurinoma with stereotactic radiosurgery P1-64 Leoncio, Arribas Alpuente (1); ML, Chust (1); A, Menendez (1); V, Crispin (1); JL, Guinot (1); JL, Mengual (1);PP, Escolar (1) (1) Instituto Valenciano de Oncología - Radiation Oncology Valencia, Spain

Vestibular schwannomas (VS): intracanalicular extension and associated hearing loss. Volumetric analyses P1-65 Ouzi, Nissim (1); Nicolas, Massager (2); Carine, Delbrouck (3); Philippe, David (4); Daniel, Devriendt (5);Françoise, Desmedt (1); Jacques, Brotchi (2); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - CentreGamme Knife; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Radiothérapie Brussels, Belgium

39

Monday

12/09/05

Page 40: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Radiosurgery of cerebellopontine angle tumors. Optimization of treatment and outcomes evaluation P1-66 Yaroslav, Parpaley (1); Miron, Sramka (1); Augustin, Durkovsky (2) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Departmentof Radiology Bratislava, Slovakia

Gamma knife radiosurgery for vestibular schwannomas P1-67 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

Limitation of size for the radiosurgical treatment of vestibular schwannomas. Comparison between 2D and 3D informations P1-68 Pierre-Hugues, Roche (1); Jean, Regis (2) (1) CHU La Timone - neurochirurgie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France

Linac radiosurgery for acoustic neuromas: experience at the

CHU of Liège P1-69 Isabelle, Rutten (1); Bruno, Kaschten (2); Snezana, Kotolenko (3); Achille, Stevenaert (2); Jean-Marie,Deneufbourg (1) (1) CHU Liège - Radiothérapie; (2) CHU Liège - Neurochirurgie; (3) C.H. de Luxembourg - Radiotherapy Liège, Belgium

Early detection of tiny vestibular schwannoma by FIESTA MR Images and treated with gamma knife radiosurgery P1-70 Chain-Fa, Su (1); Tzu-Wen, Loh (1); Chou Chin, Lee (2); Wen-Lin, Hsu (3); Shinn-Zong, Lin (1) (1) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Neurosurgery; (2) Buddhist Tzu-ChiMedical Center, Tzu-Chi University - Department of Radiology; (3) Buddhist Tzu-Chi Medical Center, Tzu-ChiUniversity - Department of Radiation Oncology Hualien, Taiwan

40

Mon

day

12/0

9/05

Page 41: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

ORAL SESSIONS 11h30 - 12h30

LARGE ARTERIOVENOUS MALFORMATIONS OS1Chairmen: Andras, Kemeny; Jason, Sheehan Room Nation

Staged gamma knife radiosurgery, with neither surgery OS1-1nor embolization, for relatively large AVMsMasaaki, Yamamoto (1); Bierta E., Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Validation of a radiosurgery-based grading system OS1-2for arteriovenous malformationsMichael, Girvigian (1); John, Lee (1); Michael, Miller (1); Javad, Rahimian (1); Joseph, Chen (1); Hugh,Greathouse (1); Michael, Tome (1) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology Los Angeles, USA

Radiosurgery of large cerebral arteriovenous malformations OS1-3Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Dae Hee,Han (2) (1) Seoul National University Hospital - Department of Neurosurgery; (2) Seoul National University Hospital -Department of Neurosurgery Seoul, Republic of Korea

Staged volume radiosurgery for large arteriovenous OS1-4 malformations: indications and outcomesDouglas, Kondziolka (1); Sait, Sirin (1); John C, Flickinger (1); Niranjan, Ajay (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA

RADIOBIOLOGY OS2 Chairmen: John, Flickinger; Ronald, Mc Garry Room

Permeke & Rembrandt

Stereotactic pulmonary hilar radiation: an animal model OS2-1of radiotoxicityBrent, Tinnel (1); Marc, Mendonca (2); Ronald, McGarry (3); Oscar, Cummings (4); Robert, Timmerman (5) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) Indiana University MedicalCenter - Radiation and Cancer Biology; (3) Indiana University Medical Center - Department of RadiationOncology; (4) Indiana University School of Medicine - Department of Pathology; (5) University of TexasSouthwestern - Department of Radiation Oncology Indianapolis, USA

41

Monday

12/09/05

Page 42: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Histopathologic changes in metastatic brain tumors OS2-2seen after gamma knife radiosurgery: the Pittsburgh experienceDave, Atteberry (1); Gyorgy, Szeifert (2); Marta, Couce (3); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) National Institute ofNeurosurgery - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Pathology Pittsburgh, USA

Early and late adverse effects of low-dose radiosurgery OS2-3in MR area Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

Alpha/beta ratios for radiosurgical target tissues OS2-4Frederik, Vernimmen (1); Jacobus, Slabbert (2) (1) Stellenbosch University - Radiation Oncology; (2) iThemba LABS - Radiation Biophysics Tygerberg, South Africa

GLIOMAS OS3 Chairmen: Minesh, Mehta; Nicolas, Massager Room Willumsen

PET-related metabolic response of glial tumors OS3-1after GK radiosurgeryNicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); Daniel, Devriendt (3); Ouzi, Nissim (4); David, Wikler (2);Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (4) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Rationale for, and results of a 6-year experience of leading OS3-2edge gamma knife Radiosurgery for Glioblastoma Multiforme: A Trend Toward Improved OutcomeChristopher M., Duma (1); W. Michael, Shea (2); Jay, Tassin (2); Peter, Chen (2); Ralph, Mackintosh (2);Marianne, Plunkett (2) (1) Hoag Memorial Hospital - Department of Neurosurgery; (2) Hoag Memorial Hospital - Radiation Oncology Newport Beach, USA

Quantification of surrogate tracers for glioma radiosensitization OS3-3 Peter, Haar (1); William, Broaddus (1); Zhijian, Chen (1); Panos, Fatouros (2) (1) Medical College of Virginia - Division of Neurosurgery; (2) Medical College of Virginia - Radiation Physicsand Biology Richmond , USA

42

Mon

day

12/0

9/05

Page 43: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

43

Role of gamma knife radiosurgery in malignant OS3-4glioma treatmentMasaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

SPONSORED SEMINAR 13h00 - 13h45

NOVALIS FOR FUNCTIONAL NEUROSURGERY Room NationSeminar and lunch sponsored by BrainLABChairman: Antonio AF De SallesAntonio AF De Salles, MD, PhD; Alessandra Gorgulho, MD; Paul Medin, PhD; Nzhyde Agazarian, PhD; TimothySolberg, Ph.D.; Michael Selch, MDUCLA - Departments of Neurosurgery and Radiation Oncology, Los Angeles, USA

ORAL SESSIONS 14h00 - 15h00

VESTIBULAR SCHWANNOMAS 1 OS4Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation

Estimating tumor definition variability in acoustic OS4-1schwannoma radiosurgery, and how it affects dosimetryJohn, Flickinger (1); Ajay, Niranjan (2); Kaan, Oysul (1); Juan, Martin (3); Sait, Sirin (4); Ann H., Maitz (5);Douglas, Kondziolka (5); L. Dade, Lunsford (5) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of PittsburghMedical Center - Neurological Surgery; (3) Department of Neurological Surgery - University of Pittsburgh; (4)University of Pittsburgh Medical Center - Department of Neurological Surgery; (5) University of PittsburghMedical Center - Image Guided Neurosurgery Pittsburgh, USA

Hearing preservation in vestibular schwannoma after gamma OS4-2knife radiosurgeryDong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Hee-Won,Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

Hearing preservation after GK radiosurgery for vestibular OS4-3schwannoma: Influence of intracanalicular dosimetric parametersNicolas, Massager (1); Ouzi, Nissim (2); Carine, Delbrouck (3); Daniel, Devriendt (4); Philippe, David (5);Françoise, Desmedt (2); David, Wikler (6); Jacques, Brotchi (1); Sergio, Hassid (7); Marc, Levivier (2) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - CentreGamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neuroradiologie; (6) Hôpital Erasme- PET Scan; (7) Hôpital Erasme - ENT Dept. Brussels , Belgium

Monday

12/09/05

Page 44: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

44

A prospective series of 1000 vestibular schwannomas treated OS4-4by “low dose” radiosurgery: long term resultsJean, Regis (1); Pierre-Hugues, Roche (2); Christine, Delsanti (3); William, Pellet (1) (1) CHU La Timone - Service de Neurochirurgie; (2) CHU La Timone - neurochirurgie; (3) CHU La Timone -Gamma Unit Marseille, France

LUNG TUMORS 1 OS5Chairmen: Ingmar, Lax; Paul, VanHoutte Room

Permeke&Rembrandt

A prospective trial on stereotactic radiotherapy of limited OS5-1stage non-small cell lung cancerMorten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars Peter, Ohlhues (2); Jorgen, Petersen (1);Hanne, Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase(1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Departmentof Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark

CT appearance of radiation injury of the lung and clinical OS5-2symptoms after stereotactic radiation therapy (SRT) for lung cancersTomoki, Kimura (1); Yuji, Murakami (2); Kanji, Matsuura (3); Yasutoshi, Hashimoto (4); Masahiro, Kenjo (5);Yuko, Kaneyasu (6); Koichi, Wadasaki (7); Yutaka, Hirokawa (8); Motoomi, Ohkawa (9); Katsuhide, Ito (10) (1) Kagawa University - Radiology; (2) Hiroshima University School of Medicine - Radiology; (3) HiroshimaUniversity School of Medicine - Radiology; (4) Hiroshima University School of Medicine - Radiology; (5)Hiroshima University School of Medicine - Radiology; (6) Hiroshima University School of Medicine - Radiology;(7) Hiroshima University School of Medicine - Radiology; (8) Juntendo University - Radiology; (9) KagawaUniversity - Radiology; (10) Hiroshima University School of Medicine - Radiology Kagawa Prefecture, Japan

CT-guided stereotactic radiotherapy for stage I non-small OS5-3cell lung cancers: 10-year experiences with the fusion of CT and Linac (FOCAL) unitMinoru, Uematsu (1); Akira, Shioda (2) (1) Keio University - Department of Radiology; (2) National Defense Medical College - Radiation Oncology Tokyo , Japan

Dose-response relationship in fractionated stereotactic OS5-4radiotherapy (FSRT) for non small cell lung cancer (NSCLC)Hilde, Van Parijs (1); Jan, Van de Steene (1); Vincent, Vinh-Hung (1); Dirk, Verellen (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels , Belgium

Mon

day

12/0

9/05

Page 45: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

45

ORAL SESSIONS 15h00 - 16h00

VESTIBULAR SCHWANNOMAS 2 OS6Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation

Radiosurgery of facial neurinoma - Long-term results OS6-1and functional outcomeYoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Risk of malignancy in the radiosurgical management OS6-2of Type 2 Neurofibromatosis (NF2)Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz(3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

Histopathological observations on vestibular Schwannomas OS6-3following gamma knife radiosurgeryGyorgy, Szeifert (1); Dominique, Figarella-Branger (2); Pierre-Hugues, Roche (3); Marc, Levivier (4); Jean, Regis (5) (1) National Institute of Neurosurgery of Budapest; (2) CHU La Timone - Department of Pathology andNeuropathology; (3) CHU La Timone - neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife; (5) CHU LaTimone - Service de Neurochirurgie Marseille, France

Avoidance of facial nerve dysfunction after GK radiosurgery: OS6-4modified dose planning techniqueMasaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Monday

12/09/05

Page 46: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

46

LUNG TUMORS 2 OS7Chairmen: Ingmar, Lax; Paul, VanHoutte Room

Permeke & Rembrandt

Dosimetric validation of a breathing synchronized irradiation OS7-1technique for hypofractionated lung treatmentsDirk, Verellen (1); Koen, Tournel (2); Nadine, Linthout (3); Guy, Storme (4) (1) AZ VUB - Physique; (2) AZ-VUB - Radiotherapy; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy Brussels, Belgium

Stereotactic body radiation therapy for lung metastases: OS7-2Impact on overall survivalMartin, Fuss (1); Charles R., Thomas Jr. (1); Bill J., Salter (2); Terence S., Herman (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio , USA

Metabolic PET imaging for stereotactic body radiation OS7-3therapy planning and therapy response assessment of pulmonary malignanciesMartin, Fuss (1); Bill J., Salter (2); Terence S., Herman (1); Charles R., Thomas Jr. (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA

Computed tomographical analysis of radiation sequelae OS7-4due to experimental stereotactic irradiation to normal rabbit lungTakatsugu, Kawase (1); Etsuo, Kunieda (2); M Deloar, Hossain (2); Satoshi, Seki (2); Akitomo, Sugawara (2);Tatsuya, Fujisaki (3); Akitoshi, Ishizaka (4); Atsushi, Kubo (2) ( 1 ) Keio University - Department of Radiation Oncology ,( 2 ) Keio University - Department of Radiology, (3)Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences , ( 4 ) Keio University- Department of Medicine

ORAL SESSIONS 17h00 - 18h00

VESTIBULAR SCHWANNOMAS 3 OS8Chairmen: L. Dade, Lunsford; Jean, D’Haens Room Nation

Five session gamma knife treatment of acoustic neuromas OS8-1Steven, Cobery (1); Melissa, Remis (2); Carla, Bradford (2); Georg, Noren (2) (1) Brown University - Department of Neurosurgery; (2) Rhode Island Hospital, Brown University - NewEngland Gamma Knife Center Providence, USA

Mon

day

12/0

9/05

Page 47: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

47

Evaluation of ophthalmological consequences of gamma OS8-2knife radiosurgery in vestibular SchwannomasManabu, Tamura (1); Noriko, Murata (2); Motohiro, Hayashi (3); Jean, Regis (4) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital -Stereotactic and Fonctional Neurosurgery; (3) Tokyo Women's Medical Univeristy - Department ofNeurosurgery; (4) CHU La Timone - Service de Neurochirurgie Marseille, France

Relative safety of gamma knife radiosurgey in CPA angle OS8-3tumors with significant brainstem compressionMohammad Ali, Bitaraf (1); Mazdak, Alikhani (2); Mazyar, Azar (3); Frarid, Kazemi (4) (1) Tehran university of medical sciences - Neurosurgery; (2) Tehran university of medical sciences -Neurosurgery; (3) Iran university of medical sciences - neurosurgery; (4) Iran university of medical sciences -Neurosurgery Tehran, Iran

Hypofractionated stereotactic radiotherapy as primary OS8-4treatment of acoustic neuroma: Interim results of the Johns Hopkins experienceOri, Shokek (1); Stephanie, Terezakis (1); Michael, Hughes (1); Lawrence, Kleinberg (1); Moody, Wharam (1);Daniele, Rigamonti (2) (1) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and MolecularRadiation Sciences; (2) Johns Hopkins University School of Medicine - Department of Neurosurgery Baltimore, USA

OTHER TUMORS OS9Chairman: Ingmar, Lax; Rita, Engenhart-Cabillic Room

Permeke & Rembrandt

Epidermoid cyst treated with gamma knife radiosurgery OS9-1Jeremy, Ganz (1); Ayman, Hafez (1); W A., Reda (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

Stereotactic radiation for cystic craniopharyngiomas OS9-2Alessandra, Gorgulho (1); Carlos, Mattozo (1); Murisiku, Raifu (1); Katayoun, Tajik (1); Michael, Selch (2);Nzhde, Agazaryan (5); Timothy, Solberg (5); Daniel, Kelly (1); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Monday

12/09/05

Page 48: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

48

Radiosurgery of epidermoid tumor - OS9-3Trial for radiosurgical nerve decompressionYoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Fulminate peritumoral brain edema following radiosurgery OS9-4 for meningiomas: Report of two cases and review of the literatureGuus, Koerts (1); Dirk, Van Den Berge (2); Christian, Raftopoulos (3); Jean, D'Haens (4) (1) Cliniques Universitaires Saint-Luc - Neurosurgery; (2) AZ VUB - Radiothérapie; (3) Cliniques UniversitairesSaint-Luc - Neurochirurgie; (4) AZ VUB - Neurochirurgie Brussels, Belgium

Scientific Program

Page 49: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

49

Scientific Program

Tuesday 13/09/05

Breakfast seminars 7h30 - 8h30

WHAT RISK OF CANCEROGENESIS IN RADIOTHERAPY BS4AND RADIOSURGERY? Room Rembrandt

Risks and relative risks of malignancy after cranial irradiation BS4-1Jeremy, Rowe

A review of the literature on cancerogenesis after radiosurgery BS4-2Jeremy, Ganz

Relative risk of cancerogenesis after fractionated BS4-3and single-dose stereotactic irradiationJohn, Flickinger

RADIOSURGERY FOR ARTERIOVENOUS MALFORMATIONS BS5Room Permeke

Challenges in AVM radiosurgery BS5-1Douglas, Kondziolka

What strategy in large AVM? BS5-2Andras, Kemeny

Lessons from the past. Issues for the future BS5-3Federico, Colombo

PHYSICS - NEW TECHNOLOGIES BS6Room Willumsen

Today’s technology and application of a dedicated BS6-1neuro-radiosurgery systemFranz, Krispel

Final design, integration and testing of the dedicated proton BS6-2SRS/SRT beamline at the NPTCMarc R., Bussière

One year of Cyberknife radiosurgery BS6-3Michael, Schulder

Tuesday13/09/05

Page 50: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

50

Scientific Program

PLENARY SESSION 8h45 - 10h00

PS2Room Nation

DATA BLITZ UPDATE 1 PS2-1Extracranial RadiosurgeryIngmar, Lax

DATA BLITZ UPDATE 2 PS2-2Vestibular SchwannomasL. Dade, Lunsford

BRAIN METASTASESChairman: Ingmar, Lax; L. Dade, Lunsford

Radiosurgery for the treatment of 239 patients with brain PS2-3metastases: estimation of patients eligibility using three stratification systemsDaniel, Devriendt (1); José, Lorenzoni (2); Nicolas, Massager (3); Philippe, David (4); David, Wikler (5); Daniel Salvador, Ruiz Gonzalez (6); Bruno, Vanderlinden (7); Paul, Van Houtte (1); Jacques, Brotchi (3); Marc,Levivier (2) (1) Institut J. Bordet - Radiothérapie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme -Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Hôpital Erasme - PET Scan; (6) Medica Sur SA de CVMSU 820125 T58 - Unidad Gamma Knife; (7) Institut J. Bordet - Physique Brussels, Belgium

Long-term Survivors after gamma knife Radiosurgery PS2-4for Brain MetastasesDouglas, Kondziolka (1); Juan, Martin (2); John C, Flickinger (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) Department ofNeurological Surgery - University of Pittsburgh Pittsburgh, USA

A randomized trial of surgery and radiotherapy versus PS2-5radiosurgery alone in the treatment of single metastasis to the brain Alexander, Muacevic (1); Berndt, Wowra (1); Joerg, Tonn (2); Hans-Jakob, Steiger (3); Friedrich, Kreth (1) (1) European Cyberknife Center Munich - Cyberknife Center; (2) Ludwig-Maximilians-University, KlinikumGroßhadern - Department of Neurosurgery; (3) University Duesseldorf - Department of Neurosurgery Munich, Germany

Tues

day

13/0

9/05

Page 51: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

51

Scientific Program

ORAL SESSIONS 10h30 - 11h30

BRAIN METASTASES 1 OS10Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation

Recursive partitioning analysis of prognostic factors for OS10-1patients treated with four or more intracranial metastases treated with radiosurgeryAjay, Bhatnagar (1); Douglas, Kondziolka (2); L. Dade, Lunsford (2); John C, Flickinger (2) (1) University of Pittsburgh Cancer Institute - Radiation Oncology; (2) University of Pittsburgh Medical Center- Department of Neurological Surgery Pittsburgh, USA

Extracranial tumoractivity determines survival after OS10-2 gamma knife radiosurgery for brain metastasesPatrick, Hanssens (1); Guus, Beute (2); Theo, Veninga (3); Suente, Lie (2); Koo, van Overbeeke (2); Danielle,Eekers (1) (1) Gamma Knife Center Tilburg - Radiation Oncology; (2) Gamma Knife Center Tilburg - Neurosurgery; (3)Gamma Knife Center Tilburg - Radiation Oncology Tilburg, The Netherlands

Diffusion magnetic resonance imaging as an early OS10-3evaluation of the response of brain metastases treated by stereotactic radiosurgeryChuan-Fu, Huang (1) (1) Chung Shan Medical University Hospital - GammaKnife Center Taichung, Taiwan

Gamma knife radiosurgery alone as an alternative treatment OS10-4for melanoma brain metastasisXavier, Muracciole (1); Jean, Regis (2) (1) CHU La Timone - Service de Radiothérapie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France

MENINGIOMAS 1 OS11Chairmen: Hidefumi, Jokura; Robert, Smee Room

Permeke & Rembrandt

Hypofractionated stereotactic radiotherapy for benign OS11-1Michael, Dally (1); Louise, Gorman (1); Jeremy, Reuben (1); Robert, Myers (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia

Tuesday13/09/05

Page 52: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

52

Scientific Program

Stereotactic Radiosurgery and Fractionated Stereotactic OS11-2Radiotherapy for Meningiomas Related to the Optic ApparatusLeonardo, Frighetto (1); Carlos, Mattozo (2); Alessandra, Gorgulho (3); Michael, Selch (4); Cynthia, Cabatan-Awang (3); Timothy, Solberg (4); Antonio, DeSalles (5) (1) University of California Los Angeles - Neurosurgery; (2) UCLA Medical Center - Neurosurgery; (3) UCLAMedical Center - Department of Neurosurgery; (4) UCLA - Radiation Oncology; (5) UCLA Medical Center -Neurosurgery Los Angeles, United States

Improvement in vision and other cranial neuropathies OS11-3after stereotactic radiotherapy for the treatment of skull base meningiomasTracy, McElveen (1); Kathleen, Settle (1); Beverly, Downes (2); Maria, Werner-Wasik (1); Wally, Curran (1);David, Andrews (3) (1) Thomas Jefferson University - Radiation Oncology/Neurosurgery; (2) Jefferson Hospital for Neuroscience -Department of Neurosurgery Philadelphia, USA

Optic nerve sheath meningiomas. OS11-4The role for stereotactic radiotherapyRobert Ian, Smee (1); Margaret, Schneider (1); Janet, Williams (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia

PHYSICS – GENERAL OS12Chairmen: Frank, Bova; Stephan G., Scheib Room Willumsen

Stereotactic IMRS for intracranial tumours OS12-1Robert Ian, Smee (1); Margaret, Schneider (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia

Monte Carlo simulation for gamma knife radiosurgery OS12-2using the GridVasu, Ganesan (1); Rami, Mehrem (2); John, Fenner (2); Lee, Walton (1) (1) University of Sheffield - Department of Medical Physics and Clinical Engineering; (2) Royal HallamshireHospital - National Centre For Stereotactic Radiosurgery Sheffield, United Kingdom

Artificial Droplets improves radiation dosimetry of IMRT OS12-3Kevin, Khadivi (1); Robert, Comiskey (2); Timothy, Klapproth (3); Craig, Hansen (3) (1) Mercy Medical Center - Radiation Oncology; (2) Radionics, a division of Tyco HealthCar - Engineering; (3)Mercy Medical Center - Radiation Oncology Springfield, USA

Tues

day

13/0

9/05

Page 53: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

53

Scientific Program

Standardization for CyberKnife Beam Dosimetry OS12-4Hidetoshi, Saitoh (1); Toru, Kawachi (2); Mitsuhiro, Inoue (3); Atsushi, Myojyoyama (4); Tatsuya, Fujisaki (5);Shinji, Abe (5); Kimiaki, Saito (6) (1) Tokyo Metropolitan University of Health Sciences - Graduate School of Health Sciences; (2) TokyoMetropolitan University - Graduate School of Health Sciences; (3) Midori Kai Neurosurgery Hospital -Yokohama CyberKnife Center; (4) Tokyo Metropolitan University - Graduate School of Health Sciences; (5)Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences; (6) Japan AtomicEnergy Research Institute - Health Physics Tokyo, Japan

ORAL SESSIONS 11h30 - 12h30

BRAIN METASTASES 2 OS13 Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation

Hypofractionated stereotactic radiotherapy for brain OS13-1metastases not amenable to radiosurgeryAntje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Oliver, Ganslandt (1); Rudolf, Fahlbusch (1); Rolf, Sauer (1);Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology

Response rate and biologically effective dose correlation OS13-2in stereotactic irradiation of adenocarcinoma brain metastasisFilippo, Grillo-Ruggieri (1); Paolo, Cavazzani (2); Massimo, Cardinali (3); Giovanna, Mantello (4); Stefania,Maggi (5) (1) Ospedali Galliera - Radioterapia; (2) Ospedali Galliera, Genova, Italy - Neurochirurgia; (3) Ospedali Riuniti,Ancona, Italy - Radioterapia; (4) Ospedali Riuniti, Ancona, Italy - Radioterapia; (5) Ospedali Riuniti, Ancona,Italy - Fisica Sanitaria Genova, Italy

Gamma knife surgery for large metastatic brain tumors OS13-3to avoid developing severe peritumoral edemaMotohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1);Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan

Tuesday13/09/05

Page 54: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

54

Scientific Program

Gamma knife surgery for metastatic brain tumors OS13-4from lung cancerToru, Serizawa (1); Yoshinori, Higuchi (2); Shinji, Matsuda (3); Junichi, Ono (4); Makoto, Sato (5); Toshihiko,Iuchi (6); Osamu, Nagano (7); Naokatsu, Saeki (8) (1) Chiba Cardiovascular Center - Department of Neurosurgery; (2) Chiba Cardiovascular Center - Departmentof Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurology; (4) Chiba Cardiovascular Center- Department of Neurosurgery; (5) Chiba Cardiovasucular Center - Department of Radiology; (6) Chiba CancerCenter - Division of Neurological Surgery; (7) Graduate School of Medicine, Chiba University - Department ofNeurological Surgery; (8) Graduate School of Medicine, Chiba University - Department of NeurologicalSurgery Chiba, Japan

MENINGIOMAS 2 OS14Chairmen: Hidefumi, Jokura; Robert, Smee Room

Permeke & Rembrandt

The Role of Radiosurgery in the Management OS14-1of Petroclival MeningiomasDong Gyu, Kim (1); Chul-Kee, Park (1); Hyun-Tai, Chung (1); Sun Ha, Paek (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

Gamma knife radiosurgery for cavernous sinus meningiomas - OS14-2ten year follow-up periodMartina, Stippler (1); John, Lee (2); John C, Flickinger (3); Douglas, Kondziolka (3); L. Dade, Lunsford (4) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) Hospital of the University ofPennsylvania - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of NeurologicalSurgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA

Gamma knife radiosurgery of skull base meningiomas OS14-3Roman, Liscak (1); Aurelia, Kollova (2); Vilibald, Vladyka (3); Gabriela, Simonova (1); Josef, Novotny Jr. (4) (1) Hospital Na Homolce - Stereotactic Neurosurgery Department; (2) Royal Hallamshire Hospital - NationalCentre For Stereotactic Radiosurgery; (3) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery; (4)Hospital Na Homolce - Medical Physics Department Prague, Czech Republic

Linac Radiosurgery for the management of cavernous OS14-4sinus meningiomasSalvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

Tues

day

13/0

9/05

Page 55: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

55

Scientific Program

PHYSICS – LEAKAGE OS15Chairmen: Stephan G, Scheib; Stéphane, Simon Room Willumsen

Measurement of the exit dose to the neck from intracranial OS15-1 stereotactic radiotherapy, using the M3 mini MLCDror, Alezra (1); Janna, Menhel (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel

Dosimetry of thyroid, parotid and ovarian glands in patients OS15-2 undergoing gamma knife radiosurgeryMahmoud, Allahverdi (1); Aliakbar, Sharafi (2); Alireza, Nikoofar (3); Hadi, Hassanzadeh (4) (1) Tehran university of medical sciences - Cancer institute,radiotherapy physics; (2) Iran Medical Science OfUniversity, Ali Asghar Hospital - Iran Gamma Knife Center; (3) Iran university of medical sciences - MedicalPhysics; (4) Iran university of medical sciences - Medical Physics Tehran, Iran

In vivo estimation of extracranial doses in stereotactic OS15-3radiosurgery with the gamma knife and Novalis systemsThierry, Gevaert (1); Dirk, Verellen (2); Stéphane, Simon (3); Françoise, Desmedt (1); Bob, Schaeken (4) (1) Hôpital Erasme - Centre Gamme Knife; (2) AZ VUB - Physique; (3) Institut J. Bordet - Physique; (4) AZMiddelheim - Physique Brussels, Belgium

Tuesday13/09/05

Page 56: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

56

Scientific ProgramTu

esda

y13

/09/

05

Page 57: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

57

Scientific Program

Wednesday 14/09/05

BREAKFAST SEMINARS 7h30 - 8h30

EPILEPSY BS7Room Rembrandt

The Ruber Hospital experience in MLTE radiosurgery BS7-1Roberto, Martinez

Radiosurgery for epilepsy: Preliminary experience BS7-2of U.S. multi-centric trialDavid, Larson

Long-term clinical results and their teachings BS7-3Jean, Regis

BRAIN METASTASES BS8Room Permeke

Evidence supporting the use of radiosurgery in brain BS8-1metastasesMinesh, Mehta

Radiosurgery for multiple brain metastases BS8-2Masaaki, Yamamoto

Role of hypofractionated stereotactic radiotherapy BS8-3in brain metastasesStecken, Ernst

PHYSICS - QUALITY ASSURANCE BS9Room Willumsen

Analyzing 3T MR-scanners for implementation BS9-1in radiosurgeryAndreas, Mack

New challenges for QA in radiosurgery BS9-2Lee, Walton

QA in the use of non stereotactic images (PET, …) BS9-3in radiosurgeryJosef Novotny Jr.

Wednesday14/09/05

Page 58: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

58

Scientific Program

PLENARY SESSION 8h45 - 10h00

PS3Room Nation

DATA BLITZ UPDATE 3 PS3-1Brain MetastasesMinesh, Mehta

DATA BLITZ UPDATE 4 PS3-2PhysicsFrank, Bova

COMPARATIVE TECHNOLOGIESChairmen: Minesh, Mehta; Frank, Bova

Patterns of practice in a radiosurgery center equipped PS3-3with both gamma knife and Linear AcceleratorRobin, Stern (1); Julian, Perks (1); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation OncologySacramento, USA

The Rotating Gamma System GammaART-6000: PS3-4A review of the first 100 patient treatmentsHelenowski Tomasz K.Stereotactic Radiosurgery Institute - NeurosurgeryGurnee, USA

Interstitial stereotactic radiosurgery PS3-5Christopher, OstertagFreiburg, Germany

Wed

nesd

ay14

/09/

05

Page 59: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

59

Scientific Program

POSTER SESSION 10h30 - 11h30

PHYSICS, MOLECULAR IMAGING, MENINGIOMAS, P2FUNCTIONAL RADIOSURGERY, SPINAL RADIOSURGERY, Room Holbein,PITUITARY TUMORS Turner & Foyer

Stereotactic neurosurgery for central pain P2-1Yong-sheng, Hu (1); Yong-Jie, Li (2) (1) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital Universityof Medical Sciences; (2) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan WuHospital, Capital University of Medical Sciences Beijing, China

Cyberknife radiosurgery for hypothalamic harmatoma in patient with medically intractable epilepsy and precocious puberty P2-2Kyung Jin, Lee (1); Kyung-Sool, Jang (2) (1) St Mary's Hospital - Department of Neurosurgery; (2) St.Mary's hospital - Neurosurgery Seoul, Republic of Korea

LINAC radiosurgery for hypothalamic hamartoma epilepsy P2-3Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil

Gamma knife radiosurgery for intracranial meningiomas: Relationship between shrinkage and symptom relief P2-4 Jeremy, Ganz (1); Amr, El Shehaby (1); Hafez, Ayman (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

A prospective multicenter study about tumor volume reduction after stereotactic radiotherapy of skull base meningiomas P2-5 Martin, Henzel (1); Markus W, Gross (1); Klaus, Hamm (2); Gunnar, Surber (3); Gabriele, Kleinert (3); Gerd,Strassmann (1); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg, Germany - Dept. of Radiation Oncology; (2) Helios Klinikum Erfurt, Germany- Dept. for Stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy andRadiooncology Department Marburg, Germany

Fractionated stereotatic radiotherapy of base of skull meningiomas: a preliminary comparison in the delineation of the gross target volume between 4 medical specialities P2-6Carine, Mitine (1); Laurent, Gilbeau (2); Frederic, Dessy (2); Christelle, Pirson (2); Jean-Francois, Rosier (2);Marie-Therese, Hoornaert (2); Ludovic, Harzee (2); Anne, Doneux (2) (1) Jolimont hospital - Radiotherapy; (2) Hôpital de Jolimont - Radiotherapie Haine St Paul, Belgium

Wednesday14/09/05

Page 60: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

60

Scientific Program

Stereotactic radiation therapy for optic meningioma; an experience of Ramathibodi Hospital P2-7 Chomporn, Sitathanee (1); Mantana, Dhanachai (1); Putipan, Puataweepong (1); Lojana, Tuntiyatorn (1);Anuchit, Poonyathalang (2); Veerasak, Theerapanchareon (3) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - Ophthalmology; (3) Ramathibodi Hospital Mahidol University - Neurosurgery Department Bangkok, Thailand

Long-term follow-up of sellar and para-sellar meningiomas treated with stereotactic radiosurgery and fractionated stereotactic radiotherapy using the UCLA grading system P2-8 Carlos, Mattozo (1); Leonardo, Frighetto (2); Alessandra, Gorgulho (3); Cynthia, Cabatan-Awang (3); TimothyD., Solberg (4); Michael, Selch (5); Antonio, DeSalles (6) (1) UCLA Medical Center - Neurosurgery; (2) University of California Los Angeles - Neurosurgery; (3) UCLAMedical Center - Department of Neurosurgery; (4) UCLA Medical Center - Department of Radiation Oncology;(5) UCLA - Radiation Oncology; (6) UCLA Medical Center - Neurosurgery Los Angeles, USA

Decision tree software: stereotactic radiation X conventional surgery P2-9 Alessandra, Gorgulho (1); Antonio, De Salles (1); Martin, Pellinat (2) (1) UCLA Medical Center - Department of Neurosurgery; (2) Idego Methodologies - VisionTree Healthcare Los Angeles, USA

Quality of life after interdisciplinary treatment of cavernous sinus meningiomas P2-10 Markus, Gross (1); Ahmed, Farhoud (2); Martin, Henzel (1); Stefan, Heinze (2); Ulrich, Sure (2); Helmut,Bertalanffy (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Philipps University Marburg - Departmentof Neurosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany

Stereotactic radiosurgery for atypical and anaplastic meningiomas P2-11 Hideyuki, Kano (1); JUn, Takahashi (2); Norio, Araki (3); Masumi, Hiraoka (3); Naohiro, Horii (4); Kasumi, Araki(1); Tetsuya, Ueba (1); Kosuke, Yamashita (1); Nobuo, Hashimoto (2) (1) Kishiwada City Hospital - Neurosurgery; (2) Kyoto University Graduate School of Medicine - Neurosurgery;(3) Kyoto University Graduate School of Medicine - Radiation Oncology Department; (4) Kishiwada CityHospital - Radiation Oncology Kishiwada, Osaka

Long-term experience of gamma knife radiosurgery for benign skull base meningiomas P2-12 Wolfgang, Kreil (1); Verena, Weigl (1); Sandro, Eustacchio (1); Josef, Luggin (1); Georg, Papaefthymiou (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria

Wed

nesd

ay14

/09/

05

Page 61: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

61

Scientific Program

Gamma knife radiosurgery for the treatment of skull base meningiomas P2-13 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

Stereotactic LINAC-radiosurgery for meningiomas P2-14 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

LINAC radiosurgery in the management of parasagittal meningiomas P2-15 Roberto, Spiegelmann (1); Jacob, Zauberman (2); Janna, Menhel (3); Rafael, Pfeffer (3); Dror, Alezra (3) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Neurosurgery; (3) ShebaMedical Center - Department of Oncology Ramat Gan, Israel

Optic nerve sheath meningioma : Comparison of 3D-conformal radiotherapy (3D-CRT), stereotactic radiotherapy (SRT), and intensity modulated radiotherapy (IMRT) P2-16 Pornpan, Yongvithisatid (1); Porntip, Thamwinitchai (2); Paitoon, Tawsagul (1); Mantana, Dhanachai (1);Sawwanee, Asavaphatiboon (3); Chumpoj, Kakanaporn (2); Wichan, Prasertsilpakul (1); Chirapha,Tannanonta (1); Jiraporn, Laothamatas (1); Prasert, Assavaprathuangkul (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Siriraj Hospital - Radiology; (3)Ramathibodi Hospital Mahidol University - Radiology Bangkok, Thailand

Does diffuse white matter change often seen after WBRT also occur after GK for multiple brain METs? P2-18 Masaaki, Yamamoto (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Stereotactic irradiation for choroidal melanoma in the elderly P2-19 Stéphanie, Bolle (1); Isabelle, Rutten (1); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie Liège, Belgium

Conformal stereotactic radiotherapy in the management of the orbital hemangioma P2-20 F, Mascarenhas (1); M, Santos (1); I, Monteiro Grillo (1); A, Almeida (2) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal- Radiology Dpt Lisboa, Portugal

Wednesday14/09/05

Page 62: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

62

Scientific Program

Accuracy in ophthalmic radiosurgery - eye fixation, imaging, dosimetry P2-21 Josef, Novotny Jr. (1); Josef, Novotny (2); Roman, Liscak (3); Vaclav, Spevacek (4); Jan, Hrbacek (5); Pavel,Dvorak (6); Tomas, Cechak (7); Josef, Vymazal (8) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na HomolceHospital - Stereotactic and radiation neurosurgery; (4) CTU in Prague, Faculty of Nuclear Science and PhysicalEngineering - Dosimetry and application of ionizing radiation; (5) CTU in Prague, Faculty of Nuclear Scienceand Physical Engineering - Dosimetry and application of ionizing radiation; (6) CTU in Prague, Faculty ofNuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (7) CTU in Prague,Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (8) NaHomolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic

Combined positron emission tomography and magnetic resonance imaging in the dosimetry planning of radiosurgery using Leksell gamma knife for intracranial tumors in children. Preliminary experience P2-23 Benoit, Pirotte (1); Serge, Goldman (2); Philippe, David (3); Daniel, Devriendt (4); Jacques, Brotchi (1); Patrick,Van Bogaert (5); Marc, Levivier (6) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neuroradiologie; (4)Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Paediatric Neurology; (6) Hôpital Erasme - CentreGamme Knife Brussels, Belgium

Integration of CT-PET and MRI images in stereotactic procedures using hardware coregistration P2-24 Piero, Picozzi (1); Luca, Attuati (2); Alberto, Franzin (2); Lorenzo, Gioia (2); Claudio, Landoni (3); V.V, Dolenc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele- Neurosurgery Department; (3) Ospedale San Raffaele - Dept. of Nuclear Medicine; (4) University of Ljubljana,Clinical Center - Department of Neurosurgery Milano, Italy

Role of positron emission tomography in stereotactic radiosurgery with gamma knife P2-25 Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Naoki, Hayashi (1); Yuta, Shibamoto (2); Jun, Yoshida (3) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiologyand Radiation Oncology; (3) Nagoya University School of Medicine - Department of Neurosurgery Nagoya, Japan

Tomotherapeutic intensity-modulated radiosurgery (IMRS): improving dose gradients and maximum dose after inverse optimization using ActiveRx P2-26 Martin, Fuss (1); Bill J., Salter (2) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA

Wed

nesd

ay14

/09/

05

Page 63: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

63

Scientific Program

Radiosurgery, staged radiosurgery and fractionated radiosurgery: experiences of gamma knife and CyberKnife P2-27 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

Today’s technology and application of a dedicated neuro-radiosurgery systems P2-28Franz, Krispel (1) (1) American Radiosurgery, Inc. - Research and Development San Diego, USA

Dynamic patient positioning using Leksell gamma knife P2-29 Stefan G, Scheib (1); Stefano, Gianolini (2); Friederike, Reich (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3)Unitversity of Applied Science Remagen - Department of Medical Engineering and Sports-MedicalEngineering Zürich, Switzerland

Extracranial stereotactic IMRT - A study of set-up reproducibility P2-30Meg, Schneider (1); Robert, Smee (1); Lyn, Emanuel (2); John, Way (3); Karl, Chan (4) (1) Prince of Wales Hospital - Department of Radiation Oncology; (2) University of New South Wales - Princeof Wales Hospital - Department of Radiation Oncology; (3) Prince of Wales Hospital - Physics Department ofRadiation Oncology Randwick, Australia

Implementation of A 6D robotic couch-top for the automation of image-guided brain SRS and spinal SRT P2-31 Almon, Shiu (1); Eric, Chang (2); Conjung, Wang (1) (1) The University of Texas M.D. Anderson Cancer Center - Radiation Physics; (2) The University of Texas M.D.Anderson Cancer Center - Radiation Oncology Houston, USA

Targeting accuracy of a novel image guided gating system for stereotactic body radiotherapy P2-32 Stephen, Tenn (1); Paul, Medin (1); Timothy D., Solberg (1) (1) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA

Comparison of five radiosurgery treatment planning techniques: Is it a case of "six of the one, half a dozen of the other?" P2-33 Hester, Burger (1); Audrey, Pentz (1) (1) Netcare Group of Hospitals - Medical Physics Division Johannesburg, South Africa

Wednesday14/09/05

Page 64: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

64

Scientific Program

Feasibility of implanted fiducial markers for patient positioning for cranial radiotherapy P2-34Rosa, Cañon (1); Ignacio, Azinovic (2); Mario, Lobato (2); Francisco, Garcia-Cases (2); Maricarmen, Heredia(2); Jose, Navarro (3); Jose, Martinez (2) (1) Hospital San Jaime - Oncology Platform, Radiation Oncology; (2) Hospital San Jaime - Oncology Platform,Radiation Oncology; (3) Hospital San Jaime - Neurosurgery Torrevieja, Spain

Dynamic extracranial robotic radiosurgery by means of a real-time motion correction system: analysis of the reduction of the planning target volume compared to the static technique P2-35Franco, Casamassima (1); Giovanni, Ambrosino (2); Paolo, Francescon (3); Carlo, Cavedon (3); Joseph,Stancanello (3); Stefania, Cora (3); Michele, Avanzo (3); Paolo, Scalchi (3) (1) University of Firenze - Department of Fisiopathology - section of Radiotherapy; (2) S. Bortolo Hospital -Vicenza - Italy - General Surgery Department; (3) S. Bortolo Hospital - Vicenza - Italy - Medical PhysicsDepartment Firenze, Italy

Monte Carlo simulation for stereostatic treatment with multiple fields P2-36 Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology Shatin, Hong Kong

The study of dose enhancement close to platinum implants for 4, 8, 14 and 18 mm collimator helmets in the gamma knife surgery P2-37 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong

Stochastic target approximation by auto-computation of spatial units for stereotactic radiosurgery P2-38 Kyoung-Sik, Choi (1); Seongjong, Oh (2); Hyun-Tai, Chung (3); Moon-Chan, Kim (4); Bo-Young, Choe (5); Suh,Tae-Suk (6) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (2)The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (3) SeoulNational University Hospital - Department of Neurosurgery; (4) Kangnam St. Mary's Hospital - Neurosurgery;(5) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (6)The Catholic University of Korea, School of Medicine - Biomedical Engineering Seoul, Korea

Wed

nesd

ay14

/09/

05

Page 65: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

65

Scientific Program

Comparison of dose calculations and dose measurements near heterogeneities in gamma knife radiosurgery P2-39 Françoise, Desmedt (1); Stéphane, Simon (2); Bruno, Vanderlinden (2); Christophe, Vandekerkhove (2);Thierry, Gevaert (1); Bob, Schaeken (3); Daniel, Devriendt (4); Nicolas, Massager (5); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Physique; (3) AZ Middelheim - Physique; (4)Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neurochirurgie Brussels, Belgium

Dynamic arc: useful or expensive toy for meningiomas treatment? P2-40 Frederic, Dessy (1); Carine, Mitine (2); Laurent, Gilbeau (1); Marie-Therese, Hoornaert (1) (1) Hôpital de Jolimont - Radiotherapie; (2) Jolimont hospital - Radiotherapy Haine Saint Paul, Belgium

Simultaneous SRS for multiple intracranial lesions with single isocenter using micromultileaf collimator P2-41 Junichi, Fukada (1); Etsuo, Kunieda (1); Osamu, Kawaguchi (1); Satoshi, Seki (1); Naoyuki, Shigematsu (1);Minoru, Uematsu (1); Atsushi, Kubo (1) (1) Keio University - Department of Radiology Tokyo, Japan

A new tool for quantitative evaluation of plan quality in Fractionated Stereotactic Radiotherapy P2-42 Janna, Menhel (1); Dror, Alezra (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel

Characterization of lung lesion doses in Stereotactic Body Radiation Therapy (SBRT) via Monte Carlo P2-43 Premavathy, Rassiah (1); Martin, Fuss (2); Bill J., Salter (3) (1) UTHSC San Antonio - Radiology; (2) UTHSC San Antonio - Radiation Oncology; (3) Cancer Therapy &Research Center - Medical Physics San Antonio, USA

In SRS treatment what factors affect the normal tissues receiving doses much less than prescription doses? P2-44 Ramaswamy, Sadagopan (1); Narayan, Sahoo (2) (1) M.D. Anderson Cancer Center - Radiation Oncology; (2) M.D. Anderson Cancer Center - Radiation Physics Houston, USA

Dosimetric verification of an IMRS dose delivery of the Novalis system P2-45 Dong-Joon, Lee (1); Moon-Jun, Sohn (1); Sung Rok, Han (1); Sang Won, Yoon (1); Gee Taek, Yee (1); C. Jin,Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery Goyang, Korea

Wednesday14/09/05

Page 66: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

66

Scientific Program

Multiple isocentric plan with Brain Lab microMLC for eight brain mets P2-46 Dinesh, Tewatia (1); S.K., Rout (1) (1) Indraprastha Apollo Hospital - Medical Physics New Delhi, India

An analysis of the impact of intrafraction internal anatomy motion on delivery of radiation therapy: a dosimetry analysis using a dynamic phantom system P2-47 Chung, Jin-Beom (1); Suh, Tae-Suk (2); Chung, Won-Kyun (3) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (2) The Catholic Universityof Korea, School of Medicine - Biomedical Engineering; (3) Seoul Health College - Radiation Science Seoul, Korea

Dynamic field shaping arc versus circular cones for treatment of AVM: a comparative study P2-48 Carole, Gallez (1); Dirk, Verellen (2); Koen, Tournel (3); Nadine, Linthout (4); Tom, Wauters (5); Jean, D'Haens(6); Guy, Storme (7) (1) VUB - ETRO; (2) AZ VUB - Physique; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy; (5) AZ-VUB -Radiotherapy; (6) AZ-VUB - Neurosurgery; (7) AZ VUB - Radiothérapie Brussels, Belgium

Gamma knife surgery for functioning pituitary adenomas extending into cavernous sinus: Advantages in robotized micro-radiosurgery with advanced MR iImaging P2-49 Motohiro, Hayashi (1); Masahiro, Izawa (1); Taku, Ochiai (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1);Kintomo, Takakura (1); Jean, Regis (2) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service deNeurochirurgie Tokyo, Japan

Efficacy of gamma knife radiosurgery in patients with recurrent or residual functioning and non functioning pituitary adenomas P2-50 Mercedes, Heureux (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Nicolas, Massager (3); Marc, Levivier (4);Bernard, Corvilain (1) (1) Hôpital Erasme - Endocrinology; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neurochirurgie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Wed

nesd

ay14

/09/

05

Page 67: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Clinical results of LINAC-based stereotactic radiosurgery and Fractionated Stereotactic Radiotherapy for pituitary adenomas P2-51Putipun, Puataweepong (1); Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1);Somjai, Dangprasert (1); Jiraporn, Laothamatas (1); Veerasak, Theerapancharoen (2); Suchart,Phuthichjaroenrat (3); Pornpan, Yongvithisatid (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - Department of Surgery; (3) Prasat Neurological Institute - Pathology Bangkok, Thailand

Gamma surgery in the treatment of nonsecretory pituitary macroadenomas P2-52 Jason, Sheehan (1); Ladislau, Steiner (2); Vincezo, Mingione (3); Edward R., Laws Jr. (1); Mary Lee, Vance (2);Chun-Po, Yen (2); Melita, Steiner (2); Matei, Stroila (2) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - neurosurgery; (3)University of Vienna - Department of Neurosurgery Charlottesville, USA

Results of steretoactic radiosurgery in patients with functional pituitary adenomas P2-53 Fabiola, Flores Vazquez (1); Pomponio, Lujan Castilla (2); Fiacro, Jimenez-Ponce (3); Francisco, Velasco (4);Mario, Enriquez (5); Luis, García (6); Eduardo, Arana (7) (1) Hospital General de Mexico - Radiotherapy; (2) Hospital General de Mexico - Radiotherapy; (3) HospitalGeneral de Mexico - Neurosurgery; (4) Hospital General de Mexico - Neurosurgery; (5) Hospital General deMexico - Radiotherapy; (6) Hospital General de Mexico - Neurosurgery; (7) Hospital General de Mexico -Radiotherapy Mexico City, Mexico

Gamma knife radiosurgery for secretory and non-secretory pituitary adenomas P2-54 Aditya, Gupta (1); Sandeep, Vaishya (1); S S, Kale (1); V S, Mehta (1) (1) All India Institute of Medical Sciences - Neurosurgery Department New Delhi, India

The radiosurgery for nonfunctioning pituitary adenomas P2-55 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Katsunobu, Yoshioka (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

LINAC stereotactic radiosurgery for pituitary adenomas P2-56 Martin, Malacek (1); Juraj, Steno (2); Ludmila, Trejbalova (3); Augustin, Durkovsky (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) Faculty Hospital of the ComeniusUniversity - Department of Neurosurgery; (3) Faculty Hospital of the Comenius University - Department ofEndocrinology; (4) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia

67

Wednesday14/09/05

Page 68: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

68

Scientific Program

Using a small diode detector for a quick quality assurance (QA) test of the Cyberknife system P2-57 Anthony K., Ho (1); Steven D., Chang (2); John R., Adler Jr. (3); Cristian, Cotrutz (4); Iris, Gibbs (5) (1) Stanford University - Radiation Oncology; (2) Stanford University - Neurosurgery; (3) Stanford University- Neurosurgery; (4) Stanford University - Radiation Oncology; (5) Stanford University - Radiation Oncology Stanford, USA

Influence of different inhomogeneities on the geometric distortion in stereotactic magnetic resonance imaging P2-58 Josef, Novotny Jr. (1); Josef, Vymazal (2); Pavel, Chuda (3); Dusan, Urgosik (4); Josef, Novotny (5); Roman,Liscak (6) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Stereotactic and radiation neuro-surgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neu-rosurgery; (5) Na Homolce Hospital - Medical physics; (6) Na Homolce Hospital - Stereotactic and radiationneurosurgery Prague, Czech Republic

Repositioning accuracy - evolution of a fractioned stereotactic system for the head and neck region P2-59John, Way (1); Margaret, Schneider (2); Robert Ian, Smee (2); Lyn, Emanuel (2); Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology; (2) University of New South Wales- Prince of Wales Hospital - Department of Radiation Oncology Shatin, Hong Kong

Applications of polymer gel dosimetry in stereotactic radiosurgery P2-60 Panagiotis, Papagiannis (1); Pantelis, Karaiskos (2); Loukas, Sakelliou (1); Panagiotis, Sandilos (2); Michael,Torrens (3) (1) University of Athens - Physics; (2) Hygeia Hospital - Medical Physics; (3) Hygeia Hospital - Gamma KnifeNeurosurgery Department Athens, Greece

Radiosurgery for vertebral angioma. Steretactic body frame P2-61 Luis, Larrea (1); E, Lopez (1); J, Bea (1); M.C., Banos (1) (1) Hospital NISA Virgen del Consuelo - Oncologia Radioterapica Valencia, Spain

Dosimetric effect of intra-fraction motion during spinal radiosurgery P2-62Martin, J Murphy (1); Cihat, Ozhasoglu (2); Warren, Kilby (3); Derek, Olender (3);(1) Virginia Commonwealth University, Richmond VA; (2) University of Pittsburgh PA; (3) AccurayIncorporated, Sunnyvale CARichmond, USA

Wed

nesd

ay14

/09/

05

Page 69: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Implementation of helical tomotherapy for spinal radiosurgery P2-63 John, Fiveash (1); Richard, Popple (2); Jennifer, De Los Santos (2); James, Markert (3); Barton L., Guthrie (4);Chris, Dobelbower (2) (1) University of Alabama at Birmingham - Radiation Oncology; (2) University of Alabama at Birmingham -Radiation Oncology; (3) University of Alabama at Birmingham - Department of Neurosurgery Birmingham, USA

Spinal radiosurgery: the consequences of “segmental image fusion technique” and its clinical experiences P2-64 Moon-Jun, Sohn (1); Dong-Joon, Lee (1); Yoon-Joon, Hwang (2); Sang-Ryong, Jeon (3); Ho-Yeon, Lee (4);Sang-Ho, Lee (5); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery; (2) Inje University Ilsan Paik Hospital -Department of Neuroradiology; (3) Asan Medical Center, College of Medicine, University of Ulsan -Department of Neurosurgery; (4) Wooridul General Hospital - Department of Neurosurgery Goyang, Korea

Non-invasive radiological evaluation of superior cerebellar artery after gamma knife radiosurgery for idiopathic trigeminal neuralgia: preliminary results of a cohort study P2-65 José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel, Devriendt (4); Françoise, Desmedt (1);Paul, Van Houtte (4); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme -Neurochirurgie; (4) Institut J. Bordet - Radiothérapie Brussels, Belgium

Stereotactic radiosurgery for trigeminal neuralgia using a non-dedicated linear accelerator P2-66 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

The complication rates after gamma knife radiosurgery for facial pain are predicted by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures P2-67 Thomas, Ellis (1); Volker W., Stieber (2); Stephen, Tatter (1); Alan, deGuzman (2); Kenneth, Ekstrand (2);Michael, Munley (2); Daniel, Bourland (2); Kevin, McMullen (2); William, Huang (2); Lovato, James (3);Christopher, Balamucki (4); Charles, Branch (1); Edward G., Shaw (2) (1) Wake Forest University School of Medicine - Department of Neurosurgery; (2) Wake Forest UniversitySchool of Medicine - Department of Radiation Oncology; (3) Wake Forest University School of Medicine -Public Health Sciences; (4) Wake Forest University - School of Medicine Winston Salem, USA

69

Wednesday14/09/05

Page 70: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

70

Scientific Program

The success of gamma knife radiosurgery for facial pain varies by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures for trigeminal neuralgia P2-68 Volker W., Stieber (1); Thomas, Ellis (2); Alan, deGuzman (1); Edward G., Shaw (1); Charles, Branch (2); Daniel,Bourland (1); Kevin, McMullen (1); Christopher, Balamucki (3); Michael, Munley (1); Kenneth, Ekstrand (1);Lovato, James (4); William, Huang (1); Stephen, Tatter (2) (1) Wake Forest University School of Medicine - Department of Radiation Oncology; (2) Wake ForestUniversity School of Medicine - Department of Neurosurgery; (3) Wake Forest University - School of Medicine;(4) Wake Forest University School of Medicine - Public Health Sciences Winston Salem, USA

ORAL SESSIONS 11h30 – 12h30

FUNCTIONAL RADIOSURGERY 1 OS16Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation

Radiosurgery of cavernous malformations associated OS16-1with intractable seizuresYoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Gamma knife radiosurgical thalamotomy for essential tremor : OS16-2a six year experienceJohn, Lee (1); Joseph, Ong (2); Douglas, Kondziolka (3) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center -Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Department of NeurologicalSurgery Philadelphia, USA

Gamma knife radiosurgery - an alternative for intractable OS16-3mesial temporal lobe epilepsySujoy, Sanyal (1); V P, Singh (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of MedicalSciences - Neurosurgery Department Calcutta, India

Wed

nesd

ay14

/09/

05

Page 71: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

Does dose rate affect efficacy ? OS16-4 The outcomes of 256 gamma knife radiosurgery procedures for facial pain as they relate to the half-life of cobalt Christopher, Balamucki (1); Thomas, Ellis (2); Alan, deGuzman (3); Edward G., Shaw (3); Michael, Munley (3);Stephen, Tatter (2); Kenneth, Ekstrand (3); William, Huang (3); Daniel, Bourland (3); Kevin, McMullen (3);Charles, Branch (2); Lovato, James (4); Volker W., Stieber (3) (1) Wake Forest University - School of Medicine; (2) Wake Forest University School of Medicine - Departmentof Neurosurgery; (3) Wake Forest University School of Medicine - Department of Radiation Oncology; (4)Wake Forest University School of Medicine - Public Health Sciences Winston-Salem, USA

IMAGING - ARTERIOVENOUS MALFORMATIONS OS17Chairmen: Philippe, David; Enrico, Motti Room

Permeke & Rembrandt

Imaging development for dose planning of radiosurgery: OS17-1Three dimensional MR (DRIVE) images and MR angiographyHiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

Integration of three-dimensional corticospinal tractography OS17-2 into treatment planning for gamma knife radiosurgeryKeisuke, Maruyama (1); Kyousuke, Kamada (1); Masahiro, Shin (1); Daisuke, Itoh (2); Shigeki, Aoki (4);Yoshitaka, Masutani (4); Masao, Tago (4); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology Tokyo, Japan

Target definition in radiosurgery of AVMs using digital OS17-3subtraction angiography time seriesHarald, Treuer (1); Moritz, Hoevels (1); Stefan, Hunsche (1); Mohamad, Maarouf (1); Jürgen, Voges (1);Martin, Kocher (2); R.-P., Müller (6); V., Sturm (1) (1) University of Cologne - Department of Stereotaxy; (2) University of Cologne - Klinik für Strahlentherapie Köln, Germany

Stereotactic radiosurgery patient response: 3-phase diary study OS17-4Janet, Williams (1); Robert, Smee (2) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (2) Princeof Wales Hospital - Department of Radiation Oncology Randwick, Australia

71

Wednesday14/09/05

Page 72: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

72

Scientific Program

EXTRACRANIAL RADIOSURGERY 1 OS18Chairmen: David, Larson; John, Buatti Room Willumsen

A prospective trial on stereotactic radiotherapy OS18-1of colo-rectal metastasesMorten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars, Ohlhuis (2); Jorgen, Petersen (1); Hanne,Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Departmentof Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark

Stereotactic body radiation therapy of early stage non-small OS18-2cell lung carcinoma: phase I study updateRonald, McGarry (1); Robert, Timmerman (2); Lech, Papiez (3); Mark, Williams (4) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) University of TexasSouthwestern - Department of Radiation Oncology; (3) Indiana University Medical Center - Department ofRadiation Oncology; (4) Richard L. Roudebush V.A. Medical Center - Pulmonary Division Indianapolis, USA

Stereotactic radiotherapy for liver tumours based on MRI OS18-3and tumor markersAlejandra, Mendez Romero (1); Wouter, Wunderink (2); Shahid M, Hussain (3); Peter JCM, Nowak (4); BenJM, Heijmen (5); Joost, Nuyttens (6); Rene P, Brandwijk (7); Jan NM, Ijzermans (8); Peter C, Levendag (9) (1) Erasmus MC - Radiotherapy; (2) Erasmus MC - Radiotherapy; (3) Erasmus MC - Radiology; (4) Erasmus MC- Radiotherapy; (5) Erasmus MC - Radiotherapy; (6) Erasmus MC - Radiotherapy; (7) Erasmus MC -Radiotherapy; (8) Erasmus MC - Surgery; (9) Erasmus MC - Radiotherapy Rotterdam, The Netherlands

Stereotactic radiation treatment (SRT) for advanced OS18-4intra-abdominal tumoursVincent, Vinh-Hung (1); Frederik, Vandenbroucke (2); Zsuzanna, B Nagy (1); Hilde, Van Parijs (1); Maria,Voordeckers (1); Jan, Van de Steene (1); Guy, Soete (1); Dirk, Van Den Berge (1); Johan, De Mey (2); Guy,Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - RadiologieBrussels, Belgium

Wed

nesd

ay14

/09/

05

Page 73: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

SPONSORED SEMINAR 13h00 - 13h45

THE COMPLEMENTARY ROLE OF INTRA OPERATIVE MRI Room NationAND RADIOSURGERYSeminar and lunch sponsored by MedtronicChairman: Jacques Brotchi

ULB Erasme experience of treating patients with PoleStar and gamma knifeProf. J. BrotchiHôpital Erasme - Neurochirurgie, Brussels, Belgium

Complementary Use of intra operative MRI technique and Radio SurgeryDr. M. SchulderNew Jersey Medical School - Department of Neurosurgery, Newark NJ, USA

ORAL SESSIONS 14h00 - 15h00

FUNCTIONAL RADIOSURGERY 2 OS19Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation

Gamma knife radiosurgery to the pituitary for thalamic OS19-1pain syndrome: clinical evaluation of recent our institutional seriesMotohiro, Hayashi (1); Takaomi, Taira (2); Taku, Ochiai (1); Mikhail, Chernov (1); Shinichi, Goto (2); Koutaro,Nakaya (1); Masahiro, Izawa (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) Tokyo Women's Medical Univeristy- Department of Neurosurgery Tokyo, Japan

Gamma knife radiosurgery for symptomatic trigeminal OS19-2neuralgia. How should we select the treatment strategy ?Hiroyuki, Kenai (1); M, Yamashita (1); T, Nakamura (1); T, Asano (1); M, Saino (1); H, Nagatomi (1) (1) Nagatomi Hospital - Department of Neurosurgery Oita, Japan

Influence on pain outcome of the neurovascular compresion OS19-3anatomy on MRI in patients with idiopathic trigeminal neuralgia treated by gamma knife radiosurgery José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel Salvador, Ruiz Gonzalez (4); Françoise,Desmedt (1); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme -Neurochirurgie; (4) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Brussels, Belgium

73

Wednesday14/09/05

Page 74: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

74

Scientific Program

Different targets in the gamma knife treatment OS19-4for intractable painDusan, Urgosik (1); Roman, Liscak (2); Josef, Novotny Jr. (3); Josef, Vymazal (4); Vilibald, Vladyka (5) (1) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (2) Na Homolce Hospital - Stereotacticand radiation neurosurgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital -Stereotactic and radiation neurosurgery; (5) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery Prague, Czech Republic

PHYSICS - NEWS OS20Chairmen: Frank, Bova; Dirk, Verellen Room

Permeke & Rembrandt

Image-guided and frameless localization in cranial stereotactic OS20-1radiotherapyJoachim, Bogner (1); Beverly, Downes-Phillips (2); Dietmar, Georg (3); David W., Andrews (2) (1) Medical University Vienna - Radiotherapy and Radiobiology; (2) Jefferson Hospital for Neuroscience -Department of Neurosurgery; (3) Medical University Vienna - Radiotherapy and Radiobiology Vienna, Austria

Treatment of ocular melanoma; X-Knife treatment planning OS20-2with optimal immobilizationSandra, de Vries (1) (1) Otago University - Radiation Therapy Dunedin, New Zealand

Initial experience with a x-ray based respiratory gating OS20-3system for lung and liverFranz, Gum (1); Reinhard, Wurm (1); Armin, Fuerst (2); Volker, Budach (1) (1) Charité University Medicine Berlin - Department of Radiation Oncology; (2) BrainLAB - Radiotherapy Berlin, Germany

Evaluating the localization accuracy of 6D Fusion software OS20-4for the Novalis body image guided system and its clinical application for spinal radiosurgeryJian-Yue, Jin (1); Samuel, Ryu (1); Jack, Rock (2); Kathleen, Faber (1); Marilyn, Gates (3); Shidong, Li (1);Benjamin, Movsas (1) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery Detroit, USA

Wed

nesd

ay14

/09/

05

Page 75: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

ORAL SESSIONS 15h00 - 16h00

FUNCTIONAL - TRIGEMINAL NEURALGIA 1 OS21Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation

Longterm clinical results for trigeminal neuralgia treated OS21-1by gamma knife radiosurgery

Murata NorikoNoriko, Murata (1); Manabu, Tamura (2); Jean, Regis (3) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital -Stereotactic and Fonctional Neurosurgery; (3) CHU La Timone - Service de Neurochirurgie Marseille, France

Outcome of patients undergoing gamma knife stereotactic OS21-2radiosurgery for medically refractory idiopathic trigeminal neuralgiaKostas, Fountas (1); Joseph, Smith (2) (1) The Medical Center of Central Georgia - Department of Neurosurgery; (2) Medical College of Georgia -Neurosurgery Macon, USA

Outcomes of gamma knife radiosurgery in trigeminal neuralgia OS21-3David, Huang (1); Danielle, Rudolph (2); Deane, Jacques (3) (1) Cancer Care Consultants/ Northridge Hospital - Radiation Oncology; (2) Independent CRA - CRA; (3) GoodSamaritan Hospital - Neurosciences Institute Northridge, USA

Gamma knife radiosurgery as primary surgery for patients OS21-4with trigeminal neuralgiaJohn, Lee (1); Jae Gon, Moon (2); Ricky, Madhok (3); Brian, Jankowitz (2); Joseph, Ong (3); Douglas,Kondziolka (4); John C, Flickinger (6); L. Dade, Lunsford (6) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center -Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurosurgery; (4) University ofPittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA

75

Wednesday14/09/05

Page 76: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

76

Scientific Program

PHYSICS - QUALITY ASSURANCE OS22Chairmen: Stephan G, Scheib; Frank, Bova Room

Permeke & Rembrandt

Using the Winston Lutz test and EPID to compare OS22-1stereotactic radiosurgery set using Radionics LTLF and BrainLab Target PositionerRobert, Myers (1); Ryan, Smith (1); Michael, Dally (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia

Assessment of the geometric accuracy in stereotactic OS22 –2PET image definitionJosef, Novotny Jr. (1); Karel, Nechvil (2); Josef, Novotny (3); Roman, Liscak (4) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na HomolceHospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic

Quality assurance in stereotactic imaging using the known OS22-3target point methodStefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1); Andreas, Mack (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3)Gamma Knife Center Frankfurt - Medical Physics Zürich, Switzerland

Quality assurance in stereotactic radiosurgery according OS22-4E-DIN 6875-1Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics Zürich, Switzerland

Wed

nesd

ay14

/09/

05

Page 77: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

ORAL SESSIONS 17h00 - 18h00

FUNCTIONAL - TRIGEMINAL NEURALGIA 2 OS23 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation

Incidence of paresthesias after radiosurgery (SRS) OS23-1for trigeminal neuralgia targeting at the root entry zoneAlessandra, Gorgulho (1); Antonio, De Salles (2); David, McArthur (3); Zachary, Smith (4); Leonardo, Frighetto(5); Carlos, Mattozo (1); Steve, Lee (6); Michael, Selch (7); Timothy, Solberg (7) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA - Neurosurgery; (3) UCLA - Neurosurgery;(4) UCLA - Neurosurgery; (5) UCLA - Neurosurgery; (6) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Robotized micro-radiosurgery for essential trigeminal neuralgia: OS23-2Evaluation and analysis of over 100 patients experience with unique methodMotohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1);Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan

Trigemina neuralgia treatment with linear accelerator OS23-3radiosurgery: results in 82 patientsMichael, Girvigian (1); Joseph CT, Chen (2) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology; (2) Kaiser Permanente MedicalCenter - Neurosurgery Los Angeles, USA

Complication of gamma knife surgery for trigeminal neuralgia OS23-4Shinji, Matsuda (1); Toru, Serizawa (2); Yoshinori, Higuchi (3); Makoto, Sato (4); Junichi, Ono (5) (1) Chiba Cardiovascular Center - Department of Neurology; (2) Chiba Cardiovascular Center - Department ofNeurosurgery; (3) Chiba Cardiovascular Center - Department of Neurosurgery; (4) Chiba CardiovasucularCenter - Department of Radiology; (5) Chiba Cardiovascular Center - Department of Neurosurgery Chiba, Japan

77

Wednesday14/09/05

Page 78: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program

SPINE OS24Chairmen: Iris, Gibbs; Antonio, DeSalles Room

Permeke & Rembrandt

Single fraction spinal radiosurgery for the treatment OS24-1of spinal metastasesPeter, Gerszten (1); Steven, Burton (2); Cihat, Ozhasoglu (3); William, Vogel (3); Annette, Quinn (3); William,Welch (4) (1) Shadyside Hospital - Department of Neurosurgery; (2) Shadyside Hospital - Radiosurgery Department; (3)Shadyside Hospital - Radiation Oncology Department; (4) University of Pittsburgh Medical Center -Department of Neurological Surgery Pittsburgh, USA

Decade of Cyberknife at Stanford University 1994-2004 OS24-2Iris, Gibbs (1); Anthony K., Ho (2); Cristian, Cotrutz (3); Steven D., Chang (4); Christopher, King (5); Albert,Koong (6); John R., Adler Jr. (7) (1) Stanford University - Radiation Oncology; (2) Stanford University - Radiation Oncology; (3) StanfordUniversity - Radiation Oncology; (4) Stanford University - Neurosurgery; (5) Stanford University - Departmentof Radiation Oncology; (6) Stanford University - Radiation Oncology; (7) Stanford University - Neurosurgery Stanford, USA

Importance of image fusion for spinal radiosurgery OS24-3Antonio, De Salles (1); Alessandra, Gorgulho (1); Paul, Medin (2); Nzhde, Agazaryan (3); Timothy, Solberg (3);Carlos, Mattozo (3); Leonardo, Frighetto (3); Cynthia, Cabatan-Awang (3); Michael, Selch (3) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Image-guided radiosurgery of the spinal nerve: OS24-4A pilot study in swinePaul, Medin (1); Bryan William, Goss (2); Dennis, Chute (3); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Radiation Oncology; (2) UCLA - Radiation Oncology; (3) UCLA -Pathology Los Angeles, USA

Wed

nesd

ay14

/09/

05

78

Page 79: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

79

Scientific Program

Thursday 15/09/05

BREAKFAST SEMINARS 7h30 - 8h30

SPINAL STEREOTACTIC RADIOTHERAPY BS10 Room Rembrandt

Challenges in spinal radiosurgery BS10-1Ingmar, Lax

Dosimetric effect of intra-fraction motion during BS10-2spinal radiosurgeryMartin J., Murphy

Evaluation of segmental image fusion in spine radiosurgery BS10-3Moon-Jun, Sohn

VESTIBULAR SCHWANNOMAS HEARING PRESERVATION BS11 Room Permeke

Hearing preservation with gamma knife radiosurgery BS11-1Seiji, Fukuoka

Hearing preservation with stereotactic radiotherapy BS11-2Daniele, Rigamonti

Hearing preservation with Linac-based radiosurgery BS11-3John, Suh

PITUITARY TUMORS: RADIOSURGERY OR RADIOTHERAPY? BS12Room Willumsen

Respective role of radiosurgery and radiotherapy BS12-1 in non-secreting adenomasIdefumi, Jokura

Respective role of radiosurgery and radiotherapy BS12-2in secreting adenomasNicolas, Massager

Pituitary gamma knife radiosurgery BS12-3Roman, Liscak

Thursday15/09/05

Page 80: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

80

Scientific Program

PLENARY SESSION 8h45 - 10h00

PS4

Room Nation

DATA BLITZ UPDATE 5 PS4-1Functional radiosurgeryDouglas, Kondziolka

DATA BLITZ UPDATE 6 PS4-2Spinal radiosurgeryIris, Gibbs

COMBINED STRATEGIES, TRIGEMINAL NEURALGIA, CANCEROGENESISChairmen: Douglas, Kondziolka; Iris, Gibbs

Combination therapy of intentional partial resection PS4-3followed by gamma knife radiosurgery for large skull base meningiomasSeiji, Fukuoka (1) (1) Nakamura Memorial Hospital - Department of Neurosurgery Sapporo, Japan

Incidence of trigeminal nerve dysfunction after trigeminal PS4-4neuralgia radiosurgery: a comparison between 3 treatment strategiesNicolas, Massager (1); Noriko, Tamura (2); Ouzi, Nissim (3); Daniel, Devriendt (4); Françoise, Desmedt (3);David, Wikler (5); Jacques, Brotchi (1); Marc, Levivier (3); Jean, Regis (6) (1) Hôpital Erasme - Neurochirurgie; (2) CHU La Timone - Gamma Knife center; (3) Hôpital Erasme - CentreGamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - PET Scan; (6) CHU La Timone - Servicede Neurochirurgie Brussels, Belgium

Estimating the risk of malignancy after radiosurgery PS4-5in the general populationJeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz(3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

Thur

sday

15/0

9/05

Page 81: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

81

Scientific Program

ORAL SESSIONS 10h30 - 11h30

ARTERIOVENOUS MALFORMATIONS 1 OS25Chairmen: Douglas, Kondziolka; Keisuke, Maruyama Room Nation

Usefulness of time resolved MR digital substracted OS25-1angiography (MRDSA) in the follow-up of cerebral arterio-venous malformations (AVMs) after gamma knife radiosurgery: preliminary resultsPhilippe, David (1); Patrice, Jissendi (1); Isabelle, Delpierre (1); Danièle, Balériaux (1); Nicolas, Massager (2);Daniel, Devriendt (5); Marc, Levivier (5); Boris, Lubicz (1) (1) Hôpital Erasme - Neuroradiologie; (2) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Clinical implications of the latent period after AVM OS25-2radiosurgeryAurelia, Kollova (1); Farouq, Din (1); Alison, Grainger (1); Jeremy, Rowe (1); Lee, Walton (2); Matthias WalterRichard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

The risk of hemorrhage after radiosurgery for cerebral OS25-3arteriovenous malformations: what is angiographic obliteration?Keisuke, Maruyama (1); Nobutaka, Kawahara (1); Masahiro, Shin (1); Masao, Tago (2); Hiroki, Kurita (3); Akio,Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology;(3) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan

Gamma knife radiosurgery as an alterative treatment OS25-4for dural AV fistulas involving the transverse-sigmoid sinusDavid Hung-Chi, Pan (1) (1) Taipei Veterans General Hospital - Department of Neurosurgery Taipei, Taiwan

Thursday15/09/05

Page 82: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

82

Scientific Program

PITUITARY & CRANIOPHARYNGIOMAS OS26Chairmen: Ajay,Niranjan; Jeremy, Ganz Room

Permeke & Rembrandt

Gamma knife surgery and dopamine agonists in combination OS26-1in the treatment of the clinical effects of prolactinomasJeremy, Ganz (1); W A., Reda (1); Ayman, Hafez (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

Gamma knife radiosurgery for non-functioning pituitary OS26-2adenomasHidefumi, Jokura (1); Jun, Kawagishi (1); Hidetoshi, Ikeda (2); Kou, Takahashi (1); Teiji, Tominaga (3) (1) Furukawa Seiryo Hospital - Jiro Suzuki Memorial Gamma House; (2) Tohoku University - Department ofNeurosurgery Furukawa, Japan

New treatment strategy for craniopharyngioma using OS26-3gamma knife radiosurgeryTatsuya, Kobayashi (1); Yoshimasa, Mori (1); Yoshihisa, Kida (2); Toshinori, Hasegawa (3); Naoki, Hayashi (1) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Komaki City Hospital - Department of Neurosurgery Nagoya, Japan

Biochemical assessment and long-term monitoring in patients OS26-4managed by radiosurgery for growth hormone secreting pituitary adenomasAjay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); Sue, Challinor (4);John C, Flickinger (3) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center- Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4)University of Pittsburgh Medical Center - Division of Endocrinology and Metabolism Pittsburgh, USA

MOLECULAR IMAGING - PET OS27Chairmen: David, Wikler; Josef, Novotny Jr. Room Willumsen

Trials to introduce the coordinate system on PET-CT image OS27-1during dose planning in gamma knife surgeryNaoki, Hayashi (1); Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Yuta, Shibamoto (2) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiologyand Radiation Oncology Nagoya, Japan

Thur

sday

15/0

9/05

Page 83: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

83

Scientific Program

PET 11C-methionine for gamma knife radiosurgery targeting OS27-2of recurrent pituitary adenomasBich-Ngoc-Thanh, Tang (1); Marc, Levivier (2); David, Wikler (1); Mercedes, Heureux (3); Nicolas, Massager (4);Daniel, Devriendt (5); Philippe, David (6); Bernard, Corvilain (4); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Endocrinology;(4) Hôpital Erasme - Neurochirurgie; (5) Institut J. Bordet - Radiothérapie; (6) Hôpital Erasme -Neuroradiologie Brussels, Belgium

Changes in amino-acid metabolism of pituitary adenomas OS27-3following GK radiosurgery evaluated by PET-methionineNicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Daniel, Devriendt (3); Françoise, Desmedt(4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (5) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Positron emission tomography target segmentation OS27-4methodology for radiosurgery treatment planningDavid, Wikler (1); Bich-Ngoc-Thanh, Tang (1); Daniel, Devriendt (2); Marc, Levivier (3); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; ( 2 ) Institut J. Bordet - Radiothérapie; ( 3 ) Hôpital Erasme - Center GammeKnifeBrussels, Belgium

ORAL SESSIONS 11h30 - 12h30

ARTERIOVENOUS MALFORMATIONS 2 OS28Chairmen: Serge, Blond; Christer, Linquist Room Nation

Long-term follow-up of quality of life after gamma knife OS28-1radiosurgery treatment for Arteriovenous MalformationsMichael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Bradley, Bagan (1); Sepehr, Sani (1); Demetrius,Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA

Novalis® based radiosurgical treatment of AVMs. OS28-2Our pre-eliminary resultsRecai, Ates (1); Maarten, Moens (1); Katrijn, Van Rompaey (1); Luc, Cavens (1); Cristo, Chaskis (1); Dirk,Vandenberge (2); Jean, D'Haens (1) (1) AZ VUB - Neurochirurgie; (2) AZ VUB - Radiothérapie Brussels, Belgium

Thursday15/09/05

Page 84: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

84

Scientific Program

Clinical outcomes following gamma knife radiosurgery OS28-3for arteriovenous malformations of the brainSait, Sirin (1); Kaan, Oysul (2); Hulya, Sirin (2); Asli, Oysul (2); John C, Flickinger (1); Douglas, Kondziolka (1);L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of PittsburghMedical Center - Department of Radiation Oncology Pittsburgh, USA

Radiosurgery of cerebral arteriovenous malformations OS28-4in the paediatric age group. About a series of 100 patientsNicolas, Reyns (1); Serge, Blond (1); G, Touzet (1); B, Coche (1); J.Y., Gauvrit (1); J.P., Pruvo (1); P, Dhellemmes(1) (1) Centre Hospitalier Régional et Universitaire de Lille - Centre Gamma Knife Lille, France

Neurological deficit rather than obliteration determines OS28-5quality of life in patients treated with radiosurgery for AVMsMeera, Ramani (1); Yuri, Souza (2); Deirdre, Dawson (3); Daryl, Scora (4); May, Tsao (5); Michael, Schwartz (6) (1) University of Toronto - Division of Neurosurgery; (2) University of Toronto - Division of Neurosurgery; (3)University of Toronto - Psychology; (4) University of Toronto - Medical Physics; (5) University of Toronto -Radiation Oncology; (6) Sunnybrook Hospital - Neurosurgery Department Toronto, Canada

EXTRACRANIAL RADIOSURGERY 2 OS29Chairmen: Morten,Hoyer; Gabriela, Simonova Room

Permeke & Rembrandt

Stereotactic radiosurger y after external radiotherapy OS29-1for nasopharynx carcinomaSelcuk, Peker (1); Beste Melek, Atasoy (2); Meric, Sengoz (2); Ufuk, Abacioglu (2); Turker, Kilic (1); Necmettin,Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

Image guided conformation arc radiosurgery for prostate OS29-2cancer: early clinical resultsGuy, Soete (1); Dirk, Verellen (2) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels, Belgium

Thur

sday

15/0

9/05

Page 85: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

85

Scientific Program

PET predicts treatment failure of extracranial stereotactic OS29-3radiosurgery before CTVolker W., Stieber (1); William, Kearns (1); William, Hinson (1) (1) Wake Forest University School of Medicine - Department of Radiation Oncology Winston Salem, USA

How can tumor effect and normal tissue effect be balanced OS29-4in stereotactic body radiotherapyWolfgang, Tome (1); John, Fenwick (1); Jack, Fowler (1); Minesh, Mehta (1) (1) University of Wisconsin Medical School - Human Oncology Department Madison, USA

IMAGING 2 OS30Chairmen: John, Flickinger; Michael, McDermott Room Willumsen

How much does the addition of stereotactic T2 images OS30-1affect tumor definition and treatment plans for acoustic schwannoma radiosurgery?John, Flickinger (1); Douglas, Kondziolka (2); Ajay, Niranjan (3); Ann H., Maitz (4); L. Dade, Lunsford (2) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of PittsburghMedical Center - Department of Neurological Surgery; (3) University of Pittsburgh Medical Center -Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA

A CT scan and anatomical cadaveric study of the OS30-2pterygopalatine ganglion for use in gamma knife treatment of Cluster HeadacheWilliam, Olivero (1); Jorge, Alvernia (2); Dan, Spomar (3) (1) OSF Saint Francis Medical Center - Department of Neurosurgery; (2) University of Illinois - Neurosurgery;(3) University of Illinois - Neurosurgery Peoria, USA

Assessment of post-radiosurgical imaging studies: OS30-3a volumetric algorithm and an estimation of its error Jason, Sheehan (1); John, Snell (2); Matei, Stroila (3); Ladislau, Steiner (1) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Lars Leksell Center forGamma Knife Radiosurgery; (3) University of Virginia - neurosurgery Charlottesville, USA

Meningiomas after radiosurgery: OS30-4When is recurrence expectable?Roberto, Spiegelmann (1); Janna, Menhel (2); Rafael, Pfeffer (2); Dror, Alezra (2) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Department of Oncology Ramat Gan, Israel

Thursday15/09/05

Page 86: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Scientific Program & Oral Presentations

CLOSING SESSION 12h30 - 13h30

2005 RECIPIENT OF THE JACOB I. FABRIKANT AWARD Room NationRadiosurgery of arteriovenous malformations :evoluation of the techniqueFederico, ColomboVincenza, Italy

YOUNG NEUROSURGEON AWARD, BEST POSTER AWARD, LOTTERY,CLOSING REMARKS

Thur

sday

15/0

9/05

86

Page 87: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

87

Description

Companies display their products and services in the exhibition on the 2nd floor, where thelunches and coffee breaks are organized.

Exhibition Opening HoursSunday Sept. 11, 2005 16h30 - 20h30Monday Sept. 12, 2005 08h30 - 18h00Tuesday Sept. 13, 2005 08h30 - 13h00Wednesday Sept. 14, 2005 08h30 - 18h00Thursday Sept. 15, 2005 08h30 - 14h00

Exhibition

Page 88: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

88

Exhibition

Floorplan & List of Exhibitors

Exhibition map

Page 89: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

89

Exhibition

Exhibitors List by alphabetical order

5 3D Line Medical Systems s.r.l.13 Accuray4 Alcis & Neuropace

15 American Radiosurgery12 BrainLABO Carl Zeiss Surgical GmBH

19 Dixi Medical / BioScan11 Elekta

10B Foundation Against Cancer, Belgium9 IBA Particle Therapy1 inomed Medizintechnik GmBH3 Medical Intelligence

18 Medtronic 10 Nomos Radiation Oncology - A Division of North American Scientific2 Orfit industries NV7 Philips

14 PTGR - Gmbh 8 Radionics, a Division of Tyco Healthcare Belgium N.V.

16 Siemens 17 TomoTherapy incorporated6 Varian Medical Systems

Page 90: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

The Organizers of the 7th ISRS Congress gratefully acknowledge the support of the following companies (listed by alphabetical order) :

3D Line Medical Systems s.r.l.3D Line Medical Systems S.r.l. is active in the fields of Radiotherapy, Radiosurgery, MedicalPhysics and Neurosurgery with user- and patient-friendly innovations.

Via Bernardo Rucellai 2320126 Milan Italywww.3dline.com

AccurayThe CyberKnife® Stereotactic Radiosurgery System is a non-invasive, 100% frameless,image-guided radiosurgery system that can ablate tumors and other lesions anywhere in thebody without open surgery. It is the only system that integrates real time image-guidanceand robotic delivery of radiation to deliver proven sub-millimeter total clinical accuracy.

Tour Ariane 33e 5 Place de la Pyramide92088 Paris La Défense Cedex Francewww.accuray.com

Alcis & NeuropaceALCIS is an independent French company which develops and markets functional andstereotactic neurosurgery devices and instruments (Depth electrodes, stereotactic frame,percutaneous screws for stereotactic frame re-positioning).

Chemin de Palente 8A 25000 Besançon Francewww.alcis.net

American RadiosurgeryAmerican Radiosurgery, Inc, booth 15, presents the GammaART 6000™ Rotational GammaSystem (RGS) for Radiosurgery, the EXPLORER-4D™ treatment planning system, and thenewly released automatic head positioner. The RGS is produced exclusively in the UnitedStates.

16776 Bernardo Center Dr., # 203San Diego, California USA 92128www.radiosurgery.net

90

Sponsors & Exhibitors Activities

Page 91: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

91

Sponsors & Exhibitors Activities

Amersham GE HealthcareGE Healthcare provides expertise in medical imaging which is dedicated to detecting disease earlier and tailoring individual treatment. More than 42,500 employees are committed to serving healthcare professionals and theirpatients in more than 100 countries.

Kouterveldstraat 20BB-1831 DiegemBelgiumwww.gehealthcare.com

BioScanBioScan offers the last generation of real-time dynamic digital X and gamma rays imagingsystems for low dose filmless diagnostic, interventional radiology, stereotactic radiosurgery,radiotherapy applications and non-destructive testing (NDT).

27, rue Pré Bouvier1217 Meyrin/GenevaSwitzerlandwww.bioscan.ch

BrainLABBrainLAB is the leader in SRS solutions for cranial and extracranial indications. Our state-of-the-art products include Novalis Shaped Beam Surgery, m3 micro-MLC, xacTrac X-Ray withAdaptive Gating, and iPlan TPS.

Ammerthalstrasse 885551 HeimstettenGermanywww.brainlab.com

Carl Zeiss Surgical GmBHRadiation Dose Directly to the Target. INTRABEAM® is a complete proven system for thedelivery of intraoperative radiation therapy (IORT) to tumors and tumor beds following re-section. For more information please contact:

Carl Zeiss-strasse73446 OberkochenGermanywww.zeiss.de/radiotherapy

Page 92: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

92

Sponsors & Exhibitors Activities

Codali - GuebertContrast for Life

Rue Henri Dunant 311140 Brussels Belgiumwww.codali.be

Dixi medicalFor over 20 years, we have developed and marketed a full range of electrodes and instru-ments intended to functional and stereotactic neurosurgery. We offer quality tools whichperfectly suit the evolution of surgical techniques.

4 Chemin de Palente, BP 88925025 Besançon Francewww.diximedical.com

ElektaFighting serious disease Elekta is an international medical-technology Group, developing theworld’s most advanced clinical solutions for high precision radiation treatment of cancer andfor non- or minimally invasive treatment of brain disorders.

Kungsstensgatan 18 - Box 7593103 93 StockholmSwedenwww.elekta.com

Foundation Against Cancer, BelgiumThe Foundation against Cancer encourages the development of new radiotherapeuticapproaches allowing more efficient and beneficial therapies.

Chaussée de Louvain 479 Leuvensesteenweg 1030 BrusselsBelgiumwww.cancer.be

Page 93: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

93

Sponsors & Exhibitors Activities

IBA Particle TherapyIBA PARTICLE THERAPY is at the leading edge of technology in the fields of cancer diagno-sis and therapy. IBA PARTICLE THERAPY also offers innovative solutions ensuring the well-being, health and safety of many of our daily actions. It is listed on the pan-European stockexchange EURONEXT and is integrated into the NextEconomy market segment and belongsto BelSmall index.

Avenue A. Einstein, 91348 Louvain-la-NeuveBelgiumwww.iba-worldwide.com

Inomed Medizintechnik GmBHInomed creates innovative products and Systems for Neuromonitoring, from the tailor-madeprobe and electrodes to the complete neuromonitoring system.

Tullastrasse 5a79331 Teningen Germanywww.inomed.com

S. Karger AGS. Karger AG is a leading international publisher of books and journals primarily in the basicand medical sciences. The largest medical and scientific publisher in Switzerland, Karger pro-duces 73 international specialty journals and approximately 60 yearly book titles covering allfields of research and practice.

Medical and Scientific PublishersAllschwilerstrasse 104009 BaselSwitzerlandwww.karger.com

Medical IntelligenceMedical Intelligence is a world leading supplier of innovative Radiation Oncology and inter-ventional guidance products for precise patient positioning and treatment. Our product linesinclude non-invasive immobilization systems and 6D robotic devices.

Feyerabendstrasse 13 - 15 86830 Schwabmünchen Germany www.medint.de

Page 94: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

94

Sponsors & Exhibitors Activities

MedtronicMedtronic is the world leader in medical technology providing lifelong solutions for peoplewith chronic disease. Each year, 5 million patients benefit from Medtronic's technology.

Route du Molliau 311131 Tolochenaz Switzerlandwww.stealthstation.com

Nomos Radiation Oncology - A Division of North American ScientificNorth American Scientific is manufacturing IMRT (PEACOCK® and CORVUS) and IGRT, (BATand nTRAK(tm)) products and brachytherapy seeds (Prospera®). Over 500 sites worldwideare equipped with the Company's clinically proven products.

A Division of North American ScientificPastoor Cramerstraat 2 h6102 AC Echt The Netherlands www.nasmedical.com

Orfit Industries NVOrfit Industries develops and produces thermoplastic materials for immobilization and fixa-tion purposes in medical applications.

Vosveld 9a2110 Wijnegem Belgiumwww.orfit.com

PfizerPartner for Better Health.

Boulevard de la Plaine, 17, Pleinlaan 1050 Brussels Belgium www.pfizer.be

Page 95: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

95

Sponsors & Exhibitors Activities

PhilipsPhilips Radiation Oncology systems provide innovative solutions to manage patient treat-ment. These include imaging, localization, simulation and planning, miminally invasive,image-guided procedures and inverse planning, conformal external beam planning andIMRT. For more information :

Philips Medical Systems Rue des Deux Gares 801070 Brussels Belgiumwww.medical.philips.com

PTGR - GmbHA main focus of the activities of our company lies in the field of quality assurance in radio-surgery and stereotactic radiotherapy (RS, SRT, ISRS, ISRT) bearing in mind the new guide-line E-DIN 6875-1.

PTGR-GmbHEduard-Spranger Str. 27/272076 TuebingenGermanywww.ptgr.de

Radionics, a Division of Tyco Healthcare Belgium N.V.Throughout the medical community, Radionics is synonymous with trusted accuracy.Radionics offers stereotactic radiotherapy technologies, including HDRT(tm)and XKnife(tm)systems, providing complete solutions for cranial, head, neck and body treatments.

A division of Tyco Healthcare Belgium N.V.Koningin Elisabethlaan 459000 GentBelgiumwww.radionics.com

ScheringAs a successful pharmaceutical company. We develop drugs of high medical value so as tocontinuously improve the quality of life. We focus on our four strategic Business Areas:Gynecology & Andrology, Oncology and Diagnostic Imaging.

J.E.Mommaertslaan, 141831 Diegem (Machelen)Belgiumwww.schering.be

Page 96: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

96

Sponsors & Exhibitors Activities

Siemens Medical SolutionsSiemens Medical Solutions - Oncology Care Systems - Your partner for treating tumorsaggressively and patients gently. With leading-edge solutions that seamlessly connect theentire continuum of oncology care. Allowing you to make earlier diagnoses, deliver moreaggressive therapies, and manage the entire process.

Oncology Care Systems4040 Nelson AvenueConcord, CA 94520 USA. www.SiemensMedical.com/oncology

TomoTherapy IncorporatedTomoTherapy's technology uniquely combines helical IMRT/IMRS with CT imaging for unsur-passed conformality and setup accuracy. TomoTherapy now offers the world's first AdaptivePlanning module to ensure your prescription is met.

1240 Deming WayMadison, WI 53717USAwww.tomotherapy.com

Varian Medical SystemsVarian Surgical Sciences produces leading-edge tools for planning and delivering image-guided Radiosurgery. The company’s technologies encompass solutions for delivering bothframed and frameless cranial and spinal IGRS treatments, using either multileaf collimatorsor cones.

Varian Medical Systems International AGChollerstrasse 386303 ZugSwitzerlandwww.varian.com

Page 97: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

97

Congress Social Program

Are you interested in one of the following activities and not yet registered? Come and visitus at the registration desks (ground floor).

Opening Ceremony & Welcome Reception

Sunday 11 September 2005, 17h00

Sheraton Hotel, 2nd floor, meeting room Nation

Ceremony, 17h00 - 18h00

Welcome Speeches :Prof. Marc Levivier (chair of the congress)Prof. Jean Regis (president of the scientific committee)Prof. Douglas Kondziolka (ISRS president)Prof. Jacques Brotchi (honorary chairman of the congress)

Followed by a lecture by Philippe Busquin (European Deputy and Former EuropeanCommissioner for Research): "The EU competitiveness and the socio-economic challenges ofradiosurgery".

Reception, 18h00 - 20h00, exhibition

Official opening of the ISRS 2005 exhibition, walking cocktail and reception with all the participants and officials.

The participation to this ceremony and to the reception is included in the registration fee.Although booking was highly recommended through the registration form, seats in themeeting room Nation will be subject to availability.

The ceremony will be broadcasted on plasma screens in the exhibition.

Participants are advised that they have to wear their badge at this event.

Gala Dinner & Concert of Toots Thielemans

Wednesday 14 September 2005, 19h30

Plaza Theater, Boulevard Adolphe Max, 126-128, 1000 Brussels

The Theater is next to the Hotel Plaza and belongs to the same building. It is located veryclose to the Sheraton: a short walk of 3 minutes is sufficient to reach the venue.

Build in 1930 in a unique Spanish-Arab-Moorish style. The theatre was restored in 1996with the absolute decision to keep the original boxes, the genuine bracket-lamps, the stage,the rich sculptured wall ornaments as well as the graceful arches and fake balconies in Araband Baroque styles.

Page 98: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

98

This special evening will be composed of a welcome cocktailand a sitting dinner in this magical place. During the dinner, aunique and exceptional concert will be held by the worldfamous harmonica jazzman Toots Thielemans.

Awards to be received at the closing session of Thursday will be announced during the gala dinner.

Members of the Quartet :

Jean Toots Thielemans LeadBert Van Den Brink KeyboardBart De Nolf ContrabasHans Van Oosterhout Drums

This outstanding evening is supported by a grant from Belgacom.

Price: A fee of 90 € (VAT included) is applied. Booking is compulsory. The nominative vouchers for pre-bookings for this evening as well as further infor-mation have been distributed together with the badge. If you are not yet registered, please come at the registration desk on MondaySeptember 12, 2005 : a limited number of vouchers may still be available. Participants are advised to bring their voucher and badge at this event.

Program

19h30 Cocktail reception in the theater foyer

20h00 Open Doors

20h15 - 21h40 Dinner

21h45 - 22h30 “Toots Thielemans Quartet”

22h30 Dessert and Coffee

Congress Social ProgramPhotographer ©

Jos Knaepen

Page 99: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

99

Tours & Accompanying Persons Program

Booking Instructions

The following tours have been proposed for the ISRS 2005 Congress. They include profes-sional guides as well as transportation and are designed to provide a memorable and com-fortable visit.

The departure will be organized from the meeting point in the congress venue (ground floor of the Sheraton hotel).

These tours have been pre-sold to participants and accompanying persons. However, a lim-ited number of tours will be available at the tour desk in the registration area (ground floor).

For delegates who have already registered, ICEO sent a written confirmation of selectedtours.

Program Overview

Day Activity Date Price

Sunday Brussels at a Glance 11/09/05 pm 33,25 €

Monday Bruges 12/09/05 all day 110,00 €

Tuesday Brussels at a Glance 13/09/05 pm 33,25 €

Wednesday Antwerp 14/09/05 all day 113,30 €

All the tours proposed are offered on a first come first served basis. In case the minimumnumber of participants is not reached, the organisers reserve the right to cancel or modifythe tours. Please contact the tours desk for an update of the program. Prices are includingbelgian VAT 21 %.

Description of the Tours

The program and its content may be subject to slight changes. Please visit us at the toursdesk in order to receive the detailed program, visits & schedule.

Brussels

This city tour gives a good overview of the city's evolution. It includes historical and currentattractions as well as an introduction to the typical and popular sights of Belgian culture.

Date Sunday, September 11, 2005 - Afternoon or Tuesday, September 13, 2005 - Afternoon

Page 100: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

100

Program

12h00 Meeting at the congress meeting point (ground floor) with your guide-lecturer and coach departs for city tour.

By coach : Place Royale, Parc Royal (18th century), Palace of Justice (firstpart of 19th century), Avenue Louise, Horta House,- Cinquantenaire(end of 19th century), Walking tour of the Grand'Place, which is the birthplace of Brussels in the early Middle Ages. During the guided tour youwill get a overview of typical Belgian architecture (Gothic andBaroque), products (chocolate, lace, glasswork, tapestries, altarpieces,...) and popular characters (Manneken Pis, Tintin, Toone,...).

± 15h00 End of the tour.

Price 33,25 € per person.

The price includes Transport by coach, conference visit with multilingual guide in History,extra guide depending on the number for the walking tour, taxes coor-dination and services.

Bruges

A stroll along the waters of the Minnewater, the canals, the white swans, the little whitehouses in the Beguinage. Here in Bruges, everything is poetry, romance and indefinablemelancholy. Join us for a guided tour of a part of Bruges that few visitors take the time todiscover: the city of the Hanseatic merchants who sell spices from the Orient, wines fromthe Rhine, furs from Russia. In the bustle of the docks you will find an atmosphere as cos-mopolitan as it was in the 16th century city : the largest port in the world !

Date Monday, September 12, 2005 - 1 day

Program

08h45 Meeting at the congress meeting point (ground floor), departure withyour guide in the city center.

Arrival at Bruges and beginning of the tour. Town Hall, Holy Blood,Basilica, St Jean Hospital Church of Our Lady, Begijnhof,...

Lunch.

Continuation of the visit. Boat trip.

End of the visit and free time.

Departure.

± 17h00 Arrival in Brussels.

Price 110 € per person.

Tours & Accompanying Persons Program

Page 101: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

101

Tours & Accompanying Persons Program

The price includes Coach transport, accompaniment and guided conference visits withmultilingual guide, lunch (starter, main course, dessert, drinks),entrance fees, tips, taxes, reservation and coordination services.

Antwerp

Belgium's 2nd city, Antwerp, is known as one of the largest ports in Europe which, over thecenturies, became fabulously rich thanks to the commerce with distant countries. Antwerpis also an artistic centre. In addition, since the 15th century, it has been the largest diamondcentre in the world with a worldwide reputation.

Date Wednesday, September 14, 2005 - 1 day

Program

08h45 Meeting with our guide at the congress meeting point (ground floor).

Departure by coach. Introduction to the day’s theme.

Arrival in Antwerp passing by the Jewish neighbourhood which is alsothe diamond centre. Visit of a diamond center, which will give youinformation about the different types of diamonds and methods of cut-ting in the world.

Visit to the Cathedral.

Lunch.

Walk around the historical heart of the city : Town Hall, CorporationsHouse, Rockox House, Saint Charles Borromée and Notre Dame,...

Departure by coach to Brussels through the port or the Art Nouveau area.

± 16h00 Arrival to Brussels.

Price 113,30 € per person.

The price includes Transport by coach, accompaniment and guided conference visits witha multilingual guide, extra guides following number of persons,entrances, lunch (drinks included: 2 glasses of wine or beer and coffee,water), tips, taxes, reservation and coordination services.

Page 102: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

102

About Brussels

City Description

In the capital of Europe, art-lovers can happily move around in their element. Art is verymuch in evidence here and always full of life. It occupies an extremely important place inthe city, from its most classical forms of expression through to waves of avant-garde. Not tomention its well-known gems of surrealism and comic strip. Music-lovers are also spoilt forchoice between famous symphony orchestras and the ever-inventive jazz; rock or worldmusic bands.

From magnificent façades to strange buildings: although very much attached to its rich royaltradition, there is no uniform look to the city, either as a shrine to period architecture or asa futuristic megalopolis, accented here and there by countless Art Nouveau gems. Yet it’salso true that there’s “a little of all that” in Brussels. And many more treasures besides, somevery much on show, others almost hidden away. But never inaccessible. Because the realambassadors of the capital are, of course, the inhabitants themselves.

The national languages in Belgium are French, Dutch (Flemish) and German. In Brussels,French is more commonly used and Flemish is understood by almost everyone. As the cap-ital of Europe, English is of course often used and understood.

Touristic informationAt the registration area on the ground floor, a hostess from the Brussels Tourism Office will help you with any question regardingthe city and its surroundings. Brochures are at your disposal at thesame desk.

Climate

The weather in Brussels is a continental one. In summer, the weather is usually warm anddry. But who knows ? This time it may not be the case, so provide you with warm clothesand an umbrella in the case of rain showers.For more information about the weather forecast, have a look at the website :www.meteo.be

Page 103: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

103

Credit Card & Currency Exchange

Major credit cards (VISA, American Express and MasterCard) are accepted in most shops,hotels and restaurants in Brussels. Automatic teller machines can be found in all parts of thecity and cash withdrawals may be made using your credit card. The logos of accepted cardsare shown on the machine.

The currency of Belgium is the Euro €. Follow this conversion table in order to get an ideaof exchange rates (information only, subject to changes).

Exchange Rates (1 €)(information only, subjected to change - made on August 30th, 2005)

1$ (USD) 1£ (GBP) 1Yen (JPY)

0,8195 € 1,4641 € 0,7364 €

In case of the loss or theft of your credit card, please call the following numbers (nationalnumbers):

Visa 24h/24h +32 (0) 70/344 344Mastercard/Eurocard 24h/24h +32 (0) 70/344 344American Express 24h/24h +32 (0) 2/676 26 26

Electricity

Electricity is supplied at 220V.

Restaurants and Places to Be

Belgium is well known for the quality of the food ! You will find a list of restaurants, barsand clubs in the “After Hours” guide available in your bag or better ask the tourist desk ofthe organisers for an good advise.

Tipping is not obligatory as service and value-added tax (VAT) are included in hotel andrestaurant prices. But if you're pleased with the service, add a little extra.

Shops Opening Hours

The banks open from Monday to Friday, 9h00-16h00. They close later on Friday. Some ofthem are open on Saturday morning.

Post offices usually open from 9h00-12h00 and from 14h00-16h00 or from 9h00-17h00 inbig shopping malls.

About Brussels

Page 104: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Most of the shops open from 9h00/10h00 and close around 18h00/19h00. Some big shop-ping centers are open until 20h00, 21h00 on Friday. In Brussels, the shops are closed onSunday. However, some shops near the Grand Place and the night shops are open.

Telephones/Fax & Useful Numbers

Public telephones may be found on the 3rd floor of the Sheraton Hotel. Credit call cards canbe purchased from any newsagent in the city.

A business center, where you can send fax, is situated in front of the reception desk of thehotel.

Nearest pharmacy Rue du Progrès 29, Brussels +32 (0) 2/203 67 29

Duty pharmacy Pharmacie Rue de Louvain +32 (0) 2/511 32 93

Nearest Hospital Clinique Saint-JeanBoulevard du Jardin Botanique 321000 BrusselsPhone : +32 (0) 2/221 91 11Fax: +32 (0) 2/219 14 92

Police 101 (national call)

Card stop (credit card lost or stolen) +32 (0) 70/344 344

Ambulances (transportation) +32 (0) 2/649 50 10

National Information Service in English 1405in French 1307in Dutch 1207

Taxis +32 (0) 2/349 49 49

STIB (www.stib.be) 0900 10 310 (national call) : local transportation

SNCB (www.b-rail.be) +32 (0) 2/528 28 28 : train transportation

Brussels Airport 0900 7 0000 (national call)

Transportation

The congress is organized right in the city center of Brussels ! Therefore, most of the placesin the center are at walking distance. For any question, please ask the Registrationarea/Touristic desk.

About Brussels

104

Page 105: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

105

Access by Train

The nearest railway station is Brussels North (walking distance 8 minutes).There are daily international trains leaving from Brussels Midi to Amsterdam, Frankfurt,London, Paris, etc. Brussels Midi is located in the South of Brussels. For further informationon timetables and availabilities of the trains, check the following website: www.b-rail.be

To reach another place in Brussels, please be advised that transportation in the city itself iseasiest by metro, tram, bus or taxi.

In the city by tram and metro

From the Gare du Midi Metro station to go to the congress venue, you can take the metroline 2 direction Simonis and stop at Rogier Station.

From the congress venue to the opposite side of the city center, you can take the trams num-ber 52, 55, 56, 81 or 3, direction Gare du Midi/ Zuidstation or Churchill. For further infor-mation on the Brussels public transportations by tram and metro, check the following web-site www.stib.be or at the information desks in most of the metro station.

In the city by taxi

Taxis (metered) are available at the Rogier Place. If you need to order a taxi please contactthe concierge at the Sheraton, he can answer your requests regarding transports 24h/24h. The fare between the centre of Brussels and the airport is normally around 30 € (accordingto your final destination) and the fare between the congress venue and the city center(Central Station, Grand Place) is around 10 €.Taxis Verts’ telephone number : + 32 (0) 2/349 49 49.

In the city by bus

Different buses are available near the Place Rogier. They can lead you to the North Stationand the Central Station. For further information, check the following website : www.stib.be

The Brussels bus company STIB/MIVB operates a bus link between the railway stationBrussels-Luxemburg and the Brussels Airport. This line operates one to three times per hour.The fare lasts about 35 minutes and cost around 3 €.

About Brussels

Any advise needed about our city ? Atouristic information ? A nice place for adinner or a simple drink ? …

DO NOT HESITATE to contact us at the registration area, ground floor. YOU areour host in our city and we strive to makeyour stay enjoyable !

Page 106: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

106

1 Sheraton - Congress Venue

2 Tulip Inn Boulevard

3 President Nord

4 Colonies

5 NH Atlanta

6 Le Métropole

7 Royal Crowne Mercure

8 Crowne Plaza

9 Le Dôme

10 Le Plaza

A city map is included in your bag or is available at the touristic information desk.

About Brussels

Page 107: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen
Page 108: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen
Page 109: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Monday 12/09/05

PLENARY SESSION 8h45 - 10h00

CONFORMITY & SELECTIVITY, LUNG CANCER, CRANIOPHARYNGIOMAS, SPINAL METASTASES PS1Chairman: Marc, Levivier Room Nation

Enhanced conformality and selectivity using robotic radiosurgery PS1-1L. Dade, Lunsford (1); Douglas, Kondziolka (1); Ajay, Niranjan (2); John C, Flickinger (1); Ann H., Maitz (3) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of PittsburghMedical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Image GuidedNeurosurgery Pittsburgh, USA

Robotic gamma knife radiosurgery using multiple isocenters results in superior dose conformality(the three dimensional conforming of isodose shells to the 3-D tumor geometry) and selectivity(the reduction of dose to tissues outside of the target). We reviewed the technical evolution ofradiosurgery as it applies to management of acoustic neuroma. Methods and Materials Since1987, 1,037 patients with acoustic neuromas have undergone gamma knife radiosurgery. Duringthe most recent five years we used the robotic automated positioning system (Model C gammaknife). This technology provides submillimeter inter-shot repositioning in order to maximize doseconformality. The usage of small beam diameters (4 mm. and 8 mm.) provided high conformali-ty and significantly reduced the integral dose to surrounding structures (high selectivity) such asthe brainstem, cochlea, and trigeminal nerve. Conformal stereotactic radiosurgery is associatedwith hearing preservation rates between 75 and 90% with a less than 1% risk of facial weak-ness. Discussion Robotic positioning with small isocenters significantly improved our ability tocontour the effective dose to the irregular three-dimensional geometry of the tumor (high confor-mality). The usage of multiple small isocenters reduced integral dose to tissue outside of the tar-get volume (enhanced selectivity). Robotic stereotactic gamma knife radiosurgery (single proce-dure) is the preferred modality. When conformality is high but selectivity is poor, stereotactichypofractionated radiation should be considered. When conformality and selectivity are both low,conventional fractionated radiation therapy, possibly enhanced by image guidance techniques,should be considered. Stereotactic radiosurgery using the gamma knife coupled with robotic inter-shot repositioning enhanced outcomes and facilitated dose delivery in a single procedure.

107

Page 110: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Stereotactic radiotherapy for patients with inoperable early stage lung cancer. A retrospective study PS1-2 Pia, Baumann (1); Lars, Ekberg (2); Ulf, Isaksson (3); Karl-Axel, Johansson (4); Ingmar, Lax (1); Rolf, Lewensohn(1); Jan, Nyman (4); Suzanne, Rehn-Eriksson (5); Lena, Wittgren (2); Signe, Friesland (1) (1) Karolinska Institutet - Department of Oncology; (2) Malmö University Hospital - Department of Oncologyand Hospital Physics; (3) Karolinska Institutet - Department of Neurosurgery; (4) Sahlgrenska UniversityHospital - Departments of Hospital Physics and Oncology; (5) Uppsala University Hospital - Departments ofHospital Physics and Oncology Stockholm, Sweden

Background: Stereotactic radiotherapy (SRT) has in our clinics been used as an alternativ treat-ment for inoperable early stage lungcancer since the beginning of 1990. Materials and methods:Ninetyfive patients with inoperable NSCLC stage I (T1 53% and T2 47%) were treated with SRTduring 1996-2003 in 4 different centres in Sweden. The cancer was cytologically verified in 68% (65/95) of cases, 35% squamous cell carcinoma, 37% adenocarcinoma and 27% other. Thepatients were considered inoperable mainly because of insufficient lung function and/or cardio-vascular disease. Five patients refused surgery. The mean age was 73 years (range 56-89 y). Fortysix were men and 49 women. SRT was delivered after immobilizing the patients in a stereotacticbody frame (SBF). 3D conformal multifield technique was used. The patients were treated withdoses from 30-45 Gy (at 65%) in 2-5 fractions. The mean gross tumour volume was 36 mm3 (3-436), the planning target volume was 98 mm3 (13-719). Results: Medium follow up time was 29months (4-89 m). The overall response rate (CR, PR, SD) was 93 % (88/95). Local tumour pro-gression was seen in 3 patients (0.03%). Four patients were not evaluable or lost for follow up.Distant metastases occured in 21 % (20/95) of the patients. Thirty one patients (57%) died ofother causes than lung cancer. The 5-year overall survival was 33 %. Toxicity was mild and 54 %(50/92) of patients had no side effects. Conclusion: Radiotherapy given with ereotactic technique,represents a promising effectiv treatment option with high local control rates and very low toxic-ity for patients with inoperable early stage lung cancer. A Nordic multicenter prospective studyusing SRT in NSCLC stage I will be finished this year for further evaluation of hypofractionatedhigh dose radiotherapy.

Quality of life after stereotactic radiotherapy for stage I non-small cell lung cancer (NSCLC) PS1-3 Frank J., Lagerwaard (1); Ylanga G., van der Geld (1); Ben J., Slotman (1); Suresh, Senan (1) (1) VU Medical Center Amsterdam - Department of Radiation Oncology Amsterdam, The Netherlands

Background: Although surgery is the treatment of choice for early-stage lung tumors, the risks ofcomplications and related mortality are substantial, particularly in older patients with poor pul-monary function and/or significant co-morbidity. It has been reported that the quality of life (QoL)is adversely affected in such patients [Sarna 04]. Stereotactic radiotherapy (SRT) is a valuablealternative to surgery for medically inoperable stage I NSCLC patients, and local control rates arein excess of 80% with low toxicity. This analysis describes the early toxicity and QoL in stage INSCLC patients following SRT. Methods: Since 2003, 84 medically inoperable stage I NSCLCpatients have been treated with SRT at our center. Data on QoL have been collected prospective-ly. Patients were asked to fill out EORTC-developed QLQ-C30 3.0 and QLQ-LC13 questionnaires

108

Page 111: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

prior to and at preset intervals after SRT. This analysis includes patients with at least 3 monthsfollow up. Results: The QoL data of 61 patients were included. Data were available at baseline,3 months, 6 months and 1 year follow up in 61, 46, 38 and 13 patients, respectively. The meanpre-treatment global health status score of this patient group was 63.8 ± 20.9, which was notsignificantly different from measurements at 3 months (66.1 ± 18.4), 6 months (64.9 ± 15.7)or 1 year (67.3 ± 14.6). The same applied for the functional (physical, emotional, social, cogni-tive and role behavior) and symptom scales. Thirty-two patients reported early toxicity includingchest wall pain, dyspnea, nausea, radiation dermatitis, fatigue and coughing. In all but one casesside effects were mild to moderate, RTOG grade 1-2. One patient required hospitalizationbecause of grade 3 radiation-induced pneumonitis. Conclusions: No significant change in Qualityof Life following SRT was detected using QLQ-C30 and QLQ-LC13 questionnaires. The reportedside effects did not influence QoL.

Role of radiosurgery in the multimodality management of craniopharyngiomas PS1-4 Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); John C, Flickinger (3)(1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center- Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA

OBJECTIVE: To evaluate the role of radiosurgery in the multimodality management of residual ofrecurrent craniopharyngiomas. METHODS: Twenty-nine patients (15 males and 14 females), witha median age of 19 years (range, 5 to 82) had gamma knife radiosurgery for recurrent or resid-ual craniopharyngioma during a seventeen-year interval. In addition to surgical resection, fivepatients received brachytherapy and three had fractionated radiation therapy prior to radio-surgery. The median interval between diagnosis and radiosurgery was 46.5 months. The medi-an tumor volume was 0.4 (range, 0.12- 6.36) cm3. One to nine isocenters of different beamdiameters were used. The median dose to the tumor margin was 12.5 Gy (range, 9-20), and themaximum dose was 25 Gy (range, 21.8-40). The dose to the optic apparatus was limited to lessthan 8 Gy. RESULTS: Clinical and imaging follow-up data were obtained at a median of 24 months(range, 13 to 150) from radiosurgery. Overall, 14 of 29 tumors regressed or vanished, and 10remained stable after radiosurgery. Further tumor growth was noted in five patients, of which 3underwent surgical resection and one had repeat radiosurgery. Two additional patients neededmanagement for cyst enlargement. One patient with prior visual defect had further vision deteri-oration 9 months after radiosurgery. No patient developed new-onset diabetes insipidus. CON-CLUSIONS: Multimodal management is often necessary for patients with solid and cystic cranio-pharyngiomas. Stereotactic radiosurgery is a valuable minimally invasive option for patients withsmall recurrent or residual craniopharyngiomas.

109

Page 112: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Image-Guided radiosurgery of single spinal metastasis PS1-5 Samuel, Ryu (1); Jack, Rock (2); Jian-Yue, Jin (3); Marilyn, Gates (2); Benjamin, Movsas (4); Jae Ho, Kim (5) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery; (3) Henry Ford Hospital- Radiation Oncology; (4) Henry Ford Hospital - Radiation Oncology; (5) Henry Ford Hospital - Division ofRadiation Oncology Detroit, USA

Purpose: Precision and accuracy of image-guided spinal radiosurgery has been previously demon-strated. We used spinal radiosurgery to treat a single spinal metastasis. This study was carriedout to determine the clinical efficacy of spinal radiosurgery for the treatment of spinal metastaseswith or without cord compression. Method: A total of 49 patients with 61 lesions of separatespinal metastases were treated with radiosurgery. All patients had pathologically-proven primarycancers and had either synchronous or metachronous metastasis to the spine. The majority of thepatients presented with back pain. All patients received single dose radiosurgery to the involvedspine only. The radiosurgery dose ranged 10-16 Gy. The dose was prescribed to the 90% isodoseline that encompassed the target volume. Followup included patient questionnaires, neurologicalexam, and radiological studies. The primary endpoint was pain control, but outcomes in neuro-logical status and radiological tumor control were also assessed. Results: Precision of spine radio-surgery has been determined within 1.5 mm. The median time to pain relief was 14 days andthe earliest time of pain relief was within 24 hours. Complete pain relief was achieved in 46%,partial relief in 18.9%, and stable in 16.2%. Neurological improvement of motor and sensoryfunction was achieved with a median time for improvement 14 days. Radiological tumor controlwas seen in patients with epidural mass or soft tissue tumor component. The dose to the spinalcord was tolerable at 10 Gy to the anterior 10% of the spinal cord. There was no detectable acuteor subacute radiation toxicity noted clinically during the followup time of longer than 36 months.Conclusion: Single dose radiosurgery achieves a rapid and durable pain relief and neurologicalimprovement in patients with spinal metastasis with or without cord compression. The resultsindicate the clinical effectiveness of spinal radiosurgery for malignant tumors of the spine or cord.

ORAL SESSIONS 11h30 - 12h30

LARGE ARTERIOVENOUS MALFORMATIONS OS1Chairmen: Andras, Kemeny; Jason, Sheehan Room Nation

Staged gamma knife radiosurgery, with neither surgery nor embolization, for relatively large AVMs OS1-1 Masaaki, Yamamoto (1); Bierta, E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Introduction: Little information is available on staged gamma knife (GK) radiosurgery with aninterval of more than 3 years, with neither surgery nor embolization, for relatively large AVMs.Patients and Methods: Among 240 AVM patients treated using a GK by one of the authors (MY)during a 15 yr period (1998-2003), the courses of 24 (10 females, 14 males, mean age; 31 yr,range; 9-67yr), were studied. Mean nidus volume was 13.8 cc, range 3.1 to 33.3 cc. The mostcommon presentation was bleeding (12 patients), followed by seizure (7), incidental (3) and oth-

110

Page 113: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ers (2). Before GK radiosurgery, although embolization was performed in three patients and sur-gery in one, no significant volume reductions were achieved. In all 24 patients, relatively lowdoses (12-16 Gy at the lesion periphery) were intentionally employied for the first GK treatment.The second GK procedure was scheduled for at least 3 yrs later. Results: To date, 14 of the 22patients have undergone the second procedure. Six of the 14 underwent DSA 3 yrs or more afterthe second GK treatment. Complete nidus obliteration was confirmed in five and nearly completeobliteration in one. Six patients (25.0%) experienced bleeding after the first GK treatment; theemortalities, two morbidities. One (4.2%) patient had treatment-related complications 24 monthsafter the second GK procedure. Conclusions: Although our final conclusion awaits further studiesand patient follow-up, these results suggest GK radiosurgery to have certain benefits even for rel-atively large AVMs.

Validation of a radiosurgery-based grading system for arteriovenous malformations OS1-2Michael, Girvigian (1); John, Lee (1); Michael, Miller (1); Javad, Rahimian (1); Joseph, Chen (1); Hugh,Greathouse (1); Michael, Tome (1) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology Los Angeles, USA

Purpose: The Spetzler-Martin grading system accurately predicts outcome after surgical resectionof arteriovenous malformations (AVM); however, its application to radiosurgery is limited becauseof insensitivity to AVM volume and location. Recently, a radiosurgical grading system was devel-oped by the Mayo Clinic/University of Pittsburgh_ to predict outcomes for Gamma Knife® radio-surgery. This retrospective study seeks to independently validate the radiosurgery grading systemand determine its application to linear accelerator-based radiosurgery. Methods and Materials: 20patients were treated with Radionics XKnife™ LINAC-based radiosurgery for AVMs between1990-2002 (median follow-up, 35 months). Outcomes based on obliteration rates and post-treat-ment neurological deficits were analyzed according to radiosurgical grade and Spetzler-Martingrade. The following equation describes the radiosurgery grading system: AVM score =(0.1)(AVM volume in cm2) + (0.02)(age in years) + (0.3)(location) with frontal/temporal = 0; parietal/occipital/intraventricular/corpus callosum/cerebellar = 1; or basal ganglia/thalamus/brainstem = 2. Results: Overall, 65% had excellent outcomes, 0% good, 5% fair, 25%unchanged, and 5% poor. For AVM scores 0.6 – 1.3, 9 of 9 patients (100%) had excellent out-comes. For AVM scores 1.4 – 1.7, 3/6 (50%) excellent, 1/6 (17%) fair, and 2/6 (33%) unchanged.For AVM scores 1.9 – 2.4, 1/5 (20%) excellent, 3/5 (60%) unchanged, 1/5 (20%) poor. TheSpetzler-Martin grade (SMG) inconsistently predicted outcomes. For SMG 1, 4 of 4 patients(100%) had excellent outcomes. For SMG 2, 5/9 (56%) excellent, 3/9 (33%) unchanged, 1/9(11%) poor. For SMG 3, 4/5 (80%) excellent, 1/5 (20%) fair. For SMG 4, 1/2 (50%) fair, 1/2 (50%)unchanged. Two patients (10%), with AVM scores of 1.9 and 1.6, suffered radionecrosis. Nopost-radiosurgery hemorrhage or AVM-related deaths occurred. Conclusions: The radiosurgerygrading system accurately predicted patient outcomes, thus validating this grading system andsuggesting its applicability to linear accelerator-based radiosurgery for AVMs.

111

Page 114: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Radiosurgery of large cerebral arteriovenous malformations OS1-3Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Dae Hee,Han (2) (1) Seoul National University Hospital - Department of Neurosurgery; (2) Seoul National University Hospital -Department of Neurosurgery Seoul, Republic of Korea

INTRODUCTION: The authors present the retrospective analysis of clinical results of large cerebralarteriovenous malformation (AVM) treated by radiosurgery. METHODS: Between 1994 and 2004,we managed 334 patients of cerebral AVM with radiosurgery and large AVM, more than 14cc involume, was present in 52 cases. The number of patient followed up more than 3 years was 41among 52 cases and only these patients were included in the analysis. LINAC radiosurgery wasperformed until 1996 and after then gamma knife (GK) was used. Mean age was 31 years andmale to female ratio was 23:18. Twenty patients had undergone endovascular treatment beforeradiosurgery. The whole nidus was covered and the radiosurgery was repeated three years afterthe first radiosurgery if there was any residual nidus. Median volume was 30cc (14~180) andmean marginal dose was 14Gy (10~27). Magnetic resonance (MR) images were obtained everysix months and trans-femoral cerebral angiography (TFCA) was performed at three years afterradiosurgery. RESULTS: Follow-up TFCA was performed in 19 patients and complete obliterationwas observed in seven patients (37%). Remaining 12 patients who had residual nidus receivedsecond radiosurgery. Three patients were followed up more than 3 years after second radio-surgery and complete obliteration was confirmed by TFCA in two patients and the nidus was notobserved on MRI in remaining one. The mean volume of nidus in second radiosurgery was 7.2cc,and it was significantly different from initial volume (p=0.02). The patients with followed up onlyby MRI were 22 and the rate of volume reduction measured in MRI was 56%. Hemorrhage afterradiosurgery was occurred in 4 patients and three patients received craniotomy. Delayed cysticcerebromalacia formation was found in two cases and asymptomatic high signal intensity on T2-weighted MR images in 5 cases. Embolization did not have an effect on obliteration. CONCLU-SION: Staged radiosurgery might be an alternative treatment option for inoperable large AVM,however, accumulation of cases and long term follow-up are mandatory.

Staged volume radiosurgery for large arteriovenous malformations: indications and outcomes OS1-4 Douglas, Kondziolka (1); Sait, Sirin (1); John C, Flickinger (1); Niranjan, Ajay (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA

The obliteration response of an arteriovenous malformation (AVM) to radiosurgery is stronglydependent upon dose and volume. For larger volumes, the dose must be reduced to maintainsafety, but this compromises obliteration. In 1992, we began to stage anatomic components ofthe nidus in order to deliver higher single doses. Numerous centers have begun to use this tech-nique, but little is known regarding results. During a 17-year interval at the University ofPittsburgh, 1040 patients underwent radiosurgery for a brain AVM. Out of 135 patients who hadmultiple procedures, 39 patients underwent prospectively staged volume radiosurgery for symp-tomatic larger malformations. The median age was 34 years (range, 12-57 years). Twelve patientshad prior hemorrhages and 17 patients had attempted embolization. Separate anatomic volumes

112

Page 115: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

were treated at 3-8 month (median 5 months) intervals in patients with AVMs larger than 15 ml.All patients except one (3 stages) had 2-stage radiosurgery. The median target volume was 12ml. (range 4.3-26 ml.) at Stage I and 11 ml. (range, 4.1-29.5) at Stage II. The median margindose was 16 Gy at both stages. The median duration of follow-up review after the last stage ofradiosurgery was 26 months (range 3-92 months). In five patients (14.2%) a hemorrhageoccurred after radiosurgery. Two patients died and three patients recovered with mild permanentneurologic deficits. New or increased neurologic deficits were seen in 7 patients. Seizure controlwas improved in three patients, stable in 20 patients and worse in two patients. Imaging showedperi-AVM edema in four patients (11%). Out of 17 patients followed for more than 36 months,7 had total (41%) and 7 near total (41%) AVM obliteration. Prospective staged volume radio-surgery for large AVMs with results that appear better than single stage radiosurgery at lowerdoses. Further evaluation of this method is required.

RADIOBIOLOGY OS2 Chairmen: John, Flickinger; Ronald, Mc Garry Room Permeke &

Rembrandt

Stereotactic pulmonary hilar radiation: an animal model of radiotoxicity OS2-1Brent, Tinnel (1); Marc, Mendonca (2); Ronald, McGarry (3); Oscar, Cummings (4); Robert, Timmerman (5) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) Indiana University MedicalCenter - Radiation and Cancer Biology; (3) Indiana University Medical Center - Department of RadiationOncology; (4) Indiana University School of Medicine - Department of Pathology; (5) University of TexasSouthwestern - Department of Radiation Oncology Indianapolis, USA

Purpose/Objective: Stereotactic body radiation therapy uses high doses/few fractions of radiationto ablate lung cancers; however concerns have been raised about toxicity on normal large airways.We have developed a model of high dose, hypofractionated radiotherapy to the pulmonary hilum.Materials/Methods: Thirty-four Sprague-Dawley rats were subjected to focal irradiation of the uni-lateral lung hilum. CT simulation at 1 mm thickness was used to acquire target information. Cohortof three animals received single fractions of Gamma-Knife radiotherapy centered on the right mainbronchus. The initial cohort received 10 Gy prescribed to the 50% isodose line, using two 4 mmcollimated 'shots', differing by 1 mm in the Z axis only. Escalating doses of 20, 40 and 80 Gy insingle fractions were performed. A second cohort was treated in the same fashion using an 8.0mmcollimator. Results: Animals were observed for toxicity until sacrifice. No changes were seen onplain films or follow-up CT scans. On histopathologic analysis, only animals irradiated with 8-mmcollimator and sacrificed at 6 months demonstrated any changes (7/34). Cellular atypia and inter-stitial pneumonitis were the most common findings. However, 3/7 showed clear bronchial dam-age and 2/7 showed vascular damage. One animal had atelectasis related to marked bronchialdamage and vascular occlusion. Statistical analysis (Fisher's Exact Test) supports a volume effect(47% of the 8-mm Vs 0% of the 4-mm demonstrated changes, p=0.0001). The time interval fromirradiation to any observed changes was also significant (0% in the 3-4 month groups had changesVs 39% of the 6 month groups p=0.01). Conclusions: Small volume/high dose radiotherapy cen-tered on the bronchus is well tolerated in rats. However, our observation of severe histopatholo-

113

Page 116: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

gical changes suggests a dose/volume relationship with damage to the surrounding stroma maybe important in the etiology of bronchial or hilar damage.

Histopathologic changes in metastatic brain tumors seen after gamma knife radiosurgery: the Pittsburgh experience OS2-2 Dave, Atteberry (1); Gyorgy, Szeifert (2); Marta, Couce (3); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) National Institute ofNeurosurgery - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Pathology Pittsburgh, USA

Background: Radiosurgery for metastatic brain tumors is widely performed. Because of the effi-cacy of this treatment, craniotomy for resection of these lesions is rarely required. Therefore, littleis known about the histologic changes that these tumors undergo after such treatment. This studyaims to characterize the histopathologic changes in metastatic brain tumors after treatment withgamma knife radiosurgery. Methods: All patients with metastatic brain tumors who were treatedat the University of Pittsburgh between June 1987 and July 2004 who underwent subsequentcraniotomy for tumor resection were studied. Demographic variables such as age, gender, andradiosurgery-craniotomy time interval (RS-CR), type of tumor, and gamma knife treatment param-eters such as volume of tumor and isodose were collected. Routine histological and immunohis-tochemical investigations were carried out on the fixed surgical specimens. The pathologic spec-imens were categorized according to type of changes seen: acute-type (necrotic activity), suba-cute-type (resorptive activity), and chronic (reparative activity). Descriptive statistics were used todescribe the findings of this case series. Results: The University of Pittsburgh radiosurgery serieswas 6, 500 patients by July 2004. Surgical pathology material was available in 11 patients (15procedures), 4-59 months after radiosurgery (mean 15 months). The age range was 41-72 (mean53), 55% were female. The lesions studied were of the following tumor types: non-small cell(NSC) lung cancer (CA) (9), breast CA (2), renal cell CA (2), melanoma (1), and small cell lung CA(1). Tumor volume varied from 268-23,600 mm3. Isodose prescriptions varied from 14 Gy/ 50%to 20 Gy/50%. Two lesions were classified as acute-type (1 NSC lung CA, 1 small cell lung CA),11 were classified as subacute-type (8 NSC lung CA, 2 renal cell CA, and 1 melanoma), and 1was classified as chronic (breast CA). The other breast CA lesion was classified as a mixture ofacute and subacute types. The three histopathologic phenotypes were largely recognized in dif-ferent tumors irrespective of their ontogenetic nature. There was no significant relationshipbetween morphologic characteristics and the RS-CR. Conclusions: This case series describes thehistopathologic changes seen in metastatic brain tumors after gamma knife radiosurgery. Theinformation gleaned from this study may help to elucidate the pathophysiologic mechanisms bywhich radiosurgery destroys tumor cells. The relative time and environment independence of thepost-radiosurgery lesions may suggest either a vascular mechanism or a genetic origin that is pre-sumably induced by the ionizing energy of high dose irradiation.

114

Page 117: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Early and late adverse effects of low-dose radiosurgeryin MR area OS2-3 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

Cranial nerve damages, cerebral edema, necrosis, arterial stenosis, intratumoral hemorrhage, cystformation, radiation induced tumors, etc. are reported as the complications of radiosurgery. Thosecomplications seem to be decreased in low-dose treatment because good functional preservationhas been obtained in vestibular schwannomas treated with low-dose. It reviewed from the casefollowed more than 10 years after treatment. The object is example of 227 of AVMs (92), schwan-nomas (67), meningiomas (41), pituitary adenomas and so on which was treated mostly withlow-dose by April, 1995. Cranial nerve symptoms which were directly related with lesions wereexcluded. Symptomatic early complications were extensive brain edema in two patients andhydrocephalus in two appeared 6 months after treatment. Delayed cyst formation was found inone patient as late complication 10 years after treatment. Asymptomatic complications werefound as brain necrosis, stenosis of the internal carotid artery and intratumoral hemorrhage.Multiple tumors appeared in one patient 7 years after treatment. However, no complication-relat-ed death was recognized to date. High dose exposure including central dose may cause long-term effects to the brain parenchyma, artery and pathologies. Sensitivity of DNA damage andtumor genesis may be not related with dose amount of treatment.

Alpha/beta ratios for radiosurgical target tissues OS2-4Frederik, Vernimmen (1); Jacobus, Slabbert (2) (1) Stellenbosch University - Radiation Oncology; (2) iThemba LABS - Radiation Biophysics Tygerberg, South Africa

Objectives Arteriovenous malformations, skull base meningiomas, and acoustic neuromas can besuccessfully treated with one fraction of radiation (radiosurgery) when conventional surgery is notpossible or desired. Extensive clinical experience with radiosurgery has been accumulated forthese lesions and interest in giving the total radiation dose in a limited number of fractions (hypo-fractionated stereotactic radiotherapy) in certain cases is growing. The dose/fractionation sched-ules used in these treatments are based mainly on general clinical assumptions. In order to cor-rectly determine the optimum dose/fractionation schedule, the repair characteristics as quantifiedby the alpha/beta ratio of the specific radiation effect on the tissue in question has to be known.Design and methods Using clinical data from the proton therapy program at iThemba LABS aswell as data from the literature, FE plots were constructed for specific end results. These relatedose per fraction given to the iso-effective dose for different treatment protocols. Data for skullbase meningiomas and acoustic neuromas were analyzed for patients that achievement long termradiological control. Arteriovenous malformations were studied in patients obtaining obliteration.All three pathologies when treated at iThemba LABS received between 1 and 3 fractions, withthe majority of patients treated in 3 fractions. These data formed the basis for this study. In addi-tion, data from the literature dealing with these same pathologies in terms of observed effect andsize of lesions were also included in the analysis to help estimate repair constants. Results Forlong-term radiological control of skull base meningiomas an alpha/beta value of 3.7 Gy wasdetermined. Long-term radiological control in acoustic neuromas is reflected in an alpha/beta

115

Page 118: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

value of 1.4 Gy. A higher then expected alpha/beta value of 9.4 Gy was found for the oblitera-tion of predominantly large cerebral AVMs. Conclusion The repair characteristics of AVMs appearto be considerable less from what is generally assumed based on clinical observations of this clas-sical radiosurgical target tissue. By contrast, alpha/beta ratios for meningiomas and schwanomasare more typical for lesions best treated in a hypo-fractionated manner. The values found in thisstudy are most useful for use in calculating the optimum dose/fractionation schedule as well asto help indicate if hypo- fractionation is indeed likely to translate in therapeutic gain for suchradiosurgical targets.

GLIOMAS OS3 Chairmen: Minesh, Mehta; Nicolas, Massager Room Willumsen

PET-related metabolic response of glial tumors after GK radiosurgery OS3-1 Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); Daniel, Devriendt (3); Ouzi, Nissim (4); David, Wikler (2);Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (4) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Objective: To evaluate the metabolic response of cerebral gliomas after gamma knife radiosurgery(GKR). Material & Methods: Between December 1999 and December 2004, 55 patients weretreated by GKR in our center for a cerebral glioma using a combination of MR and PET guidance.One or multiple PET-scan were performed in the clinical follow-up for 38 patients, including 16patients with a low-grade glioma (LGG) and 22 patients with a high-grade glioma (HGG). The PETradiotracer was FDG for 13 patients (including 10 patients with HGG) and methionine for 25patients (including 13 patients with LGG). We analyzed the relation between modifications in theuptake of PET radiotracer after radiosurgery, histology and the volumetric and dosimetric param-eters of the GKR procedure. Results: One to 10 serial PET-scan was acquired during the follow-upof those patients, ranging from 3 months to 5 years (mean: 14 months). The PET-related metabol-ic activity of the tumor reduced significantly for 21 patients (55%), remained stable for 6 patients(16%) and increased for 11 patients (29%). Significant changes of tumor metabolism after GKRwere more frequent with the use of methionine than FDG (64 vs 38%, respectively). For somepatients, we have registered an initial reduction of tumor metabolism after radiosurgery, followedby an increase in metabolism. No statistically significant relation was found between histology,volumetric and dosimetric parameters of the radiosurgical procedure and the metabolic responseof the tumor. For all patients, failure of tumor control occured by an increase in glioma metabo-lism assessed by PET prior to apparition of signs of tumor growth on MRI. Conclusion: PET-scancan help in the follow-up of patients with LGG and HGG after GKR. The metabolic response seemsnot to be related to any volumetric or dosimetric parameters of the GKR procedure.

116

Page 119: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Rationale for, and results of a 6-year experience of “Leading Edge” gamma knife radiosurgery for glioblastoma multiforme: a trend toward improved outcome OS3-2Christopher M., Duma (1); W. Michael, Shea (2); Jay, Tassin (2); Peter, Chen (2); Ralph, Mackintosh (2);Marianne, Plunkett (2) (1) Hoag Memorial Hospital - Department of Neurosurgery; (2) Hoag Memorial Hospital - Radiation Oncology Newport Beach, USA

Glioblastoma multiforme (GBM) fails current therapies due to poor local control. The tumor is radi-ation sensitive, yet failure within the treatment area of involved field radiation therapy is usuallythe rule. We contend that GBM is a “local disease” that has spread in a predictable pattern downwhite matter tracts. For the past 6 years, we have targeted known tumor migration pathwaysusing high-dose single-fraction radiosurgery distant from the enhancing margin of the tumorusing MR-SPECT and MR FLAIR sequences for direction. Sixty-eight consecutive patients withnewly diagnosed GBM were treated using up-front leading edge gamma knife radiosurgery(LEGKR). Ages ranged from 20 to 83 years (median: 58). The high-signal regions on MR FLAIRsequences and/or MR Spect-positive zones outside of the gadolinium-enhancing portion of thetumor were targeted. Forty percent had received IFXRT and 45% had received chemotherapy priorto their treatment. Nine patients had 2 LEGKRS treatments. An additional 23 patients with recur-rent disease were treated in the same fashion. Median age was 56 (24-78). Four patients had 2LEGKR treatments. Ninety-five percent had IFXRT and 45% had chemotherapy pre-LEGKR.Median leading edge volume for the two groups was 26.5 cm3 (median diameter 3.7 cm.).Median dose was 11 Gy at the 50% isodose line. Follow-up for the up-front treated group rangedfrom 4 to 64 months after diagnosis (median: 8 months) and from 1 to 60 months (median: 10months) after radiosurgery. The median projected survival using the technique of Kaplan andMeier for patients undergoing LEGKR as part of their initial treatment was 82.2 weeks. Medianprojected survival of patients treated for recurrent disease was 86 weeks from diagnosis and 26weeks from LEGKR. Seven patients required hospitalization for intravenous mannitol and dexam-ethasone; 4 patients in the up-front group and none from the recurrent group required surgicaldebulking for mass effect. Eight patients (9%) are alive more than 3 years from diagnosis. Theconcept of radiosurgical treatment of the “leading edge” of these tumors is a novel one that hasnot been formally tested in earlier clinical studies. Based on these data further evaluation of thistechnique is clearly warranted, perhaps with a multi-institution study. We contend that radio-surgery does have a place in the treatment of GBM.

Quantification of surrogate tracers for glioma radiosensitization OS3-3 Peter, Haar (1); William, Broaddus (1); Zhijian, Chen (1); Panos, Fatouros (2) (1) Medical College of Virginia - Division of Neurosurgery; (2) Medical College of Virginia - Radiation Physicsand Biology Richmond, USA

PURPOSE: Glioma radiosensitization, in which an agent such as HSV-TK is delivered intratumoral-ly via direct positive-pressure infusion, has recently shown significant therapeutic potential.However, in order for radiosensitization to be used effectively with stereotactic radiosurgery, spa-tial concentration distributions of a delivered therapeutic agent must be accurately quantifiedthroughout the brain. For these reasons, methods were explored to non-invasively quantify three-

117

Page 120: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

dimensional profiles of a gadolinium-based surrogate tracer in the setting of brain infusion.MATERIALS AND METHODS: Two studies were performed: first, an MRI method was calibratedto quantify a surrogate tracer in brain parenchyma; second, this method was used to observe,over time, brain distributions of a surrogate tracer following brain infusion. In the first study, solu-tions of three different concentrations of Gd-DTPA were infused over 50 minutes to the right cau-date-putamen of 15 rats. Changes in T1 relaxation rates, measured with magnetic resonanceimaging (MRI), were compared to 1mm brain slice concentrations determined with inductivelycoupled plasma atomic emission spectroscopy (ICP-AES) to calculate the specific relaxivity of Gd-DTPA in brain. Additionally, samples of cerebrospinal fluid (CSF), blood and urine were analyzedto evaluate Gd-DTPA clearance from the brain. In the second study, a Gd-DTPA solution wasinfused over 50 minutes to the caudate-putamen in five rats, then allowed to diffuse for 80 min-utes. In each rat, computed T1 map data sets were acquired at thirteen time points throughoutthe duration of the experiment, and were used to calculate three-dimensional Gd-DTPA concen-tration distributions at each time point. The experimental results were evaluated statistically interms of volume of distribution of tracer, total content of tracer in the brain, and average tissueconcentrations of tracer. RESULTS: The relaxivity of the tracer Gd-DTPA following brain infusionwas measured to be 5.34 (mM*s)^-1 in a 2.4 T field, a value considerably higher than previousestimates. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demon-strated a high degree of coincidence, indicating the accuracy of this quantification approach.Clearance of Gd-DTPA in the CSF, blood and urine was measured to be minimal at the time pointimmediately after infusion. The measured average volume of distribution increased linearly witha regression slope of 0.673 mm^3/minute during the infusion period, after which it leveled,with a slope not statistically different from 0 (p < 0.01). The average measured brain content oftracer similarly increased linearly during the infusion with a slope of 0.172 nanomoles/minute,reflecting the constant infusion flow rate. Following the end of infusion, the average tissue con-centrations of tracer declined at a rate of -0.0012 nanomoles/mm^3/minute, suggesting diffu-sive transport. CONCLUSIONS: These results demonstrate that MRI T1 mapping can be used effec-tively to measure surrogate tracer concentrations, allowing accurate, non-invasive visualization ofinfused medications. This surrogate tracer approach will allow radiosurgical doses to be precise-ly adjusted on the basis of known local drug concentrations and expected radiosensitivities.

Role of gamma knife radiosurgery in malignant glioma treatment OS3-4 Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Introduction: The clinical efficacy of gamma knife (GK) radiosurgery for managing patients withmalignant gliomas is not yet fully understood. Treatment results for our series of patients whounderwent GK radiosurgery are described. Patients: Among our consecutive series of 2426patients who underwent GK radiosurgery from July, 1998 through June 2004, 84 whose tumorswere histologically verified as malignant gliomas were selected for this study. The mean patientage was 57 years, range from 24 to 83 years. There were 32 females and 52 males. Histologicaldiagnosis was grade III (gr-III) in 36 patients, grade IV (gr-IV) in the other 48. Results: When themedical records of the 84 patients were reviewed in mid-March of 2005, nine patients were alive

118

Page 121: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

and the other 75 were confirmed to be deceased. Causes of death were brain tumor progressionin 69 and unrelated diseases in three. The remaining three had been found in a state of cardiopul-monary arrest, and could not be resuscitated. Median survival times (MSTs-months) from the timeof GK until death caused by tumor progression were 12 in gr-III and 10 in gr-IV patients (p=.0123). GK radiosurgery was performed as one of the initial treatment procedures in 28 patients.In this group, MSTs were 13 for gr-III and 12 for gr-IV (p=.6009). Although MSTs did not differbetween two treatment strategies, GK only versus radiotherapy (RT) plus a GK booster, there wasa significant MST difference between these treatments in a special group of patients who under-went more than 95% tumor removal; 30 for GK only and 16 for RT plus GK (p=.0165).Furthermore, if sufficiently high doses were given using GK only, the MST of 15 was essentiallythe same as that in patients undergoing RT plus GK (p=.3558). In contrast, in the other 56 ofour 84 patients, GK radiosurgery was performed for recurrent tumors. In this group, MSTs were11 for gr-III and 8 for gr-IV patients (p=.0061). Conclusion: GK radiosurgery may replace RT inthe initial management of selected patients with malignant gliomas. GK radiosurgery is applica-ble to recurrent malignant gliomas.

ORAL SESSIONS 14h00 - 15h00

VESTIBULAR SCHWANNOMAS 1 OS4Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation

Estimating tumor definition variability in acoustic schwannoma radiosurgery, and how it affects dosimetry OS4-1 John, Flickinger (1); Ajay, Niranjan (2); Kaan, Oysul (1); Juan, Martin (3); Sait, Sirin (4); Ann H., Maitz (5);Douglas, Kondziolka (5); L. Dade, Lunsford (5) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of PittsburghMedical Center - Neurological Surgery; (3) Department of Neurological Surgery - University of Pittsburgh; (4)University of Pittsburgh Medical Center - Department of Neurological Surgery; (5) University of PittsburghMedical Center - Image Guided Neurosurgery Pittsburgh, USA

Objective: Different physicians vary in what they define as tumor volumes for radiosurgery. Wesought to define this variability in acoustic schwannomas and to assess how it affects assess-ments of treatment coverage by radiosurgery plans. Methods: Gross tumor volumes (GTV) weredrawn after completion of gamma knife radiosurgery to ten unilateral acoustic schwannomas.Four physicians drew each contour three separate times. Prescription doses varied from 12-13 Gy(12.5 Gy in 7/10) to the 50-60 % isodose (median 50%) using 3-9 isocenters (median 6). To cre-ate uniformity in assessing the dosimetry for this study we normalized prescription doses to 12.5Gy for the 3 cases prescribed to 12 or 13 Gy. Results: The mean GTV varied from 0.097-1.275mL (median 0.271 mL). The mean per cent difference between individual GTV’s and the meanGTV for each tumor was 7.4 +/-5.9 % (range 0.13-28.9%), dropping to 2.1 +/-1.5 % for theaverage from one contour each from 3 different physicians. Mean tumor coverage by the prescrip-tion dose varied from 87.7-97.6 % (mean 94.3 +/-3.8 %). The mean difference between theindividual tumor coverage percentages and the mean for each tumor was 1.5 +/-1.5 % (range0-10.5 %), dropping to 0.7 +/-0.34 % for averaging one contour each from 3 physicians. Mean

119

Page 122: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

dose covering 99 % of the tumor (Dose@99%) varied from 8.2-12.5 Gy (median 10.9). Themean difference between the individual Doses@99% and the mean for each tumor was 0.43+/-0.38 Gy (range 0-1.82 Gy), dropping to 0.16 +/-0.13 Gy for the average from 3 physicians.The mean absolute minimum tumor dose (Dmin) varied from 7.3-9.4 Gy (mean 8.3 +/-1.4 Gy).The mean difference between the individual Dmin values and the mean for each tumor was 0.84+/-1.02 Gy (range 0-3.54 Gy), dropping to 0.29 +/-0.23 Gy for the average from 3 physicians.Conclusion: Variability in defining a tumor volume for radiosurgery leads to different estimates oftumor volume, per cent tumor coverage, Dose@99%, and absolute minimum tumor dose.

Hearing preservation in vestibular schwannoma after gamma knife radiosurgery OS4-2Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Hee-Won,Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

Introduction: To evaluate hearing preservation rate and its prognostic factors after gamma kniferadiosurgery (GKS) in vestibular schwannoma, the authors analyzed the outcomes of the hearingafter the GKS. Methods: Between 1998 and 2003, we managed 296 patients who were diag-nosed as vestibular schwannomas with GKS and among them, 46 patients in serviceable hear-ing with a sporadic vestibular schwannoma had been enrolled. Neurofibromatosis type 2 patientswere excluded. The mean age was 48 years (21–71). Twenty eight patients were in the Gardner-Robertson (G-R) grade I and eighteen patients in G-R grade II before GKS. The median tumor vol-ume was 2.0cc (0.1-19) and mean prescription dose was 12.0 Gy (9-15) at an isodose line of50%. Clinical assessments including neurological examination, audiometries, and neuroimagingstudies were performed every six months after GKS. The median follow-up periods for audiome-try and MR images were 27 months (2-70) and 30 months (6-75), respectively. Results: Tumorcontrol was achieved in 44 patients (96%), and tumor size was decreased in 27 patients,remained stable in 17 patients. Among the patients with tumor growth, one patient wasobserved without further treatment, and the other patient underwent microsurgery. New facial ortrigeminal nerve dysfunction was not happened while the preexisting trigeminal nerve dysfunc-tion was aggravated in one patient. Serviceable hearing was remained in twenty seven(59%)patients and among them, fourteen (30%) patients remained in the same G-R grades as the pre-GK G-R grades. Multivariate analysis demonstrated that the G-R grade I, dose(less than 12 Gy),tumor volume(less than 4cc), and the absence of cystic portion were the factor associated withhearing preservation (p<0.05). Conclusion: GKS may be good for hearing preservation in smalland solid vestibular schwannoma. The GKS is a good alternative modality for hearing preserva-tion in the patients with vestibular schwannoma.

120

Page 123: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Hearing preservation after GK radiosurgery for vestibular schwannoma: Influence of intracanalicular dosimetric parameters OS4-3 Nicolas, Massager (1); Ouzi, Nissim (2); Carine, Delbrouck (3); Daniel, Devriendt (4); Philippe, David (5);Françoise, Desmedt (2); David, Wikler (6); Jacques, Brotchi (1); Sergio, Hassid (7); Marc, Levivier (2) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - CentreGamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neuroradiologie; (6) Hôpital Erasme- PET Scan; (7) Hôpital Erasme - ENT Dept. Brussels, Belgium

Objective: To analyze the relationship between hearing preservation after gamma knifeRadiosurgery (GKR) treatment of vestibular schwannoma (VS) and the volumetric and dosimetricparameters of the intra- and extracanalicular parts of VS. Material & Methods: Between January2000 and December 2004, 165 patients with a VS were treated by GKR in our center. Amongthese patients, we have selected 82 patients with the following characteristics: no NF2 disease,Gardner-Robertson hearing class 1-4 the day before the treatment, a margin dose of 12 Gy, anda radiological and audiological follow-up ¡_1 year post-GKR. On the radiosurgical planning ofeach patient, we measured the volume, the mean and the integrated dose delivered to both theentire tumor volume and the intracanalicular part of the tumor. We correlated those values to theauditory outcome of patients. Results: The mean hearing follow-up was 1.79y (range 1-4y); 52patients (63.4%) had no hearing worsening on last audiological follow-up and 30 patients hadan increase of ¡_1 class on the Gardner-Robertson classification. Mann-Whitney statistical testwas used to analyze relation between audiological outcome and the median total tumor volume,intracanalicular tumor volume, ratio intracanalicular volume/total volume, conformity index, meandose delivered to the total tumor volume and to the intracanalicular tumor volume, integrateddose delivered to the total tumor volume and to the intracanalicular tumor volume. Among thegroup of patients with hearing worsening after GKR, none had a entirely extracanalicular VS and23.3% were entirely intracanalicular, compared to 9.6% and 17.3% respectively in the group withno hearing reduction after GKR. Conclusion: hearing preservation after GKR for VS is related tosome volumetric and dosimetric parameters of the intracanalicular part of the tumor.

A prospective series of 1000 vestibular schwannomas treated by “low dose” radiosurgery: long term results OS4-4 Jean, Regis (1); Pierre-Hugues, Roche (2); Christine, Delsanti (3); William, Pellet (1) (1) CHU La Timone - Service de Neurochirurgie; (2) CHU La Timone - neurochirurgie; (3) CHU La Timone -Gamma Unit Marseille, France

Background : Historical series of radiosurgery for acoustic are usually long term results for lesionstreated with relatively high doses (>14Gy) at the margin. Long term results of radiosurgery withlow marginal dosage remains poorly documented. Material and method : Since the 14th of july1992, 1500 vestibular schwannomas have been treated and followed prospectively in MarseilleTimone University hospital. We have analysed the results of the first 1000 patient treated withmarginal doses lower than 14Gy with more than 3 years follow up (treated between july 1992and January 2002). Results : According to the Koos topographical classification, there were pre-operatively 84 stage I, 538 stage II, 322 stage III, and 56 stage IV cases. A significant transientincrease in tumor size was recorded in 15 % of the patients. Tumor control was achieved in 97%

121

Page 124: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

of cases. Transient facial palsy was observed in 0,7%. Among the 175 patients, with a VS andfunctional preoperative hearing (Gardner and Robertson 1 or 2) functional hearing preservationwas achieved in 60% of the patients. Univariate and multivariate analysis have revealed param-eters which influence the probability of functional hearing preservation at 3 years. These param-eters include: a limited hearing loss (Gardner/Robertson stage 1), the presence of a tinnitus,younger age of the patient, and small lesion size. Functional hearing preservation at 3 years is77.8% in patients with stage 1 hearing, 80% in patients with tinnitus as a first symptom, and95% when the patient has both stage 1 hearing and tinnitus. Conclusion : Long term tumor con-trol in vestibular schwannomas treated with low dose radiosurgery appears satisfactory. Thisseries confirm that a high rate of functional hearing preservation can be reached in selected can-didates with radiosurgery.

LUNG TUMORS 1 OS5Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke &

Rembrandt

A prospective trial on stereotactic radiotherapy of limited stage non-small cell lung cancer OS5-1 Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars Peter, Ohlhues (2); Jorgen, Petersen (1); Hanne,Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1)(1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Departmentof Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark

Surgery is the principal treatment of patients with limited stage non-small cell lung cancer(NSCLC). However, a large proportion of patients are not suitable for thoracotomy due to severeco-morbidity. Stereotactic body radiotherapy (SBRT) have been used for treatment of patients withlimited stage NSCLC who are unfit for resection. Forty patients with stage I NSCLC were includedinto a phase II trial. The patients were immobilized by the Elekta stereotactic body frame (SBF) ora custom made body frame. SBRT was given on standard LINAC with standard multi-leaf collima-tor. Central dose was 15 Gy x 3 within 5-8 days. Median follow-up time af the patients was 2,4years. Eight (20%) patients obtained a complete response, 15 (38%) had a partial response and12 (30%) had no change or could not be evaluated. Only 3 patients had a local recurrence andlocal control rate two years after SBRT was 85%. At two years, 54% were without local or dis-tant progression and overall survival was 47%. Within 6 months after treatment, one or moregrade 2 reactions such as chest pain, skin reaction, increased used of analgesics, dyspnoea anddeterioration in WHO performance status to 2 or higher was observed in 48% of the patients.Sixty-two percent and 63% of the patients experienced transient or permanent deterioration inlung function (grade>1) or performance status (WHO>1) during follow-up. SBRT in patientswith limited stage NSCLC resulted in high probability of local control and promising survival rate.The toxicity after SBRT of lung tumours was moderate. However, deterioration in performance sta-tus, respiratory insufficiency and other side effects were observed.

122

Page 125: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

CT appearance of radiation injury of the lung and clinical symptoms after stereotactic radiation therapy (SRT) for lung cancers OS5-2 Tomoki, Kimura (1); Yuji, Murakami (2); Kanji, Matsuura (3); Yasutoshi, Hashimoto (4); Masahiro, Kenjo (5);Yuko, Kaneyasu (6); Koichi, Wadasaki (7); Yutaka, Hirokawa (8); Motoomi, Ohkawa (9); Katsuhide, Ito (10) (1) Kagawa University - Radiology; (2) Hiroshima University School of Medicine - Radiology; (3) HiroshimaUniversity School of Medicine - Radiology; (4) Hiroshima University School of Medicine - Radiology; (5)Hiroshima University School of Medicine - Radiology; (6) Hiroshima University School of Medicine - Radiology;(7) Hiroshima University School of Medicine - Radiology; (8) Juntendo University - Radiology; (9) KagawaUniversity - Radiology; (10) Hiroshima University School of Medicine - Radiology Kagawa Prefecture, Japan

(Purpose) The purpose of this study was to evaluate the CT appearance of radiation injury to thelung, clinical symptoms and the effect of pulmonary emphysema after SRT (stereotactic radiationtherapy) for lung cancers. (Methods and Materials) In this analysis, 38 patients with 44 primaryor metastatic lung cancers were enrolled. SRT was performed using 3D conformal method whichdelivers a single high dose to the tumor. We evaluated the CT appearance of acute radiationpneumonitis (within 6 months) and radiation fibrosis (after 6 months) after SRT. Clinical symptomswere evaluated by CTCAE ver.3.0. (Results) CT appearance of acute radiation pneumonitis wasclassified as follows ;1)diffuse consolidation in 16 lesions (36.4%), 2) patchy consolidation andground-grass opacities (GGO) in 6 lesions (13.6%), 3) diffuse GGO in 6 patients (13.6%), 4)patchy GGO in 1 lesion (2.3%), 5) no evidence of increasing density in 15 lesions (34.1%). CTappearance of radiation fibrosis was classified as follows; 1) modified conventional pattern (con-solidation, volume loss and bronchiectasis similar to, but less extensive than conventional radia-tion fibrosis) in 23 lesions (52.7%), 2) mass-like pattern (focal consolidation limited around thetumor) in 10 lesions (22.7%), 3) scar-like pattern (linear opacity in the region of the tumor asso-ciated with volume loss) in 11 lesions (25.0%). Sixteen patients had pulmonary emphysema(42.1%) and its percentage was significantly high in patients who were classified into no evi-dence of increasing density or scar-like pattern (p=0.0002, 0.0003, respectively). (Conclusion) CTappearance after SRT was classified into five patterns of acute radiation pneumonitis and threepatterns of radiation fibrosis. Most of patients who were classified into no evidence of increasingdensity or scar-like pattern had pulmonary emphysema and were not also diagnosed with morethan grade 2 pneumonitis.

CT-guided stereotactic radiotherapy for stage I non-small cell lung cancers: 10-year experiences with the fusion of CT and Linac (FOCAL) unit OS5-3 Minoru, Uematsu (1); Akira, Shioda (2) (1) Keio University - Department of Radiology; (2) National Defense Medical College - Radiation Oncology Tokyo , Japan

Stereotactic radiotherapy (SRT) is highly effective for brain metastases from non-small cell lungcancers (NSCLC). As such, primary lesions of NSCLC may also be treated well by similar SRT.Between 1994 and 2002, with the fusion of CT and Linac (FOCAL) unit, 100 patients with patho-logically proven T1-2N0M0 NSCLC were treated by CT-guided focal high-dose SRT at the NationalDefense Medical College in Japan. Of these 49 were medically inoperable, and remaining 51were medically operable but refused surgery. In most patients, SRT was 50-60 Gy in 5-10 frac-

123

Page 126: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

tions over 1-2 weeks. Twenty-five patients also received conventional radiotherapy before SRT toreduce the tumor volume. With a median follow-up period of 62 months, the 5-year overall andcause-specific survival rate was 51% and 72%, respectively. The crude local progression free ratewas 97%. There was one treatment-related death and the crude motality rate was 1%. The otheradverse effects were not severe. Among 51 patients who were medically operable but refusedsurgery, the 5-year overall survival rate was 78% and as high as those following surgery. CT-guid-ed focal high-dose SRT was acceptably safe and effective for patients with stage I NSCLC. Sinceapril 2004, treatment fees of this new approach was covered by the governmental health insur-ance in Japan.

Dose-response relationship in fractionated stereotactic radiotherapy (FSRT) for non small cell lung cancer (NSCLC) OS5-4 Hilde, Van Parijs (1); Jan, Van de Steene (1); Vincent, Vinh-Hung (1); Dirk, Verellen (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels , Belgium

Objective/Purpose: Our objective was to examen a possible dose-response relationship in frac-tionated stereotactic radiotherapy (FSRT) for NSCLC. Materials/Methods: Records of 25 patientsfrom the AZ-VUB who received FSRT for NSCLC between July 2001 and May 2004 were reviewed.All patients were part of a hypofractionation study. Fractionation schemes ranged from 10 x 5 Gyto 2 x 20 Gy when curative intent, from 7 x 5 Gy to 3 x 10 when palliative. All doses mentionedare 2 Gy equivalence doses (2GyEQD), calculated with an a/b = 8. Included were 20 male and5 female patients with NSCLC stage I (10), II (1), III (13) or IV (1). Treatment planning was per-formed with image fusion of CT and FDG-PET scan. The PET-scan integrates tumour-movementdue to breathing. Treatment was delivered with X-ray image guidance (IGRT). IGRT was based onfiducial metallic markers (Fibered Platinum Coil, Boston Scientific/Target Therapeutics, Fremont,CA) implanted intra-tumouraly in 7 cases. IGRT was based on bone structures in the other 18patients. PTV was enclosed by the 95%-isodose. The PTV-margins were 4-8 mm in case of mark-ers, 10-12 mm without marker. This population was devided into two groups: a low dose groupreceiving <= 66 Gy (14) and a high dose group receiving > 66 Gy (11). 11 patients (10 stageIII, 1 stage I) received chemotherapy prior to FSRT (9 in the low dose and 2 in the high dosegroup). Results: The mean dose delivered was 61.7 Gy in the low dose group and 89.9 Gy in thehigh dose group. In the low dose cohort the results were: 4 CR, 7 PR, 2 SD and 1 PD. In the highdose cohort we observed 6 CR, 3 PR, 2 SD and 0 PD. The outcome was better with higher doses,the results were statistically significant (Chi_: P = 0.039). 8 patients had a local relapse, 6 in thelow dose and 2 in the high dose group. Conclusion: There is a positive dose-response correlationfor FSRT in NSCLC.

124

Page 127: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ORAL SESSIONS 15h00 - 16h00

VESTIBULAR SCHWANNOMAS 2 OS6Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation

Radiosurgery of facial neurinoma - Long-term results and functional outcome OS6-1 Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Since 1991, fifteen cases of facial neurinoma have been treated with gamma knife. There are 6males and 9 females, ages ranged from 28 to 70 years with a mean of 46 years. Many of themcomplained of facial palsy or hearing disturbance. Majority of the tumors are located in internalmeatus(2), geniculate gangliona and middle fossa (8) or in CP angle (4). Some are extending intocavernous sinus (1). Tumor size at radiosurgery are ranged from 12 to 34 mm with a mean diam-eter of 20.5 mm(mean volume: 5.84 cc). At radiosurgery tumors were treated with a mean max-imum dose of 24.2 Gy and a marginal dose of 12.9 Gy (range:11-16 Gy). In the mean follow-upof 28.3 months, 8 cases showed PR, 2 cases disclosed MR and 5 cases are unchanged in size.Thus the response rate and the control rate are 53% and 100% respectively. Hearing disturbanceare generally unchanged, but facial palsy are either improved(33%) or unchanged(53%) exceptfor worsening in one case just after the treatment. As adverse effects, hydrocephalus and a wors-ening of facial palsy.were seen in one case each. In conclusion, radiosurgery for facial neurinomais apparently useful and better than the results of operation in terms of tumor control as well asfunctional outcome. Small tumor less than 30 mm in mean diameter, recurrent or residual tumorafter operation should be treated with radiosurgery.

Risk of malignancy in the radiosurgical management of Type 2 Neurofibromatosis (NF2) OS6-2 Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz(3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

Introduction: Whilst minimally invasive radiosurgical treatments are clearly an attractive manage-ment strategy in NF2, there is obvious concern about the use of radiation in a condition arisingfrom tumour suppressor gene mutations. Clinical material: In our systematic study cross-referenc-ing radiosurgery patients with national mortality and cancer databases, we identified 118patients with NF2, who underwent 144 radiosurgical treatments for 146 vestibular schwanno-mas (VS), 23 meningiomas and 4 other tumours. This constitutes 906 patient-years of follow-upfrom first radiosurgical treatment. The mean±SD age at diagnosis was 25±12 years, and attreatment 32±14 years. Results: Two new malignant intracranial tumours were reported afterradiosurgery. One, previously reported, was a rapidly growing VS before radiosurgery, which atsubsequent resection had malignant histology.[1] The other was a glioblastoma reported three

125

Page 128: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

years after VS radiosurgery. Discussion: The significance of detecting these malignant tumours isdifficult to evaluate. One was rapidly growing before radiosurgery, and 4% of NF2 patients devel-op gliomas.[2] Furthermore, with an average interval between diagnosis and radiosurgical treat-ment of 7 years, and a mean follow-up from radiosurgery in excess of a further 7 years, thesedata nearly cover the natural history of the condition. The mean age at death in NF2 has beenreported as 36 years, an average of 15 years from diagnosis, 98% of deaths being from NF2 relat-ed complications.[2] Certainly the incidence of malignancy is no greater than the 2.4% mortalityquoted in the largest NF2 VS surgical series.[3] Considering these factors, we believe that radio-surgery remains a useful management option for selected NF2 patients. 1. Bari ME et al. Br JNeurosurgery 2002, 16:284-9. 2. Evans DGR et al. Q J Med 1992, 304:603-18. 3. Samii M etal. Neurosurgery 1997, 40:696-706.

Histopathological observations on vestibular Schwannomas following gamma knife radiosurgery OS6-3 Gyorgy, Szeifert (1); Dominique, Figarella-Branger (2); Pierre-Hugues, Roche (3); Marc, Levivier (4); Jean, Regis (5)(1) National Institute of Neurosurgery of Budapest; (2) CHU La Timone - Department of Pathology andNeuropathology; (3) CHU La Timone - neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife; (5) CHU LaTimone - Service de Neurochirurgie Marseille, France

Background: Although the number of treated cases has been increasing continuously we knowrelatively little about the biological effect of high dose irradiation on vestibular schwannomas(VSs) following radiosurgery. The purpose of this study was to analyze histopathological changesin VSs after Leksell gamma knife (LGK) radiosurgery. Methods: Surgical pathology material from20 cases (17 from Marseille, 3 from Brussels) who underwent craniotomy following radiosurgerywere studied. Routine histological and immunohistochemical investigations were performed onthe tissue samples. Histopathological findings were compared with clinical and radiological fol-low-up data. Results: Coagulation necrosis in the central part of the schwannomas surroundedwith a transitional zone containing loosened tissue structure of shrunken tumor cells covered withan outer capsule of vigorous neoplastic cells was the basic histopathological lesion. Granulationtissue proliferation with inflammatory cell infiltration, different extent of hemorrhages and scar tis-sue development was usually present. Endothelial destruction or wall damage of vascular chan-nels was a common finding. Analyzing the follow-up data it turned out that 7 patients out of the20 were operated on because of radiological progression only without clinical deterioration and4 of them was removed during the latency period after radiosurgery. Conclusion: Results of thepresent histopathological study suggest that radiosurgery works with double effect on VSs: itseems to destroy directly tumor cells (with necrosis or inducing apoptosis), and causes vasculardamages as well. The loss of central contrast enhancement on CT and MR images followingradiosurgery might be consequence of necrosis and vascular impairment. From clinical-patholog-ical point of view we think that patients should not undergo craniotomy just because of radiolog-ical progression of the tumor without clinical deterioration, mainly in the latency period.

126

Page 129: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Avoidance of facial nerve dysfunction after GK radiosurgery: modified dose planning technique OS6-4 Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Introduction: GK radiosurgery is currently being used for primary or postoperative managementin an increasing number of vestibular schwannoma (VS) patients. Early GK radiosurgery experi-ences included post-treatment facial nerve (VII) complication incidences of 3% or slightly more.In 1995, when the Leksell GammaPlan System (Elekta, AB, Stockholm) became available, theauthors modified a dose planning technique to reduce VII dysfunction rates. Patients andTechniques: The greater part of a tumor is covered with a 12 Gy isodose gradient while the ante-rior part of the intracanal portion and a small anterior-superior region of the cisternal portion arecovered with a 10 Gy isodose gradient. Using this modified dose-planning technique, the authorshave treated 191 VS patients during the 10-year period since 1995. Results: In our initial seriesof 120 patients who underwent GK radiosurgery before March of 1992 (follow-up period of 3years or more), rates of tumor control and a preservation of serviceable hearing were was 97.5%and 55.0%, respectively. A V-P shunt procedure was required for post-GK hydrocephalus in 5.8%.However, in the entire group of 191 patients, no additional permanent VII dysfunction occurredand only one experienced transient deterioration of VII function, which appeared after partialremoval of the tumor but had subsided by the time of GK. Conclusion: Using this dose planningtechnique, the risk of postradiosurgical VII dysfunction can be virtually eliminated without increas-ing the risk of tumor control failure.

LUNG TUMORS 2 OS7Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke &

Rembrandt

Dosimetric validation of a breathing synchronized irradiation technique for hypofractionated lung treatments OS7-1 Dirk, Verellen (1); Koen, Tournel (2); Nadine, Linthout (3); Guy, Storme (4) (1) AZ VUB - Physique; (2) AZ-VUB - Radiotherapy; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy Brussels, Belgium

Background and Purpose: Evaluation of the technical feasibility of a prototype developed forbreathing synchronized irradiation in combination with intensity modulated radiation therapy.Material and Methods: DMLC-IMRT fluence patterns acquired on radiographic film, generated bythe linac in non-gated and gated mode, have been imported into the initial TPS. The effect of pos-sible interplay between organ motion and leaf motion and the efficacy of a breathing synchro-nized irradiation technique (an adapted version of a commercially available image-guidance sys-tem: NOVALIS BODY / ExacTrac4.0, BrainLAB AG) has been evaluated using radiographic filmmounted to a simple phantom simulating a breathing pattern of 16 cycles per minute and cover-ing a distance of 4 cm to obtain the resulting fluence maps. Additional ionization chamber meas-urements have been performed using the same cycling phantom. Two situations have been inves-tigated: (a) A tumor located close to the diaphragm to assess the influence of organ motion onthe dose to the target volume as well as to the gastro-intestinal tract that presents a high risk at

127

Page 130: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

intersecting with the beam during the breathing cycle. (b) A thoracic lesion requiring complicat-ed fluence patterns to assess the possible interplay between leaf motion and organ motion.Results: Importing measured fluence maps yielded highly disturbed reconstructed dose distribu-tions in case of the non-gated delivery with the phantom in motion (both orthogonal and paral-lel to the leaf direction), whereas the measurements from the static (film fixed in space) and thegated delivery showed good agreement with the original theoretical dose distribution. Thesefindings have been confirmed by the dose-volume histograms, corresponding tumor control prob-abilities (almost identical for the original, static and gated measurements; yet reduced with a fac-tor 2 for the “in motion and non-gated” delivery), conformity index and dose heterogeneity val-ues (increased with a factor 3 to 6 -depending on the case- when motion was induced, where-as again similar values have been obtained applying the original, static and gated fluence maps).The normal tissue complication probability seems to be affected to a lesser degree, which con-curs with the observation that the interplay effects result in a dose spread in the direction ofmotion. Ionization chamber measurements yielded a dose reduction exceeding 50% whenmotion is involved, which restored within 5% of the prescribed dose applying breathing synchro-nized irradiation. The applied breathing synchronization technique introduced an increased treat-ment time with a factor 3 to 4. Conclusions: The use of measured fluence fields, delivered by thelinac in non-gated and gated mode, as imported fluence maps for the treatment planning systemis an interesting quality assurance tool and revealed the dramatic impact of interplay betweenDMLC-IMRT dose delivery and organ motion, as well as the advantage of breathing synchroniza-tion to resolve this issue. The latter should, however, be outweighed against the increased treat-ment time.

Stereotactic body radiation therapy for lung metastases: Impact on overall survival OS7-2 Martin, Fuss (1); Charles R., Thomas Jr. (1); Bill J., Salter (2); Terence S., Herman (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio , USA

Hypofractionated or single dose stereotactic body radiation therapy (SBRT) for a limited numberof lung metastases has been documented to be feasible and to yield excellent local tumor con-trol. The aim of this analysis was to determine if SBRT contributes to prolonged survival in apatient population with systemic disease manifestation. Between 8/01 and 11/04, 50 patientswere treated by SBRT for lung metastases (1-4 metastases, median 1) with maximum diameter<6 cm. A sequential tomotherapeutic intensity-modulated radiation technique (Peacock IMRT,Nomos) was used to deliver 3 fractions of 12 Gy (total dose 36 Gy). Doses were prescribed as theminimum dose to the planning target volume (PTV) which included safety margins of 5 mm axi-ally and 10 mm cranio-caudally to the gross tumor volume (GTV). We analyzed overall survivalin this population. Results: The median GTV and PTV treated was 16 and 43 cm3 (range GTV: 1-135 cm3; PTV: 12-256 cm3). At a respective mean and median clinical follow-up of 10.2 and 7.4months, 10 patients have expired. Median time to death was 3.6 months. Cause of death wasnew metastatic disease to lung, liver and/or brain. At the time of death, 8/10 patients had doc-umented local control of SBRT treated lesions. Follow-up in patients alive ranges from 2.5 to 34months (mean 9.9, median 7.7 months). Of 41 patients treated at least 12 months prior to analy-

128

Page 131: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

sis, 31 were alive at last follow-up. Of those, 21 patients were alive with imaging confirmed sys-temic disease progression, including 2 with local recurrence or lack of response to SBRT.Conclusions: SBRT in patients with a limited number of pulmonary metastases results in encour-aging preliminary survival rates and may result in an increased intermediate-term survival for asubset of patients. However, cause of death in the majority of cases was systemic disease pro-gression indicating that SBRT can only be one tool in the multi-disciplinary disease managementfor this patient population.

Metabolic PET imaging for stereotactic body radiation therapy planning and therapy response assessment of pulmonary malignancies OS7-3 Martin, Fuss (1); Bill J., Salter (2); Terence S., Herman (1); Charles R., Thomas Jr. (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA

Target delineation for lung SBRT is typically based on CT imaging. Metabolic tumor informationderived from FDG-PET may allow to more accurately target pulmonary malignancies and to assesstumor response. Between 5/02 and 11/04, 38 patients underwent FDG-PET imaging in additionto CT simulation for lung SBRT. Tomotherapeutic IMRT was used to deliver 3x12 to 3x20 Gy (totaldoses: 36 Gy (metastases) and 48-60 Gy (stage 1 NSCLC). We analyzed the impact of metabolicimage information on target delineation. Additionally, 30/38 patients had PET studies acquired at4 to 12 weeks following SBRT, and 18 patients had additional PET studies acquired at 6 to 28months of follow-up. A pathologic SUV of >3.0 at baseline was observed in 35/38 studies. FDG-PET metabolic information changed the GTV in 8/34 cases where tumor associated lung atelec-tasis or regional fibrosis was observed. Here, the FDG uptake region was used for GTV delin-eation. Changes in tumor SUV were observed as early as 4 weeks following SBRT. A decline toSUV <3.0 was consistently observed at 12 weeks (28/30 patients with PET follow-up, including2/3 patients with low initial SUV showing minor decline). In long-term PET follow-up, furtherreduction in uptake to normal tissue levels was observed. Two patients who failed to show adecline in FDG uptake failed SBRT locally. Although the small patient number studied may limitour ability to comprehensively assess the value of implementing FDG-PET into SBRT treatmentplanning and therapy response assessment for pulmonary malignancies, our preliminary experi-ence supports three conclusions: (1) FDG-PET may be especially useful for SBRT planning oflesions masked by fibrosis, or atelectasis; (2) early decline in FDG uptake may prognosticate long-term local tumor control; (3) lack of SUV decline within 12 weeks may precede local failure.

Computed tomographical analysis of radiation sequelae due to experimental stereotactic irradiation to normal rabbit lung OS7-4 Takatsugu, Kawase (1); Etsuo, Kunieda (2); M Deloar, Hossain (2); Satoshi, Seki (2); Akitomo, Sugawara (2);Tatsuya, Fujisaki (3); Akitoshi, Ishizaka (4); Atsushi, Kubo (2) (1) Keio University - Department of Radiation Oncology, (2) Keio University - Department of Radiology, (3)Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences, (4) Keio University -Department of Medicine

Background: Stereotactic irradiation (STI) to treat early non-small cell lung cancer in Japan may bea possible alternative to surgical treatment. We tried to establish an STI technique by irradiating

129

Page 132: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

normal rabbit lung and examining the radiation sequelae using computed tomography (CT)images. Materials and Methods: Institutional guidelines for the care and use of laboratory ani-mals were followed in all experiments, and the use of rabbits was approved. Seven JapaneseWhite Rabbits were anesthetized and partial spherical volume of each left lung was stereotacti-cally irradiated with 4 MV of X-ray energy with a narrow beam of size 11mm x 11mm. Three non-coplanar arcs (couch rotation: 0 deg ± 45 deg) were employed for arc rotation. Each gantry rota-tion arc was 160 deg. Total irradiated dose of each rabbit was 21, 30, 39, 48, 60, 60, 60 Gy,respectively. After the irradiation, each rabbit was scanned with a CT scanner approximatelybiweekly. All rabbits were examined for 24 weeks after irradiation. Round regions of interest, cor-responding to the stereotactically irradiated area and the comparable part of the contralaterallung were delineated on CT image viewer. The ratio of CT values (irradiated part to comparablepart of the contralateral normal lung) was calculated for each scanned rabbit lung image.Additionally the ratio after irradiation was divided by the ratio before irradiation and used to com-pare seven time course variations under the same conditions. Results: Localized attenuating opac-ities suggesting emphysematous change appeared consistently in the irradiated parts of severalrabbits 7-14 weeks after irradiation. The findings persisted after then. The time course curve ofthe ratios was variable and indicated no significant regularity. Conclusions: Though the singledose of STI was high, the sequelae were subtle. Rabbit lung might be more tolerant to acute andsubacute radiation effects than human lung.

ORAL SESSIONS 17h00 - 18h00

VESTIBULAR SCHWANNOMAS 3 OS8Chairmen: L. Dade, Lunsford; Jean, D’Haens Room Nation

Five session gamma knife treatment of acoustic neuromas OS8-1 Steven, Cobery (1); Melissa, Remis (2); Carla, Bradford (2); Georg, Noren (2) (1) Brown University - Department of Neurosurgery; (2) Rhode Island Hospital, Brown University - NewEngland Gamma Knife Center Providence, USA

Purpose: To assess the tumor volume control and hearing preservation after gamma knife frac-tionated radiosurgery (GKFR) for acoustic neuroma. Methods: Between May 1999 and February2004, 25 patients with unilateral acoustic neuromas underwent a fractionated radiosurgical pro-tocol using the Leksell gamma knife (Elekta Instruments, Inc., Norcross, GA). Mean tumor diam-eter ranged from 9.1 to 36.0 mm. The fractions were given daily over 5 consecutive days. Thestereotactic coordinate frame was affixed prior to the first fraction on Day 1 and removed follow-ing the last fraction on Day 5. A fraction dose of 3 Gy was prescribed to 48 - 50%, for a totaldose of 15 Gy. Conformality was assured through the use of multiple isocenters, averaging 22isocenters per patient (range 5-44) per fraction. Tumor size was measured on preoperative andfollow-up MRI. Gardner-Robertson (GR) scale was used to classify hearing. Followup, whichentailed clinical examination by a physician, MRI, and audiometric testing, occurred at 6 monthintervals for the first year and annually thereafter. Failure of local control of tumor size was definedas the need for any additional intervention, including open resection, additionalradiosurgery/therapy, or any combination of the two. Results: Follow-up ranged from 12 to 64

130

Page 133: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

months postoperatively. Tumor control was achieved in 96% of cases. Hearing preservation in theserviceable range (Gardner Robertson scale of I or II) was achieved in 86% of cases. One patientexperienced a transient, postoperative tinnitus, which resolved after a course of steroids. No facialor trigeminal neuropathy occurred postoperatively. Conclusion: GKFR may provide greater poten-tial for the preservation of hearing by ensuring precision and conformality not available with otherstereotactic radiosurgical or radiotherapeutic systems. This fractionated radiosurgical procedureseems to offer increased protection of surrounding neural structures, particularly hearing system,in comparison to other techniques.

Evaluation of ophthalmological consequences of gamma knife radiosurgery in vestibular schwannomas OS8-2 Manabu, Tamura (1); Noriko, Murata (2); Motohiro, Hayashi (3); Jean, Regis (4) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital -Stereotactic and Fonctional Neurosurgery; (3) Tokyo Women's Medical Univeristy - Department ofNeurosurgery; (4) CHU La Timone - Service de Neurochirurgie Marseille, France

Objective : Due to the synergic role of the facial nerve and the nervus intermedius in the mechan-ical protection of the eye, Vestibular Schwannomas (VS) and/or their treatment are dangerous forthe visual function. Our goal is to evaluate the subjective and objective impact of the gamma knifeRadiosurgery (GKS). Material and Method : A functional questionnaire evaluating among otheritems the patient complaints related to the eye has been addressed to a series of 100 patients 3years after the GKS, of a unilateral VS and not previously operated. Schirmer’s test was addition-ally performed before GKS and more than 2 years after GKS to evaluate the injury of the lacrimalcomponent of the nervus intermedius in 66 patients. Results : Among 68 patients responding tothe questionnaire, 9 (13.2%) patients complained of dry eye, 10 (14.7%) pts. of burning eye, 1(1.5%) pt. of crocodile tears and 10 (14.7%) pts. of eye crying after GKS. No patients had newfacial motor palsy after GKS. In 64 patients with no facial palsy before (nor after) GKS, a dry eyeis reported in 8 (12.5%), a burning eye in 9 (14.1%), crocodile tears in 1 (1.6%) and eye cryingin 9 (14.1%) after GKS. Thus patients with no clinical signs of impairment of the VII motor nerveare presenting in 14% of cases sign of indicating the injury of the intermedius nerve. In theSchirmer test before GKS, 27 of 66 (40.9%) patients had already showed the abnormal lacrima-tion that means less lacrimation in the tumour side than the contra lateral side. As we followedthe patients for 4.8 years after GKS, 51 patients resulted in normal lacrimation, while 15 cases(22.7%) remained abnormal function (4 cases) or deteriorated (11 cases), which indicates thepatients of abnormal lacrimation decreased after GKS significantly (Chi-test, p=0.0249). We alsoexamined the predictive factor that might cause the result of the Schirmer test after GKS in thetreatment of VS. Among the variates before GKS, abnormal lacrimation, facial motor palsy,hypoesthesia, sex, tumour size, age, dose rate of GKS, tumour volume, peripheral and maximumdose of GKS were analyzed. Patients presenting with an infraclinical injuries of the lacrimal com-ponent of the intermedius nerve before GKS, have a higher possibility to suffer from a clinicalsigns specially dry eye after GKS (Chi-test, p=0.021). Conclusions : This study is the first demon-strating that Radiosurgery can improve or impair nervus intermedius function in non-rare percent-age of cases. Sub-clinical evaluation before GKS on the nervus intermedius predict the ocularsymptom after GKS and must be part of all evaluation before and after radiosurgery in VS.

131

Page 134: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Relative safety of gamma knife radiosurgey in CPA angle tumors with significant brainstem compression OS8-3Mohammad Ali, Bitaraf (1); Mazdak, Alikhani (2); Mazyar, Azar (3); Frarid, Kazemi (4) (1) Tehran university of medical sciences - Neurosurgery; (2) Tehran university of medical sciences -Neurosurgery; (3) Iran university of medical sciences - neurosurgery; (4) Iran university of medical sciences -Neurosurgery Tehran, Iran

Significant brain stem compression is considered to be a relative contraindication for radio-surgery,due the risk of possible brain stem radiation changes and also adverse effect of progres-sion and mass effect of tumor on the brain stem.In the present report we investigated 80 menin-gioma and acoustic schwanoma patients in whome moderate to sever compression of brain stemwas present.Clinical studies showed that patients presented with a comparable spectrum of signsand symptoms regardless of th degree of compression possibly due to the plasticity of CNS neu-rons.Patients underwent radiosurgery using leksell model C gamma knife unit and were followedup for a median of six months. A grading system was develpoed and degree of brain stem dis-tortion was graded as a 1+ to 4+ grade. No case had pre-radiosurgery brain stem edema.Among the 95 patients, no pateints showed post-operative brain stem radiation changes.Clinicalconditions of the pateints were either improved or unchanges following radiosurgery in 76patients .In the relatively short period follow-up only 4 patient deveolped new signs or symptomsas a consequence of brain stem compression.One patient required urgent microsurgery 6 monthsafter treatment despite tumor shrinkage in MRI.All four patients with new neurological symptomswere in grade 4 of brain stem compression according to our grading system.In the subset ofpatients with follow-up imaging,evidence of intratumor necrosis or reduction in tumor size waspresent in 85% of cases.Our results indicate that brain stem compression might be considered asa relatively safe alternative to the microsurgery specially in under-developed countries were skullbase microsurgery poses multiple dilemmas.

Hypofractionated stereotactic radiotherapy as primary treatment of acoustic neuroma: Interim results of the Johns Hopkins experience OS8-4Ori, Shokek (1); Stephanie, Terezakis (1); Michael, Hughes (1); Lawrence, Kleinberg (1); Moody, Wharam (1);Daniele, Rigamonti (2) (1) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and MolecularRadiation Sciences; (2) Johns Hopkins University School of Medicine - Department of Neurosurgery Baltimore, USA

Purpose/Objective: To report our institution’s experience in the primary treatment of acoustic neu-roma with hypofractionated stereotactic radiotherapy, specifically in regard to rates of local con-trol, hearing preservation, and facial nerve injury. Materials/Methods: Between November 1995and March 2003, 375 radiographically diagnosed acoustic neuromas were treated in 373 evalu-able patients (two patients with type II neurofibromatosis received bilateral treatment). The medi-an age of the entire cohort was 53 yr (mean 53 yr; range 17–86 yr). Patients were treated with6 MV or 10 MV linac stereotactic radiotherapy. Three fractionation protocols were utilized, andthe choice of protocol was influenced by tumor dimensions, as follows: (a) The most commonprotocol, used in 333 tumors, was 25 Gy in five daily fractions. In patients treated using this pro-tocol, the median maximal tumor diameter was 15.0 mm (mean 15.6 mm; range 1.8–36 mm),

132

Page 135: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

and the median contoured volume was 0.69 cc (mean 1.8 cc; range 0.02–14.4 cc). (b) 30 Gy in10 daily fractions was used in 37 tumors, with a median maximal tumor diameter of 31.0 mm(mean 32.0 mm; range 12–42 mm) and a median contoured volume of 10.7 cc (mean 11.1 cc;range 1.1–20.2 cc). (c) 40 Gy in 20 daily fractions was used in 4 tumors, with a median maximaltumor diameter of 37.5 mm (mean 36.5 mm; range 31–40 mm) and a median contoured tumorvolume of 21.3 cc (mean 22.5 cc; range 21.1–26.3 cc). A single patient (whose tumor measured10 mm/0.07 cc) did not complete treatment; she received 16.7 Gy in three fractions, and treat-ment was halted because of the on-treatment onset of CN VII palsy. Results: With a median fol-lowup interval of 21 months (mean 24 months; range 2–96 months), local regrowth was seenin 12 cases, documented at a median post-treatment interval of 28.1 months (mean 28.9months; range 12.0–42.2 months). The median pre-treatment maximal diameter in these caseswas 20.0 mm (mean 19.25 mm; range 9–31 mm; raw data 9, 13, 13, 15, 18, 20, 20, 22, 22,23, 25, and 31 mm), and the median pre-treatment contoured volume was 1.95 cc (mean 3.47cc; range 0.27–9.21 cc; raw data 0.27, 0.31, 0.69, 1.01, 1.15, 1.60, 2.29, 5.81, 6.22, 6.35,6.74, and 9.21 cc). The Gardner-Robertson classification was used for audiologic evaluation. Pre-and post-treatment data were available for 212 patients, with a median audiologic followup of15.8 months (mean 18.1 months; range 1–60 months). Serviceable hearing was defined asGardner-Robertson class (GRC) 1 or 2. There were 150 patients with serviceable hearing pre-treat-ment, of whom 89 (59%) retained serviceable hearing post-treatment. There were 62 withoutserviceable hearing pre-treatment, of whom 8 (13%) gained serviceable hearing post-treatment.Those with pre-treatment GRC 1 (n = 106) had median change of -1 GRC (mean _1.0). Thosewith pre-treatment GRC 2 (n = 44) also had a median change of _1 (mean _1.0). Those withpre-treatment GRC 3 (n = 35) had a median change of zero (mean _0.5). Two patients with pre-treatment GRC 4 both gained 1 GRC. Those with pre-treatment GRC 5 (n = 25) had a medianchange of zero and a mean change of +0.9. Cranial nerve VII deficits were noted in eightpatients and resolved in all except two. Conclusions: Hypofractionated stereotactic radiotherapyas primary treatment of acoustic neuroma, with interim followup, provides a high rate of localcontrol, with moderate hearing preservation and rare facial nerve injury.

OTHER TUMORS OS9Chairmen: Ingmar, Lax; Rita, Engenhart-Cabillic Room Permeke &

Rembrandt

Epidermoid cyst treated with gamma knife radiosurgery OS9-1Jeremy, Ganz (1); Ayman, Hafez (1); W A., Reda (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

Objective: To recount the case history of the first patient with an epidermoid cyst to be treatedwith radiosurgery. Case Material: The patient was a 9 year old young lady who presented with ahistory of recurrent attacks of meningitis every 3 weeks. She was found to have a lesion betweenthe pons, medulla and the clivus. This was operated twice but some cyst material had to be leftbehind because of adherence to nerves and blood vessels. Further surgery was considered inad-visable. A review of the literature produced one case with the same diagnosis, where a positiveresponse to radiotherapy had been achieved. It was considered this little girl had nothing to lose

133

Page 136: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

by being treated. Results: The patient was treated on the September 2003. The 1.7 cm3 lesionreceived 12 Gy to the 55% isodose with 92% cover and a conformity index of 1.25. She has beenfollowed for 15 months. Since treatment she has only had one attack of meningitis in November2003 a few weeks after the gamma knife. Since then there have been no attacks. At follow up inSeptember 2004 the lesion was smaller than at treatment and she was in good health and spir-its. Conclusion: This is a rare condition which may often be impossible to remove in toto becauseof its adherence to local tissues. In view of the response in this patient it is suggested that gammaknife radiosurgery may be an alternative management. However, it should be explained to thepatient and / or family that this treatment is experimental at present and should only be used inpatients for whom nothing else is available and who are suffering intolerable discomfort from thelesion.

Stereotactic radiation for cystic craniopharyngiomas OS9-2Alessandra, Gorgulho (1); Carlos, Mattozo (1); Murisiku, Raifu (1); Katayoun, Tajik (1); Michael, Selch (2);Nzhde, Agazaryan (5); Timothy, Solberg (5); Daniel, Kelly (1); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Purpose: Craniopharyngiomas cysts are challenging since recurrence is very common with con-ventional approaches. This report evaluates cyst control after stereotactic radiation. Materials andMethods: Between July/1996-July/2003, 27 patients with craniopharyngiomas were treated withradiosurgery (SRS)/stereotactic radiation therapy (SRT) at UCLA. Fifteen had predominant cystcomponent (2 excluded due to incomplete follow-up). Mean age was 44.1 years (9-71y), 7male:6 female. Eleven presented with visual deficits (84.62%), 8 headaches (61.54%), 4 mentalconfusion (30.77%), 2 hypopituitarism(15.38%). Nine (69.23%) underwent transnasal transphe-noidal surgery(TNTS), 7(53.85%) craniotomy, 5(38.46%) stereotactic drainage(SD) prior and/orafter SRT. Two(15.38%) cases had radiological total resection confirmed. All but one received SRT.Mean SRT maximal dose of 45.8Gy (12.6-54Gy) was prescribed to mean 90±3.13 isodoseline.Mean fractions were 25.5±5.77 (8-30). SRS maximal dose was 22.86Gy. Mean initial tumor vol-ume was 14.86cc (1.77-47.45cc). Mean follow-up was 40.67±21.9 months (10-90 months).Results: Cyst control rate was 92.3%. Final mean cyst volume was 0.55±1.24cc while mean pre-radiation cyst volume was 9.41cc(0.95-41.32cc). Initial response was: 8(61.53%) decreased,1(7.69%) stabilized, 4(30.8%) increased. Two of these patients underwent placement of Rickmanreservoir, one had stereotactic followed by TNTS drainage. The fourth deceased 7 months afterSRT. Mean volume aspirated was 16cc (2-25cc). Mean SRT-SD interval was 43.8 days (1-90days).Final cyst response was: 5 (38.46%) disappeared, 6(46.15%) decreased from which 2(15.38%)collapsed, 1(7.69%) remained stable and 1 increased (deceased patient). Time to final cystresponse was 288.22±307.78 days (27-1029 days). Visual improvement occurred in 4 (31%)cases, 69% remained stable. Two (15.38%) developed hypopituitarism. One reservoir wasremoved due to infection. Conclusions: The excellent cyst control achieved suggests that stereo-tactic radiation should be the treatment of choice for residual/recurrent cysts, especially in a pop-ulation already submitted to multiple prior procedures. The radiation response is not alwaysimmediate, so drainage may be necessary until cyst is controlled.

134

Page 137: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Radiosurgery of epidermoid tumor - Trial for radiosurgical nerve decompression OS9-3Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Long-term results of radiosurgery for epidermoid tumors are reported. There are 8 cases includ-ing 3 males and 5 females, ages ranging from 6 to 63 (mean: 37.8 years). At radiosurgery wholetumor was covered in 4 and partially covered in 4 for the attempt of relieving cranial nerve signslike trigeminal neuralgia (5 cases) and facial spasm (1 case). The mean maximum and marginaldose were 27.1 Gy and 14.6 Gy respectively. In the mean follow-up of 42.8 months, all thetumors showed a good tumor control without any progression and tumor shrinkage is confirmedin 2 out of 8 cases. Among them symptomatic trigeminal neuralgia improved or disappeared inall 5 cases who complanied of before radiosurgery, and facial spasm disappeared in one. No neu-rological deterioration was found in any case after the treatment. In conclusion it is apparent thatepidermoid tumors do respond well to radiosurgery and the accompanying hyperactive dysfunc-tion of cranial nerves are significantly improved by gamma knife treatment either with entire orpartial tumor coverage. Therefore the radiosurgical nerve decompression for epidermoid tumor isseemingly achieved by gamma-radiosurgery.

Fulminate peritumoral brain edema following radiosurgery for meningiomas: Report of two cases and review of the literature OS9-4Guus, Koerts (1); Dirk, Van Den Berge (2); Christian, Raftopoulos (3); Jean, D'Haens (4) (1) Cliniques Universitaires Saint-Luc - Neurosurgery; (2) AZ VUB - Radiothérapie; (3) Cliniques UniversitairesSaint-Luc - Neurochirurgie; (4) AZ VUB - Neurochirurgie Brussels, Belgium

Introduction: Resection of skull base meningiomas remains difficult and is associated with signif-icant morbidity. Radiosurgery is an excellent alternative and high tumor control rates with mini-mal morbidity have been reported. Nowadays radiosurgery is also performed for superficiallylocated meningiomas. We report two cases of fulminate edema after radiosurgery and review theliterature analysing the risk factors. Case reports: The first patient had a recurrent parietalparasagittal meningioma despite postoperative fractionated radiotherapy. Three months postradiosurgery he developed headache and hemiparesis due to peritumoral edema. The secondhad an asymptomatic occipital parasagittal meningioma and was treated by radiosurgery on herrequest. Seven months later she developed peritumoral edema with hemiparesis and confusion.Both received 14Gy on the 80% isodose line and recovered completely after administration ofsteroids. Discussion: Several reports concerning tumor control (95%), outcomes, and complica-tions after meningioma radiosurgery have been published. Cranial nerve deficit or carotid arterystenosis are reported after radiosurgery for cavernous sinus meningiomas. Peritumoral brainedema following radiosurgery for skull base meningiomas is rare(1-6%). However in non-basalmeningiomas( convexity) edema is reported in 5%-50% of cases. It typically appears after a laten-cy period 3-8 months. Duration and severity of symptoms can be troublesome but most patientswill recover after administration of oral steroids. Radiosurgical parameters have been examinedto explain this phenomenon. Tumor volume, tumor margin dose, tumor maximum dose, and dose

135

Page 138: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

to adjacent brain were not statistically correlated to edema post-radiosurgery. The only significantfactor seems to be tumor location. Peritumoral edema is most prominent in convexity menin-giomas. Unlike skull base meningiomas,which are surrounded by cisterns, hemispheric menin-giomas lack any intervening arachnoid or cerebral spinal fluid barrier between the tumor and cor-tical surface. Conclusion: Radiosurgery of convexity meningiomas is not without complicationsand primary surgery should be considered whenever possible.

136

Page 139: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Tuesday 13/09/05

PLENARY SESSION 8h45 – 10h00

PS2Room Nation

DATA BLITZ UPDATE 1Extracranial Radiosurgery PS2-1Ingmar, Lax

DATA BLITZ UPDATE 2Vestibular Schwannomas PS2-2 L. Dade, Lunsford

BRAIN METASTASESChairmen: Ingmar, Lax; L. Dade, Lunsford

Radiosurgery for the treatment of 239 patients with brain metastases: estimation of patients eligibility using three stratification systems PS2-3Daniel, Devriendt (1); José, Lorenzoni (2); Nicolas, Massager (3); Philippe, David (4); David, Wikler (5); DanielSalvador, Ruiz Gonzalez (6); Bruno, Vanderlinden (7); Paul, Van Houtte (1); Jacques, Brotchi (3); Marc, Levivier (2) (1) Institut J. Bordet - Radiothérapie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme -Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Hôpital Erasme - PET Scan; (6) Medica Sur SA de CVMSU 820125 T58 - Unidad Gamma Knife; (7) Institut J. Bordet - Physique Brussels, Belgium

Objective: To test three patients’ stratification systems, the recursive partitioning analyze (RPA),the score index for radiosurgery in brain metastasis (SIR) and a newly proposed Basic Score forBrain Metastases (BS-BM), as predictors of survival, that could help in patient’s selection.Materials and methods: Between December 1999 and May 2005, 239 patients with 606 brainmetastases were treated with a gamma knife C. Median marginal prescription dose was 20 Gy,at a median 50% isodose. BS-BM was calculated evaluating 3 main prognostic factors: Karnofskystatus 80 or more, control of primary tumor, and existence of extracranial metastases. Results:Median survival was 23 months for RPA class I, 13 months for class II and 3 months for class III,(p<0.0001). According to SIR system, median survival was 21 months, 11 months, 4 monthsand less than 3 months for scores 8 to 10, 5 to 7, 4 and 0 to 3 respectively, (p< 0.0001). Mediansurvival was 23 months for patients with BSBM 3 points, 13 months with 2 points, 5 monthswith 1 point , (p<0.0001). Conclusion: RPA, SIR and BS-BM seem to be useful tools to estimateoutcome. Among them, BS-BM system is a simple and useful tool for patient’s selection. Thesesystems are also able to identify patients with short survival (SIR 0-3 , RPA III and BSBM 0-1).

137

Page 140: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Long-term survivors after gamma knife radiosurgery for brain metastases PS2-4Douglas, Kondziolka (1); Juan, Martin (2); John C, Flickinger (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) Department ofNeurological Surgery - University of Pittsburgh Pittsburgh, USA

Object. Stereotactic radiosurgery, with or without whole brain radiation therapy, has become avalued management choice for patients with brain metastases, although median survivals remainlimited. In patients with successful extracranial cancer care, patients who have controlled intracra-nial disease are living longer. We evaluated all brain metastasis patients who lived more than fouryears after radiosurgery to determine clinical and treatment patterns potentially responsible fortheir outcome. Methods. Six hundred and seventy-seven patients with brain metastases under-went 781 radiosurgery procedures between 1988 and 2000. We reviewed data from this entireseries, and evaluated patients with at least four years survival for information on brain andextracranial treatment, symptoms, imaging responses, need for further care, and managementmorbidity. These patients were compared to a cohort who lived less than three months afterradiosurgery (n=100). Results. Forty-four patients (6.5%) survived more than four years afterradiosurgery (mean = 69 months with 16 patients still alive). The mean age at radiosurgery was53 years (maximum, 72) and the median Karnofsky Performance Score, 90. Lung cancer (n=15),breast (n=9), kidney (n=7), and melanoma (n=6) were the most frequent primary sites. Two ormore organ sites outside the brain were involved in 18 patients (41%), the primary plus nodalinvolvement in 10 (23%), the primary only in 9 (20%), and only the brain disease in 7 (16%),indicating that extended survival was possible even in patients with multi-organ disease. Serialimaging of 133 tumors showed that 99 were smaller (74%), 22 were unchanged (17%), and 12were larger (9%). Four patients had a permanent neurological deficit after brain tumor manage-ment and six underwent a resection after radiosurgery. In comparison to patients with limited sur-vival (< 3 months), long-term survivors had higher initial Karnofsky Performance Score (p=.01),fewer brain metastases (p=.04), and less extracranial disease (p<.00005). Conclusion. Althoughthe expected survival of patients with brain metastases may be limited, selected patients witheffective intracranial and extracranial cancer care can have prolonged, good quality survivals. Theextent of extracranial disease at the time of radiosurgery is predictive of outcome, but does notnecessarily mean that patients cannot live for years if treatment is effective.

A randomized trial of surgery and radiotherapy versus radio-surgery alone in the treatment of single metastasis to the brain PS2-5Alexander, Muacevic (1); Berndt, Wowra (1); Joerg, Tonn (2); Hans-Jakob, Steiger (3); Friedrich, Kreth (1) (1) European Cyberknife Center Munich - Cyberknife Center; (2) Ludwig-Maximilians-University, KlinikumGroßhadern - Department of Neurosurgery; (3) University Duesseldorf - Department of Neurosurgery Munich, Germany

Objective: To assess whether outpatient radiosurgery alone is as effective as surgery and wholebrain irradiation (WBRT) for survival and neurologic control of disease in patients with singlemetastases to the brain. Methods: Sixty-four patients with a single metastasis with a diameter<=3 cm were randomly assigned to either microsurgery followed by whole brain radiotherapy(surgical group, 33 patients) or radiosurgery alone (radiosugery group, 31 patients). All patients

138

Page 141: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

had tumors eligible for radiosurgical treatment. Primary end point was survival, secondary endpoints were tumor response and local control rates, overall intracranial recurrence rates, cause ofdeath, and quality of life measurements (QL). Survival time was analyzed with the Kaplan Meiermethod. Prognostic factors were obtained from the Cox model. QL was assessed using theEuropean Organization for Research and Treatment of Cancer Quality of life Questionaire (EORTCQLQ-C30 (+3) and the Brain Cancer Module 20 (BCM20). There was no significant differencebetween the 2 groups in overall length of survival (9.5 months surgery group, 10.3 months radio-surgery group; p=0.8) and local tumor control (82% surgery group, 97% radiosurgery group;p=0.06). Patients in the radiosurgery group experience more often distant recurrences (p=0.04)which could be effectively controlled with additional radiosurgical treatments. By multivariateanalysis survival was similar for RPA class 1 and 2 patients (p=0.12). Unfavorable predictor ofsurvival was a diagnosis of lung cancer (p=0.045). The median neurological death rates were29% (surgery group) and 16% (radiosurgery group) (p=0.8). Radiosurgery was associated withan improved quality of life 6 weeks after treatment. Overall morbidity were 21.2% (7 patients) inthe resection group, and 19.3% (6 patients) in the radiosurgery group, respectively (p>0.1).Conclusions: In selected patients with cancer and single metastases to the brain radiosurgeryshould be considered as primary treatment option because it is as effective as surgery and radio-therapy and offers a good quality of life.

ORAL SESSIONS 10h30 - 11h30

BRAIN METASTASES 1 OS10Chairmen: Masaaki,Yamamoto; Minesh, Mehta Room Nation

Recursive partitioning analysis of prognostic factors for patients treated with four or more intracranial metastases treated with radiosurgery OS10-1Ajay, Bhatnagar (1); Douglas, Kondziolka (2); L. Dade, Lunsford (2); John C, Flickinger (2) (1) University of Pittsburgh Cancer Institute - Radiation Oncology; (2) University of Pittsburgh Medical Center- Department of Neurological Surgery Pittsburgh, USA

Objective: The current prognostic recursive partitioning analysis (RPA) system for patients withintracranial metastases is based on prior RTOG trials which primarily involved patients with soli-tary brain metastasis who received whole brain radiation (WB-RT). The purpose of this study isto devise a new RPA classification for patients with four of more intracranial metastases treatedwith a single stereotactic radiosurgery procedure. Methods: 189 patients underwent gammaknife radiosurgery for four or more intracranial metastases (median = 5, range 4-18) during onesession. The median total treatment volume was 6.8 cc (range 0.6-51.0 cc). Radiosurgery wasused as sole management (17% of patients), or in combination with WB-RT (46%), or after fail-ure of WB-RT (38%). The median marginal radiosurgery dose was 16 Gy (range 12-20 Gy).Median follow up was 8 months. RPA assessed the effects of age, Karnofsky >70, extracranialdisease, visceral metastases, number of metastases, total treatment volume, history of breast andmelanoma primaries on survival. Results: The median overall survival after radiosurgery for allpatients was 8 months. RPA identified a favorable subgroup of 78 patients (43 % of the entire

139

Page 142: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

series) with a total treatment volume <7 cc and < 7 brain metastases (Class 1), with a mediansurvival of 13 months. The survival of this favorable subgroup was significantly better (p<0.00005) than the remaining patients (Class 2) (n=111) with a median survival of 6 months.Conclusion:The new RPA classification for multiple brain metastasis patients identified Class 1patients who have a total treatment volume <7 cc and < 7 metastases (4-6) that represent alarge subgroup with favorable survival after radiosurgery, who may be reasonable candidates forfurther clinical studies. Class 2 comprises the remaining patients who have a total treatment vol-ume > 7 cc and/or > 7 metastases who have a significantly poorer survival.

Extracranial tumoractivity determines survival after Gamma Knife radiosurgery for brain metastases OS10-2Patrick, Hanssens (1); Guus, Beute (2); Theo, Veninga (3); Suente, Lie (2); Koo, van Overbeeke (2); Danielle,Eekers (1) (1) Gamma Knife Center Tilburg - Radiation Oncology; (2) Gamma Knife Center Tilburg - Neurosurgery; (3)Gamma Knife Center Tilburg - Radiation Oncology Tilburg, The Netherlands

Objective: To evaluate survival and patterns of failure after radiosurgery for brain metastases(BM). Methods: 275 patients with BM were treated in our center between June 10, 2002 andJune 30, 2004. The majority (145/275) had BM from a NSCLC, the second and third most com-mon primary tumor being breast cancer (36/275) and renal cell cancer (28/275). 80% of thepatients had ¡Ü 4 BM. Treatment planning was based on T1 weighted MRI with triple dose gado-lineum. A dose of 18-25 Gy was prescribed to the isodose line encompassing ¡_ 90% of the tar-get volume. Radiosurgery was not combined with WBRT. Alle patients had follow-up MRI scansat 3 months interval until death or deterioration of their condition due to untreatable extracranialtumorprogression. If appropriate (no untreatable extracranial tumorprogression) , patients withrecurrent intracranial tumor activity received salvage treatment (either surgery, repeated radio-surgery or WBRT). Results: Median survival of the group is 6,96 months with 71% of the patientsdying due to extracranial progression. 29% of the patients died without clinical evidence ofextracranial progression. The median time to extracranial and intracranial progression is 4,6 and6,6 months respectively. Survival is significantly determined by onset and/or progression ofextracranial tumor activity and not by the number of metastases treated. Patients with KarnofskyIndex 100 without extracranial tumoractivity have a median survival of 22,3 months. The 1 and2 year local control rate of radiosurgically treated BM is 78% and 75% respectively. The overallintracranial tumor control rate is significantly determined by the number of metastases.Conclusions: gamma knife radiosurgery yield high local control rates. Survival after radiosurgeryis determined by extracranial tumoractivity. The number of BM determines the overall intracranialtumor control rate but not the survival, probably due to salvage treatment options in patientswithout untreatable extracranial tumorprogresion.

140

Page 143: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Diffusion magnetic resonance imaging as an early evaluation of the response of brain metastases treated by stereotactic radiosurgery OS10-3Chuan-Fu, Huang (1) (1) Chung Shan Medical University Hospital - GammaKnife Center Taichung, Taiwan

Objective: Conventionally, treatment response of brain tumors is observed by comparison ofsequential magnetic resonance imaging (MRI) or computed axial tomography (CAT), but it is rel-atively slow changing in volume and time consuming. This study utilized diffusion MRI to evalu-ate cellular changes of metastatic brain tumors treated with stereotactic radiosurgery (SRS) tosearch for a method to detect an earlier therapeutic response. Methods: We conducted a prospec-tive trial in 20 patients with 32 metastatic brain tumors treated by SRS with a 201 - source cobaltin our gamma knife center. Mean dose to tumor margin was 15.2 Gy (range 12-19.6 Gy). Allpatients received complete diffusion MRI before SRS, at 1 week, 1 month, and 3-month intervalsfollowing SRS. An apparent diffusion coefficient (ADC) map was calculated from echoplanar dif-fusion-weighted images and mean ADC values were compared with each other. MRI results andclinical outcome were evaluated at the same intervals. Results: ADC values for water of themetastatic tumors were 0.97 x 10-3 mm2/s ± 0.25 ´10-3. ADC significantly (P=0.009)increased 7 days after SRS continuing through the later one-month and 3-month interval follow-up period (p=0.0001). MRI results at 3-month intervals demonstrated stable or smaller tumorsize in all patients except 2, whose tumors had enlarged due to tumor necrosis. Enhanced MRIwas difficult to differentiate recurrence from radiation necrosis in those tumors, but ADC favorednecrosis due to the high values. One patient with tumor regrew at 15 months after treatment alsorevealed pretreatment ADC level at same time and rose after retreament. Conclusion: ADC valuesof brain metastases after SRS kept upward trend it can be used to predict the successful treatmentand differentiate radiation necrosis or recurrence.

Gamma knife radiosurgery alone as an alternative treatment for melanoma brain metastasis OS10-4Xavier, Muracciole (1); Jean, Regis (2) (1) CHU La Timone - Service de Radiotérapie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France

PURPOSE: To assess the control rate of melanoma brain metastasis (BM) treated with Gamma-Knife radiosurgery alone (SRS) the factors that predicted best survival using this strategy.PATIENTS AND METHODS: 241 intracranial melanoma metastasis in 106 patients were consecu-tively treated by GK between juanary 1993 and december 2003. Overall survival and brain-metastasis-free survival from the date of first GK were calculated using the Kaplan-Meyer method.Relevant factors affecting survival were considered for univariate analysis, and multivariate analy-sis with classification and regression tree models were performed and compared RPA, SIR andBSBM pronostic classifications. RESULTS: Median age was 56 years (range, 26-82 years). MedianKarnofsky index was 90. A total of 65 patients ( 61%) was treated for a single BM in which 18had no extracranial metastasis (17%), 20 for 2 BM and 21 3 BM. Only 14 patients were free ofhistory of extracranial metastasis. 80 patients presented an active extracranial metastasis at thetime of RS. 98 patients were classified in RPA class 2 and , 45 with SIR 6-7 and 78 with BSBM.

141

Page 144: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

The median tumor volume was 1.2 cm3 (range, 0.4-33.5). The median marginal dose and iso-dose were 25 Gy (range, 14-40 Gy) and 50% (range, 40%-70%), respectively. The median fol-low-up was 4 months, 46 patients were still alive 6 months after GK, 25 after 9 months and 14at 1 year. The 1-year local control (LC) for evaluated patients (54% of entire population) was 66%and 24/118 had recurred. The median distant brain metastasis-free survival and overall survivalwere 4 and 5 months respectively. Survival rate was 43% at 6 months, and 13% at 1 year. Inmultivariate analysis, Karnofsky Index > 90, absence of brain stem, central nuclei or cerebellumlocalisations, isolated and solitary BM, and SIR > 6 were independantly associated with a bet-ter survival rate. According to logistic regression, short term survival (> 6 months) was best pre-dicted by SIR > 6 (p=0.001) and solitary brain metastasis without other visceral metastasis(p=0.03). DISCUSSION : GK surgery alone obtained high local control as neurosurgery approach.Although prolonged survival is rare in this population, GK offered a significant quality of life inmost patients with melanoma BM. In our series, BM were a late event in metastatic melanomawith a very poor outcome. Initial RC alone was an effective treatment modality for cortical cere-bral melanoma BM and should be considered in patients with SIR >6. A new pronostic classifi-cation was established with 4 classes taking into account Karnofski index, age and BM location,with a better accuracy (AUC =0.712) than the others classifications.

MENINGIOMAS 1 OS11Chairmen: Hidefumi, Jokura; Robert, Smee Room Permeke &

Rembrandt

Hypofractionated stereotactic radiotherapy for benign meningioma OS11-1Michael, Dally (1); Louise, Gorman (1); Jeremy, Reuben (1); Robert, Myers (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia

Aim: To examine the safety and efficacy of hypofractionated stereotactic radiotherapy with refer-ence to one particular scheme in the treatment of benign meningioma. Total dose of between 35- 40 Gy in 15 fractions over 3 - 3.5 weeks were prescribed to the periphery of the tumour basedon traditional hypofractionated radiotherapy as used at the Christie hospital in Manchester.Methods: 40 patients with a total of 41 tumours were treated between May 1997 and May2004. The median dose prescribed was 37.5 Gy to the 80% isodose. Patients were followedprospectively with annual MRI and clinical assessment with mean and median follow-up of 35.4and 28.7 months respectively. Results: 11 males and 29 females of median age 55 years receivedtreatment. 16 tumours involving cavernous sinus and/or Meckel's cave and 17 involving thePetro-clinoid area were noted. Twenty-five patients had previously undergone a biopsy or partialresection. Two were treated after recurrence. The remaining 14 were diagnosed on radiologicalgrounds alone. Where histology was available, grade 1 histology was noted for except two withatypical features. Malignant tumours and Hemangiopericytoma were excluded. Clinical follow-upnoted no change or improvement in 33 patients. Temporary increase in speech and swallowingdisturbance was noted in one patient with radiological evidence of radiation necrosis. A tempo-rary worsening of V2 paraesthesia or diplopia were observed in two patients without associatedradiological changes. MRI scans showed no change in 29 patients, a reduction of tumour size in

142

Page 145: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

10. One patient had progression on MRI scan and received further treatment. Conclusion. Earlydata would suggest conventional hypofractionated radiotherapy schemes for benign CNS diseasemay be useful in conjunction with stereotactic techniques. Such schemes are attractive in termsof resource allocation and are an alternative to stereotactic radiosurgery where tumour size, posi-tion or cranial nerve tolerance is of concern.

Stereotactic radiosurgery and fractionated stereotactic radiotherapy for meningiomas related to the optic apparatus OS11-2Leonardo, Frighetto (1); Carlos, Mattozo (2); Alessandra, Gorgulho (3); Michael, Selch (4); Cynthia, Cabatan-Awang (3); Timothy, Solberg (4); Antonio, DeSalles (5) (1) University of California Los Angeles - Neurosurgery; (2) UCLA Medical Center - Neurosurgery; (3) UCLAMedical Center - Department of Neurosurgery; (4) UCLA - Radiation Oncology; (5) UCLA Medical Center -Neurosurgery Los Angeles, United States

Objective: To evaluate treatment outcomes of Stereotactic Radiosurgery (SRS) and FractionatedStereotactic Radiotherapy (SRT) for meningiomas related to the optic apparatus regarding tumorcontrol and optic toxicity. Materials and Methods: This study included 50 patients harboringmeningiomas related to the optic apparatus treated at UCLA. There were 37 females (74%) and13 males (26%). SRS was the treatment of choice in 15 (30%) and SRT in 35 (70%) patients. Themedian follow-up was 72 (6-141) and 44 (7-89) months respectively. The median dose for SRSwas 1600 cGy (1200-2000) prescribed to a median isodose line of 50%. A median dose of 4860cGy (2380-5040) prescribed to a median isodose line of 90%, was administered for SRT patients.Tumors were located with a maximal distance of 1.2 mm from the optic apparatus for patientstreated with SRT and 2.5 mm for patients treated with SRS. Results: Tumor control was 93.3% forSRS and 97.1% for SRT. One SRS patient (6.6%) recurred at 57 months of follow-up requiringmicrosurgery. A patient treated with SRT (2.8%) presented with recurrence at 38 months and wastreated with SRS. Side effects for SRS were limited to three patients (20%), one presenting withfacial hypoesthesia and two with decrease in visual acuity. A patient treated with SRS for a cav-ernous sinus tumor presented with a stroke related to carotid artery stenosis by the tumor. Twopatients submitted to SRT also presented with facial hypoesthesia and one complained of subjec-tive worsening of a previously existing diplopia. The overall rate of side effects for SRT was 8.5%.Visual improvement occurred in four patients (11.4%) in the SRT group. Conclusions: SRS and SRTwere both effective in providing tumor control. An absence of visual acuity complications and thecapability of visual improvement were observed when SRT was used for meningiomas related tothe optic structures.

143

Page 146: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Improvement in vision and other cranial neuropathies after stereotactic radiotherapy for the treatment of skull base meningiomas OS11-3Tracy, McElveen (1); Kathleen, Settle (1); Beverly, Downes (2); Maria, Werner-Wasik (1); Wally, Curran (1);David, Andrews (3) (1) Thomas Jefferson University - Radiation Oncology/Neurosurgery; (2) Jefferson Hospital for Neuroscience -Department of Neurosurgery Philadelphia, USA

Purpose: To evaluate the outcome of cranial neuropathies in patients treated with stereotacticradiosurgery for meningiomas in the anterior skull base. Patients and Methods: Two hundred andthirty nine patients were treated with fractionated stereotactic radiosurgery for meningiomas atthe Jefferson Hospital for Neurosciences between 1994 and 2002. Of these patients, 117 hadtumors located in the anterior skull base. All patients were immobilized using a GTC relocatableframe and underwent CT-MRI fusion for treatment planning. The mean target volume was 11.7cc(range 0.7 - 45.1cc). Patients were treated with a dedicated 6 MV linear accelerator using circu-lar collimators directed in noncoplanar arcs with an average of 2.6 isocenters (range 1 - 7). Dosewas delivered in 1.8 Gy fractions to a median cumulative dose of 54.0 Gy (range, 9.0 - 56.0 Gy),during a 5-week period. The median follow-up time was 32 months (range 7 – 96 months).Patients were examined and imaged with MRI during the first 3 months after receiving SRT andevery 6 months thereafter. Baseline cranial neuropathies were evaluated clinically and character-ized as stable, improved, resolved or progressive in the follow-up period. Pre- and post-radiother-apy serial radiographic evaluations, including MRI scans were compared to establish objectivetumor response and local control. Results: Fifty-two patients had deficits in visual fields or acuitythat were associated with their tumors and potentially reversible with treatment. At the latest fol-low up, eleven patients (21%) had a stable visual examination as measured by refraction, nearcard evaluation, confrontation or automated perimetry. Twenty-seven patients (52%) had docu-mented improvement in vision, and three patients (6%) had complete resolution of all visualdeficits. The median time to visual improvement or resolution was 52 weeks by hazard plot.Seven patients (13%) experienced progressive vision loss after treatment, five of which corre-sponded to radiographic tumor progression. Six patients were lost to follow-up and visual out-comes are therefore unknown. Fifty-nine patients had cranial neuropathies, which did not involvethe optic nerve. Of these, 18 patients (31%) had stable symptoms, 15 patients (25%) hadimprovement in their deficits and 11 patients (19%) had complete resolution of all cranial neu-ropathies. These results demonstrate a 68% chance of cranial nerve improvement by cumulativehazard plot. Nine patients (15%) had progressive cranial nerve findings, five of which were attrib-uted to progressive disease. Complete serial MRI evaluation was available on 107 patients andrevealed stable disease in 88 patients (82%). Twelve patients (11%) showed tumor regressionoccurring at a median time of 52 weeks (range 12 - 261). Seven patients (6%) had radiographicprogression of the treated lesion. Local control was 94% in our series. Conclusion: This reportincludes one of the largest series of anterior skull based meningiomas and confirms that fraction-ated stereotactic radiotherapy is a safe and effective treatment modality. Patients with tumor-asso-ciated cranial neuropathies have a high likelihood of improvement in their symptoms within thefirst year of treatment. Stereotactic radiotherapy provides excellent tumor control and offerspreservation or improvement of function to patients with tumors in these challenging locations.

144

Page 147: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Optic nerve sheath meningiomas. The role for stereotactic radiotherapy OS11-4Robert Ian, Smee (1); Margaret, Schneider (1); Janet, Williams (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia

PURPOSE: Primary orbital meningiomas are rare, the usual site of origin being the optic nervesheath. These represent 1-2% of all meningiomas. This is a review of a single centre’s experience.MATERIALS AND METHODS: Between 1990 and February 2004 27 patients were referred and 17patients were treated by radiotherapy (mean age 51 years). This retrospective study evaluated 17patients – 18 tumours (1 patient with NF2 had bilateral optic nerve tumours). Nine patients weretreated with newly diagnosed lesions, and 8 recurrent after prior treatment including radiothera-py for 2 patients. The median duration of symptoms to onset was 2 months. Treatment consist-ed of SRS (median dose 20Gy) where vision was not a consideration, and fractionated SRT (medi-an dose 5040Gy in 28fx) for vision preservation. RESULTS: Median follow up is 46.8 months.Each recurrence after SRT occurred in 1 patient leading to progressive disease and blindness, thisnew lesion was treated with SRS, the tumour controlled with subsequently some vision improve-ment. Only one other patient had progressive disease, thus for an ultimate local of 94%. For frac-tionated patients only the above patient had worse vision after treatment. CONCLUSION:Radiotherapy provides high local control, utilising fractionated treatment provided it covers thefull length of the nerve, is necessary to have the option of preserving vision.

PHYSICS – GENERAL OS12Chairmen: Frank, Bova; Stephan G., Scheib Room Willumsen

Stereotactic IMRS for intracranial tumours OS12-1Robert Ian, Smee (1); Margaret, Schneider (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia

PURPOSE: There is a size limit to the lesions that can be treated by SRS. To investigate whetherusing a MMLC will enable larger lesions to be treated in a single fraction. MATERIALS AND METH-ODS: Intensity Modulated Radiotherapy enables the definition of dose limiting structures, creat-ing a safer dose hierarchy relative to the tumour being treated. Sharper conformity provided byMMLC defines tumour borders, and thus can be used to exclude normal tissue. These two con-cepts can be wedded to provide single dose treatment for lesions too large for FRS. A rigid QAsystem is required to assure accuracy and precision. Over the last 3 years of 290 patients havingSRS, this was delivered as IMRS in 32. The conditions treated were: meningioma 25, pituitary 3,AVM 2, Others 2 with a median dose of 14Gy. Median diameter was 3.5cm and the volume15.4ccm. The only extra step was the QA procedure developing the fluence maps, with mediantreatment time of 25 minutes for 4000 monitor units. This is given as multiple fixed fields. Theprocedure itself was tolerated well with no added untoward side effects other than increased like-lihood of hair loss. All the meningiomas were controlled with no cranial nerve or brain stem relat-ed deficit. One of the 2 AVMs treated was obliterated after 2 years follow up. CONCLUSION: Largeintracranial tumours may be able to be treated as a single fraction, to give local control and lowmorbidity, using IMRS.

145

Page 148: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Monte Carlo simulation for gamma knife radiosurgery using the Grid OS12-2Vasu, Ganesan (1); Rami, Mehrem (2); John, Fenner (2); Lee, Walton (1) (1) University of Sheffield - Department of Medical Physics and Clinical Engineering; (2) Royal HallamshireHospital - National Centre For Stereotactic Radiosurgery Sheffield, United Kingdom

Objective: To validate the viability of the GRID resource for the Monte Carlo simulation of gammaknife radiosurgery plans. Introduction: Grid Enabled Medical Simulation Services (GEMSS) was aproject developed by the European Union to validate the application of a Grid of powerful com-puters for the solution of complex medical computational problems. The GRID contains about 70processors placed in Austria and Germany for the GEMMS applications. As one such application,Sheffield Teaching Hospitals in collaboration with Sheffield University tested the grid for the sim-ulation of gamma knife Dosimetry using Monte Carlo techniques. Materials and Methods: LeksellGamma-Plan (LGP) the commercially available system for calculating the treatment plans gives adose distribution with an assumption of a homogeneous medium using a simplistic algorithm.Monte Carlo techniques provide a more robust solution and will ultimately enable the incorpora-tion of in-homogeneity corrections (although for the purposes of this work a homogeneous medi-um is assumed presently). A Monte Carlo code called RAPT (Radiotherapy Application for ParallelTechnology) code was used to simulate the beams of each of the 4 collimator sizes 4,8,14 and18 mm of the Gamma knife. The dose distribution of a single collimator helmet (201 beams) pro-duced by a Leksell Gamma plan was compared with the Monte Carlo RAPT produced ones.Software was developed using MATLAB to simulate the patient’s head from the skull radii meas-ured using the bubble-head. This software enabled actual plans including single isocentre shots,multiple isocentric treatment plans, plans with combination of several collimator helmets andplans with plugging patterns. A Graphical User Interface (GUI) was developed using MATLAB tocompare the treatment plans made by RAPT and LGP. The GUI gives a facility of overlaying andcorrelating the isodoses patterns produced by RAPT and LGP in all the three planes (Axial, coro-nal and sagittal). Also the treatment times were calculated and compared with the LGP treatmenttimes. A study was made to optimise the no of photons required for the simulation. About 2-3million photons per beam were used for the simulation. Results and Discussion: The GUI givesan excellent correlation of the isodoses produced by RAPT and LGP. A Monte Carlo simulation,which takes several hours with a single processor, was reduced using the GRID to less than anhour. It was found that 3 million photons will be required to simulate the 201 beams. And whensome sources were made plugged, the number of photons was increased to compensate the flu-ence. About hundred actual radiosurgery treatment plans were compared with the RAPT pro-duced plans and found to be in very good agreement.

Artificial Droplets improves radiation dosimetry of IMRT OS12-3Kevin, Khadivi (1); Robert, Comiskey (2); Timothy, Klapproth (3); Craig, Hansen (3) (1) Mercy Medical Center - Radiation Oncology; (2) Radionics, a division of Tyco HealthCar - Engineering; (3)Mercy Medical Center - Radiation Oncology Springfield, USA

In an inverse-planned IMRT the judicious use of dose constraints in a “fake structure” minimizesdose to a sensitive structure. However, the shielding effect of the fake structures could adversely

146

Page 149: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

influence the dose coverage of the target. Artificial Droplet is a new technique that improvesdosimetry of IMRT. XKnife TM RT was used to test phantom and clinical cases in Linac-basedstereotactic radiation therapy planning. Instead of using a solid structure as a fake, the treatmentplanner would use a mesh structure, i.e., artificial droplets, with appropriate dose constraints.This approach provides shielding of the sensitive structure, e.g., cord, parotids, while permittingpencil beams to penetrate through the “droplets” and reach parts of the planning target volumethat would have seen considerably less primary beam radiation. Further, the different sizes of thedroplets may be spread at different distances to various drawn structures to promote a relocationof undesired radiation hot spots. The influence of pattern (i.e., degree of divergence of the meshlines), size, and population density of the droplets have been studied. Moreover, the dosimetricresponse of different algorithm platforms to artificial droplets will be presented. The results ofphantom studies and clinical cases demonstrating the favorable dosimetric influence of the artifi-cial droplets in complex head and neck IMRT will be presented.

Standardization for CyberKnife Beam Dosimetry OS12-4Hidetoshi, Saitoh (1); Toru, Kawachi (2); Mitsuhiro, Inoue (3); Atsushi, Myojyoyama (4); Tatsuya, Fujisaki (5);Shinji, Abe (5); Kimiaki, Saito (6) (1) Tokyo Metropolitan University of Health Sciences - Graduate School of Health Sciences; (2) TokyoMetropolitan University - Graduate School of Health Sciences; (3) Midori Kai Neurosurgery Hospital -Yokohama CyberKnife Center; (4) Tokyo Metropolitan University - Graduate School of Health Sciences; (5)Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences; (6) Japan AtomicEnergy Research Institute - Health Physics Tokyo, Japan

Purpose: In Japan, the number of the CyberKnife systems is increasing significantly for severalyears, and extracranial cancer might be a target before long. The CyberKnife system has uniquetreatment head structure and beam collimating system. Therefore the global standard dosimetryprotocols have not been applied. To standardize dosimetry protocol, standard conditions ofdosimetry, beam quality index and beam quality conversion factors were proposed. A summaryof standard dosimetry protocol for CyberKnife beam in Japan will be reported. Methods andMaterials: To obtain standard and variance, depth dose distributions of CyberKnives were inves-tigated. Then energy spectra of x-ray beams which agreed with the actual depth dose distribu-tions were simulated with conscientious geometry using OMEGA BEAMnrc code system.Furthermore, mean restricted mass stopping power and mass absorption coefficient for air, waterand several wall materials were computed for CyberKnife beam. As a result, the relation betweenbeam quality factor for several ionization chamber and TPR20,10 as beam quality index weredetermined. Results: In spite of absence of beam flattening filter causes softer photon energyspectra and smaller field than ordinary Linacs, the beam quality conversion factors were approx-imately similar as ordinary 6 MV Linacs. Field by 6 cm collimator was recommended as the refer-ence field because flat range of off-axis ratio was narrow.

147

Page 150: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ORAL SESSIONS 11h30 - 12h30

BRAIN METASTASES 2 OS13 Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation

Hypofractionated stereotactic radiotherapy for brain metastases not amenable to radiosurgery OS13-1Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Oliver, Ganslandt (1); Rudolf, Fahlbusch (1); Rolf, Sauer (1);Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation OncologyErlangen, Germany

Purpose/Objective: Primary therapy for brain metastases (mets.) is surgical resection followed bywhole brain radiotherapy (WBRT) or radiosurgery (RS) w/o WBRT. Nevertheless, in case of mets.located in eloquent regions, high volume, number >2, irregular contrast enhancement, thesetherapies may either not be practicable or not promising good results. This study evaluated radi-ological/clinical side effects and response to hypofractionated stereotactic radiotherapy (hfSRT) formets. not amenable to surgery or RS. Materials and methods: From 1/2003 to 2/2005, 51 pts.with 72 mets. received either 5x6 Gy hfSRT plus WBRT (n=44 mets.) or 5x7 Gy without WBRT(n=28 mets.), prescribed to the 90%-isodose. Patient positioning and isocenter verification wasdone by ExacTrac at the Novalis System (BrainLAB, Heimstetten, Germany). Maximum number ofmets. was 4 in 2 pts.. 16 mets. were irradiated by static beam, all others by dynamic conformalarc treatment. Results: Median FU is 7.2 mos..RTOG-quality assurance criteria were in all casesfullfilled with a median homogeneity, conformity index of 1.12 and 1.22 and a median coverageof 99%, respectively. Cause of death was brain failure in 27%, extracranial failure in 18%. 55%are alive or died due to other causes than tumor until last follow up. Brain-specific-survival/over-all-survival at median FU are 71% and 68%, respectively. The only significant parameters influ-encing both kinds of survival were gross tumor volume (GTV) and planning target volume (PTV)with a positive influence of GTV < 6 cc and PTV < 13 cc. Response of metas-tases was as fol-lows: no change 12.5%, partial response 18.1%, complete response 66.7% and progressive dis-ease 2.8%. Side effects as necrosis, increase in edema and time of steroid medication after hfSRTwere influenced by the volume of normal brain treated > 4 Gy / fx. Conclusions: HfSRT is aneffective treatment for large volume and ring enhancing metastases regardless their histology.Significant factors influencing survival are GTV and PTV. Side effects significantly correlate with theirradiated volume of normal brain tissue above 4 Gy per fraction.

148

Page 151: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Response rate and biologically effective dose correlation in stereotactic irradiation of adenocarcinoma brain metastasis OS13-2Filippo, Grillo-Ruggieri (1); Paolo, Cavazzani (2); Massimo, Cardinali (3); Giovanna, Mantello (4); Stefania,Maggi (5) (1) Ospedali Galliera - Radioterapia; (2) Ospedali Galliera, Genova, Italy - Neurochirurgia; (3) Ospedali Riuniti,Ancona, Italy - Radioterapia; (4) Ospedali Riuniti, Ancona, Italy - Radioterapia; (5) Ospedali Riuniti, Ancona,Italy - Fisica Sanitaria Genova, Italy

Purpose. To compare Biologically Effective Dose (BED) and response rate in stereotactically irradi-ated adenocarcinoma brain metastasis. Material and Methods. 55 patients, 36 male, 19 female,64 years (44-79), ECOG P.S. >= 60, with 67 MRI staged adenocarcinoma brain metastasis weretreated using the same treatment planning system (Plato), 6 MV beam energy from Varian 2100C/D linac, conical tertiary collimation with 10 mm (4 lesions), 15 mm (7), 20 mm (9), 22.5 mm(2), 25 mm (15), 27.5 mm (3), 30 mm (20), 35 mm (6) and 40 mm (1) diameters at isocenter,fixed or relocatable Leksell type frame, 4 to 6 arcs and prescribed isocenter dose with at least 90%isodose covering the PTV. The only main difference has been single dose (34 pts) versus fraction-ated dose (21 pts) stereotactic irradiation. Results. Total Doses from 16 to 25 Gy, transformed intoLinear-Quadratic Model BED ( with 10 as alfa/beta ratio value for tumor), resulted into BED dosefrom 22,5 to 87,5 Gy10. In 61 lesions, evaluable with CE CT at three months follow up, BED <60Gy10 (fractionated) resulted into 1 CR, 7 PR, 8 SD, 1 PD, while, after 60 Gy10 and > 70 Gy10single fractions, 6 CR, 12 PR, 2 SD, 2 PD and 9 CR, 9 PR, 3 SD, 1 PD were obtained, respective-ly (P = 0.014). Conclusions. Pretreatment BED calculation could be used to increase the physicaldose of fractionated stereotactic treatments to BED equivalent to single fractions, in order toprospectively achieve the same response rate, using a non invasive relocatable frame with betterpatient comfort.

Gamma knife surgery for large metastatic brain tumors to avoid developing to severe peritumoral edema OS13-3 Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1);Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan

Rationale: In Gamma knife surgery (GKS), metstatic brain tumor is the most common indicationin Japan. Majority of patients with metastasis maintained highly QOL even though a few dayshospitalization. However, not few patients with large metastatic brain tumor experienced postop-erative complication, severe radiation injury, after GKS based on an inadequate dose planning. Tothe purpose of keeping patients’ QOL, we prefer not to perform over-irradiation to the surroundnormal brain tissue. Methods: We treated 542 cases with brain metastasis with GKS using modelC-APS for these 2 years (since Jan 2003). We did use 16-24Gy, which was determined on tumorvolume, as a prescription dose at 50% isodose. Our treatment strategy was tumor covering withhighly conformity and homogeneity, in addition no putting each isocenter on the outer side oftumor edge. We calculated energy (mJ), unit energy (mJ/cc), and average dose (Gy) in both tumorand surround brain tissue for each patient. Results :Local tumor control rate was observed in97.2% (527/542). 8.9% (48/542) of the patients experienced radiation injury, and 1.1% (6/542)

149

Page 152: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

of them developed radiation necrosis. On the other hand, prior to this methodology, radiationinjury was observed in 16.7% in our institute on between Jan and Dec in 2002. The most impor-tant matter is that unit energy of surround brain tissue should be decreased as much as possible(< 7.0mJ/cc). Conclusions: We supposed the optimal dose planning for large metastatic tumorsand evaluated clinical results taking account for patients’ QOL. Radiosurgery is not radiation ther-apy, so that we should pay attention to the location of each isocenter keeping not beyond to thesurround normal barin tissue.

Gamma knife surgery for metastatic brain tumors from lung cancer OS13-4Toru, Serizawa (1); Yoshinori, Higuchi (2); Shinji, Matsuda (3); Junichi, Ono (4); Makoto, Sato (5); Toshihiko,Iuchi (6); Osamu, Nagano (7); Naokatsu, Saeki (8) (1) Chiba Cardiovascular Center - Department of Neurosurgery; (2) Chiba Cardiovascular Center - Departmentof Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurology; (4) Chiba Cardiovascular Center- Department of Neurosurgery; (5) Chiba Cardiovasucular Center - Department of Radiology; (6) Chiba CancerCenter - Division of Neurological Surgery; (7) Graduate School of Medicine, Chiba University - Department ofNeurological Surgery; (8) Graduate School of Medicine, Chiba University - Department of NeurologicalSurgery Chiba, Japan

Purpose: This study was deigned to evaluate results of a local treatment protocol using gammaknife surgery (GKS) for brain metastases from lung cancer. Materials and Methods: Among 659cases with brain metastases from lung cancer treated with GKS at Chiba Cardiovascular Centerfrom 1998 through 2004, 608 consecutive patients who satisfied the following 4 criteria wereanalyzed: 1) no prior whole brain radiation therapy (WBRT), 2) a maximum of 5 tumors with adiameter of >=20 mm; 3) no cerebral dissemination (<=25); 4) no large (>35 mm) tumors.All lesions were treated with GKS without upfront WBRT. New distant lesions, detected with fol-low-up MRI every two to three months, were appropriately re-treated with GKS. Overall survival(OS), neurological survival (NS), qualitative survival (QS) and new lesion-free survival (NLFS) werecalculated and the prognostic values of the covariates were obtained. Results: In total, 1204 sep-arate sessions were required to treat 6427 lesions. Median OS period was 8.9 months. In multi-variate analysis, significant prognostic factors for OS were systemic control (risk factor: uncon-trolled), initial KPS score (<70) and gender (male). NS and QS at 1 year were 88.6% and 81.3%,respectively. The only significant poor prognostic factor for NS was carcinomatous meningitis(CM). Lack of systemic control, poor KPS and CM were significant factors influencing QS. NLFS at6 months and 1 year were 72.5% and 47.4%. Three hundred seventy-six (62%) patients did notrequire salvage treatment. WBRT was employed in 8 (1.3%) for cerebral dissemination. Patientswith numerous (>10) tumors had a significantly poorer prognosis than those with <=10.Conclusion: Our local protocol, aggressively applying GKS, provides excellent results in selectedpatients with <=10 brain lesions and no CM.

150

Page 153: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

MENINGIOMAS 2 OS14Chairmen: Hidefumi, Jokura; Robert, Smee Room Permeke &

Rembrandt

The role of radiosurgery in the management of petroclival meningiomas OS14-1Dong Gyu, Kim (1); Chul-Kee, Park (1); Hyun-Tai, Chung (1); Sun Ha, Paek (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

INTRODUCTION. Experience with the management of petroclival meningiomas was analyzed toevaluate the optimal role of radiosurgery. METHODS. The records of 61 patients with petroclivalmeningioma were reviewed. Their mean age was 46.2 years. The population was divided into asurgery group (n = 49) and a radiosurgery group (n = 12). In the surgery group, the mean vol-ume of the tumor was 46.9cc (range 5.2-235.8). The tumor was completely resected in 10patients. Eleven of the 39 patients with incomplete resections sequentially underwent adjuvantradiation therapy or radiosurgery. The median follow-up period was 86 months (range 48–210).The radiosurgery group was treated with gamma knife surgery. The mean volume of the tumorwas 5.46cc (range 2.1-17.2) and the median follow-up period was 52 months (range 48–71).Management outcomes were evaluated with respect to tumor control rate, neurological deficitand functional status. RESULTS. In the surgical group, 11 patients (22.4%) eventually showedtumor progression. However, there was only one recurrence if adjuvant therapy was used afterincomplete removal. The incidence of favorable outcomes for cranial neuropathies and function-al status were better in the incomplete resection group (69.2% and 76.9%) than for patients inthe complete resection group (20% and 30%) significantly (p=0.032 and p-0,049). Besides, thedisease was stable in all patients of radiosurgery group during the follow-up period, with func-tional status and cranial nerve function perfectly preserved in these patients. CONCLUSIONS.Because the growth rate of petroclival meningioma is low and good functional status can beguarantied, incomplete resection of large tumor should be considered as an acceptable treatmentoption. And adjuvant radiosurgery is useful in the control of residual tumors. Radiosurgery mayalso be appropriate as the primary treatment in small tumors. The selection of treatment shouldtake into consideration the quality of life of the patients, as well as tumor control.

Gamma knife radiosurgery for cavernous sinus meningiomas - ten year follow-up period OS14-2Martina, Stippler (1); John, Lee (2); John C, Flickinger (3); Douglas, Kondziolka (3); L. Dade, Lunsford (4) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) Hospital of the University ofPennsylvania - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of NeurologicalSurgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA

Introduction: The long term results after gamma knife radiosurgery for benign cavernous sinusmeningiomas remain controversial. The authors retrospectively reviewed their experience withthose patients who had a minimum of ten years possible follow-up. Methods: Eighty-one patientswith cavernous sinus meningiomas were treated at the University of Pittsburgh from 1987 to1995. Three patients were lost to follow-up. 49 patients (62%) had a prior craniotomy. Results:

151

Page 154: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

The median age for group at time of radiosurgery was 56 years (range 12-87 years). Fifty-ninepatients (73%) were female. The median tumor volume was 6.5 cm3, and the median marginaldose was 15Gy. The median neuroimaging follow-up period for these patients was 79 months(range 2-169 months). Four patients have demonstrated increases in the size of their tumor,resulting in an overall actuarial tumor control rate of 96 ± 2.6% at five years and 85 ± 8.1% atten years. Three of the four imaging-documented treatment failures occurred in patients who hadprior craniotomies. The ten year actuarial tumor control rate in patients who have not had priorcraniotomy is 96 ± 4.1%. Conclusion: Gamma knife radiosurgery is an effective procedure forpatients with cavernous sinus meningiomas. The long-term results demonstrate a favorable con-trol rate with minimal complications.

Gamma knife radiosurgery of skull base meningiomas OS14-3Roman, Liscak (1); Aurelia, Kollova (2); Vilibald, Vladyka (3); Gabriela, Simonova (1); Josef, Novotny Jr. (4) (1) Hospital Na Homolce - Stereotactic Neurosurgery Department; (2) Royal Hallamshire Hospital - NationalCentre For Stereotactic Radiosurgery; (3) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery; (4)Hospital Na Homolce - Medical Physics Department Prague, Czech Republic

Meningiomas are the most frequently treated benign tumors by gamma knife radiosurgery andthe majority of them are located on the skull base. Between 1992 and 1999, 197 skull base-located meningiomas in 192 patients were treated by gamma knife in Prague. Contact with thechiasma or optic tract was not regarded as a contraindication for gamma knife radiosurgery andthis contact was observed in 32% of the skull base meningiomas treated. 176 patients weremonitored for a median of 36 months, of whom 73% showed a decrease in tumor volume, nochange was observed in 25% and continued growth was observed in 2%. Neurodeficit improvedin 63% of patients, temporary morbidity occurred in 11% and persistent morbidity remained in4.5%. Radiosurgery induced edema in 11%. Significantly lower edema occurrence was observedafter radiosurgery in patients with no history of edema prior to radiosurgery, where the tumorwas located in the posterior skull base and where the dosage to the tumor margin was lowerthan or equal to 14 Gy. Radiosurgery of skull base meningiomas has been proven to be safe andefficient. We consider gamma knife treatment for skull base meningiomas to be the method ofchoice whenever tumors are within the volume limits and there is no need for an urgent decom-pressive effect from the open operation.

Linac radiosurgery for the management of cavernous sinus meningiomas OS14-4Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

Introduction: The authors retrospectively reviewed their 5-year experience to evaluate the effica-cy of stereotactic Linac radiosurgery in patients with cavenous sinus meningiomas. Methods:Between July 2000 and September 2004, 63 patients with meningiomas were treated with linacradiosurgery at La Floresta Medical Institute. Twelve patients had cavernous sinus meningiomas.The median age for the subgroup was 46.5 y.o. (range 21 to 67 years). There were 9 women and3 men. Two patients underwent partial surgical removal procedures. A mean radiation dose of

152

Page 155: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

14.22 Gy was delivered to the tumor margin. The median follow-up was 33.2 months (range 8to 57 months). Results:Tumor control was achieved in all of the patients. Treatment-related com-plications included only one case with moderate facial hypoesthesia in V1 distribution. No othercomplications were noted. Improvement of existing cranial neuropathies was observed in 4patients (25%). There is no mortality as a consequence of the treatment. Conclusions: Linac radio-surgery is a safe and effective procedure for patients with cavernous sinus meningiomas offeringan excellent control for residual or recurrent tumors as well as for previously non-treated tumors.

PHYSICS - LEAKAGE OS15Chairmen: Stephan G, Scheib; Stéphane, Simon Room Willumsen

Measurement of the exit dose to the neck from intracranial stereotactic radiotherapy, using the M3 mini MLC OS15-1 Dror, Alezra (1); Janna, Menhel (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel

Introduction: The purpose of this study was to measure the exit dose to the neck from intracra-nial stereotactic radiation delivered using the BrainLab M3 mini MLC. The dose to the surface ofthe larynx was measured in-vivo in patients treated with either single fraction radiosurgery (SRS)or fractionated stereotactic radiotherapy (FSR). 4 to 5 conformal arcs were used to deliver SRSdoses ranging from 13 Gy up to 20 Gy, FSR total doses were 50.4 Gy delivered in 28 fractions of1.8 Gy. An ionization chamber was used to record the dose to the larynx. This dose was meas-ured above the larynx in order to represent the maximum dose to the thyroid gland which is theorgan most likely to develop long term toxicity from the radiation. Additional studies were carriedout with a phantom. Results: A significant difference was found in the exit dose to the larynx.This was more dependent on field size (jaws positions) and less on other parameters such asisocenter position and arc arrangement. The exit dose to the larynx is increasing significantlywhen the field size is 6x6 cm or larger. The dose to the larynx can change from 0.3% of the totaldose in smaller fields to 2.5% in field’s larger then 6x6 cm. That relationship can be described bya simple function that estimates the exit dose to the neck. Conclusion: When planning single frac-tion stereotactic radiosurgery in which field sizes are usually below 5 x 5 cm the exit dose to thelarynx and thyroid is usually below 0.3%, On the other hand when planning stereotactic fraction-ated irradiation where the field size is often significantly greater the use of a sagittal arcs whichmay exit through the neck and thyroid gland should be avoided in order to minimize the risk ofhypothyroidism and radiation-induced malignancy, particularly in younger patients.

153

Page 156: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Dosimetry of thyroid, parotid and ovarian glands in patients undergoing Gammaknife radiosurgery OS15-2Mahmoud, Allahverdi (1); Aliakbar, Sharafi (2); Alireza, Nikoofar (3); Hadi, Hassanzadeh (4) (1) Tehran university of medical sciences - Cancer institute,radiotherapy physics; (2) Iran Medical Science OfUniversity, Ali Asghar Hospital - Iran Gamma Knife Center; (3) Iran university of medical sciences - MedicalPhysics; (4) Iran university of medical sciences - Medical Physics Tehran, Iran

The purpose of this study was to indentify the dose delivery to the parotid,ovaries and thyroidglands during the Gammaknife radiosurgery procedure. A three-dimensional,anthropomorphicphantom was developed using natural human bone material,paraffin and sodium chloride as theequivalant tissue.The Phantom was composed of a body,head and neck and hip.In the naturalplaces of thyroid ,parotid (bilatreal sides) and the ovaries(midline ) some cavities were made toplace the thermoluminescence dosimeters(TLDs). Three TLDs were inserted in a batch (probe) with1cm space between the TLDs and each batch was instered into a single cavity. The final depth ofTLDs was 3 cm from the surface for parotid and thyroid and was 15 cm for the ovarianglands.Similar probes were placed superficially on the phantom. The phantom was gamma irra-diated using Leksell model C Gammaknife unit .Subsequently ,the same probes were placedsuperficially over thyroid ,parotid and ovaries in 12 patients who were undergoing radiosurgerytreatment for brain tumors.The mean dosage for treating these patients was 15.8 Gy in the 50%isodose curve. There was no signficant difference bwtween the superficial and deep probes in thephantom studies.The mean delivery dose to the parotid ,thyroid and ovaries in human subjectswas 15.3 ± 8.9cGy ,9.2± 4.4 cGy and 0.6 ±0.3 cGy ,respectively. The data can be used in deci-sion making for special clinical situations such as treating pregnant patients who need radio-surgery for eradication of brain tumors.

In vivo estimation of extracranial doses in stereotactic radiosurgery with the gamma knife and Novalis systems OS15-3Thierry, Gevaert (1); Dirk, Verellen (2); Stéphane, Simon (3); Françoise, Desmedt (1); Bob, Schaeken (4) (1) Hôpital Erasme - Centre Gamme Knife; (2) AZ VUB - Physique; (3) Institut J. Bordet - Physique; (4) AZMiddelheim - Physique Brussels, Belgium

OBJECTIVE: The purpose of this work is to investigate the extracranial doses in vivo duringintracranial treatments comparing the gamma knife-system with the Novalis-system for the samepathologies. The analysis is limited to single fraction stereotactic radiosurgeries. METHODS:Measurements were performed with TL dosimeters positioned on the lateral canthus, thyroid,breasts and gonads to obtain the dose received to these anatomical regions. Based on theseobservations, an estimate of the risk for cancer induction and detriment will be proposed. Themeasured doses were normalised to 24 Gy, and the influence of target maximum dose, referenceisodose volume, equivalent treatment time (which is related to the activity of the cobalt-60sources for the gamma knife) and distance on extracranial doses are analysed. RESULTS: The aver-age extracranial dose with a normalised prescription dose of 24 Gy is comparable for bothmachines.Gamma knife: For the lateral canthus, thyroid, breast and gonads the median doseswere 435, 103, 47, and 5.9 mGy, respectively. Novalis: For the lateral canthus, thyroid, breastand gonads the median doses were 233, 83, 45 and 2.8 mGy, respectively. For the gamma knife-

154

Page 157: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

system as well as the Novalis-system no correlation could be found between maximum dose, ref-erence isodose volume and extracranial doses. On the other hand for the gamma knife-systemthe equivalent treatment time and distance have a significant influence on doses received onextracranial sites. For the Novalis-system only the distance and the geographical placement of thearcs will influence the extracranial dose. CONCLUSIONS: Doses to extracranial sites are small,ranging from 1,4 % of the prescribed dose (24 Gy) for the lateral canthus to 0,02 % for thegonads for the gamma knife and in the range of 0,97 % of the prescribed dose (24 Gy) for thelateral canthus, to 0,01 % for the gonads for the Novalis. According ICRP-60, the risk for cancerinduction after a radiosurgical treatment is estimated to about 0,2 % for both the gamma knifeand Novalis systems; the risk for detriment is estimated at 0,3 % for both systems. Although theserisks are very small, they must be kept to a minimum value for long life expectancy patients, bychoosing the appropriate treatment strategy.

155

Page 158: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Wednesday 14/09/05

PLENARY SESSION 8h45 – 10h00

PS3Room Nation

DATA BLITZ UPDATE 3Brain Metastases PS3-1Minesh, Mehta

DATA BLITZ UPDATE 4Physics PS3-2Frank, Bova

COMPARATIVE TECHNOLOGIESChairmen: Minesh, Mehta; Frank, Bova

Patterns of practice in a radiosurgery center equipped with both gamma knife and Linear Accelerator PS3-3Robin, Stern (1); Julian, Perks (1); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation OncologySacramento, USA

Purpose: Due to the fundamental differences in treatment delivery, Linear-accelerator-based radio-surgery can be complementary to gamma knife for intracranial lesions. We reviewed the effect ofadding gamma knife to an existing Linac-based radiosurgery practice and analyzed case selec-tions for the two modalities. Material and Methods: UC Davis Medical Center installed a Leksellgamma knife Model C in October 2003 to supplement an established Linac-based radiosurgeryprogram. Radiosurgery indications for the 15 months before and after installation were com-pared. Results: Radiosurgery cases expanded by two-fold from sixty-eight patients before gammaknife installation to 139 after, with 106 treated by gamma knife and 33 by Linac. Besides a majorincrease for trigeminal neuralgia and a general growth for acoustic neuroma, meningioma andbrain metastases, case numbers for glioma and AVM remained stable. Considering case selec-tions for Linac, glioma decreased from 28% to 18%, while meningioma and metastases increasedfrom 9% to 24% and 38% to 46%, respectively. The Linac patients receiving fractionated treat-ment also increased from 37% to 61%. Conclusions: While the majority of patients were treatedwith gamma knife, a significant proportion was judged to be suited for Linac treatment. This lat-ter group included particularly patients who benefit from fractionated therapy. The availability ofboth delivery modalities accommodates the full range of intracranial stereotactic indications andallows treatment technique to be tailored to the individual patient's needs.

156

Page 159: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

The Rotating Gamma System GammaART-6000: A review of the first 100 patient treatments PS3-4 Tomasz K., Helenowski (1)(1) Stereotactic Radiosurgery Institute - NeurosurgeryGurnee, USA

The GammaART-6000 Rotating Gamma System has been in use at the Rotating Gamma SystemInstitute in Gurnee, IL, USA, for over a year. The first 100 cases treated with the system are dis-cussed. Treatments for benign tumors, malignant tumors, and trigeminal neuralgia have beenperformed with this new technology.

Interstitial stereotactic radiosurgery PS3-5Christopher, Ostertag Freiburg, Germany

ORAL SESSIONS 11h30 – 12h30

FUNCTIONAL RADIOSURGERY 1 OS16Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation

Radiosurgery of cavernous malformations associated with intractable seizures OS16-1Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan

Since the installation of gamma knife in 1991, we have treated 147 cases of symptomatic cav-ernous malformations(CMs) with radiosurgery. Among them there are 25 cases of CM associatedwith intractable seizure, which occurred more than twice a week. Complex partial seizures werepredominant and followed by simple partial seizures. The mean age of the patients was 30.4years. Almost all the lesions are located supratentorially, chiefly in temporal and frontal lobes. Themean diameter of lesions was 16 mm and the lesions were treated by gamma knife with themean maximum dose of 31.4 Gy and mean marginal dose of 17.3 Gy. In the mean follow-upperiod of 49 months, seizures disappeared in 7, considerably decreased in 7, and unchanged in10. Meanwhile 11 lesions decreased and 14 were unchanged in size on follow-up MRIs. Fourcases were operated on because of hemorrhage (2) and uncontrollable seizure(2). In conclusion,seizures associated with supratentorial CMs are improved after the radiosurgery in a half of thecases. Since the seizure focus which is available with MEG are always outside and adjacent tothe lesions, these informations should be incorporated into the planning of radiosurgery in orderto improve the seizure outcomes.

157

Page 160: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Gamma knife radiosurgical thalamotomy for essential tremor: a six year experience OS16-2John, Lee (1); Joseph, Ong (2); Douglas, Kondziolka (3) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center -Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Department of NeurologicalSurgery Philadelphia, USA

INTRODUCTION: Essential tremor is the most common adult movement disorder. Those affectedare often forced to change jobs or retire early, since symptoms are typically progressive and dis-abling. For patients who fail medical management, surgical options include thalamic deep brainstimulation (DBS) and gamma knife thalamotomy. In this study we examine the effectiveness andsafety of gamma knife thalamotomy in treating essential tremor. METHODS: We reviewed themedical and imaging records of 23 patients who underwent gamma knife thalamotomy for refrac-tory essential tremor over an 8-year interval. There were 12 men and 11 women with an aver-age age of 75 years. The average duration of tremor was 18 years. The target in all cases wasthe ventralis intermedius thalamic nucleus based on standard AC-PC line coordinates. Stereotacticradiosurgical thalamotomy was performed using the model U Leksell gamma knife. A central doseof 130 to 140 Gy was delivered with a single 4 mm isocenter. Items from the Fahn-Tolosa clini-cal tremor rating scale were used to grade tremor and handwriting before and after treatment.RESULTS: Three patients were lost to follow-up. The average follow-up period was 17 months.The mean preoperative Fahn-Tolosa tremor and scores was 3.8 ± 0.4, and after radiosurgery was1.4 ± 1.2. The mean preoperative Fahn-Tolosa writing score was 2.6 ± 1.0, and after radio-surgery was 1.3 ± 1.1. Two patients had no significant tremor relief after the procedure. Twopatients had post-procedure right arm weakness and dysarthria, and minor weakness persistedin both cases. There were no other complications associated with the procedure. CONCLUSIONS:gamma knife thalamotomy for essential tremor is effective and has an acceptable complicationrate. For patients with essential tremor who fail medical management and are poor DBS candi-dates or refuse DBS, Gamma knife thalamotomy is a reasonable minimally-invasive alternative.

Gamma knife radiosurgery - an alternative for intractable mesial temporal lobe epilepsy OS16-3Sujoy, Sanyal (1); V P, Singh (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of MedicalSciences - Neurosurgery Department Calcutta, India

INTRODUCTION The investigation of radiosurgery in the management of intractable MesialTemporal Lobe Epilepsy (MTLE) is part of the quest of identification of novel therapeutic strategiesfor intractable epilepsy. METHODS 5 patients with MTLE were treated with gamma knife (GK) afterobtaining an informed consent. Age ranged from 23-44 years and the duration of seizures pre-GK ranged from 6-23 years with a seizure frequency of 1-4/wk. MRI revealed right mesial tem-poral sclerosis (MTS) in 3, left MTS in 1 and bilateral MTS (left>right) in 1. Video-EEG and SPECTcorroborated MRI findings. In the 5th patient, VEEG and SPECT localized to the left side whichwas therefore treated. The target volumes of 6.9-7 cc encompassed the amygdala (sparing thesupero-medial part), the head and anterior half of the hippocampal body and the anterior part of

158

Page 161: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

the parahippocampal gyrus. Two 18 mm collimators delivered a dose of 25 Gy to the 50% iso-dose which corresponded to the target volume margin. RESULTS 4 patients developed radiationreactions extending into the temporal lobe white-matter at 8, 12, 13 & 14 months respectively.1 patient lost to follow-up did not develop a reaction till 10 months when seizures had decreasedmarginally. All 4 who developed a radiation reaction experienced a dramatic decrease in seizuresat the same time and went on to complete seizure remission. They have been followed for 2 yearsand all remained seizure and aura free except 1 patient who had 1 seizure on aggressive drugwithdrawal. Oral steroids were started at the time of appearance of the radiation reactions whichwere tapered depending on their resolution which took around 5-11 months. 1 patient devel-oped dysphasia with mild right facial paresis which recovered following administration of methyl-prednisolone. 1 other patient was symptomatic for the radiation changes with diplopia whichrecovered. None developed raised intracranial tension, cognitive deficits or visual field defects orany steroid-induced complications. CONCLUSIONS Radiosurgery seems to offer the option ofseizure control while sparing normal brain tissue and function unlike most surgical procedures butrequires more investigation. Though lower doses avoiding radiation reactions may be effective iffollowed for longer, the optimal dose for seizure control within a reasonable time-frame for MTSseems to be around 25 Gy to the target volume margin.

Does dose rate affect efficacy?The outcomes of 256 gamma knife radiosurgery procedures for facial pain as they relate to the half-life of cobalt OS16-4 Christopher, Balamucki (1); Thomas, Ellis (2); Alan, deGuzman (3); Edward G., Shaw (3); Michael, Munley (3);Stephen, Tatter (2); Kenneth, Ekstrand (3); William, Huang (3); Daniel, Bourland (3); Kevin, McMullen (3);Charles, Branch (2); Lovato, James (4); Volker W., Stieber (3) (1) Wake Forest University - School of Medicine; (2) Wake Forest University School of Medicine - Departmentof Neurosurgery; (3) Wake Forest University School of Medicine - Department of Radiation Oncology; (4)Wake Forest University School of Medicine - Public Health Sciences Winston-Salem, USA

Introduction: A biological model taking into account repair and dose rate suggests that over therange of typical treatment times of 25-60 minutes, the biologically effective dose (BED) could varyup to 31%. We examined whether the decrease in dose rate and increase in treatment time over4.6 years between cobalt source replacement at our institution affected the control rates of facialpain for patients undergoing GKRS. Clinical Material and Methods: Between September 1999 andMarch 2004, 326 GKRS procedures for patients with facial pain were performed. The outcomesfor 256 evaluable patients were analyzed. The biological model used was that developed byThames and Nilsson for continuous radiation. Logistic regression was used to model the logit ofresponse as a function of treatment time. The resulting coefficient was converted to an estimat-ed probability of response at the range of typical treatment times, 25 and 60 minutes. These esti-mated probabilities were compared to yield the estimated difference of BED from 25 to 60 min-utes. This difference was used to back-calculate a clinical value for the nerve repair half-time (T_). Results: The statistical analysis of the dose rate accounted for changes in prescription doseover time in order to prevent prescription dose from being a confounding variable. Neither doserate nor treatment time were significantly associated with either the control rate or degree of painrelief. The estimated difference of BED from 25 to 60 minutes (95% CI) was – 11%. Calculating

159

Page 162: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

backwards, this resulted in a T_ = 1.28 hours. Discussion: The model appeared to accuratelypredict that the relative biologic efficacy would remain constant for a fixed prescription dose,regardless of dose rate. The T_ we have calculated should be interpreted as a clinical value in thecontext of GKRS.

IMAGING - ARTERIOVENOUS MALFORMATIONS OS17Chairmen: Philippe, David; Enrico, Motti Room Permeke &

Rembrandt

Imaging development for dose planning of radiosurgery: Three dimensional MR (DRIVE) images and MR angiography OS17-1Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

To avoid radiosurgical complications of vascular and cranial nerve insults, exact evaluation ofthese structures are necessary before dose planning. Three dimensional magnetic resonance (3D-MR) images and MR angiography are used for the evaluation of lesions and their relationshipbetween arteries, cranial nerves and brain structures. 3D-MR images were reconstructed using3D-MR angiogram (TOF), MR image of cisternal structures (DRIVE) and MR image of lesionsobtained from Gd-enhanced images. MR images were transported with DICOM files to a person-al computer and 3D images were reconstructed and exported using the software of ExaVision(Ziosoft). Fusion images of MRA and DRIVE-image were made using the software of GyroscanIntera (Philips). 3D-MR images were useful for detection of lesions in relation to vascular and neu-ral structures in the basal cistern, cavernous sinus, petrous and clivus bone. In trigeminal neural-gia, the exact point of vascular compression was visualized on 3D-MR images of nerves in rela-tion with the whole length of related vessels. Exact evaluation of structures was helpful for exclu-sion of the important part from prescribed isodose lines. 3D-MR DRIVE image and MRA TOFimage are useful for dose planning of radiosurgery.

Integration of three-dimensional corticospinal tractography into treatment planning for gamma knife radiosurgery OS17-2Keisuke, Maruyama (1); Kyousuke, Kamada (1); Masahiro, Shin (1); Daisuke, Itoh (2); Shigeki, Aoki (4);Yoshitaka, Masutani (4); Masao, Tago (4); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology Tokyo, Japan

Object. In the radiosurgical treatment of critically located lesions, the effort to minimize the risk ofcomplication is essential. In this study the integration of diffusion tensor (DT) imaging-based trac-tography was clinically applied to treatment planning for gamma knife radiosurgery (GKRS).Methods. Seven patients with cerebral arteriovenous malformations located adjacent to the cor-ticospinal tract (CST) underwent this technique. Data provided by DT imaging were acquiredbefore the frame was affixed to the patient's head and the CST of DT tractography was createdusing our original software. Stereotactic three-dimensional imaging studies were obtained afterframe fixation and then coregistered with the data from DT tractography. After image fusion of

160

Page 163: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

the two studies, the combined images were transported to a GKRS treatment-planning worksta-tion. The spatial relationship between the dose distribution and the CST was clearly demonstrat-ed within the 2 hours it took to complete the entire imaging process. The univariate logisticregression analysis of transient or permanent motor complications revealed a significant inde-pendent correlation with the volume of the CST that received 25 Gy or more and with a maxi-mum dose to the CST (p<0.05). Conclusions. The integration of DT tractography into the GKRStreatment planning was highly useful in confirming the dose to the CST during treatment plan-ning. (JNS 102: 673, 2005).

Target definition in radiosurgery of AVMs using digital subtraction angiography time series OS17-3Harald, Treuer (1); Moritz, Hoevels (1); Stefan, Hunsche (1); Mohamad, Maarouf (1); Jürgen, Voges (1);Martin, Kocher (2); R.-P., Müller (6); V., Sturm (1) (1) University of Cologne - Department of Stereotaxy; (2) University of Cologne - Klinik für Strahlentherapie Köln, Germany

Successful radiosurgery of arteriovenous malformations (AVMs) requires accurate and completelocalization of the nidus. Although not full three-dimensional, two plane digital subtractionangiography (DSA) is the state of the art imaging modality for AVMs, mainly due to the high con-trast and high temporal resolution. Unfortunately, many treatment planning systems do not sup-port nidus localization on time series, but only on a very limited number of single time frames.We have developed a software tool that takes advantage of the high temporal resolution and thehigh contrast of DSA and minimizes some of the drawbacks of DSA, i.e. image distortion, poorvisibility of the fiducials on subtraction images, and high image noise. The program automatical-ly imports and sorts dicom images into angiographic times series and calibration images. The cal-ibration images of a grid phantom are semi-automatically analyzed for image distortions and cor-responding patient images are appropriately unwarped. Then, for each time series the fiducialsare segmented manually on the unsubtracted mask image. Now the nidus may be outlined, visu-alized and edited on any of the images of a time series. For noise reduction, temporal filtering issupported as well as cine mode display with adjustable speed. The ROIs of corresponding later-al and frontal image series are exported, together with the segmented fiducials, to our treatmentplanning software (STP3.5) for further processing. The program was put to clinical routine inFeb/2005 and readily accepted. Especially the availability of complete time series in the stereo-tactic treatment planning computer was found to be very helpful in target definition.

Stereotactic radiosurgery patient response: 3-phase diary study OS17-4Janet, Williams (1); Robert, Smee (2) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (2) Princeof Wales Hospital - Department of Radiation Oncology Randwick, Australia

PURPOSE: In Australia, 1400 people are diagnosed with a brain tumour every year. There are 40major types of brain tumours including benign tumours, primary malignant neoplasms and second-ary malignancies arising from other primary sites. This ethics approved prospective study investi-gates the symptom profile and emotional functioning for patients undergoing stereotactic radio-surgery. This is a 3-phase study assessing patients at baseline (pre-radiosurgery), 1 week and 3

161

Page 164: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

months post SRS using diary format measuring mood state and physical symptoms using the Likertscale. MATERIALS AND METHODS: Questions included in this study were based on the experiencesof 100 previously treated stereotactic patients. The purpose of this study is to assess the emotionaland physical state of the patient at the time of SRS and measure the changes in their physical symp-toms in relation with their emotions. Phase 1 diary is to establish the physical and emotional pro-file of the patient at treatment, phase-2 is collected one week post SRS and assess the changes intheir emotions with their physical symptoms. Phase-3 of the study at three months post SRS againassesses the fluctuations of the patient’s responses. It is anticipated that during the three monthperiod post SRS, the emotional state of the patient will improve, the radiosurgery side effects willsubside and the patient’s mood state will improve. It is anticipated that p=50 for initial analysis.RESULTS: Feedback from patients is encouraging and has confirmed that on reflection, the events ofthe day’s procedure were not as physically or emotionally draining as anticipated. CONCLUSION: Atinitial analysis it is anticipated there will be sufficient data to analyse the responses at the time ofSRS treatment, changes in physical symptoms and responses to their emotions and evaluate theoverall improvement of the emotional state and general health status of the patient.

EXTRACRANIAL RADIOSURGERY 1 OS18Chairmen: David, Larson; John, Buatti Room Willumsen

A prospective trial on stereotactic radiotherapy of colo-rectal metastases OS18-1Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars, Ohlhuis (2); Jorgen, Petersen (1); Hanne,Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Departmentof Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark

Large retrospective studies have shown that resection of colo-rectal metastases (CRM) in the liverresults in long term survival of 25-30% of the patients. Unfortunately, more than 80% of patientswith CRM of the liver and even more patients with extrahepatic CRM are considered inoperable.Radio-frequency ablation and stereotactic body radiotherapy (SBRT) are alternatives to resectionand they may increase the number of patients that can receive local treatment for CRM. We havetested the effect of SBRT in the treatment of patients with CRM in a phase II trial. Sixty-ninepatients with each 1-6 CRM in liver, lung or suprarenal gland were included into the trial. Thepatients were immobilized by the Elekta stereotactic body frame (SBF) or a custom made bodyframe. SBRT was given on standard LINAC with standard multi-leaf collimator. Central dose was15 Gy x 3 within 5-8 days. Preliminary results of the study showed that 82% of the tumours werecontrolled by SBRT. Only 75% of the patients had overall local control since they were treated formore than one tumour. Due to progression elsewhere, only 15% were without progression and28% were alive 2 years after treatment. No difference in survival was observed between patienttreated for hepatic- or extra-hepatic CRM. In general, toxicity was limited. However, 47% of thepatients experienced grade> 1 toxicity within 6 months after SBRT. Most frequent side effectswere nausea, diarrhoea, pain and skin reaction. SBRT in patients with CRM resulted in high prob-ability of local control and acceptable survival rate. The toxicity after SBRT of CRM was moderate.The final results with more than 2,5 years follow-up time will be presented at the meeting.

162

Page 165: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Stereotactic body radiation therapy of early stage non-small cell lung carcinoma: phase I study update OS18-2Ronald, McGarry (1); Robert, Timmerman (2); Lech, Papiez (3); Mark, Williams (4) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) University of TexasSouthwestern - Department of Radiation Oncology; (3) Indiana University Medical Center - Department ofRadiation Oncology; (4) Richard L. Roudebush V.A. Medical Center - Pulmonary Division Indianapolis, USA

Purpose ¨C a phase I dose escalation study of stereotactic body radiation therapy (SBRT) to assesstoxicity and local control rates for patients with medically inoperable Stage I lung cancer. Materialsand Methods - All patients had non-small cell lung carcinoma, stage T1a or T1b, N0, M0. Allpatients had significant cardiovascular and/or pulmonary pathology which prohibited surgicalresection. Patients were immobilized in a stereotactic body frame and treated in escalating dosesof radiotherapy beginning at 24 Gy total (three 8 Gy fractions) using 7-10 beams. Cohorts weredose escalated by 6.0 Gy total with appropriate observation periods. Most patients received PETscans as a staging evaluation and preliminary analysis will be available. Results - The maximumtolerated dose (MTD) was not achieved in the T1 stratum (maximum dose = 60 Gy), but withinthe T2 stratum, the MTD was realized at 72 Gy for tumors larger than 5 cm. Dose limiting toxic-ity included predominantly bronchitis, pericardial effusion, hypoxia, and pneumonitis. Local fail-ure occurred in 4/19 T1 and 6/28 T2 patients. 9 local failures occurred at doses ¡Ü16 Gy and only1 at higher doses. Local failures occurred between 3-31 months from treatment. Within the T1group, 5 patients had distant or regional recurrence as isolated events, where as 3 patients hadboth distant and regional recurrence. Within the T2 group, 2 patients had solitary regional recur-rences and the 4 patients who have failed distantly also failed regionally. A single patient autop-sy result showed only interstitial fibrosis in the treated are with no residual tumour. Conclusions- SBRT appears to be a safe, effective means of treating early stage lung cancer in medically inop-erable patients. Excellent local control was achieved at higher dose cohorts with dose-limitingtoxicities achieved in patients with larger tumors.

Stereotactic radiotherapy for liver tumours based on MRI and tumor markers OS18-3Alejandra, Mendez Romero (1); Wouter, Wunderink (2); Shahid M, Hussain (3); Peter JCM, Nowak (4); BenJM, Heijmen (5); Joost, Nuyttens (6); Rene P, Brandwijk (7); Jan NM, Ijzermans (8); Peter C, Levendag (9) (1) Erasmus MC - Radiotherapy; (2) Erasmus MC - Radiotherapy; (3) Erasmus MC - Radiology; (4) Erasmus MC- Radiotherapy; (5) Erasmus MC - Radiotherapy; (6) Erasmus MC - Radiotherapy; (7) Erasmus MC -Radiotherapy; (8) Erasmus MC - Surgery; (9) Erasmus MC - Radiotherapy Rotterdam, The Netherlands

Purpose: To evaluate tumor response based on serial pre-and post MRI imaging and tumor mark-er values as well as toxicity after treatment with Stereotactic Radiotherapy (SRT) for primary andmetastatic liver tumours. Methods and Materials: Between October 2002 and March 2005, 17patients with 32 lesions, not suitable for other local treatments, underwent SRT. The lesionsincluded 8 hepatocellular carcinoma (HCC), 7 patients, and 22 metastases (Mets), 10 patients.Median follow-up is 14 months (range: 4-27). Median size was 4.5 cm (range: 0.5-7.2).Treatment schemes were 3 x 12.5 Gy at the 65% for liver metastases and HCC < 4 cm and 5 x5 Gy or 3 fractions of 8-10 Gy at the 65% for HCC > 4 cm. All lesions were evaluated with MRI

163

Page 166: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

and tumour markers, carcinoembryonic antigen (CEA) or alpha-fetoprotein (AFP), before treat-ment and periodically after that. Local failure was defined as increase in tumor size and/or increas-ing tumor marker without evidence of new lesions, at any point during the follow-up. Acute tox-icity was scored following the Common Toxicity Criteria v 2.0 and late toxicity with the SOMA/LENT classification. Results: Local failure was observed in 2 of 32 lesions ( 6.3%) in 2 of 17(11.8%) patients. Both patients were treated with 5 x 5 Gy. Retreatment was performed with 3 x8 Gy. One lesion stays in local control and the other one underwent surgery. Acute toxicity grade¡_3 was seen in 1 HCC patient who presented liver decompensation together with an infectionand died (grade 5). One late toxicity was observed in 1 patient with metastases who developeda portal hypertension syndrome with one episode of melena (grade 3) Conclusions: The resultsshow that stereotactic radiotherapy for liver tumors offers the possibility of excellent local controlwith acceptable toxicity in otherwise untreatable patients.

Stereotactic radiation treatment (SRT) for advanced intra-abdominal tumours OS18-4Vincent, Vinh-Hung (1); Frederik, Vandenbroucke (2); Zsuzanna, B Nagy (1); Hilde, Van Parijs (1); Maria,Voordeckers (1); Jan, Van de Steene (1); Guy, Soete (1); Dirk, Van Den Berge (1); Johan, De Mey (2); Guy,Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Radiologie Brussels, Belgium

Purpose: To evaluate our experience with the Novalis SRT in advanced abdominal tumours.Methods: A search of our database for patients treated in 2000-2004 with SRT for inoperable pri-mary or metastatic abdominal tumours retrieved 91 cases. Survival estimates were computed bythe product-limit method. Multivariate analyses used proportional hazards. Variables includedwere age, gender, tumour size, radiation treatment duration and doses.Results: Localizations were: liver 56 cases (62%), pancreas 7 (11%), other 28 (46%). Meantumour size was 6.4 cm (range 1.8-12.5 cm). Mean number of sites treated was 1.5 (1-6).Fraction doses were mainly 4-10 Gy, 3-10 fractions, mean duration 6 days (2-48). Treatment wasdelivered under X-ray image guidance (XRG). XRG was based on implanted metal markers in 23patients, based on bone structures in others. Overall survival (OS) was 25 months, local progres-sion free survival (PFS) 13 months, and time to response (TTR) 10 months. Use of markers wasassociated with better PFS (median 16 vs. 12 months without marker), and better TTR (median 4vs. 10 months, P=0.008). In multivariate analyses, factors associated with improved survival andresponse were: higher radiation doses, P=0.001 for OS, P<0.001 for PFS, P=0.007 for TTR,and smaller number of fractions, P=0.05 for PFS, P=0.07 for TTR.Conclusion: The dose-effect relationship suggests that the utility of local control should not bedismissed in metastatic cases. Furthermore, improved time to response using markers indicatesthat palliative cases might benefit from high precision treatment.

164

Page 167: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ORAL SESSIONS 14h00 - 15h00

FUNCTIONAL RADIOSURGERY 2 OS19Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation

Gamma knife radiosurgery to the pituitary for thalamic pain syndrome: clinical evaluation of recent our institutional series OS19-1Motohiro, Hayashi (1); Takaomi, Taira (2); Taku, Ochiai (1); Mikhail, Chernov (1); Shinichi, Goto (2); Koutaro,Nakaya (1); Masahiro, Izawa (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) Tokyo Women's Medical Univeristy- Department of Neurosurgery Tokyo, Japan

Rationale: Thalamic pain syndrome is one of represented intractable pain. However, there wasone clinical report, it could be controlled with chemical hypophysectomy with developing to tran-siently diabetes insipidus. This historical evidence prompted us to perform Gamma knife radio-surgery (GKR) to the normal pituitary gland–stalk in aiming to try to control of this kind ofintractable pain. Material and Method: An indication of this treatment for our proposal indication:1) The pain should be typical thalamic pain syndrome, 2) No any other effective treatment priorto GKR, 3) Patients with poor condition, which means impossible to be treated under generalanesthesia , 4) Main complaint is “pain”, not “numbness”. In our institutional series experience,we have treated 27 patients who were suffered from thalamic pain syndrome with GKR, whoseonset was cerebral infarction/ hemorrhage in 26, and was malignant lymphoma in one. The tar-get was the just pituitary gland involving a part of the pituitary stalk with 8mm collimator.Prescribed maximum dose was 140 to 180Gy. We could follow up more than 6 months and eval-uate the 24 patients. Results: Initial significant pain reduction was observed in 70.8% (17/24).All effective cases experienced significant pain reduction within 4 days. Long term effective (>1year) was observed in 25.0% (5/20). No any important postoperative complication was observedexcluding only two patients who developed transiently diabetes insipidus. Conclusions: Thalamicpain syndrome is still too difficult to be cured with any treatment protocol. However, we have pro-vided significant pain reduction and overcoming daily life to the majority of the patients, whowere treated by GKR to the pituitary. Otherwise, we should know why GKR to the pituitary iseffective for this kind of pain on not only clinical but also experimental aspect. We suppose thatGKR to the pituitary has an overestimated potential and will play an important role in the field ofthe management of intractable pain.

Gamma knife radiosurgery for symptomatic trigeminal neuralgia.How should we select the treatment strategy ? OS19-2Hiroyuki, Kenai (1); M, Yamashita (1); T, Nakamura (1); T, Asano (1); M, Saino (1); H, Nagatomi (1) (1) Nagatomi Hospital - Department of Neurosurgery Oita, Japan

Introduction For the treatment of essential trigeminal neuralgia(TN), Gamma kniferadiosurgery(GKRS) is widely adopted now. But there are few reports about GKRS for symptomaticTN which caused by the tumor, AVM, etc.. Generally, pains of symptomatic TN are controlled ear-lier than essential TN by GKRS for the lesion. We also have experienced some symptomatic TN.

165

Page 168: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Here we summarized the results of our cases and reviewed the strategy of GKRS for symptomaticTN. Methods From January 2001 to December 2004, seventeen patients suffering from sympto-matic TN were treated with GKRS in our institution. Of them, fourteen patients that could be fol-lowed for a minimum of 6 months were retrospectively examined. The mean follow-up was23.9months. There were 4 men and 10 women with a mean age of 73.7years(range, 58-82).Results In 10 of 14 cases, pains could be controlled by GKRS for the lesion. But in some cases,pains could not be controlled in spite of the lesion control through GKRS. In these cases, painscould be controlled by adding GKRS of targeting the fifth nerve directly. And, in the cases thatGKRS was not indicated for treatment of the lesion or in the cases of emergency, using or addingthe same GKRS for essential TN from the first was effective. Conclusions We reviewed the strate-gy of GKRS for symptomatic TN from our experienced cases. In some symptomatic TN cases, painscould not be controlled only by the lesion control through GKRS. Although GKRS for symptomaticTN should be directed to the lesion rather than the trigeminal root originally, it was indicated thatusing or adding the same GKRS for essential TN was effective and safe for the treatment of symp-tomatic TN.

Influence on pain outcome of the neurovascular compresion anatomy on MRI in patients with idiopathic trigeminal neuralgia treated by gamma knife radiosurgery OS19-3José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel Salvador, Ruiz Gonzalez (4); Françoise,Desmedt (1); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme -Neurochirurgie; (4) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Brussels, Belgium

Objective: To study the relationship between the pain outcome and the anatomical characteristicsof the neurovascular compression on MRI in patients with idiopathic trigeminal neuralgia treatedby gamma knife Radiosurgery. Material and Methods: Analysis of the anatomy of trigeminal nerve,brain stem and the vascular structures related to the nerve was made in 100 consecutrive patientstreated by Leksell gamma knife for ITN. One mm thick axial slices MRI (T1, T1 enhanced and T2SPIR) with coronal and sagital reconstructions was viewed in a dynamic manner using the softwareGamaPlan. Three-dimensional reconstructions were made as well. Pain outcome was consideredexcellent if there was total pain remission and no medication was needed. 89 of these patientshave follow up of 6 months or more. Results: In 93 patients (93%), one or more vascular struc-tures in contact with the trigeminal nerve or the brain stem near the nerve insertion were found.Superior cerebellar artery was in 71 cases (76%). Other vessels identified were the antero-inferiorcerebellar artery, basilar artery, vertebral artery, and some veins. In 39 patients (42%), vascular con-tact was located proximally (less than 3mm to the brain stem) and in 42, (45%) in a distal loca-tion. Nerve dislocation by the vessel was observed in 30 cases (32%), and nerve atrophy in 25(27%). The two variables associated with a poor outcome were a proximal nerve compression anda great vessel contacting the nerve (basilar or vertebral artery). The dose received by the nerve atthe neurovascular compression as well as nerve atrophy or nerve dislocation by the vessel was notassociated to pain outcome. Conclusions: The anatomical characteristics of trigeminal nerve com-pression could be important in predicting pain outcome in patients with ITN treated by radio-surgery. This approach could be ussefull also, for the planification of an open surgery for ITN.

166

Page 169: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Different targets in the gamma knife treatment for intractable pain OS19-4Dusan, Urgosik (1); Roman, Liscak (2); Josef, Novotny Jr. (3); Josef, Vymazal (4); Vilibald, Vladyka (5) (1) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (2) Na Homolce Hospital - Stereotacticand radiation neurosurgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital -Stereotactic and radiation neurosurgery; (5) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery Prague, Czech Republic

Introduction: Various pain syndromes require various therapeutic approaches. That was the rea-son, we used the different targets for gamma knife surgery (GKS) in different cases. Material andMethods: Since the end of 1995 we have used these targets for our pain patients: 1) The rootentry zone (REZ) of trigeminal nerve for trigeminal neuralgia (TN), 2) ganglion sphenopalatinnumfor sphenopalatine neuralgia, 3) ganglion inferior of the ninth cranial nerve for glossofaryngealneuralgia, 4) ganglion ciliare for vegetative orbital pain, 5) medial parts of thalamus for thalam-ic pain and unilateral pain of other origin, 6) rostral parts of gyrus ciguli mainly for pain of malig-nant origin, 7) pituitary gland for pain caused by skeletal metastatis of different types of cancer.All targets were irradiated by Leksell gamma knife. In majority of anatomical structures we haveused a 4 mm collimator and single shot, only for hypophysectomy 8 mm collimator has beenapplied and for cingulotomy four shots with 4 mm collimators. A maximal dose has ranged from70 to 80 Gy in the case of cranial nerves irradiation, 150 Gy in the thalamic target, from 160 to200 Gy in hypophysectomy and 150 Gy has been applied during cingulotomy. Results: The bestinitial pain relief (successful rate to 96%) was reached after GKS in REZ area for essential TN. Alsohypophysectomy for cancer pain was successful (rate to 75%). Only partially satisfactory resultswere achieved after thalamotomy and cingulotomy (successful rate to 50 %). Conclusion:Versatility and accuracy of GKS allow us to treat the patients with various types of pain. GKS isthe method of the first choice in TN patients and appropriate complementary method in otherpain syndromes.

PHYSICS - NEWS OS20Chairmen: Frank, Bova; Dirk, Verellen Room Permeke &

Rembrandt

Image-guided and frameless localization in cranial stereotactic radiotherapy OS20-1Joachim, Bogner (1); Beverly, Downes-Phillips (2); Dietmar, Georg (3); David W., Andrews (2) (1) Medical University Vienna - Radiotherapy and Radiobiology; (2) Jefferson Hospital for Neuroscience -Department of Neurosurgery; (3) Medical University Vienna - Radiotherapy and Radiobiology Vienna, Austria

Purpose: The purpose of this study is to assess the accuracy of ExacTrac X-ray as a patient posi-tioning device for stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT)in cranial applications. Specifically, a new approach of frameless localization is commissioned forvarious stereotactic immobilization devices and compared to conventional stereotactic patientpositioning with a target positioning box. Material and Methods: New software developments inBrainSCAN and ExacTrac X-ray enable direct transfer of isocenter coordinates and CT data sets ofcranial patients. Thus, a comparison of isocenter position between the frameless localization of

167

Page 170: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ExacTrac X-ray and the localization by means of a target positioning box is possible.Measurements were performed with a RANDO head phantom, which was fixated in three differ-ent stereotactic immobilization devices (head-ring for SRS, stereotactic mask and a bite-block sys-tem for FSRT). Based on spiral CT scans with 1.5 mm slice thickness two isocenters were set,resembling either a tumor position near optic structures or in a posterior, parietal position. In addi-tion a sequential CT scan with 2 mm slice thickness was recorded in order to check the influenceof DRR quality to the resulting isocenter position and we studied the impact of different X-rayenergies and DRR grey-scale parameters. Finally the response of the localization system to inten-tional couch translations in vertical, longitudinal and lateral directions starting from an optimizedisocenter position was investigated. Results: Averaged over all tumor sites and fixation devicesthe difference between the isocenter determined by ExacTrac and the isocenter determined by tar-get positioning box is 0.10 ± 0.40 mm, 0.05 ± 0.31 mm, and -0.77 ± 0.42 mm in longitudi-nal, lateral and vertical direction, respectively. Angular deviations were -0.03 ± 0.23º, -0.06 ±0.13º, and -0.01 ± 0.17º for the longitudinal, the lateral and the isocentric table axis, respec-tively. No significant difference in isocenter position was found employing either the 2 mmsequential or the 1.5 mm spiral CT sequence. For both tumor positions simulated the rathersevere artefacts from the respective immobilization device in the X-ray images showed no signif-icant influence on target precision. The dependence of the ExacTrac precision on the parametersX-ray energy and DRR settings is small. Only complete lack of bony anatomy in either the X-rayimage or the DRR leads to variations of isocenter position greater than 1 mm. The response ofExacTrac X-ray to intentional couch translation of 2 mm, 4 mm, and 6 mm was found to be exactwithin 0.25 mm on average. Conclusion: ExacTrac X-ray provides a new tool for frameless stereo-tactic patient positioning. The present study on various phantoms and immobilization devices cansuccessfully demonstrate the high accuracy of the system to be well within the required tolerancesfor SRS/FSRT. A patient study comparing the repositioning accuracy of stereotactic mask and bite-block system with the help of ExacTrac X-ray is in progress.

Treatment of ocular melanoma; X-Knife treatment planning with optimal immobilization OS20-2Sandra, de Vries (1) (1) Otago University - Radiation Therapy Dunedin, New Zealand

In 2001 the first Stereotactic Radiotherapy treatment of an Ocular Melanoma was performed atthe Dunedin Oncology department. Since then another 13 cases have been treated. The principalaim is to achieve tumour control and preservation of the eye without unduly compromising sight.The Gill-Thomas-Cosman relocatable headframe was used to accurately immobilize the head. Tofixate the eye a light source was used and the treatment was given under video surveillance. X-Kife was used to plan the treatment. This presentation/poster will discuss the disease, diagnosticmethods, current treatment options and the rationale for treatment with StereotacticRadiotherapy. The presentation will also describe the immobilization of the eye and the technicaldifficulties encountered defining the tumour volume within stereotactic coordinates. The methodof immobilization used in Dunedin results in delivery of a high dose of radiation to the eye thatcan be given with a relocation accuracy of 1mm.

168

Page 171: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Initial experience with a x-ray based respiratory gating system for lung and liver OS20-3Franz, Gum (1); Reinhard, Wurm (1); Armin, Fuerst (2); Volker, Budach (1) (1) Charité University Medicine Berlin - Department of Radiation Oncology; (2) BrainLAB - Radiotherapy Berlin, Germany

Purpose/ Objective: A commercially available, x-ray based image guidance system (Novalis Body/ ExacTrac X-Ray 6D, BrainLAB) has been modified to allow respiration triggered treatments. Acommercially available, x-ray based image guidance system (Novalis Body / ExacTrac X-Ray 6D,BrainLAB) has been modified to allow respiration triggered treatments. Methods and Materials:The system features real-time tracking of the patients’ external breathing signal via infrared reflec-tive markers attached to the patients’ skin and an infrared tracking device. Additionally, stereo-scopic x-ray images are acquired at user-defined moments within the patient’s breathing cycle toimage the position of an implanted marker. As such a relation between the externally detectedbreathing curve and internal tumor motion can be established to first set-up the moving targetcorrectly and second establish a gating window. To verify system performance and accuracy aspecial gating phantom, simulating a breathing pattern was developed. The phantom consists ofa moving platform, a slab-phantom with film inserts and integrated radio-opaque markers. Themarkers are used for positioning and tracking. The phantom was used to assess: (a) the abilityand accuracy of positioning a moving target to a specific point within the breathing pattern.Positioning verification was undertaken via a Winston-Lutz test on the positioned marker (b) thereal-time capabilities of the system by measuring system latency (c) the correctness of the trigger-ing of the linear accelerator by performing a triggered Winston-Lutz test and (d) the verificationof a treatment plan delivered under gating, which was matched on the moving slab phantom.First clinical application of the gating prototype system was performed on lung and liver patients.Therefore radio-opaque gold markers (Visicoil, RadioMed Inc.) were implanted into the tumorunder CT / ultrasound guidance. Gated treatments were performed and the system capabilitieswere assessed to: (a) usability on real patients (b) x-ray tracking accuracy of the implanted mark-er (c) treatment efficiency and accuracy. Results: The data measured on the phantom was in goodagreement with the expected data. No measurable delay in the triggering of the linac wasobserved. Set-up accuracy of the moving target was within the mechanical tolerance and meas-urement accuracy of the phantom. System latency, important for the real-time capability of thesystem was in the order of 200 msec. Treatment plans under gated delivery showed good agree-ment with the original theoretical dose distribution with the deviations depending on the gatingwindow size. Patient treatments demonstrated the capabilities and limitations of the system inclinical routine. System performance was significantly dependent on patient, indication and tumorlocation. A fairly stable relationship between the external breathing signal and internal tumormotion was detected in the area of exhalation, which was also chosen for treatment. Verificationimages acquired during treatment showed a good overall agreement of marker position, with thedeviations being dependent on tumor location and the amount of the entire tumor motion.Treatment times were in a range of 30 to 40 min, depending on gating window size, which wasin the order of 25 to 30 %. Conclusions: Phantom tests and first patient treatments for breathingsynchronized irradiation showed promising results. Certainty in accurately delivering radiation tothe target and therefore the ability to reduce safety margins are the most important factors. Withthis new gating technology safety margins could already be reduced by a significant factor. The

169

Page 172: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

biggest issues arose from the often unstable and varying breathing signals of the patients. Furtherinvestigations are planned to overcome these related problems. Conflict of interest: This work hasbeen supported in part by BrainLAB AG.

Evaluating the localization accuracy of 6D Fusion software for the Novalis body image guided system and its clinical application for spinal radiosurgery OS20-4 Jian-Yue, Jin (1); Samuel, Ryu (1); Jack, Rock (2); Kathleen, Faber (1); Marilyn, Gates (3); Shidong, Li (1);Benjamin, Movsas (1) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery Detroit, USA

Purpose: Accurate target localization is key for spine radiosurgery because the target is usuallyclose to the spinal cord, which may suffer irreversible injury if a high radiation dose is received.Recently, a 6D fusion algorithm, which takes into account rotational setup error, was clinicallyreleased. This study evaluates the localization accuracy of this software and its application inspinal radiosurgery. Materials and Method: BrainLab ExacTrac 3.5 and the Novalis radiosurgeryunit were used in this study. An anthropomorphic torso phantom was implanted with six 2-mmdiameter metal balls in the vertebral region. The phantom was scanned in a CT scanner with slicethicknesses of 2 mm and 3 mm respectively. The centers of the 6 metal balls were identified inthe CT images, and one of the centers was used as the isocenter for treatment. The phantom wasthen positioned in the treatment couch with intentional translational and rotational offsets to theisocenter. Two X-ray images were taken and fused with the simulation CT images using (1) 3Dfusion algorithm, (2) 6D fusion algorithm, and (3) implanted marker algorithm. For 3D and 6Dfusions, the image areas with implanted metal balls were excluded. Localization accuracy for eachalgorithm was evaluated by comparing the fusion results. The phantom position was then read-justed according to the 6D fusion results. Two kV X-ray images were taken for the new position,and localization accuracy was evaluated by comparing the X-ray system’s isocenter position to thecenter of the metal ball in the images. Two MV portal films were also taken to further evaluatethe localization accuracy related to the linac’s isocenter system. Results: We have tested 6 isocen-ters in different positions in the vertebral region. The localization accuracy related to the X-ray sys-tem’s isocenter for 6D fusion algorithm is 0.56 ±0.25 mm and 0.74±0.27 mm for 2 mm and 3mm CT slice thicknesses, respectively. The localization accuracy related to the Linac’s isocenter is0.72 ±0.12 mm and 0.74±0.2 mm for 2 mm and 3 mm CT slice thickness, respectively. Thelocalization accuracy related to the implanted marker system (assuming the implanted marker isthe golden standard) is 0.57±0.32 mm and 2.44±0.73 mm for the 6D fusion and 3D fusionalgorithms, respectively. We have also used the 6D fusion software to localize the target for over40 spine radiosurgery patients. The localization accuracy can be easily evaluated by comparinganatomic structures in the overlying kV X-ray images and the DRRs of the patient. In addition,comparing AP and lateral MV port films with the DRRs using the vertebral bone structure yieldedfurther confidence that accurate target localization was achieved. Conclusion: The 6D fusion soft-ware can achieve sub-millimeter localization accuracy, even when the patient has a rotationalsetup error (up to 4 degrees). Unlike the accuracy of 3D fusion, the accuracy of 6D fusion is inde-pendent of rotational offsets.

170

Page 173: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ORAL SESSIONS 15h00 - 16h00

FUNCTIONAL - TRIGEMINAL NEURALGIA 1 OS21Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation

Longterm clinical results for trigeminal neuralgia treated by gamma knife radiosurgery OS21-1Noriko, Murata (1); Manabu, Tamura (2); Jean, Regis (3) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital -Stereotactic and Fonctional Neurosurgery; (3) CHU La Timone - Service de Neurochirurgie Marseille, France

Objective : To evaluate the long-term effect of gamma knife Radiosurgery (GKS) for typicalTrigeminal Neuralgia. Material and Methods : Between December 1992 and May 2005, 325patients underwent radiosurgery for trigeminal neuralgia in Marseille Timone University hospital.A minimum follow up of 1 year is available for 260 patients. All these patients have been treat-ed with an anterior target/high dose strategy. A multiple sclerosis was diagnosed in 21 patients8%. A previous surgical treatment of the TN was applied in 39,6% patients (103/260). Results :The median follow up (FU) was 3,2 years (range 1-12,5). The median distance between the cen-ter of the shot and the emergence was 8,35 mm (range 4,3-16,8). The median dose at the cen-ter of the single 4mm collimator was 85 Gy (range 70-90). The median delay for pain cessationwas 14 days (range 0-150). The initial pain free rate is 88,5 % (among 230 patients). Amongthese patient the number of patient still free of pain at 1 year, 2 years, 3 years, 4 years, 5 years,6 years, 7 years and at the last FU was respectively 63,9% (46/72); 71,7% (38/53); 72,4%(21/29); 76,0% (19/25): 75,0% (21/28): 92.3% (24/26): 62,5% (10/16). At the last follow upamong the total population 183 were still pain free (69,8%) and 101 still pain free without anymedication (38,8%). Due to failure an additional surgery was performed in 58 patients (22,3%).At the last follow up a new hypoesthesia was observed in 45 patients (17.3 %) of 260 patients.Conclusion : This study shows that gamma knife Radiosurgery applied to the cisternal anteriorTrigeminal Nerve using high doses provided safe and effective for treatment of TrigeminalNeuralgia in the long-term.

Outcome of patients undergoing gamma knife stereotactic radiosurgery for medically refractory idiopathic trigeminal neuralgia OS21-2Kostas, Fountas (1); Joseph, Smith (2) (1) The Medical Center of Central Georgia - Department of Neurosurgery; (2) Medical College of Georgia -Neurosurgery Macon, USA

The role of stereotactic radiosurgery in the management of medically refractory trigeminal neural-gia has been well established in the literature. However, a significant variation exists between thereportable success rate among different clinical series. In our retrospective clinical study, we pres-ent our experience in treating patients diagnosed with idiopathic trigeminal neuralgia withgamma-knife. In our institution during the last five years (2000-2004) 77 patients (54 femalesand 23 males) with the diagnosis of idiopathic trigeminal neuralgia underwent gamma knife

171

Page 174: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

radiosurgery on outpatient basis. Their mean age was 67.3 years while their age range was 42-81 years. Stereotactic radiosurgery via a gamma-knife unit was applied in all of them. The modeadministered dose was 80Gy at 100% isodose. Our follow-up time ranged between 6-60 monthswhile our mean follow-up time was 21.1 months. Fifty-two patients (67.5%) had no previousprocedures while 25 patients (32.5%) had previously undergone one or more surgical or percu-taneous procedures. The mean pain-free period was 15.9 months (range 0-60 months).Interestingly, the mean pain-free period among patients with no previous procedures was 23.6months while the respective one for patients with previous procedures was 10.1 months. Nointraoperative or late major complications occurred in our series. Five patients (6.5%) developedlocal clinical symptomatic post-radiation necrosis, which was medically treated. Eleven patients(14.3%) developed moderate to severe, post-treatment facial numbness. Stereotactic gamma-knife surgery represents a safe alternative treatment for medically refractory trigeminal neuralgia.In our series the pain free period appears to be shorter than previously reported in the literature.Patients with no previous procedures responded significantly better to gamma-knife surgery.

Outcomes of gamma knife radiosurgery in trigeminal neuralgia OS21-3David, Huang (1); Danielle, Rudolph (2); Deane, Jacques (3) (1) Cancer Care Consultants/ Northridge Hospital - Radiation Oncology; (2) Independent CRA - CRA; (3) GoodSamaritan Hospital - Neurosciences Institute Northridge, USA

PURPOSE: gamma knife Radiosurgery (GKRS) is a treatment option used to control pain inpatients with medically refractory trigeminal neuralgia (TN). However, its efficacy is sometimeslimited and recurrences may develop. This study was done to assess the overall outcomes andpatient satisfaction with this modality. MATERIALS AND METHODS: Between 1992 and 2004,371 patients were treated for TN with GKRS in a single institution. All patients were treated usingone 4 mm shot, targeting the trigeminal nerve at the pontine junction. The median dose pre-scribed was 87.2 Gy (range 65- 98.1 Gy). In 2004, a questionnaire was sent to all treatedpatients to assess long term outcomes. 108 patients responded to the questionnaires. Medianfollow up was 44 months (range 6-120 months). RESULTS: Out of the 108 evaluable patients, 92patients (85.2%) initially demonstrated excellent or good pain control (feeling no further pain,without or with medications respectively) Nine patients (8.3%) felt they had fair pain control (feel-ing less pain). Seven patients (6.5%) failed treatment. At last follow up, only 62 patients (57.4%)had excellent or good pain control and 23 patients (21.3%) had fair pain control. Twenty-threepatients (21.3%) had failure to control pain. Some recurrences were treated with repeat SRS in29 patients (26.9%). Of these, 10 patients (34%) had excellent pain control, 3 (10.3%) had goodpain control, and 8 (27.6%) had fair pain control. Eight patients (27.6%) failed retreatment. Mildcomplications (numbness, weakness, or paresthesias) occurred in 17 patients (15.7%) after thefirst procedure. Nine patients experienced complications after a second procedure, and the over-all rate of complications was 24.1%. The overall satisfaction rate was 77.8%. CONCLUSIONS:Despite recurrences, complications, and the need for repeat treatments, overall degree of paincontrol and satisfaction rates remain good for GKRS used for TN.

172

Page 175: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Gamma knife radiosurgery as primary surgery for patients with trigeminal neuralgia OS21-4John, Lee (1); Jae Gon, Moon (2); Ricky, Madhok (3); Brian, Jankowitz (2); Joseph, Ong (3); Douglas,Kondziolka (4); John C, Flickinger (6); L. Dade, Lunsford (6) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center -Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurosurgery; (4) University ofPittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA

Introduction: Stereotactic radiosurgery is the least invasive surgical option for patients withtrigeminal neuralgia. It mainly has been used for patients who have failed other procedures. Todetermine the effect of radiosurgery as the primary surgical management for patients withintractable trigeminal neuralgia, we studied those patients who had radiosurgery without anyprior surgical treatments (microvascular decompression or percutaneous rhizotomy). Methods:Over a nine-year period, 480 patients underwent gamma knife radiosurgery for intractabletrigeminal neuralgia at the University of Pittsburgh. 211 patients had radiosurgery as first-linetreatment. 149 of the 211 patients had over six months of follow-up. Gamma knife radiosurgerywas performed using a single 4-mm isocenter targeted to the trigeminal nerve, just proximal toits entry into the brainstem. A median maximum dose of 80 Gy was prescribed (70-90 Gy). Themean follow-up was 37 months (6-109 months). Pain relief was classified into three categories:pain-free with or without medications, partial pain relief (>50%), and little or no relief (<50%).Results: Three months after gamma knife radiosurgery, 87% of 149 patients described themselvesas being pain-free. At final follow-up (mean=37 months after gamma knife radiosurgery), 63%of 149 patients described themselves as being pain-free. Eleven percent (23 of 211) of patientsdeveloped numbness in the trigeminal distribution. Three percent (6 of 211) of patients devel-oped paresthesia or dysesthesias. No patient developed corneal abrasion or keratitis. Conclusion:Gamma knife radiosurgery is a minimally invasive surgical option for patients with trigeminal neu-ralgia that can be used as a primary surgery for medically refractory patients.

PHYSICS - QUALITY ASSURANCE OS22Chairmen: Stephan G, Scheib; Frank, Bova Room Permeke &

Rembrandt

Using the Winston Lutz test and EPID to compare stereotactic radiosurgery set using Radionics LTLF and BrainLab Target Positioner OS22-1Robert, Myers (1); Ryan, Smith (1); Michael, Dally (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia

Using the Winston Lutz test and EPID to compare Stereotactic setup using Radionics LTLF andBrain Lab Target Positioner. Aim : To determine if there is any difference in the accuracy of patientset-up using the Radionics system alone or Radionics couch hardware and Brainscan (by Brainlab)computer generated Target Overlays used in conjunction with BrainLab Target Positioner fittedwith printed target overlays. Method: A Rando Phantom with a 6.0mm bearing inserted in theleft side of the cranium was set up for stereotactic treatment in the CRW head ring. A CT was per-

173

Page 176: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

formed and sent to the planning system. A spherical volume was placed around the bearing anda rectangular field 24mm square was formed with MLC leaves. The isocenter was positioned cen-trally within the bearing. Three fields were planned, a right lateral, left lateral and anterior.Routine William Buckland Radiothery Center (WBRC) stereotactic Quality Assurance (QA) wasdone and LTLF set for the isocenter coordinates generated by Brainscan in the usual fashion. Theroom Lasers were checked against LTLF without any micro adjustment. Films in all 3 projectionswere taken in 3 planes, as were EPID images. This was repeated after micro adjustment to theset up (micro adjustment positions the planned isocenter at the mechanical isocenter of themachine) was made. The alignment of the isocenter of the Brain Lab target overlays was com-pared to the LTLF isocenter before and after adjustment. Results. There was no discernable differ-ence between the LTLF and the Target Positioner with respect to alignment to the mechanicalisocenter of the Linac after micro adjustment. It is the intention to repeat the test a number oftimes to measure reproducibility of the results.

Assessment of the geometric accuracy in stereotactic PET image definition OS22-2Josef, Novotny Jr. (1); Karel, Nechvil (2); Josef, Novotny (3); Roman, Liscak (4) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na HomolceHospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic

Aim of this study was to evaluate three different techniques used for stereotactic PET image def-inition. A special head phantom with spherically shaped glass test vessel simulating pathologiclesion was used to simulate patient stereotactic imaging procedures. The phantom and test ves-sel were filled with fluoro-deoxy-glucose (18F-FDG) in water solution. Leksell stereotactic MRIindicator box was filled with FDG water solution too. The head phantom underwent subsequent-ly following imaging procedures: 1) PET imaging with MRI stereotactic indicator filled with FDG,2) PET imaging without any stereotactic indicator, 3) PET/CT imaging with CT stereotactic indica-tor, 4) CT imaging, 5) MRI imaging. All images were transferred into Leksell SurgiPlan softwareused for stereotactic planning and targetting procedures. Images performed with stereotactic indi-cator were defined according to standard procedures using fiducial markers presented on givenimage modality. Images without stereotactic indicator were co-registered by Leksell SurgiPlansoftware subsequently with CT and MRI stereotactic images. Stereotactic X,Y,Z coordinates of thecenter of the spherical vessel were determined for each PET image definition and compared withCT reference image. Measured deviations in X, Y, Z coordinates were as follows: 1) for PET withstereotactic radioactive markers 0.1±0.3 mm, 0.5±0.4 mm, 1.6±0.7 mm, 2) for PET co-regis-tered to MRI 0.1±0.4 mm, 0.2±0.3 mm, 0.4±0.5 mm and for PET co-registered to CT 0.4±0.4mm, 0.6±0.5 mm, 0.6±0.6 mm, 3) for PET/CT with stereotactic non-radioactive markers0.2±0.2 mm, 0.4±0.3 mm, 0.5±0.8 mm. All three evaluated stereotactic PET image definitiontechniques indicated very good geometric accuracy entirely accepted by clinical requirements.

174

Page 177: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Quality assurance in stereotactic imaging using the known target point method OS22-3Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1); Andreas, Mack (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3)Gamma Knife Center Frankfurt - Medical Physics Zürich, Switzerland

Two roughly identical phantoms have been designed to determine known target points based onstereotactic imaging modalities and stereotactic localisation in order to determine the geometri-cal accuracy of stereotactic imaging modalities. Each phantom is made of 8 PMMA plates, whichfits by means of a base plate into the Leksell stereotactic frame and is imaged together with theappropriate fiducal marker box in the typical patient set up. The CT/DSA phantom holds 45 steelspheres (diameter = 1 mm) positioned at known Leksell coordinates. The MR phantom holds 21three dimensional cross hairs. Each cross hair consist of 5 individual glass vials positioned at aknown Leksell coordinate. The positions of the phantom markers are known with a precision ofbetter than 0.1 mm. After imaging, the data are imported into LGP where the stereotactic coor-dinates of the visible markers are determined and compared with the known coordinates.Depending on the MR imaging protocol (2D/3D) applied, increased deviations between measuredand known coordinates are found near the stereotactic frame. The mean (max) value of the deter-mined deviation is between 0.3 (1.1) and 1.6 (3.6) mm. Dependent on the CT image acquisition(axial/helical) the mean (max) deviation found was between 0.37 (0.73) und 0.75 (1.35) mm. Amaximum deviation of 2.5 mm was found in image intensifier based angiographic images,whereas the maximum deviation in plane films was less than 0.5 mm. Special attention must bepaid to the geometrical accuracy of stereotactic imaging modalities, because their geometricaluncertainties usually dominate the overall geometrical accuracy of the treatment. The implemen-tation of adequate imaging protocols and quality assurance procedures are a prerequisite for pre-cise lesion targeting. The use of the described phantoms facilitate this task considerably. However,patient related artefacts, leading to geometrical targeting uncertainties cannot be monitoredusing this method.

Quality assurance in stereotactic radiosurgery according E-DIN 6875-1 OS22-4Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics Zürich, Switzerland

The E-DIN 6875-1 standard deals with QA criteria and test methods for linear accelerator andgamma knife based stereotactic radiosurgery (SRS)/radiotherapy (SRT). E-DIN 6875-1 covers func-tional performance characteristics, test conditions and test procedures to describe acceptance andregular constancy tests for SRS/SRT therapy systems. The aim of this standard is the comparabil-ity of functional performance characteristics for different irradiation devices for different manufac-turers. This DIN covers dosimetric and geometrical performance characteristics, treatment plan-ning, imaging accuracy and a system test to check the whole chain of uncertainties, from imag-ing through to irradiation based on the unknown target point method. Our existing QA program,based on dedicated phantoms and test procedures, has been refined to fulfil the demands of thenew DIN. The radiological and mechanical isocenter correspond within 0.16 mm and the meas-

175

Page 178: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ured 50 % isodose line is in agreement to within 1 mm. However, significant deviations betweenthe measured and the calculated dose profiles have been found (up to 8 % in the shoulder regionfor the 8 mm collimator helmet). The measured absorbed dose is within 3 % using variousdosimeters. The resultant output factors measured for the 14, 8 and 4 mm collimator helmet were0.9870 +/- 0.0086, 0.9578 +/- 0.0057 and 0.8741 +/- 0.0202 respectively. For 170 consec-utive system tests using MR imaging the mean geometrical accuracy is 0.48 +/- 0.23 mm. Thistargeting uncertainty is dominated by the targeting uncertainty of the MR scanner. QA in radio-surgery is labour intensive and time consuming, but an essential basis for a successful clinical out-come. Besides QA phantoms and analysis software developed and tested in house, the use ofcommercially available dedicated tools facilitates and speeds up the QA according the E-DIN6875-1 to which our results comply.

ORAL SESSIONS 17h00 - 18h00

FUNCTIONAL - TRIGEMINAL NEURALGIA 2 OS23 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation

Incidence of paresthesias after radiosurgery (SRS) for trigeminal neuralgia targeting at the root entry zone OS23-1Alessandra, Gorgulho (1); Antonio, De Salles (2); David, McArthur (3); Zachary, Smith (4); Leonardo, Frighetto(5); Carlos, Mattozo (1); Steve, Lee (6); Michael, Selch (7); Timothy, Solberg (7) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA - Neurosurgery; (3) UCLA - Neurosurgery;(4) UCLA - Neurosurgery; (5) UCLA - Neurosurgery; (6) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Purpose: Evaluate the incidence and analyze possible correlations for the development of pares-thesias after SRS for Trigeminal Neuralgia (TN). Materials and Methods: From August/1995 toApril/2003, 104 patients were treated with SRS for TN, 94 had comprehensive follow-up. Meanage was 64.45±13.25 (29-88) years, 44 female, 50 underwent previous treatment. Sixty-eight(72.34%) had Essential TN, 19 (20.21%) Secondary TN and 9 (9.57%) had Atypical TN. Dosesprescribed were: 70Gy (13 patients), 75Gy (5 patients), 80Gy (3 patients), 85 Gy (1 patient), 90Gy(72 patients). Isocenter was placed with the 50% isodoseline (IDL) tangent to the brainstem sur-face. The 5mm collimator was used in 78(82.9%) cases. Results: Paresthesias were observed bysubjective report and/or follow-up neurological examination in 50 (53.2%) patients, graded assevere in 3 (3.2%) cases. Good/Excellent outcomes were sustained in 55 (58%) cases at mean 23months follow-up. Recurrence occurred in 4 cases (5.5-10 months post-SRS). No anesthesiadolorosa or ophthalmologic problems were noticed. TN etiology correlated with paresthesias afterSRS (p= 0.02). Paresthesias also correlated with enhancement observed in follow-up MRIs scans(p=0.02), either the nerve or the pons. Patients presenting better pain control did not present ahigher rate of paresthesias (p=0.4). No correlation was found between paresthesias and gender(p=0.67), any previous treatment (p=0.67), only previous radiofrequency rhizotomy (p=0.81)or microvascular decompression (p=0.27) or SRS (p=0.24) and prescribed dose (< 90 or 90 Gy)(p=0.4). Conclusions: A higher rate of paresthesias was observed in this series where the isocen-ter was placed closer to the brainstem and a high dose was delivered (90 Gy) for the absolute

176

Page 179: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

majority of the patients. Essential TN and Secondary TN were associated with more paresthesiasafter SRS than atypical TN. Enhancement noticed in follow-up MRI scans also correlated withparesthesias development. No additional factors correlated with paresthesias occurrence.

Robotized micro-radiosurgery for essential trigeminal neuralgia:Evaluation and analysis of over 100 patients experience with unique method OS23-2Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1);Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan

Rationale: Gamma knife surgery (GKS) is a minimally invasive treatment for brain diseases, andis currently used for functional disorders. Moreover, refining new Gamma knife system, “ModelC-APS (automatic positioning system)” has just been installed since 2002 in Japan. The advan-tage of this system is to provide us to automatically set every coordination with 0.1 mm leveladjustment. We’d like to compare between the latest method using APS and the previous oneusing manual coordination, and evaluate the efficacy and safety of APS treatment for essentialtrigeminal neuralgia(eTGN). Methods: We have completed a retrospective study of 200 patientssuffering from eTGN treated by GKS whose target was localized on the retro-gasserian portion ofthe nerve. Among the patients, the 152 could be followed up more than 3 months. We assignedinto 3 groups according to the term; 1st group(27pts): patients were treated by Model B withoutcompleted fusion images (CFI) in between 1999 and 2001, 2nd group(19pts): treated by ModelB with CFI in 2002, and 3rd group (104pts): treated by model C-APS with CFI since 2003. Results:Clinical result, initial severe pain(= electric discharge) free was observed in 62.9%(1st group),85.7%(2nd group), 98.1% (3rd group), complete recurrence was observed in 11.8% (1st group),5.2 % (2nd group), 0 % (3rd group), and postoperative complication was observed in 14.8% (1stgroup), 14.3% (2nd group), 9.6% (3rd group). In 3rd group, we found significant difference inbetween excellent results (rapidly effect without any pain) and fair results (late response with tem-porally recurrence) group, that higher unit energy to the nerve (median: 39.2 vs 33.9 mJ/cc) andlower dose to the Gasserian ganglia (median: 31.9 vs 70.6 Gy) were seen in the excellent group.Conclusions: We suppose, automatically coordinate system with 0.1 mm adustment, so called“Robotized Micoro-Radiosurgery” should be needed to obtain satisfied results. Additionally, inthe dose planning, targeting to the nerve should be located on just a little bit more posterior fromthe trigeminal incisula with “pinpoint” irradiation after adjustment of positional distortion on MRIto provide the patients to relief from severe pain.

Trigemina neuralgia treatment with linear accelerator radiosurgery: results in 82 patients OS23-3Michael, Girvigian (1); Joseph CT, Chen (2) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology; (2) Kaiser Permanente MedicalCenter - Neurosurgery Los Angeles, USA

Introduction: Radiosurgical treatment for trigeminal neuralgia has been well investigated withgamma-unit device. Few reports exist concerning the treatment of trigeminal neuralgia using lin-

177

Page 180: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ear accelerator (LINAC)-based devices. In recent years these devices have reached the level ofmechanical precision required for such functional treatments. We describe our initial experiencewith radiosurgical treatment for trigeminal neuralgia employing a BrainLAB Novalis LINAC device.Methods: A total of 82 patients were treated. The median age was 63 years (range 29-88). Allpatients were BNI grade IV or V prior to treatment. Three cases were complicated by multiple scle-rosis. Patients undergoing initial radiosurgical treatments were treated to the cisternal portion ofthe trigeminal nerve and received 85 to 90 Gy utilizing a 5 or 7 non-coplanar arc single isocen-ter plan with a 4 mm circular collimator. Cases involving radiosurgical repeat treatment received60 Gy. Results: Overall good and excellent results (BNI level I, II or III) were obtained in 83%.Median time to pain relief was 4 weeks. Fair and poor results (BNI level IV or V) were seen in17%. Three patients demonstrated new trigeminal dysfunction following treatment, but in nopatient was the corneal reflex lost. No other complications were seen in this series.Responsiveness to anticonvulsant medication was a significant prognostic indicator for treatmentsuccess (p<0.05)

Complication of gamma knife surgery for trigeminal neuralgia OS23-4Shinji, Matsuda (1); Toru, Serizawa (2); Yoshinori, Higuchi (3); Makoto, Sato (4); Junichi, Ono (5) (1) Chiba Cardiovascular Center - Department of Neurology; (2) Chiba Cardiovascular Center - Department ofNeurosurgery; (3) Chiba Cardiovascular Center - Department of Neurosurgery; (4) Chiba CardiovasucularCenter - Department of Radiology; (5) Chiba Cardiovascular Center - Department of Neurosurgery Chiba, Japan

Object: gamma knife surgery (GKS) is one of effective treatment options for intractable trigeminalneuralgia (TN). Majority of Complications were not severe. However, the incidence of complica-tion in recent reports was higher than that in pervious reports. We reviewed the results of ourseries and evaluated factors correlated with complications. Methods: Seventy-four medicallyrefractory TN patients were treated with GKS between August 1998 and December 2004. Fifty-three patients received 80Gy at proximal trigeminal nerve root, and 21 received 90Gy at retro-gasserian portion with a single isocenter using 4-mm collimator. Follow-up was obtained by clin-ic visits every three or six months after GKS. Improvement, recurrence, complications and changesin magnetic resonance imaging were recorded. Relations between complication and patient’scharacteristics, treatment techniques or pain relief were analyzed with univariate analysis.Results: The follow-up duration was 3-60 (mean 27) months. Forty-six patients showed excellentresults (pain free without any medication), 18 patients good (pain free with some medication), 9patients fair (50% or more decreased in pain), and 1 patient showed poor results (less than 50%improvement in pain). Nine patients suffered from recurrence of neuralgia. Complications wereobserved in 22 patients at 9 to 36 months after GKS. These patients complained of facial numb-ness, and hypoesthesia was found. Six of them complained their numbness was bothersome.Three of these 6 patients complained of “dry eye” with diminution or absence of corneal reflex.On univariate analysis, patient’s characteristics or treatment techniques were not associated withcomplications. Satisfactory pain control was significantly related to complications (p=0.003,Fisher’s exact test). Conclusion: In this study, complication was significantly related to good paincontrol. Trigeminal nerve damage following irradiation is important for both complication andpain control. If both of patients and clinician expect satisfactory pain control, mild numbnesswould be accepted.

178

Page 181: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

SPINE OS24Chairmen: Iris, Gibbs; Antonio, DeSalles Room Permeke &

Rembrandt

Single fraction spinal radiosurgery for the treatment of spinal metastases OS24-1Peter, Gerszten (1); Steven, Burton (2); Cihat, Ozhasoglu (3); William, Vogel (3); Annette, Quinn (3); William,Welch (4) (1) Shadyside Hospital - Department of Neurosurgery; (2) Shadyside Hospital - Radiosurgery Department; (3)Shadyside Hospital - Radiation Oncology Department; (4) University of Pittsburgh Medical Center -Department of Neurological Surgery Pittsburgh, USA

This study evaluated the effectiveness of radiosurgery for the treatment of spinal metastases. 450patients were treated with single fraction radiosurgery (mean age 56 years; 206 men; 244women) (69 cervical, 184 thoracic, 130 lumbar and 67 sacral) using the CyberKnife (Accuray, Inc.,Sunnyvale, CA). The most common histologies were renal (n=80), breast (n=68), lung (n=64),colon (n=30) and melanoma (n=30). Three hundred eight lesions received prior external beamirradiation. All dose plans were calculated upon CT images using 1.25 mm slices. PTV wasdefined as radiographic tumor volume without margin. Radiosurgical circular cones ranged from5 to 40 mm. Tumor dose was maintained at 12-25 Gy to the 80% isodose line (mean 18 Gy).The maximum intratumoral dose ranged from 15 to 25 Gy (mean 21 Gy). Tumor volume rangedfrom 0.16 to 298 cc (mean 31.3 cc). The spinal canal volume receiving greater than 8 Gy rangedfrom 0.0 to 1.7 cc (mean 0.3 cc). No radiation toxicity occurred during follow-up (3-48 months).Axial and/or radicular pain improved in 264 of 290 patients (91%). Twenty-nine of 34 patients(85%) with neurological deficits prior to treatment experienced improvement In the largest seriesof its kind to date, spinal radiosurgery was found safe and clinically effective for spinal metas-tases. Major potential benefits of radiosurgical ablation of spinal metastases are short treatmenttime in an outpatient setting with rapid recovery and good symptomatic response. This techniqueoffers an important new alternative therapeutic modality for spinal tumors not amenable to opensurgical techniques, in medically inoperable patients, lesions located in previously irradiated sites,or as an adjunct to surgery.

Decade of Cyberknife at Stanford University 1994-2004 OS24-2Iris, Gibbs (1); Anthony K., Ho (2); Cristian, Cotrutz (3); Steven D., Chang (4); Christopher, King (5); Albert,Koong (6); John R., Adler Jr. (7) (1) Stanford University - Radiation Oncology; (2) Stanford University - Radiation Oncology; (3) StanfordUniversity - Radiation Oncology; (4) Stanford University - Neurosurgery; (5) Stanford University - Departmentof Radiation Oncology; (6) Stanford University - Radiation Oncology; (7) Stanford University - Neurosurgery Stanford, USA

Introduction: Stanford University has a long legacy of contributions to the field of radiation ther-apy. In 1994, the first Cyberknife prototype was introduced at Stanford University Medical Center.Since then, over 1900 lesions have been treated. Here we present a review of these treatments.Methods: We reviewed the records of all patients treated on the Stanford Cyberknife from 1994-2004. The data are summarized according to type of lesion treated. Trends in the data are shown

179

Page 182: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

graphically and descriptively. Results: Between 1994 and 2004, over 1550 patients with morethan 1900 lesions were treated including both intracranial and extracranial lesions. Fewer than100 lesions were treated 1994-1999. However, by 2003 over 475 lesions were treated annual-ly. Though intracranial lesions constitute the majority of lesions, in the current year nearly one-third of the patients were treated for extracranial lesions. The most rapid rise in extracranial treat-ments was experienced for spine, pancreas, and prostate tumors. We show improved local con-trol in the nasopharynx, good palliation in pancreatic tumors, pain relief for metastatic spinallesions, control of benign spinal tumors, and feasibility of radiosurgery in the prostate, liver, andrecurrent rectal tumors. Conclusion: The Stanford Cyberknife radiosurgery program has beenhighly successful. We have expanded the flexibility of treating intracranial lesions and pioneeredtreatments of extracranial lesions of the spine, lung, pancreas, prostate, and liver. The trendtoward treatment of extracranial neoplasms has paralleled the improvements dose rate, respira-tory tracking, and image-guidance.

Importance of image fusion for spinal radiosurgery OS24-3Antonio, De Salles (1); Alessandra, Gorgulho (1); Paul, Medin (2); Nzhde, Agazaryan (3); Timothy, Solberg (3);Carlos, Mattozo (3); Leonardo, Frighetto (3); Cynthia, Cabatan-Awang (3); Michael, Selch (3) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of RadiationOncology Los Angeles, USA

Introduction: Dynamics of the spine must be taken in consideration during image acquisition forstereotactic radiation (SR). Materials and Methods: From July/2002 to April/2005, 32 patientswere treated with single dose (SRS). There were metastases, neurofibromas, meningiomas andarteriovenous malformation. Lesions were cervical, thoracic and lumbar. Symptoms before SRwere pain, paresthesias, weakness or no symptoms. Spine surgery and instrumentation weretaken into account for imaging modality of choice. Multiset imaging fusion MRI, CT and DigitalPlain films were used to ascertain spine stability and correlation of bone, cord and spinal nerveanatomy during planning and treatment. Patients who received conventional radiation before SRSwere also scrutinized for maximal dose to the spinal cord. The dose of choice was 12Gy„b2.7Gy(8-21) prescribed to mean 90% isodoseline (85-97). Intensity Modulation was used when tumorembraced the spinal cord, dynamic multileaf and static beams were also used. Lesion volume var-ied from 0.75-91.8cc. Follow up ranged from 1 to 34 months. Results: Multiset fusion provedinvaluable to define tumor and AVM volume and their relationship with structures needing spar-ing. The main symptomatic response was resolution of pain. Weakness improvement was alsoobserved, new neurological deficits related to radiation damage or edema was not observed.Less than 50% of the lesions decreased in size, the majority remained the same and only fewmetastases progressed when receiving 12 Gy to the periphery of the lesion. Dose to the cord waslimited to 8Gy. No complications of shaped-beam and IMRS/IMRT techniques were observed.Conclusions: Multiset imaging fused and visualized simultaneously during planning help ascer-tain spine stability, soft tissue relationships and precision of radiation delivery. The lack of com-plication suggests that higher doses can be delivered to improve the control rate in metastasispatients.

180

Page 183: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Image-guided radiosurgery of the spinal nerve: A pilot study in swine OS24-4 Paul, Medin (1); Bryan William, Goss (2); Dennis, Chute (3); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Radiation Oncology; (2) UCLA - Radiation Oncology; (3) UCLA -Pathology Los Angeles, USA

Purpose: A pilot study was performed in two Yucatan minipigs to investigate the potential use ofa non-invasive, image-guided spinal radiosurgery method to irradiate spinal nerves for the reliefof dermatomal pain. Methods and Materials: Mature minipigs (41 kg, 40 weeks old) were usedfor their anatomical similarities to humans. A CT scan and multiple MRI sequences were acquiredand fused for treatment planning. Two consecutive left-sided lumbar spinal nerves were targetedin each animal. ExacTrac infrared tracking and the Novalis Body kilovoltage image guidance sys-tem (BrainLAB, AG) were used for patient positioning. A maximum dose of 90 Gy was deliveredto each target using a 5 mm diameter collimator directed through 8 noncoplanar arcs. Behaviorand gait were monitored and crude sensory evaluation was performed up to eight months post-radiosurgery. MRI sequences were acquired at the study’s conclusion. Results: Both animalsmaintained normal behavior and gait throughout the study. One animal became non-responsiveto pinching stimulation in its left hind leg four months post radiosurgery. No histological changeswere seen in any DRG or spinal cord sections which received maximum doses of approximately20 Gy and 9 Gy, respectively. Two of the three spinal nerves available for evaluation showedmarked changes including a profound loss of myelinated axons and Wallerian degeneration.Conclusions: Axial CISS MRI (0.5 mm) provided the clearest visualization of the spinal nerve. Theimage guidance technique used is capable of positioning functional targets in the spine.Refinements in imaging and image-guidance may improve targeting. Numbness is a potentialside effect of this procedure.

181

Page 184: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Thursday 15/09/05

PLENARY SESSION 8h45 - 10h00

PS4Room Nation

DATA BLITZ UPDATE 5

Functional radiosurgery PS4-1Douglas, Kondziolka

DATA BLITZ UPDATE 6Spinal radiosurgery PS4-2Iris, Gibbs

COMBINED STRATEGIES, TRIGEMINAL NEURALGIA, CANCEROGENESISChairmen: Douglas, Kondziolka; Iris, Gibbs

Combination therapy of intentional partial resection followed by gamma knife radiosurgery for large skull base meningiomas PS4-3Seiji, Fukuoka (1) (1) Nakamura Memorial Hospital - Department of Neurosurgery Sapporo, Japan

Objective: The purpose of this study was to evaluate the efficacy of gamma knife radiosurgery(GKRS) when used as a treatment modality for skull base meningiomas (SBMs), with particularattention paid to whether or not a combination therapy of intentional partial resection (IPR) fol-lowed by GKRS constituted an appropriate method for larger SBMs. Method: Of the 101 SBMpatients, 38 patients were classified as cavernous sinus meningiomas (CSMs), and 63 with pos-terior fossa meningiomas (PFMs). All patients were treated according to a set protocol. Small tomedium sized SBMs (8 CSMs, 49 PFMs) were treated solely by GKRS. To minimize any risk of func-tional deficit, larger tumors were treated by a combination therapy of IPR followed by GKRS (11CSMs, 8 PFMs). Residual or recurrent tumors in patients who had undergone extirpations prior toGKRS (19 CSMs, 6 PFMs) are not included in this treatment method. Results: The mean follow upperiod was 51.9 months (6 to 144 months). The tumor control rate was 95.5% in CSMs and98.4% in PFMs. Almost all tumors treated solely by GKRS were well controlled without anydeficits. Furthermore, none of the patients who had undergone prior surgeries experienced anynew neurological deficits after GKRS. While newly appearing neurological deficits (total 7)occurred far less in the combination therapy, extirpations tended to be associated with a higherincidence of new deficits or worsening of already existing deficits. Forty six such deficits wereidentified, only 4 of which showed improvement after GKRS. Conclusion: This study indicates thatGKRS can be recommended as a safe and effective treatment of SBMs with small to medium sizedtumors. It also demonstrates that larger SBMs can be effectively treated, minimizing any possiblefunctional damage, by this combination therapy.

182

Page 185: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Incidence of trigeminal nerve dysfunction after trigeminal neuralgia radiosurgery: a comparison between 3 treatment strategies PS4-4Nicolas, Massager (1); Noriko, Tamura (2); Ouzi, Nissim (3); Daniel, Devriendt (4); Françoise, Desmedt (3);David, Wikler (5); Jacques, Brotchi (1); Marc, Levivier (3); Jean, Regis (6) (1) Hôpital Erasme - Neurochirurgie; (2) CHU La Timone - Gamma Knife center; (3) Hôpital Erasme - CentreGamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - PET Scan; (6) CHU La Timone - Servicede Neurochirurgie Brussels, Belgium

Objective: The aim of this study was to analyze the incidence of facial numbness or dysesthesiasfollowing gamma knife radiosurgery (GKR) for trigeminal neuralgia (TN), when 3 different strate-gies of planning are used. Material & Methods: We reviewed the incidence of facial numbness inpatients treated for TN in GKR centers of Marseilles and Brussels. In both centers the plexus tri-angularis target was used. For patients with a large perimesencephalic cistern, a maximum doseof 90 Gy was used (group 1, both centers). For patients with a small cistern, to reduce the dosedelivered to the brainstem, either the maximum dose was reduced (group 2, Marseilles method),or plugs were used (group 3, Brussels method). We analyzed the mean dose delivered to thetrigeminal nerve in those 3 groups. Results: The data of 358 patients were analyzed (group 1:169 patients (Marseilles=109 +Brussels=60); group 2: 140 patients; group 3: 49 patients). Theincidence of trigeminal nerve dysfunction was of 21% in group 1, 7% in group 2 and 49% ingroup 3. We found a statistically significant relation between induced trigeminal dysfunction andthe use of plugs. For each patient, the mean dose and the integrated dose delivered to the trigem-inal nerve were calculated. We found a significant association between incidence of facialhypo/paresthesias and the mean dose delivered to the nerve: average values of the mean dosedelivered to the trigeminal nerve were 38.01 Gy for group 1, 32.17 Gy for group 2 and 42.86Gy for group 3. Conclusion: Use of plugs increases the mean dose delivered to the trigeminalnerve and is associated with an increased incidence of trigeminal nerve dysfunction. To reducethe irradiation of the brainstem during GKR for TN, reduction of the prescription dose seems tobe a better option than beam channel blocking.

Estimating the risk of malignancy after radiosurgery in the general population PS4-5 Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz(3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

Introduction: To address frequently raised concerns, we attempted a systematic estimate of therisk of intracranial malignancy after stereotactic radiosurgery. Clinical material: From 1985-2004the Sheffield Unit treated 5014 UK residents. From these, 118 neurofibromatosis patients wereexcluded. Records were cross-referenced against national mortality and cancer databases. Thisconstitutes over 30,000 completed patient-years of data; 2372 patients having less than 5 years,1476 patients 5-10 years, 740 patients 10-15 years and 308 patients more than 15 years of fol-

183

Page 186: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

low-up. The mean age at treatment was 45±17 years, there being an equal sex distribution. Asa measure of ascertainment, 111 patients with cerebral metastases were treated in this period.Results: Of the 4896 patients, two possible new cases of malignant brain tumour were detected.One was an astrocytoma reported eight years after radiosurgery for a cavernoma. The secondpossible case was reported in 1994 as a malignant brain tumour, further details are currentlybeing sought. Correcting for age, sex and follow-up, using national cancer incidence figures,[1]we would expect 2.14 cases of central nervous system malignancy to occur spontaneously. Interms of ascertainment, 90% of patients with cerebral metastases were detected by the cross-ref-erencing process. Conclusion With over 30,000 patient-years of data, more than 3,700 years ofwhich was collected after a period of more than 10 years had elapsed since the time of radio-surgery, no excess incidence of intracranial malignancy could be detected. This clearly supportsthe long-term safety record of gamma knife stereotactic radiosurgery. 1. Cancer Incidences in FiveContinents. Ed Parkin DM, Muir CS, Whelan SL, Gao Y-T, Ferlay J, Powell J. International agencyfor research on cancer. Lyon 1992.

ORAL SESSIONS 10h30 - 11h30

ARTERIOVENOUS MALFORMATIONS 1 OS25Chairmen: Douglas, Kondziolka; Keisuke, Maruyama Room Nation

Usefulness of time resolved MR digital substracted angiography (MRDSA) in the follow-up of cerebral arterio-venous malformations (AVMs) after gamma knife radiosurgery: preliminary results OS25-1Philippe, David (1); Patrice, Jissendi (1); Isabelle, Delpierre (1); Danièle, Balériaux (1); Nicolas, Massager (2);Daniel, Devriendt (5); Marc, Levivier (5); Boris, Lubicz (1) (1) Hôpital Erasme - Neuroradiologie; (2) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Purpose : To evaluate the usefulness of MRDSA in the follow-up of cerebral AVMs treated bygamma knife radiosurgery. Material and methodes: From december 2000 to february 2005, 76patients were treated by gamma knife surgery for cerebral AVMs. Patient were prospectively fol-lowed at 6,12,18,24 and 36 month by MRI , MRA and MRDSA. When MRDSA concluded to acomplete obliteration of the nidus a digital substracted angiography (DSA) was then performed.Results A total of 70 MRDSA allowed to study both size and dynamic evolution of the flow in thenidus. Until now, 14 patients presented a complete obliteration of the nidus on MRDSA. In allthose cases DSA confirmed the total obliteration of the nidus. Conclusions : Those prelimaryresults illustrate the potential usefulness of MRDSA as a non invasive study of both size and flowin AVMs nidus after gamma knife radiosurgery.

184

Page 187: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Clinical implications of the latent period after AVM radiosurgery OS25-2Aurelia, Kollova (1); Farouq, Din (1); Alison, Grainger (1); Jeremy, Rowe (1); Lee, Walton (2); Matthias WalterRichard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield -Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department ofNeurosurgery Sheffield, United Kingdom

Introduction: In AVM radiosurgery, it is recognized that there is a latent period before throm-boobliteration occurs and the patient is protected from haemorrhage. To examine this, wereviewed the data of fatal haemorrhages from the database of Office of National Statistics of U.K.that occurred in our patient series. Clinical material: In 2990 treated AVM patients, 93 fatal bleedswere identified. The timing of these events and the radiosurgical and clinical characteristics of theAVMs were reviewed. Results: There was a striking temporal sequence, 48 fatal bleeds (52%)occurring within first two years, 18 bleeds occurring 2-4 years after the treatment and 27 bleedsbetween 4 and 14 years after radiosurgery. Of the 48 early deaths, 35 had had previous haem-orrhage. We have observed haemorrhages even after complete angiographic conclusion. TheAVMs with fatal haemorrhage after radiosurgery were significantly ( p<0.001) larger than ourgeneral AVM population treated with radiosurgery: 8.8±8.1ccm compared with 4.8±6.9 ccm.The marginal dose was also significantly less (p<0.01), 22.5±2.7 Gy compared with 23.3±2.7Gy. Discussion: The majority of fatal rebleeds occur relatively soon after radiosurgery. In ourpatient series we would however predict over 500 bleeds, given the length of follow-up andaverage AVM bleed rates. As the observed occlusion rate is less than 90%, this may suggest thatradiosurgery provides some protection against haemorrhage, even if there is incomplete angio-graphic obliteration. It is clear, that AVM size is a major adverse factor in determining fatal bleeds,although the other treatment options for such malformations may of course be limited.

The risk of hemorrhage after radiosurgery for cerebral arteriovenous malformations: what is angiographic obliteration? OS25-3Keisuke, Maruyama (1); Nobutaka, Kawahara (1); Masahiro, Shin (1); Masao, Tago (2); Hiroki, Kurita (3); Akio,Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology;(3) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan

Background: Angiography shows that stereotactic radiosurgery obliterates most cerebral arteri-ovenous malformations (AVMs) after a latency period of a few years. However, the effect of thisprocedure on the risk of hemorrhage is poorly understood. Methods: We retrospectively reviewed500 patients with AVMs who underwent gamma knife radiosurgery. The rates of hemorrhagewere assessed during three periods: before radiosurgery, between radiosurgery and angiograph-ic obliteration (latency period), and after angiographic obliteration. Results: Forty-two hemorrhag-es were documented before radiosurgery (median follow-up, 0.4 year) and 23 during the laten-cy period (median follow-up, 2.0 years). Six patients developed hemorrhage after obliteration(median follow-up, 5.4 years). Their histological findings showed occlusion of the AVM by thick-ening of the intimal layer with dense hyalinization as well as a small amount of residual AVM ves-

185

Page 188: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

sels and a tiny vasculature. As compared with the period between diagnosis and radiosurgery,the risk of hemorrhage decreased by 54% during the latency period (hazard ratio, 0.46; 95%CI,0.26-0.80; P=0.006) and by 88% after obliteration (hazard ratio, 0.12; 95%CI, 0.05-0.29; P <0.001). The reduction was similar in analyses that took into account the delay in confirming oblit-eration by means of angiography and analyses excluded data obtained during the first year afterdiagnosis. Conclusions: Radiosurgery significantly decreases the risk of hemorrhage in patientswith AVMs, even before angiographic obliteration. The risk of hemorrhage is further reduced,although not eliminated, after obliteration. (NEJM 352:146, 2005 & JNS 102:844, 2005)

Gamma knife radiosurgery as an alterative treatment for dural AV fistulas involving the transverse-sigmoid sinus OS25-4David Hung-Chi, Pan (1) (1) Taipei Veterans General Hospital - Department of Neurosurgery Taipei, Taiwan

A retrospective analysis was performed in 41 patients with DAVFs involving the transverse-sig-moid sinus, who were treated by gamma knife radiosurgery (GKS) alone (24 cases) or combinedwith surgery and/or embolization (17 cases) between June 1995 and June 2004. The indicationsfor GKS include progressive intolerable headache and bruits, increased intracranial pressure, hem-orrhage and failure of prior treatments. Based on the Cognard’s angiographic classification, therewere 13 type I, 13 type IIa, 3 type IIb and 12 type IIa+b. Radiosurgery was performed usingmultiple (mean 11) shots irradiation to the involved segment of the dural sinus wall in whichDAVF nidus located. The margin dose / maximum dose to the nidus ranged from 16.5-20 Gy /25-36 Gy respectively. Median follow-up was 36 months (range 6-98 months). Of 22 patientswho had undergone follow-up angiography, 19(86%) showed complete obliteration of DAVFs,other 3 (14%) showed subtotal or partial obliteration. Symptomatic cure was observed in 71%(29/41) of all patients. There was one complication (2.4%) caused by intracerebral venous hem-orrhage one week after GKS. Other 40 patients experienced smooth and gradually improved clin-ical course. Conclusion: GKS provides a safe and effective therapeutic option for the managementof DAVFs. For those DAVFs with mild venous restriction, radiosurgery may be indicated as a pri-mary treatment. However, for some aggressive DAVFs with severe venous reflux and hyperten-sion, initial treatment with embolization or surgery for prompt elimination of aggressive compo-nent of the DAVF is necessary. Radiosurgery may provide an effective djuvant for futher manage-ment of such complex DAVFs.

PITUITARY & CRANIOPHARYNGIOMAS OS26Chairmen: Ajay, Niranjan; Jeremy, Ganz Room Permeke &

Rembrandt

Gamma knife surgery and dopamine agonists in combination in the treatment of the clinical effects of prolactinomas OS26-1Jeremy, Ganz (1); W A., Reda (1); Ayman, Hafez (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

Objective: gamma knife Surgery (GKS) for prolactinomas remains the subject of controversy. An

186

Page 189: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

attempt is made here to improve and define appropriate treatment measures and to managethese tumours as consistently as possible. This report is an early review of the results obtained inthis way. Material and Methods: Fifteen patients with an endocrinopathy. The median follow upis 35 months (range 10 to 44 months). An attempt was made to treat all patients with 35 Gy tothe 50% isodose with more than 90% coverage and a conformity index of less than 1.25. Thedose to the visual pathway was kept below 8 Gy and this can require decreasing the prescriptiondose reducing the coverage in some patients. Thus the median prescription dose was 25 Gy(range 12 to 35 Gy). The median percentage cover was 91 (range 66% to 99%). A lower coverwas always to avoid damaging the visual pathway. The median target volume was 2.2 cm3(range 0.2 to 9.7 cm3) The median conformity index was 1.38 (range 1.19 to 2.63). One of 7acromegalic patients had not been operated. Three of 14 patients with a prolactinoma had notbeen operated but all three had received dopamine agonists. Results: All patients were kept ondopamine agonists after radiosurgery. No tumour has grown and no visual field has deteriorat-ed. Prolactinomas are treated in combination with a dopamine agonist. In 10 cases the prolactinhas normalised and in 2 it is falling. Five of 8 women have had a return of their menstruation.Four of the 7 men have an improvement in potency. In one female patient the prolactin has nor-malised but the periods have not returned. Failure to normalise a hyperprolactinaemia was notassociated with dose, tumour volume or duration of follow up. In two patients it may have beendue to lack of cooperation with medication. Conclusions: This work suggests that the clinicaleffects of endocrinopathies can be corrected in a substantial percentage of prolactinomas in ashort time if dopamine agonists are not stopped after radiosurgery. Thus, GKS is an acceptableand safe secondary treatment in these conditions. It is suggested the dosimetry described here iscrucial for good results. It is further suggested that continuing dopamine agonist treatment maybe necessary for a substantial time after radiosurgery if the best clinical result is to be achieved.

Gamma knife radiosurgery for non-functioning pituitary adenomas OS26-2Hidefumi, Jokura (1); Jun, Kawagishi (1); Hidetoshi, Ikeda (2); Kou, Takahashi (1); Teiji, Tominaga (3) (1) Furukawa Seiryo Hospital - Jiro Suzuki Memorial Gamma House; (2) Tohoku University - Department ofNeurosurgery Furukawa, Japan

Most of Non-functioning pituitary adenomas show their signs and symptoms by compressing sur-rounding structures like optic nerve and chasm. Immediate surgical decompression must be thechoice of treatment in this situation, but complete surgical removal is often impossible whentumor invaded into cavernous sinus. We summarize our result of gamma knife radiosurgery fornon-functioning pituitary adenomas after surgical decompression. Sixty-four patients had beentreated between Novemer 1991 and March 2003. Twenty-seven were male and 37 were female.Age ranged between 30 to 75 years and the average was 52 years. All but two patients whowere old and had medical risks had been operated prior to radiosurgery and in which 22 patientshad been operated more than twice. Radiosurgery was performed at the time of recognition ofregrowth of tumors in 47 and in 17 patients, immediately after the surgical decompression.Volume of tumor ranged from 0.2 to 21 ml and average was 3.3 ml. Tumor marginal dose rangedfrom 14 to 30 Gy and the average was 21.1 Gy. Follow up clinical information was available inall cases and MRI images 12 to 145 months after radiosurgery (average 60.5) were obtained all

187

Page 190: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

but 2 patients. During the follow-up, one patient died of parasellar aspergillosis. Surgical removalwas needed in 2 patients 7 and 10 years after radiosurgery respectively and the tumor controlrate at the last follow up was 97%. We saw no new permanent cranial nerve dysfunction includ-ing optic nerve. During the follow up period, steroid replacement started in one patient who hadnot been replaced at the time of radiosurgery and one other patient needed thyroid replacementadding to steroid. Gamma knife radiosurgery is very powerful and safe adjuvant for non-funci-tioning pituitary adenomas after adequate surgical removal.

New treatment strategy for craniopharyngioma using Gamma Knife radiosurgery OS26-3Tatsuya, Kobayashi (1); Yoshimasa, Mori (1); Yoshihisa, Kida (2); Toshinori, Hasegawa (3); Naoki, Hayashi (1) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Komaki City Hospital - Department of Neurosurgery Nagoya, Japan

The treatment of craniopharyngiomas has been controversial. Total removal is ideal but completeremoval without deterioration of neuro-endocrinological functions has been difficult. By the com-bined treatment with partial removal and fractionated radiotherapy, cure or complete control ofthe tumor has also been difficult and late radiation injury can produce major side effects.Stereotactic radiosurgery has been found to be effective and safe for this tumor. New strategy oftreating craniopharyngioma using gamma radiosurgery is needed and presented from our expe-riences of long-term results of 98 cases. The rational observations for a strategy are: 1).Nine-teen(19.4%) of 98 showed complete response (CR), which was stable and unchanged for mean of75.1 months. 2).The favorable prognostic factors which gave rise to obtain CR by gamma kniferadiosurgery were: tumor with adult patient, solid tumor, the mean diameter of 15.9 mm andmean marginal dose of 12.1 Gy. 3).The reduction of the marginal dose resulted in decreasedresponses and increased tumor progression, although the rate of visual and pituitary function lossalso decreased. 4).The common site of residual and recurrent tumor was located at retro-chiasmand ventral stalk area, where should be avoided from total removal. Excellent outcome (cure) canbe obtained by gamma knife radiosurgery of relatively small tumors at the retro-chiasm and ven-tral stalk area, using marginal doses of approximately 12 Gy, without neuro-endocrinologicaldeficits.

Biochemical assessment and long-term monitoring in patients managed by radiosurgery for growth hormone secreting pituitary adenomas OS26-4Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); Sue, Challinor (4);John C, Flickinger (3) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center- Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4)University of Pittsburgh Medical Center - Division of Endocrinology and Metabolism Pittsburgh, USA

OBJECTIVE: To evaluate the effect of stereotactic radiosurgery on growth hormone (GH) secretion,in patients with newly diagnosed or residual GH secreting pituitary adenomas. METHODS:Twenty-Four patients (10 men, 14 women) who had gamma knife radiosurgery for growth hor-mone secreting pituitary adenoma and were followed at the University of Pittsburgh Medical

188

Page 191: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Center were evaluated. Nineteen had prior transsphenoidal tumor resection and one had priorradiation therapy. The median tumor volume was 3.0 ml (range 1.2 – 8.4 ml) and the mediantumor margin dose was 20 Gy (range 12.5 - 30 Gy) and median central dose was 40 Gy (range,25-54.5). Median dose to optic apparatus was 6.5 Gy (range, 3-10). Selected beam blocking wasused in 6 patients. All patients had serial clinical, radiological, and endocrine assessments. Thecure was defined as a growth hormone value of less than 1 ng/ml along with normal IGF-1(somatomedin C) levels. A complete pituitary hormone profile was requested to assess new hor-mone deficiency. RESULTS: Biochemical cure was achieved in 13 patients (54 %) at a median fol-low-up of 4 years (range, 1-12). Growth hormone and IGF-1 levels were normalized on medica-tion in additional 4 patients (17%) and decreased in seven patients (29%). New hormone defi-ciencies were detected in four patients (17%) one to three years after radiosurgery. No patientreported vision deterioration after radiosurgery. Radiological tumor control was achieved in all 24patients. CONCLUSIONS: gamma knife radiosurgery is a valuable management option for GHsecreting Pituitary adenomas. Regular endocrine follow-up is essential to define cure and detectnew pituitary hormone deficiencies.

MOLECULAR IMAGING - PET OS27Chairmen: David, Wikler; Josef, Novotny Jr. Room Willumsen

Trials to introduce the coordinate system on PET-CT image during dose planning in gamma knife surgery OS27-1Naoki, Hayashi (1); Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Yuta, Shibamoto (2) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiologyand Radiation Oncology Nagoya, Japan

We use magnetic resonance imaging (MRI) and/or computed tomography (CT) for dose planningin gamma knife stereotactic radiosurgery. Positron emission tomography (PET) provides usefuladditional information as functional image. However, spatial resolution of PET image is not goodand voxel size is not fine enough for reference in dose planning of radiosurgery. PET-CT combinesmulti-slice CT system and PET scanner and generates high quality PET and CT images of a patientin a single study. Two image data sets are registered and fused to form a single image that showsthe anatomical location from CT along with the metabolic activity of PET. In some brain tumorcases we take PET-CT with Leksell G-frame and fiducial indicator on the patient head to utilize thesame stereotactic coordinate system as that of gamma knife dose planning. Because PET-CT isintegrated modality of PET and CT, we can get the coordinates of a certain area on PET by calcu-lating with the fiducials on CT image. We can evaluate findings on PET images precisely with thesame coordinates on MRI/CT used for dose planning. This method is useful to evaluate metabol-ic activity of the lesion in detail with coordinate information, especially when the target lesion issmall, cystic or heterogeneous, for example, containing necrotic parts.

189

Page 192: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

PET 11C-methionine for gammaknife radiosurgery targeting of recurrent pituitary adenomas OS27-2Bich-Ngoc-Thanh, Tang (1); Marc, Levivier (2); David, Wikler (1); Mercedes, Heureux (3); Nicolas, Massager (4);Daniel, Devriendt (5); Philippe, David (6); Bernard, Corvilain (4); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Endocrinology;(4) Hôpital Erasme - Neurochirurgie; (5) Institut J. Bordet - Radiothérapie; (6) Hôpital Erasme -Neuroradiologie Brussels, Belgium

Purpose: Our purpose was to evaluate whether PET with 11C-methionine (PET-MET) improves themanagement of recurrent or residual pituitary adenoma (PA), and whether this metabolic infor-mation is a convenient method for guiding gammaknife radiosurgery (GKRS) treatment of PA.Methods: 33 patients with were PA evaluated post-operatively by PET-MET, either because of bio-logical evidence of active residual tumor or because of MRI demonstration of non-functional ade-noma growth. We studied 24 secreting adenomas and 9 non-functional adenomas. Results: In30 patients, PET-MET detected abnormally hypermetabolic tissue. In 14 out of these, MRI did notdifferentiate between residual tumor and scar formation. In another group of 16 patients, bothPET-MET and MRI detected abnormal tissue. In 1 case, neither MRI nor PET-MET detected PA.Finally, abnormal tissue was detected in 2 patients on MRI solely. Among the initial 33 patientsincluded in the trial, a total of 18 patients were treated by a GKRS procedure planned on the basisof PET-MET and MRI stereotactic integration. Five categories of situations were encountered: i)target volume only defined on PET due to the absence of tumor signal on MRI (G1a; n=4); ii)MRI target initially non detectable, but apparent on PET-MRI co-registration (G1b; n=4); iii) tar-get volume on PET perfectly matches MRI target volume (G2a; n=2); iv) target volumes partial-ly match and consequently adjustments are made to define final therapy target (G2b; n=5); andv) target volume is only defined on MRI (G3; n=3). In our study, the overall success of GKRS was16/18 89%). Conclusions: We suggest that PET-MET is a sensitive technique for the managementof recurrent PA. Because of MRI limitations in detection these tumors, PET-MET provides decisiveinformation to determine target volume in radiosurgical procedures, extending GKRS indicationsto more difficult cases in terms of lesion detection.

Changes in amino-acid metabolism of pituitary adenomas following GK radiosurgery evaluated by PET-methionine OS27-3Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Daniel, Devriendt (3); Françoise,Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (5) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

Objective: To analyze modifications of the metabolism of methionine of pituitary adenomas (PA)induced by a gamma knife radiosurgery (GKR) procedure. Material & Methods: BetweenSeptember 2000 and September 2004, 17 patients with a recurrent or residual PA after surgerywere treated by GKR in our center using a combination of MR and PET-methionine guidance.There was 3 non-secreting PA, 7 prolactinoma, 6 ACTH-secreting PA and 1 GH-secreting PA. Allthese patients were followed biologically and by MRI after the GK procedure. A PET-scan withmethionine was performed for all patients at 1 year after GKR. We have measured the difference

190

Page 193: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

in methionine metabolism of the PA between the PET-scan performed the day of the GKR and thePET-scan performed 1 year later. We have analyzed the relation between metabolic modificationof the PA and biological parameters of the PA and dosimetric parameters of the GKR procedure.Results: Among 17 patients treated, 15 patients (88%) had a favourable biological and MRI-relat-ed outcome. Significant reduction of the metabolism of methionine 1 year after GKR was shownin 14 patients; 3 patients had no assessed modification in the uptake of methionine, includingthe 2 patients with unfavourable outcome following GKR. Conclusion: A significant reduction inthe methionine uptake of PA seems to be related to a favourable biological and MRI-relatedresponse to GKR.

Positron emission tomography target segmentation methodology for radiosurgery treatment planning OS27-4David, Wikler (1); Bich-Ngoc-Thanh, Tang (1); Daniel, Devriendt (2); Marc, Levivier (3); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Centre Gamme KnifeBrussels, Belgium

The integration in gamma knife radiosurgery treatment planning of Positron EmissionTomography (PET) images is now possible. Our group has assessed in previous studies the clini-cal validity of the accuracy that can be achieved with both frame-based stereotaxic PET andframeless PET. However, in order to take advantage of the PET metabolic information in the spa-tial definition of the lesion, one must be able to accurately delineate the margins of the PET hyper-metabolic signal. As PET does not provide quantitative data and do present a low frequency spec-trum, the segmentation of the lesion boundaries is usually dependent on the sole nuclear physi-cian expertise. We propose a segmentation method based on the lesion average and maximumvoxel values ratio. 13 lesions referred to gamma knife for previously untreated brain metastasesunderwent either stereotaxic (10) or frameless (3) PET Methionine investigation. For each patient,the lesion was segmented by two nuclear physicians according to a fusion with magnetic reso-nance imaging (MRI) T1 with transfer of magnetization contrast agent enhancement. Matching ofphysicians segmentation results was assessed by a statistically significant linear regression(R2=0.9934). For each lesion, the maximum and the average voxel values in the defined PET vol-umes were recorded. In order to identify whether a segmentation rule could be established outof these parameters, linear regression analysis was performed. A statistically significant(R2=0.9545) linear relationship between the maximum and the average voxel values of a PETMethionine hyper-metabolic volume of interest (VOI) was found (Mean (VOI) = 0.733 xMaximum (VOI) + 677.24). This linear relationship can therefore be used as a mean to automat-ically define the target volume for radiosurgery treatment. In the future, we plan to evaluate thevalidity of this expression for the delineation of low grade gliomas imaged by PET Methionine.

191

Page 194: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ORAL SESSIONS 11h30 - 12h30

ARTERIOVENOUS MALFORMATIONS 2 OS28Chairmen: Serge, Blond; Christer, Linquist Room Nation

Long-term follow-up of quality of life after gamma knife radiosurgery treatment for arteriovenous malformations OS28-1Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Bradley, Bagan (1); Sepehr, Sani (1); Demetrius,Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA

Background: gamma knife Radiosurgery (GKR) is a standard treatment modality for intracranialarteriovenous malformations (AVMs). The efficacy and safety of this procedure is well accepted;yet, there is a relative lack of evidence in the literature to support its low morbidity. The goal ofthis study is to obtain quality of life and complication rate data at long-term follow-up on patientswith AVMs treated by GKR. Methods: We independently reviewed 177 GKR procedures per-formed between 1989 and 2001 at a single institution for the treatment of intracranial AVM.Through chart review and direct patient contact, we attained greater than four year follow-up on40 patients. Clinical outcome was evaluated using a Modified Rankin Scale. Linear regression andKaplan-Meier survival curves were then employed to analyze the data. Results: Average follow-up was 100 months +/- 52.41 (range 48 to 188.5) with median follow-up of 68 months.Average pre-operative Rankin score was 1 +/- 0.6 (range 0 to 2), compared to average post-opRankin score of 0.8 +/- 0.7 (p = 0.003). 33 (83%) patients had the same pre and post Rankinscore, seven (17%) patients improved, and no patients worsened. Only two (5%) patients expe-rienced major complications requiring surgery for radiation necrosis. Four (10%) others sufferedminor transient events including new onset of seizure (n = 2), transient hemifacial paresis (n =1), and transient visual disturbance (n = 1). No correlation was found between outcome andAVM grade, location, radiation dose, method of presentation, or age of patient. Conclusion: GKRis a safe and effective modality for the treatment of AVM. The immediate impact of treatment onquality of life is minimal. However, we recommend extended follow-up of these patients for sur-veillance of potential long-term complications.

Novalis® based radiosurgical treatment of AVMs. Our pre-eliminary results OS28-2Recai, Ates (1); Maarten, Moens (1); Katrijn, Van Rompaey (1); Luc, Cavens (1); Cristo, Chaskis (1); Dirk,Vandenberge (2); Jean, D'Haens (1) (1) AZ VUB - Neurochirurgie; (2) AZ VUB - Radiothérapie Brussels, Belgium

Introduction: Between May 2000 and August 2003, 43 radiosurgical treatments, using theNovalis® linear accelerator equipped with an adjustable micro-multileaf collimator, were per-formed in a population of 42 patients carrying AVM’s. We report our experience and results ofthe treatment in 31 patients followed up correctly. Material and methods: The target is deter-mined after fusing MRi with stereotactical CT and biplanar angiographical images. A single doseof 20 Gy, exceptionally lower in giant AVM’s, was given to the margin of a single isocentre. 31

192

Page 195: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

patients, having an angiographical study available 2 years after radiosurgery or earlier if a MRi orCT-angio supposes an occlusion, are included in our study. The mean irradiated volume is 2.38cc.42% of the AVM’s are located in an eloquent or deep region. We define a patient cured if noangiographical signs of the malformation are left. The slightest residual nidus is enough to definethe patient as not cured. In our institution a non-occlusion is seen as definitive if there is no com-plete obliteration after 3 years follow up. Three groups were identified in which we can classifyour patients: group1. complete angiographical occlusion, group2. non-occlusion after 3 years,group3. non-occlusion after 2 years, 3th year angiography not yet performed. Results: Group 1contains 24 patients leading to an occlusion rate of 77.5%. We classify 3 patients in group 2(9.7%) and 4 patients in group 3 (12.9%). As morbidity, we report two cases of a single epilep-tic insult shortly after radiosurgery and 1 case of temporary local alopecia. Re-bleeding due toincomplete obliteration (a volume of 0.55cc was reduced to 0.07cc) occurred in only one case.Headache was the only symptom from which this patient was suffering. Conclusion: Comparingthe literature, our pre-eliminary occlusion rate with the Novalis® is very satisfactory. The proce-dure is very safe with a low morbidity, all temporary.

Clinical outcomes following gamma knife radiosurgery for arteriovenous malformations of the brain OS28-3Sait, Sirin (1); Kaan, Oysul (2); Hulya, Sirin (2); Asli, Oysul (2); John C, Flickinger (1); Douglas, Kondziolka (1);L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of PittsburghMedical Center - Department of Radiation Oncology Pittsburgh, USA

Stereotactic radiosurgery is now a well-accepted approach for patients with selected brain arteri-ovenous malformations (AVMs). We studied a long-term experience with AVM radiosurgery toevaluate clinical outcomes. Between August 1987 and October 2004, 906 patients with AVMunderwent one or more stereotactic radiosurgeries. Of these patients, 145 (16%) had multipleprocedures either for reirradiation of non-obliterated nidus or prospective staging for large AVMs.Patients presented with an intracranial hemorrhage in 47% and with a seizure in 23%. Two-hun-dred-forty-nine patients (27%) had at least one attempted embolization. The majority of patients(68%) had Spetzler-Martin Grade 3 or higher AVMs. Thalamus, basal ganglia, brainstem, corpuscallosum, pineal region and intraventricular locations were seen in 258 patients (28%). The medi-an AVM volume was 3.4 ml (mean 4.83 ml, range 0.065-57.7 ml) and the median margin dosewas 20 Gy (range, 13-32 Gy). Out of 602 patients followed more than 24 months, 445 (74%)had total obliteration confirmed either by magnetic resonance imaging (MRI) or angiography.Intracranial hemorrhage after treatment occurred in 38 (4%) patients during the latency period.Cyst formation or encephalomalacia as a late radiation effect was seen in 16 (1.7%) patients,whilst 8 (0.9%) patients developed persistent regions of increased signal on long-TR MRI. No sec-ondary cancer was observed in the follow-up. Analysis of a large group of AVM patients whounderwent stereotactic radiosurgery demonstrated that radiosurgery is an effective approach forpatients with AVM with an excellent long-term safety profile.

193

Page 196: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

Radiosurgery of cerebral arteriovenous malformations in the paediatric age group. About a series of 100 patients OS28-4Nicolas, Reyns (1); Serge, Blond (1); G, Touzet (1); B, Coche (1); J.Y., Gauvrit (1); J.P., Pruvo (1); P, Dhellemmes (1) (1) Centre Hospitalier Régional et Universitaire de Lille - Centre Gamma Knife Lille, France

OBJECTIVE In order to assess the safety and effectiveness of radiosurgery for arteriovenous mal-formations (AVMs) in the paediatric age group. METHODS We reviewed the data of 100 children(44F/56M) presenting 103 AVMs treated by Linear Accelerator radiosurgery between December1988 and May 2002. Mean patients age was 12 years old (range 2-16). Around 70% of patientspresented intracranial haemorrhage as the first symptom. Sixty seven AVMs (65%) were in func-tional locations and 30% were inoperable. Mean AVMs volume was 2.8 cc (range 0.9-21.3).Mean marginal dose was 23 Gy (range 15-25) requiring 1 to 4 isocenters. 50 patients had mul-timodal treatments with embolization and or surgery before and or after radiosurgery. Since 16patients had 2 sessions and 1 patient had 3 sessions of radiosurgery, 119 radiosurgical treat-ments were delivered. Clinical and angiographical follow-up were longer than 36 months, unlessearlier angiography showed complete disappearance of the AVM. Successive MRI were per-formed to document parenchymal modifications. All AVMs obliterations were confirmed byangiography. Univariate and multivariate analysis were performed to determine predictive factorsof obliteration. RESULTS Complete obliteration was achieved in 72 AVMs (70%) with a meandelay to obliteration of 33 months. The morbidity rate was 4.2%, 3 patients presenting aradionecrosis, 1 patient a monocular cecity and 1 patient medically controled seizures. Onepatient died because of rebleeding. No patient presented bleeding after an angiographycally con-trolled AVM obliteration. Major predictive factors of obliteration were AVMs volume and no priorembolization. CONCLUSION Radiosurgery may be considered as a safety and effective treatmentof AVMs in the pediatric age group. Obviously, its role must be discussed in a multidisiplinaryapproach and regurarly associated to embolization and/or surgery.

Neurological deficit rather than obliteration determines quality of life in patients treated with radiosurgery for AVMs OS28-5Meera, Ramani (1); Yuri, Souza (2); Deirdre, Dawson (3); Daryl, Scora (4); May, Tsao (5); Michael, Schwartz (6) (1) University of Toronto - Division of Neurosurgery; (2) University of Toronto - Division of Neurosurgery; (3)University of Toronto - Psychology; (4) University of Toronto - Medical Physics; (5) University of Toronto -Radiation Oncology; (6) Sunnybrook Hospital - Neurosurgery Department Toronto, Canada

Objective: There is a dearth of literature about the quality of life (QOL) of patients treated for brainarteriovenous malformations (AVMs). This study evaluates the factors that predict the QOL afterradiosurgical treatment of patients with AVMs. Method: Between 1989-2000, 228 patients weretreated at the University of Toronto using a LINAC system. 181 had a complete radiological andclinical follow-up, including 7 who died. Of the 174 remaining patients, it proved possible to noti-fy 113 by telephone that a three-part questionnaire consisting of questions concerning their neu-rological status before and after treatment and a Medical Outcomes Study questionnaire (SF-36)would be sent. Results: Of the 113 forms sent, 66 (58.4%) were adequately completed andreturned. There were no significant differences in age, AVM location and volume betweenpatients who returned the questionnaires, patients who didn’t return the questionnaires, and

194

Page 197: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

patients who could not be contacted. However, patients who returned the questionnaires had ahigher rate of permanent deficit (10.6% vs. 8.1% and 4.4%) and a lower obliteration rate (54.2%vs. 68.8% and 70.3%) than those who didn’t return the questionnaires, and those who could notbe contacted, respectively. In a multivariate analysis, the most important predictor of quality oflife was permanent deficit. In order of importance, permanent deficit affected the various aspectsof QOL as follows: role physical, physical functioning, social functioning and vitality (P= 0.000,0.006, 0.040, 0.049, respectively). AVM obliteration was not a predictor of QOL, even for theemotional scales. Conclusion: Permanent deficits were associated with a lower quality of life andthis should be considered a strong end-point in the choice among treatment modalities.Surprisingly, AVM obliteration was not a predictor of the quality of life for these patients.

EXTRACRANIAL RADIOSURGERY 2 OS29Chairmen: Morten, Hoyer; Gabriela, Simonova Room Permeke &

Rembrandt

Stereotactic radiosurgery after external radiotherapy for nasopharynx carcinoma OS29-1Selcuk, Peker (1); Beste Melek, Atasoy (2); Meric, Sengoz (2); Ufuk, Abacioglu (2); Turker, Kilic (1); Necmettin,Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

The aim of this study is to evaluate the efficacy of gamma knife radiosurgery on nasopharynx car-cinoma which had external radiotherapy. There were 10 patients (6 male, 4 female) in this series.The median age of the patients was 56. Gamma knife radiosurgery was performed as a boost in4 patients, and for recurrent disease in the others. Median dose to the periphery of the tumor was11 Gy (7-20 Gy). In 7 patients the local control of the tumor was achieved. One patient was dieddue to the local invasion of the tumor. 2 patients were died due to the distant metastasis. Oneyear survival rate was found to be 33% (median 12 months) and local growth control rate was75%. Gamma knife radiosurgery seem to be partly effective on local growth control of nasopharynx carcinoma.

Image guided conformation arc radiosurgery for prostate cancer: early clinical results OS29-2Guy, Soete (1); Dirk, Verellen (2) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels, Belgium

Purpose: To evaluate clinical results in prostate cancer patients treated with image guided confor-mation arc radiosurgery using a minimultileaf collimator and daily X-ray assisted patient position-ing. Methods and Materials: Between May 2000 and November 2004, 238 cT1-T3N0M0 tumorswere treated. Isocenter dose was 70 or 78 Gy, depending on the risk group the patient belongedto. Seventy patients in addition received neoadjuvant and/or concurrent hormonal treatment.Median follow-up is 18 months (range: 4-55 months). Acute side effects were scored using theRTOG/EORTC criteria. Late side effects were assessed using a modified ("clinical") SOMA scale. The

195

Page 198: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

ASTRO consensus definition was used to define biochemical failure. Freedom from late toxicityand biochemical control were calculated with the Kaplan-Meier method. Results: Grade 1, 2 and>2 acute side effects occurred in 19, 6 and 0% (gastrointestinal) and 37, 16 and 0% (genitouri-nary) of the patients. No relation between radiation dose and early side effects was observed.Four-year freedom from ¡_ grade 2 late GI side effects was 98.9%. Four-year freedom from ¡_grade 2 late GU side effects was 99.2%. Four-year freedom from biochemical failure was 95.2%.Conclusion: Patients treated with image guided conformation arc radiosurgery experience a lowrate of grade 2 (i.e. requiring medication) early side effects. The evaluation of late side effects andbiochemical control requires further follow-up.

PET predicts treatment failure of extracranial stereotactic radiosurgery before CT OS29-3Volker W., Stieber (1); William, Kearns (1); William, Hinson (1) (1) Wake Forest University School of Medicine - Department of Radiation Oncology Winston Salem, USA

Purpose/Objectives: Extracranial Stereotactic Radiosurgery delivers a single inhomogenous doseto a lesion in the body. We present the imaging results of a subgroup of patients who underwentPET imaging on an ongoing Phase I/II study. Materials/Methods: Eligibility criteria included a well-circumscribed malignant tumor with a maximum diameter of 6 cm. Patients had to be age >=18 years with a life expectancy >= 3 months. No chemotherapy was allowed 3 weeks prior toor planned for 4 weeks after treatment. The Primary Endpoints were acute toxicity using NCICommon Toxicity Criteria 3.0 (Phase I) and local control by CT RECIST (PD/SD/PR/CR) criteria(Phase II). Results: 28 patients have so far been enrolled. Two dose escalations have been com-pleted. 12 (43%) patients have undergone PET imaging. For this group, median follow-up so faris 377 days. Median survival has not yet been reached. 3 deaths have occurred. For these 3patients, median survival from time of treatment was 250 days. Local control at 3 months was100 %. The median change in tumor diameter at 3 months was -14% for a median RECIST =SD. The median corrected SUV change at 3 months was -57%. At last follow-up, 8 patients havehad no PD. For 7/8, the SUV decreased and had not increased by the last follow-up. 4 patientshave had PD by RECIST. 3/4 had a corresponding rise in correct SUV, which preceded the RECISTprogression by a median of 71 days. The median time to RECIST failure for these patients was238 days. Overall, the correlation between RECIST control and PET control was 0.71. Discussion:In the late phase, (> 3 months) PET progression appears to precede RECIST PD by 2.4 months.This may have implications for the initiation of subsequent therapy (e.g. chemotherapy).

How can tumor effect and normal tissue effect be balanced in stereotactic body radiotherapy OS29-4Wolfgang, Tome (1); John, Fenwick (1); Jack, Fowler (1); Minesh, Mehta (1) (1) University of Wisconsin Medical School - Human Oncology Department Madison , USA

Methods for selection of an appropriate dose fractionation schedule for stereotactic body radio-therapy that has both an equivalent tumor effect for lesions of varying size and at the same timeensures an acceptable risk of clinically manifest radiation pneumonitis have not been adequatelyaddressed. We have developed a model-based methodology for selection of an appropriate dose

196

Page 199: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

fractionation schedule for radioablation of peripheral T1/T2 N0 M0 lung tumors that lets oneachieve a progression free survival at 30 months of larger or equal to 80% while keeping the inci-dence of significant radiation pneumonitis below 20%. Because of the short schedules used inSBRT, accelerated repopulation is not a concern and therefore a schedule that has a BED10 ≥100 Gy10 is projected to achieve greater than 80% of progression free survival at 30 months.Our modeling shows that in order to keep the mean normalized total dose to the residual healthylung (both lungs – PTV) below 19Gy3, the dose at which the risk of pneumonitis would beacceptable, the selection of a dose fractionation schedule depends on both the ratio of thePrescription Isodose Volume (PIV) to the residual healthy lung volume and the late local damageBED3 associated with this fractionation schedule within the PIV one is willing to tolerate for a tar-geted 30 month progression free survival of 80% or higher. The model, its background, and clin-ical implementation will be discussed.

IMAGING 2 OS30Chairmen: John, Flickinger; Michael, McDermott Room Willumsen

How much does the addition of stereotactic T2 images affecttumor definition and treatment plans for acoustic schwannoma radiosurgery? OS30-1John, Flickinger (1); Douglas, Kondziolka (2); Ajay, Niranjan (3); Ann H., Maitz (4); L. Dade, Lunsford (2) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of PittsburghMedical Center - Department of Neurological Surgery; (3) University of Pittsburgh Medical Center -Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA

Objective: We sought to assess the effect of using stereotactic T2 imaging in addition standardT1 contrast-enhanced images to define the contours of acoustic schwannomas for radiosurgery.Methods: After completion of gamma knife radiosurgery to ten unilateral acoustic schwanno-mas,.tumor contours were drawn first using T1 contrast-enhanced images alone, and a secondtime using T1 and T2 images. This process was repeated two more times to create three pairs ofimages using T1 alone versus T1 plus T2 images. The contours of the cochlea and vestibule weredrawn using T2 images. Four tumors were purely intracanalicular and six extended into the cere-bellar pontine angle. Prescription doses varied from 12-13 Gy (12.5 Gy in 7/10) to the 50-60 %isodose (median 50%) using 3-9 isocenters (median 6). We created inverse treatment plans with-out manual adjustments from contours drawn for T1 images alone versus T1 plus T2 imaging foran unbiased assessment of the effects on the treatment plan and doses to the cochlea andvestibule. Results: In all cases, we reduced tumor volumes from T1 images alone after reviewingT2 images. Volume reductions occurred at the lateral tip of the tumor close to the cochlea and atinterphases with blood vessels and meninges. The median volume reductions and % reductionsfor the intracanalicular schwannomas were 7.3 mm3 (range: 5-25.6) and 6.7 % (3.4-13.6), com-pared to 19.1 mm3 (12.3-39.9) and 3.7 % (1.2-8.7) for the extracanalicular tumors. Planning tar-get volumes were smaller with T2 imaging in 7/10 cases for a median difference of 5.0 % (range:-7.7 to 28.1 %). T2 imaging lead to reductions in mean cochlear dose in 9/10 patients as well asmaximum cochlear, mean and maximum doses to the vestibule in 8/10 patients (p=0.060,0.033, 0.052, 0.095 paired t-tests respectively, with mean dose reductions of 25, 18, 35, and 25

197

Page 200: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

% respectively) . Conclusion: Adding T2 imaging to standard T1 stereotactic imaging for acousticschwannoma radiosurgery results in a reduction in treatment volume that results in a decreaseddose to inner ear structures in the vast majority of cases.

A CT scan and anatomical cadaveric study of the pterygopalatine ganglion for use in gamma knife treatment of cluster headache OS30-2William, Olivero (1); Jorge, Alvernia (2); Dan, Spomar (3) (1) OSF Saint Francis Medical Center - Department of Neurosurgery; (2) University of Illinois - Neurosurgery;(3) University of Illinois - Neurosurgery Peoria, USA

Objectives: Gamma knife radiosurgery is used to treat patients with Cluster Headaches. Both thetrigeminal root and the pterygopalatine ganglion(PPG) have been targeted. However, there areno clear-cut anatomical landmarks on CT scan or MRI that accurately identify the PPG. Therefore,we performed microsurgical dissections on injected cadaver heads to expose the PPG and corre-lated the findings with thin slice axial CT scans with 3D reconstruction on the same heads todetermine how best to target the PPG. Methods: Three cadaver heads(5 sides) previously inject-ed with colored latex were dissected in order to identify the PPG and surrounding structures. Thenmeasurements to different bony landmarks such as the foramen rotundum, vidian canal etc. weremade. The PPG was marked with a radiopaque marker then thin slice CT scans performed on thecadaver heads to attempt to develop some CT correlates that could be used to identify where thePPG is located on CT scan. Results: The PPG was clearly identified in all specimens with an aver-age diameter of 3.58 mm +/-0.6mm. The PPG was always located in the same plane (lat andvertical) as the vidian canal and was on average 2.7 mm anterior to the end of the canal. Thevidian canal was clearly identified on the coronal reconstructed CT scan with a diameter of3.05mm. Conclusion: There was a constant relationship between the PPG and vidian canal. Thevidian canal is easily identified on coronal reconstructed CT scan and can be used as a landmarkto target the PPG with gamma knife.

Assessment of post-radiosurgical imaging studies: a volumetric algorithm and an estimation of its error OS30-3Jason, Sheehan (1); John, Snell (2); Matei, Stroila (3); Ladislau, Steiner (1) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Lars Leksell Center forGamma Knife Radiosurgery; (3) University of Virginia - neurosurgery Charlottesville, USA

Objective: The gamma knife is playing an increasingly important role in the treatment of neuro-surgical patients. The goal of the tool is not necessarily to totally obliterate a tumor but to induceits control. During planning, dose-volume histograms require accurate volumetric analysis of thelesion. Also, accurate follow-up volumetric analysis is important to compare to the lesion volumeat the time of radiosurgery . Methods: The accuracy of the estimation of volume or volumechange of anatomical structures as they appear in medical imagery is limited by a number of errorsources. We consider the sampling geometry of tomographic modalities and its contribution tovolumetric error through a simulation framework. In addition to providing empirical bounds onvolumetric error, this approach provides a tool for guiding the specification of imaging protocols

198

Page 201: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Oral Presentations Abstracts

when a specific volumetric accuracy, or volume change sensitivity, for particular structures issought a priori. Results: Using computational geometry techniques, the error associated with vol-umetry was shown to be dependent upon the number of slices through the region of interest andlesion volume. With a minimum of five slices through the region of interest, the volume of a lesionbetween 0.1 to 15 cc could be computed accurately with less than a 10% error. When fewer than5 tomographic slices through the region of interest were obtained, then the potential differencebetween the actual and computed volume increased substantially. Conclusions: These volumet-ric tools are particularly relevant for radiosurgical treatment planning and follow-up analysis.Through the application of this volumetric methodology and a better understanding of the errorassociated with it, a more accurate assessment of the treatment result is probable.

Meningiomas after radiosurgery: When is recurrence expectable? OS30-4Roberto, Spiegelmann (1); Janna, Menhel (2); Rafael, Pfeffer (2); Dror, Alezra (2) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Department of Oncology Ramat Gan, Israel

During a 12-year period 312 meningiomas at different locations were treated with LINAC radio-surgery at our center. 55 tumors with less than 2 y follow up were discarded. 6 patients died earlyafter treatment, 3 had surgery due to radiation injury. 59 patients did not have adequate follow-up (19%). 189 patients had follow-ups ranging from 24 to 144 months (mean 54/median 48months). Recurrence defined as persistent growth of more than 20% of the original volume wasobserved in 11 tumors (5.8%). All of them occurred between 15-48 months after treatment. Notumor growth was observed in 75 patients followed for 5 years or more (mean 81 months/medi-an 72 months). Volume reduction was observed in 117 tumors (62%) overall. Tumor shrinkageincidence tend to increase over time (48% at 2 years, 60% at 3 years, 72% at 5 years, 54% at6-8 years, and 78% at 9-12 years). While recurrence of meningiomas after conventional surgerypeaks at 3-4 years, it may be observed at random even 2 decades after surgery. Recurrence afterradiosurgery as per this series was only observed during the first 4 years following treatment.

199

Page 202: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

200

Page 203: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Posters Abstracts

Monday 12/09/05

POSTER SESSION 1 10h30 - 11h30

GENERAL, EXTRACRANIAL RADIOSURGERY,VESTIBULAR SCHWANNOMAS, ARTERIOVENOUSMALFORMATIONS, METASTASES, GLIOMAS,RADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY

Clinical and radiobiological advantages of stereotactic light ion beam radiation therapy for large intracranial arteriovenous malformations P1-1Bahram, Andisheh (1); Bengt, Lind (1); Mohammadali, Bitaraf (2); Panayiotis, Mavroidis (1); Anders, Brahme (1) (1) Karolinska Institutet - Department of Medical Radiation Physics; (2) Iran Medical Science Of University, AliAsghar Hospital - Iran Gamma Knife Center Stockholm, Sweden

Objective: The special characteristics of high linear energy transfer (LET) light ion beams offer sev-eral advantages over photon and proton beams for single dose stereotactic radiation therapy ofintracranial arteriovenous malformations (AVMs). These include more favorable depth dose-dis-tribution in tissue, almost negligible lateral scattering, a sharper penumbra as well as a steepdose fall-off beyond the Bragg peak. A comparison between different radiation modalities hasbeen made with the effectiveness of Bragg peak radiosurgery. These features include higher flex-ibility in designing optimal treatment plans for intracranial lesions, so that critical structures, couldbe avoided. Methods and Materials: Dose Volume Histograms (DVHs) and peripheral doses forlarge AVMs from different centers were collected and dose-response parameters derived by amaximum likelihood fitting of the Binomial model to these data. The present Binomial modelquantitates the effective number of crucial vessels such as feeding arteries in AVM. Results: A bet-ter angiographic obliteration rate as well as lower complication rate and lower white matternecrosis for stereotactic radiosurgery with heavy charged particles was observed which followedwith more favorable clinical outcome. For larger AVMs a higher number of effective vessels waspredicted which complies with the fact that a large AVM typically has more compartments withmore feeding arteries and draining veins. Conclusion: The better dose distribution of Ion beamsand the dose homogeneity in the target volume is an advantage over conventional photon radi-ation modalities. The unique physical and biological characteristics of light ion beams are of con-siderable advantage for the treatment of large AVMs. Bragg peak radiation therapy has been rec-ommended for most large and irregular AVMs and for the treatment of lesions located in front ofor adjacent to sensitive and functionally important brain structures. The binomial model based onthe effective number of crucial vessels in the AVM predicts AVM obliteration probability for smalland large AVMs quite well both for photon and light ions.

201

Page 204: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Gamma knife radiosurgery for cerebral arteriovenous malformation P1-2Maheep Singh, Gaur (1) (1) VIMHANS Complex - Department of Gamma Knife Radiosurgery New Delhi, India

Introduction: Aim of the study is to assess efficacy of gamma knife Radiosurgery for managementof cerebral Arteriovenous malformation as single primary modality. Method: We have treated 148patients with cerebral arteriovenous malformation between April 1998 and April 2005. Of these123 patients were followed for a year or more. No patient was operated and 5 patients had par-tial emoblization elsewhere. Forty seven patients had AVMs located deep or in eloquent areas.Sixty one [50%] patients presented with hemorrhage, 48 [39%] with seizures and rest 13 [11%]were incidental or with other deficit. Mean Treatment volume was 6.86cc [0.1-49.2]. None of thepatients were advised emobilization or surgery irrespective of size or location. Mean prescriptiondoes was 22.07 Gy covering 99.42% [94-100] treatment volume, with a mean prescription iso-dose of 47.48% [40-60] . Mean dose at maximum was 46.59 Gy [30-65.5]. Results: Twenty-sixpercent patients obliterated in first year, 53.6 %in 1.5 years, and 12.4% by the end of second year.Over all 92% obliteration by the end of two years. Two patients had bleed and died. Two patientsdevelop cyct formation at 2 year and 3-year follow up Conclusion: Gamma knife radiosurgery canbe adopted as primary treatment for cerebral Arteriovenous malformation without emobilization

Management and outcomes of hemorrhage for cerebral arteriovenous malformations treated with radiosurgery P1-3 Tomoyuki, Kouga (1); Keisuke, Maruyama (1); Masahiro, Shin (1); Hiroki, Kurita (2); Nobutaka, Kawahara (1);Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) Kyorin University Hospital - Department ofNeurosurgery Tokyo, Japan

OBJECTIVE: Appropriate management of hemorrhage after radiosurgery for cerebral arteriovenousmalformations (AVMs) is poorly understood. METHODS: Among 467 patients followed for 1 to154 months (median 69 months) after radiosurgery, 32 patients suffered a hemorrhage.Hemorrhage developed even after angiographic obliteration in 5 (2.1%) out of 239 patients fol-lowed at a median of 75 months post-obliteration. They had been treated according to theirpathological condition. Management results of them and their outcomes were retrospectivelyreviewed. RESULTS: As a management for pre-obliteration hemorrhage, intracerebral hematomaalong with an AVM nidus was removed in four patients, and chronic encapsulated hematomawas removed in three. Among 11 patients conservatively managed, AVMs were finally obliterat-ed in five, including three who received repeated radiosurgery. Intracerebral hematoma fromangiographically obliterated AVMs was radically resected in two patients, including one who alsounderwent an aspiration of accompanying symptomatic cyst. Intraoperative bleeding was easilycontrolled in these patients. Outcomes after hemorrhage measured with modified Rankin scalescores was significantly better in patients with post-obliteration hemorrhage than those with pre-obliteration hemorrhage (P<0.05). CONCLUSION: Various types of hemorrhagic complicationsafter radiosurgery for AVMs could properly be managed by understanding each pathological con-dition. Although a small risk of bleeding remains after obliteration, surgery for such AVMs was

202

Page 205: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

safe, and their outcomes were more favorable. Radical surgical resection to prevent further hem-orrhage is recommended for ruptured AVMs after obliteration, because such AVMs can causerepeated hemorrhages.

Follow-up to cure of intracranial arteriovenous malformations after gamma knife radiosurgery P1-4 Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA

Background: Gamma knife radiosurgery (GKR) is a well accepted treatment modality for intracra-nial arteriovenous malformations (AVMs) based on the excellent results and low morbidity asso-ciated with this procedure. In particular, stereotactic radiosurgery is of primary importance in thetreatment of AVMs located in deep or eloquent brain, as well as in AVMs of high Spetzler-Martingrade. Reports in the literature, however, on nidus obliteration rates after GKR vary significantly.The goal of this study is to analyze factors associated with angiographic cure of AVM after GKR.Methods: We performed an independent review of 177 GKR procedures done over a period of11 years at a single institution for the treatment of intracranial AVM. Only 109 charts were avail-able to us for review, and we selected only those patients who had angiographic follow-up foranalysis. Angiographic follow-up was performed on 67 patients at a range of 11 to 138 months(median was 23mos.). The remainder of the patients were followed with CT, MRI, or no imagingat all. AVM cure was defined as angiographic confirmation of complete nidus obliteration. Weconstructed a Kaplan-Meier survival cure to analyze the probability of AVM cure as a function oftime. Using logistic regression, we evaluated multiple factors as indicators of AVM cure includingclinical presentation, AVM location, AVM grade, pre-operative imaging used for dose planning,maximum radiation dose, peripheral radiation dose, number of shots delivered, and patient ageat time of GKR. Results: AVM cure was determined on angiography in 43 (65%) of the 67 patientswith adequate follow-up in this series. Median time to angiographic cure was 26.5 months(range 11 to 38 mos.). Patients chosen for GKR therapy of their AVM were found to be well-select-ed against surgical intervention as evidenced by a high percentage of AVMs located in eloquentbrain (73%) and median Spetzler-Martin grade of 3 at presentation. The Spetzler-Martin gradedistribution was as follows: I-3(5%), II-11(16%), III-27(40%), IV-16(24%), V-3(5%), indetermi-nate-7(10%). We constructed a Kaplan-Meier survival cure to plot angiographic cure of AVM andfound that the probability of AVM cure in patient’s who had follow-up angiography approaches90% over extended follow-up. Although many factors contribute to treatment modality selectionin patients with AVM, we found no correlation between probability of AVM cure and clinical pres-entation, location, grade, dose, imaging used for dose planning or age of the patient at time ofGKR. Only dose delivered to the periphery of the target approached marginal significance(p=0.11). Conclusions: We conclude that the probability of AVM nidus obliteration in our popu-lation of patients who had angiographic follow-up after treatment of high grade AVMs locatedprimarily in eloquent brain tissue is superior to obliteration rates associated with other treatmentmodalities given similar grade and location of AVM. Furthermore, the length of clinical follow-upcorrelated to angiographic follow-up achieved in this study speaks for the durability of GKR in thetreatment of AVM. We found no influence of patient condition at presentation, location and gradeof AVM, level of dose delivered or patient age at time of GKR on cure rate of AVM after GKR.Raza Shaan

203

Page 206: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Fractionated stereotactic radiosurgery for large intracranial arteriovenous malformations P1-5 Shaan, Raza (1); Quoc-Anh, Thai (1); Salma, Jabbour (2); Gustavo, Pradilla (1); Lawrence, Kleinberg (3);Moody, Wharam (3); Daniele, Rigamonti (1) (1) Johns Hopkins University School of Medicine - Department of Neurosurgery; (2) The Johns HopkinsUniversity School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences Baltimore, USA

OBJECTIVE: The treatment of high grade (Spetzler-Martin III-V) arteriovenous malformations(AVM) remains a challenge. There is a paucity of literature addressing the efficacy of radiosurgeryin the management of this group. We review our experience with fractionated radiosurgery oflarge intracranial AVMs. METHODS: Between 1989 and 2004, 15 patients with large AVMsdeemed to be non-operative candidates were treated with fractionated radiosurgery. Patientswere treated either on a LINAC or gamma knife based system at 2-3 year intervals. Treatmentdoses were chosen based on Flickinger graphs predicting the chance of symptomatic radiationnecrosis, or the volume receiving 12 Gy or more for a particular location in the brain. Patients whodid not receive their full treatment course or follow-up at the institution were excluded. RESULTS:The complete obliteration rate was 33% while the remaining 66% experienced partial response(Mean volume reduction 53%). Mean follow-up was 18 months. Twenty percent of grade III and50% of grade IV experienced cure. Treatment complications included: two post-treatment hem-orrhages (2 patients), persistent headaches (2 patients). One patient died as a result of hemor-rhage. No statistical difference was noted between the obliterated and partially obliteratedgroups with regards to mean pre-treatment volume (24.87 cm3), median Spetzler-Martin grade(IV), mean follow-up, total delivered dose (3550 cGy), mean dose/fraction (13 Gy), median num-ber of fractions (2) or mean interval between treatment fractions (40 months). CONCLUSION: Thepresent study demonstrates the potential role of fractionated radiosurgery in the treatment of thiscohort when compared to the published data in the context of our short follow-up. The benefitsof staged therapy could be derived from using lower doses per session and staged targeting ofthe lesion in an effort to increase response and decrease complication rates. It is evident thatstaged stereotactic radiosurgery could be employed in the treatment of large intracranial AVMsin the framework of a multimodality approach with surgery and embolization.

Fractionated stereotactic radiotherapy in residual or recurrent nasopharyngeal carcinoma P1-6 Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1);Putipun, Puataweepong (1); Ladawan, Narkwong (1); Jiraporn, Laothamatas (1); Boonchu, Kulapraditharom(2); Veerasak, Theerapancharoen (3); Ekaphop, Sirachainan (4); Pornpan, Yongvithisatid (1); Prasert,Assavaprathuangkul (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - ENT; (3) Ramathibodi Hospital Mahidol University - Department of Surgery; (4) RamathibodiHospital Mahidol University - Medicine Bangkok, Thailand

Purpose: To evaluate results of fractionated stereotactic radiotherapy (FSRT) in patients with resid-ual or recurrent nasopharyngeal carcinoma (NPC) in terms of local progression-free and overallsurvival rate and complications after treatment Methods: From August 1998-March 2004 there

204

Page 207: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

were 32 residual or recurrent NPC patients treated with FSRT using linac-based radiosurgery sys-tem. Time from the previous radiotherapy to FSRT was 1-165 (median,15) months. Two patientswere treated for the second and one for the third recurrence. Thirteen patients also receivedchemotherapy with FSRT. Tumor volume ranged from 6.2-215 (median,44.4) cc. Average FSRTdose was 17-59.4 (median,34.6) Gy in 4-25 (median,6) fractions in 1-5.5 (median,3) weeks.Results: Follow up time ranged from 3-56 (median,21) months. Local progression-free survivalrate at 1 and 3 years after FSRT was 67.4% and 31.4%. Overall survival rate at 1 and 3 yearswas 89.1% and 70.3%. If all patients who were lost to follow up were assumed death the over-all survival rate at 1 and 3 years would be 73.8% and 39.4%. Eight patients had complicationsafter FSRT (more trismus in 4, decreased hearing in 4, transient ischemic brain symptoms in 1,dysphagia and hoarseness in 1, and headache in 1). Conclusion: FSRT was useful for patientswith residual or recurrent NPC and was well tolerated.

Linac radiosurgery in extracerebral head and neck lesions P1-7Miron, Sramka (1); Augustin, Durkovsky (2); Arpad, Viola (3); Yaroslav, Parpaley (1); Peter, Strmen (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Departmentof Radiology; (3) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (4) ComeniusUniversity hospital - Department of ophtalmology Bratislava, Slovakia

Purpose: Malignant eye melanomas are one of difficult topics of contemporary ophthalmology.Using of mini- invasive radiosurgery opens new perspectives for treatment of patients withabsolute or partial contraindications for surgery or brachyterapy.Advantage of the treatment byLinac in comparison with gamma knife is in better ability to focus on marginal areas. Since 1992we have operated 627 patients with Linac . 25 patients of them had extracerebral cranial lesions.Methods: We have selected patients with malignant uveal melanoma, who had tumor elevatiuonmore than 8 mm or the localization on posterior retina. Eye fixation was made by ophthalmogistthrough extraocular muscles by stitches, direct eye muscles at stereotactic frame to have the eye inthe same position during MRI and CT examination and radiation. Low set of stereotactic framegives possibility to treat extracerebral lesions like chemodectomas under skull base to treat extrac-erebral lesions like chemodectomas under skull base to level C3 with radiosurgery. Results: Weoperated 16 patients with uveal melanoma and 10 patients with chemodectomas. Two patientshad combination of intracranial and extracranial lesions, which were operated together in the sametime. Therapeutic dose at margin of the tumor was 35 and 38 Gy for melanomas and 16 – 18 Gyfor chemodectomas. Complications after stereotactic radiosurgery like cataract and secondary glau-coma are possible. Conclusions: Long term results show us, that radiosurgery is an effectivemethod of treatment of eye uveal melanoma and is comparable with brachyterapy , gamma knifeor proton beam therapy or as a first step procedure before intravitreal endoresection. Our experi-ence shows that linac radiosurgery is an effective method for treatment of extracerebral craniallesions and enables treatment of pathological lesions of neck eye and maxilofacial area.

205

Page 208: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Endocavitary irradiation of glioma cysts with 90-Yttrium colloid solution P1-9 Arpad, Viola (1); Jeno, Julow (1); Balint, Katalin (2); Istvan, Nyary (3) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute ofNeurosurgery, Budapest, Hungary - Department of Pathology; (3) National Institute of Neurosurgery,Budapest, Hungary - Department of Neurosurgery Budapest, Hungary

Objective: To evaluate the role of stereotactic endocavitary irradiation of glioma cysts, we retro-spectively reviewed our experience with 17 patients (8 female, 9 male). Methods: All 17 patientshad one or more CT or MR imaging guided, stereotactic cyst endocavitary 90 Yttrium colloid irra-diation. Eight patients had low grade and 9 patients had high grade gliomas. The mean cyst vol-ume was 40 cm3 (4.8 – 115). The cysts’ wall dose ranged from 300 Gy to 350 Gy. Results: Inthe immediate postoperative period, 12 out of the 17 (70 %) patients experienced symptomaticimprovement. No procedure-related morbidity was encountered. In high-grade gliomas the ben-efit of possible shrinkage and/or disappearance of the cyst was vanished by solid tumor progres-sion. In low grade gliomas more than 50 % of the cysts disappeared and 25 % of them shrunk-en up to one third of starting volume. Conclusion: The low surgical invasiveness, the absence ofsevere side effects and good therapeutic results induce us to propose this as a primary treatmentin inoperable expanding cysts of gliomas.

Specific nurse attendance during routine Leksell Gama Knife radiosurgery in children P1-10Elisabeth, Rioz Galvez (1); Benoit, Pirotte (2); Patricia, Palacio (1); Arlette, Dewil (1); Philippe, David (3); Daniel,Devriendt (4); Françoise, Desmedt (5); Michel, Baurain (6); Jacques, Brotchi (2); Marc, Levivier (7) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme -Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Centre Gamme Knife; (6) HôpitalErasme - Anaesthesiology Brussels, Belgium

Objective. To define the characteristics of the nurse attendance specific to Leksell Gamma-Kniferadiosurgery (LGK) in children. Methods. In the 2000-2005 period, a total of 1033 LGK procedureswere performed at Erasme Hospital, Brussels, Belgium. Among them, 24 were performed in chil-dren (9 females and 15 males; aged 6 < 5 years; 9 between 5 and 10 years; 9 > 10 years). Theunderlying disease was either an arterio-venous malformation (n=8) or an intracranial tumor(n=16) (3 ependymomas, 3 pilocytic astrocytomas, 3 glioblastomas, 2 choroid plexus carcinomas,2 schwanomas, 1 craniopharyngioma, 1 meningioma, 1 hamartoma). All radiosurgical proceduresused the LGK model C and were based on combined Computed Tomography (CT) and MagneticResonance (MR) imaging. Positron Emission Tomography (PET) images were performed in 8 chil-dren with tumors and were combined to MR images in the dosimetry planning according to amethodology described elsewhere. The characteristics of the nurse attendance specific to childrenwere studied. Conclusions. In all cases, the PET/CT/MR/selective angiography images wereacquired in frame-based stereotactic conditions on the same day as the radiosurgical procedure.All procedures were performed under general anesthesia (GA) with the attendance of a senioranaesthesiologist. The main characteristics specific to LGK treatment in children appeared to bethe long duration of the GA (from 6 to 8 hours), especially in PET-guided procedures and the

206

Page 209: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

potential devastating morbidity from patient’s inaccurate positioning during long-lasting GA. Allpotential sources of complications due to the positioning and to the technical devices (imaging,therapeutic and anesthetic) were checked systematically. Inaccurate positioning might generateprolonged compression of numerous structures and cause: 1) ischemic (cutaneous); 2) hemody-namic (low cardiac outflow, increased venous pressure); 3) traumatic (tendinous elongation, cer-vical spine subluxation) lesions. Hypothermia should not be underestimated. A practical check-listfor routine use by the nurse team is presented. This study emphasized the important routine roleof the nurse team for avoiding morbidity which is not acceptable nowadays.

Gamma knife radiosurgery in pediatric population. Early Mexican experience P1-11 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, De Anda Ponce de Leon (1); Miguel, PerezPastenes (1); Juan, Ortiz Retana (1); Manuel, Martinez Lopez (1); Josue, Estrada (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Mexico, Mexico

Radiosurgery is a highly technified stereotactic procedure that applies a single session of ionizingradiation guiding its effect to a target I specify sparing the normal adjacent structures. This pro-cedure is used frequently to treat different types from cerebral diseases. The indications for its usehave been increasing with the passage of time, initially the main indication was the treatment ofvascular malformation, at the moment is indicated to treat different types of benign and malig-nant tumor and functional pathology. Initially Radiosurgery was used in adult patients, laterAtschuler et al. (1989) published their clinical experience with radiosurgery in the pediatric pop-ulation. The outcomes are related to the specific disease. As we know the conventional radiother-apy produce important side effects mainly on neurocognitive function, the more severe theyounger is the patient. Also as we know the side effects of the radiotherapy appear between 2 –3 years after the treatment. In the present work we showed our early experience and results inthe pediatrics patients treated with gamma knife radiosurgery for benign and malignant tumors,vascular and functional disease.

Stereotactic radiosurgery for benign brain tumors - A single institution experience P1-12 George, Pissakas (1); V, Georgolopoulou (2); M, Kalogeridou (3); E, Andriotis (4); K, Doukaki (3); S, Kosmidou(3); S, Mourgela (5); G, Arhontakis (7); E, Pappas (2); V, Kouloulias (6); I, Kouvaris (10); A, Sotiropoulou (3) (1) ALEXANDRA Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3)St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Radiology; (5) St.Savvas Hospital -Neurosurgery; (6) University of Athens - Radiation Oncology Athens, Greece

Purpose/Objective: Stereotactic radiosurgery (SRS) is applied for the treatment of specific intracra-nial lesions in an increasing number of centers worldwide. A linac-based radiosurgery program isimplemented in our hospital since 2000. The current study presents our experience from using SRSto treat patients with acoustic neuromas and meningiomas. Materials/Methods: SRS treatmentsare applied in our hospital using a 6 MV linac beam, a floorstand isocentric subsystem attachedto the linac gantry, circular collimators and a dedicated workstation for image fusion and treat-ment planning. Patients having received treatment for benign tumors in the interval between May

207

Page 210: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

2000 and October 2003, were 17 acoustic neuroma cases (14% males, 76% females, age range:50 to 80 years, median 64, lesion size range: 0.78-15 cc, median: 6.0) and 14 with meningiomalesions (30% males, 70% females, age range: 35-83 years, median: 65, lesion size range from3.1 to 12 cc, median: 6.1). Neuromas were treated with a surface dose of 11-13 Gy using singleor multiple isocentres depending on their shape (median maximum tumor dose: 22.5 Gy). Thedose given to the surface of the meningiomas ranged from 14 to 17.5 Gy with 1-6 isocentersdepending on the shape of the lesion (median maximum tumor dose: 23.7 Gy). Results: In theacoustic neuroma patient group follow up times range from 5 to 45 months (median: 21). MRI/CTimages of the treated area taken 6 months and yearly after treatment show local control in allpatients. From the 15 patients that have completed follow up times longer than one year, nonehas shown tumor growth, central necrosis is seen in ten cases and lesion reduction in three.Hearing preservation was not an issue as all patients selected to undergo treatment suffered fromloss of hearing. In one patient facial weakness appeared 13 months after treatment. The followup times in the meningioma patient group range from 11 to 39 months (median: 25). Imaging ofthe treated area indicates local control for all patients. For two patients a reduction in tumor sizeis observed one year after treatment. One patient suffered from transient facial weakness 10months after treatment. Conclusion: These relatively early results are comparable to publishedresults from centers with longer follow up times and larger patient series and support the evidencethat radiosurgery is a useful therapeutic technique for the treatment of benign brain tumors.

Gamma knife radiosurgery for skull base tumors - Complications and outcome P1-13 Sujoy, Sanyal (1); Sandeep, Vaishya (2); Aditya, Gupta (2); S S, Kale (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of MedicalSciences - Neurosurgery Department Calcutta, India

Introduction Gamma-knife-radiosurgery has become popular for skull-base-tumors because ityields good functional preservation of the patient. Our objective was to evaluate complicationsand outcome following radiosurgery for skull-base-tumors with a relatively low 12-Gy margin-dose (except for glomus-tumors). Materials and methods We treated 129 acoustic-neuromas(including 11 NF-2 patients), 119 skull-base-meningiomas, 21 5th-nerve and 14 lower-cranial-nerve(LCN)-neurofibromas with a mean volume of 4.5-cc, with a 12-Gy median margin-dosegenerally prescribed to the 50%-isodose volume. Multiple isocentres were used to ensure confor-mal planning. We also treated 8 glomus-jugulare-tumors with a mean volume of 12.65-cc, with12-20 Gy to the tumor-periphery (mean margin-dose of 15.6-Gy). Results We have a median clin-ical-follow-up of 25.6-months. Among 33 acoustic-neuromas with pre-gamma-knife functional-hearing, 2 improved, 4 deteriorated while 27 remained same yielding a hearing-preservation-rateof 88%. The hearing-preservation-rate among NF-2-patients was 50% only. Among skull-base-meningiomas, only one had hearing deterioration with facial paresis. Hearing was preservedamong all patients of glomus and 5th/LCN-neurofibromas. Among acoustic-neuromas, only onecase each of trigeminal and transient-LCN-dysfunction (due to perilesional-edema) was observed.Two patients with sphenoid-wing-meningiomas developed trigeminal-neuralgia. Three patientsof 5th–nerve-neurofibromas had improved facial-sensation while one developed 3rd-nerve palsyand another developed gait-ataxia due to perilesional-cerebellar-edema. Careful planning

208

Page 211: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

ensured no visual complications. One acoustic-neuroma-associated-cyst recurrently increasedleading to ataxia and trigeminal-neuralgia requiring repeated cyst-tapping. Hydrocephalus devel-oped/worsened in 3 skull-base-meningiomas. Radiological-follow-up is available at a median of26-months. Among the non-NF-2 acoustic-neuromas, 9 decreased, 2 increased, and 34 remainedstable. Among 10-NF2 patients, 2 had one-sided-increase, 1 had one-sided-decrease while 7 hadstable tumor-size yielding a tumor- growth-control-rate of 80% in NF-2-patients and 95% in non-NF2-patients. Among skull-base-meningiomas, 2 increased (surgery revealed a malignant-menin-gioma and a hemangiopericytoma), 10 decreased while 50 remained stable yielding a tumor-growth-control-rate of 97%. Among 5th /LCN-neurofibromas, 4 decreased, 14 remained samewhile 1 increased yielding a tumor-growth-control-rate of 95%. Among glomus-tumors, tworeceiving 12-Gy and 18-Gy to the tumor-periphery decreased while 2 receiving 15-Gy and 18-Gyremained same. One tumor treated primarily as a fifth-nerve-neurofibroma increased and wasoperated revealing a mesenchymal-chondrosarcoma. Another treated primarily as a cavernous-sinus-meningioma developed multiple lesions suggestive of metastases. This exposes an inher-ent drawback of primary gamma-knife-radiosurgery based on imaging diagnosis. ConclusionsCranial-nerve preservation following radiosurgery has undergone a quantum jump with theadoption of MR-based multiple-isocentric lower-dose conformal-planning. However improvedfunctional outcome using a 12Gy margin-dose needs long-term analysis to ensure good tumor-control although preliminary results seem encouraging. As for glomus-jugulare-tumors, moreanalysis is needed for arriving at a suitable treatment-dose.

Image guided micro radiosurgery for brain tumors to avoid underlining dysfunction of the surrounding vital structure: technical note P1-16 Motohiro, Hayashi (1); Jean, Regis (2); Taku, Ochiai (1); Koutaro, Nakaya (1); Mikhail, Chernov (1); Masahiro,Izawa (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service deNeurochirurgie Tokyo, Japan

Rationale: gamma knife surgery is one of “Image guided surgery” for brain tumors. Preciselytumor visualization should be needed to complete dose planning to control tumor progeression.In particular, the surrounding vital structures also should be defined more clearly for the tumorswhich were adjacent to them to keep their underlining function. Recently, we selected the spe-cial sequence of MRI dedicated to skull base and suprasellar tumors. We’d like to report the use-fulness technical point of view and evaluate clinically. Method and Results: Normally, we areusing high quality of MRI and CT for tumor radiosurgery. For skull base and suprasellar tumors,additionally, we prefer to use dedicated sequence, “3D heavily T2WI axial 0.5mm thickness withgadolinium enhancement” according to Timone university method (supervised by prof REGIS).Each structure which was adjacent to the tumor could be visualized more clearly than that with-out gadolinium, because tumor became lucid on the MRI without change the findings of sur-rounding structures after injection of gadolinium. For acoustic tumors, we could visualize 5th, 7th,and 8th nerves in not only cisternal portion but also intrameatal portion, which could be distin-guished the tumor. For cavernous sinus tumors, we could visualize optic nerve, pituitary gland,lateral wall of the sinus, and the other nerves which were located in the cistern which also could

209

Page 212: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

be distinguished the tumor. And for suprasellar tumors, we could completely distinguish betweentumor and adjacent optic pathway. Finally, we could perform optimal dose planning in everytumor to keep highly conformity and selectivity to keep their underlining function. Conclusions:We demonstrate to establish optimal dose planning for brain tumors with dedicated specialsequence of MRI. In the nearest future, we hope that most majority of patients who are treatedby Gamma knife will experience no complaint of new neurological deterioration and overcometheir still existed neurological deficit.

Preliminary experience with MMLC at the INNN in Mexico City. 804 patients treated in a singular facility P1-17Miguel Angel, Celis-Lopez (1); Jose, Suarez-Campos (1); Sergio, Moreno (1); Leopoldo, Herrera (1); Jose M,Larraga (1); Amanda, Garcia G (1); Mariana, Hernandez B (1) (1) National Institute of Neurology and Neurosurgery - Radioneurosurgery Mexico City, Mexico

INTRODUCTION: We present preliminary results of the first radiosurgical LINAC exclusively dedi-cated for neurosurgical diseases. This is a the first Novalis (BrainLab, Inc) coupled with a 3T MRI(GE) for novel imaging planning with this system, furthermore every patient was evaluated andsocioeconomic considerations were made in the case of a financial assistace was needed. METH-ODS:The treatment planning was performed with Brain Scan V.5.2 (BrainLab,Inc,2002) based onCT imaging with head frame for single fraction or a mask for fractionated radiotherapy, imagefusion with 3T MRI (angio-MRI or Conventional angio for AVM`s)Treatment delivery was per-formed with the Novalis micromultileaf system (m3-mMLC (R) by statis conformal beams, dynam-ic arcs or Intensity Modulated Radiation Surgery Therapy (IMRS/IMRT)RESULTS:From decembeer2002 to april 2005 a total of 804 patients were treated. Ages ranged from 2 to 77 years old.were Pathologieswere benign tumors 429 (53%), gliomas 143 (18%), vascular 136 (17%)Funcional 31 (4%)A team of social workers evaluated the social conditions of every patient inorder to give support to those patients with special needs. In this way a large recuitment wasobtained in a short period of time. CONCLUSIONS: This a preliminary experience and longer fol-low up in neccesary .

The use of tissue equivalent Super Stuff Bolus (TM) material to treat skull metastases with gamma knife radiosurgery P1-18 Lilyana, Angelov (1); Gennady, Neyman (2); Gene H, Barnett (3); Betty, Jamison (4); John H., Suh (5); Lilyana,Angelov (6) (1) Cleveland Clinic Foundation - Department of Neurosurgery; (2) Cleveland Clinic Foundation - Departmentof Radiation Oncology; (3) Cleveland Clinic Foundation - Brain Tumor Institute; (4) Cleveland ClinicFoundation - Brain Tumor Institute; (5) Cleveland Clinic Foundation - Gamma Knife Center; (6) Cleveland ClinicFoundation - Brain Tumor Institute Cleveland, USA

Introduction: Gamma Plan(TM) software is known to inaccurately calculate surface dose as itscomputation algorithm does not take into account the surface build-up region. This can lead togross underdosing of the skin and near surface regions of the head. We present a novel approachto the treatment of skull metastases within 5 mm of the scalp surface using gamma knife radio-surgery. Method: A patient with a history of a T1N0M0 adenocarcinoma of the lung, metastatic

210

Page 213: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

to the brain status post whole brain radiation therapy, presented 3 years later with a solitaryoccipital calvarial lesion and no other evidence of systemic disease. Since the lesion was verysuperficial, we decided to use tissue equivalent Super Stuff Bolus(TM) material applied to theaffected calvarial area to prevent underdosing. The problem of immobilizing the bolus materialwas effectively solved with the use of a snug fitting elasticized swimming cap. Results: The SuperStuff Bolus(TM) material could be effective molded to the patient’s head and held in place withthe swimming cap. The Leksell frame was placed, pinning through the bathing cap. The patienttolerated the bolus material and bathing cap well during the entire treatment and the radiosurgi-cal treatment proceeded in the standard manner. These measures allowed for improved accuracyin the planning and delivery of the treatment. The accuracy was confirmed using the Lucy(TM)3D+ Universal QA Phantom and direct experimental measurement of surface dosing with andwithout tissue equivalent surface buildup. Preliminary results using the QA Phantom suggest thatwithout the use of Super Stuff Bolus Material(TM) superficial lesions can be underdosed as muchas 50%. Conclusion: Our study shows that Super Stuff Bolus(TM) material immobilized with abathing cap allows for an innovative, simple and more accurate treatment of very superficiallesions using gamma knife radiosurgery.

Magnetic resonance image distortion: a phantom study with varying parameters for stereotactic radiosurgery P1-19 Sawwanee, Asavaphatiboon (1); Ladawan, Worapruekjaru (2); Jiraporn, Laothamatas (2); Pornpan,Yongvithisatid (2); Wiboon, Suriyajakyuthana (2); Lojana, Tuntiyatorn (2); Mantana, Dhanachai (2) (1) Ramathibodi Hospital Mahidol University - Radiology; (2) Ramathibodi Hospital Mahidol University -Department of Radiology Bangkok, Thailand

MR image distortion is one of the main factors, affecting the accuracy of stereotactic target local-ization. Image distortions result from inhomogeneity of the main magnetic field, non-linearity ofmagnetic gradients and eddy current effects, the severity of which depends on the type of pulsesequence and parameters. Therefore, we assessed the image distortions of the cylindrical phan-tom with three techniques, SE, FSE and 3DFSPGR seqyences, providing T1W contrast; with vary-ing parameters (TR, TE, phase encoding, bandwidth and NEX) using a 1.5T magnet (GE Medicalsystem, USA). Using computed tomographic data as the reference standard, the studies showedthat the greatest distortion was found around the periphery zone especially in 3DFSPGR at theposition +60mm from the center and the least distortion was present in the middle zone. In alltechniques, when the slice position was far from the center (Position=0), the image distortionwill be greater. The maximal values of the displacement in the periphery zone when using SE,FSE, and 3DFSPGR were 1.5 mm (range,0-1.5mm), 1mm(range,0-1mm) and 2mm(range,0-2mm)respectively while the maximal values of the displacement in the middle zone, when using Spin-echo(SE), Fast- spin echo(FSE), and 3D spoil Gradient echo(3DFSPGR) were 0.5 mm (range,0-0.5mm), 0.5mm(range,0-0.5mm) and 1mm(range,0-1mm), respectively. For all parameters,bandwidth is a single parameter affecting image distortion. We conclude that for all techniques,the accuracy of target localization for SRS can be achieved within the center of the image. Theimage distortion will be decreased by increasing bandwidth.

211

Page 214: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

The use of T2 weighted MRI for post gamma knife follow-ups P1-20 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong

Introduction: The blood-brain barrier prevents low-life forms (such as toxins) that make it into theblood stream from tainting the brain's pristine nerve cell habitat. However, the blood-brain barrierof normal brain tissues close to the treated tumour may break down after gamma knife surgery.Therefore, some abnormal contrast enhancement surrounding the treated tumour may appear onT1 weighted MR images with contrast injection. An apparent increase of tumour volume in postgamma knife follow-up MR scans may result. Methodology: A T2 weighted MR scan without con-trast injection before a routine T1 weight MR scan with contrast injection was done with the sameFOV for the post gamma knife follow-ups. There must be no re-centring of slides between the T2and the T1 scans. Therefore, the coordinate relationship between these two scans was maintained.A coordinate system was assigned for these two MR scans by using the non-fiducial based tech-nique (Cheung et al 1998). A mapping using GammaPlan v3.x on the T2 slides could be project-ed on the T1 slides. Discussion and Conclusions: The projection of the mapping of an selectedgamma knife follow-up patient showed discrepancy between the T2 and the T1 images. The dis-crepancy was due to the abnormal contrast enhancement surrounding the treated tumour on theT1 MR images. The contrast enhancement was explained by the breaking down of blood-brainbarrier after gamma knife surgery. We suggested that it always performs the T2 weighted MR scanwithout contrast injection for the post gamma knife follow-ups, in order to provide an additionalinformation. Reference: Cheung Y. C. Joel, Yu C. P., Ho T. K. Robert, Tweaked GammaPlan for tar-get volume measurement in non-fiducial based images: a simple routine for follow up assessment,Stereotactic & Functional Neurosurgery, Vol. 70, Suppl. 1, 1998, pp. 243-248.

Effects of fiducial marker defects in image registration P1-21 Hyun-Tai, Chung (1); Dong Gyu, Kim (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea

Introduction: Defects in fiducial markers in stereotactic radiosurgery images are usually ignored inimage registration procedure. The authors assessed the effects of defects in fiducial markers usinga software generated virtual phantom method. Methods: Virtual phantom images with six fidu-cial markers of Leksell G-frame® were generated using IDL® v6.0. A virtual phantom consistedof 81 slices of thickness 1.0mm(z=-40.0 to 40.0). Image resolution was 256x256 and field ofview was 256mm. Each slice had six fiducial markers in square shape with length 3.0mm. Inaddition to fiducial markers, the phantom had three slices which had nine check points atz=30.0, 0.0, and -30.0, respectively. These 27 points were used to measure the errors in posi-tion calculation. Several types of defects in fiducial markers were generated in three consecutiveslices and images were registrated using Leksell Gamma Plan® v5.40. The errors in fiducial mark-er registration and in position calculation of the check points were evaluated. Results: The maxi-mum errors in image registration varied from 0.2mm to 1.4mm depending on type of defects infiducial markers while the mean error were 0.1mm. The error was most severe when only smallpart of a fiducial marker was included in registration. Virtual phantoms with missing fiducial mark-

212

Page 215: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

ers had less error than phantoms with deformed markers. When images with deformed markerswere excluded, the resulting error was same with phantoms with missing markers. Ordinarymean errors in position of check points was 0.1+/-0.1mm. The image set with largest image reg-istration error showed 0.2+/-0.1mm error in position calculation. Conclusion: The image regis-tration was affected by defects in fiducial markers. The effect was most severe when only smallportion of fiducial markers (largest defects) were included. Though resulting error in positionmeasurement is small, it is better to exclude images with defective fiducial markers in image reg-istration process.

The impact of different ways of image definition on the z-position of the target P1-22 Andreas, Mack (1); Stefan, Scheib (2); Marcus, Rieker (3); Dirk, Weltz (4); Robert, Wolff (5); Hans-Jürg, Kreiner(6); Volker, Seifert (7); Heinz, D., Böttcher (8) (1) Gamma Knife Center Frankfurt - Medical Physics; (2) Klinik im Park - Medical Radiation Physics; (3) PTGR-GmbH - Software Development; (4) PTGR-GmbH - Software Development; (5) Gamma Knife Center Frankfurt- Neurosurgery; (6) GKS-GmbH - Management; (7) Johann Wolfgang Goethe University - Neurosurgery; (8)Johann Wolfgang Goethe University - Radiotherapy Frankfurt, Germany

Purpose/Introduction: Given the high mechanical accuracy of the Leksell gamma knife, the mostsensitive technical factor having an influence on the overall precision of radiosurgery is the imag-ing (mainly MRI) study. When checking the accuracy of the 3D-sequence with dedicated phantomswe observed inconsistencies when defining the images in different ways. Material and Methods:Different phantoms and patient studies were used to evaluate this phenomenon. A cylindricalphantom with an embedded equidistant grid was used as well as a known target phantom withembedded cross vials at known geometrical positions related to the stereotactic coordinate sys-tem of the Leksell frame. Automatic and manual defintion (at different positions of the imagestack) were performed. Further on a independent software was used to analyze the images.Results: Different ways of defining images lead to different z-values of the images within the stack.Deviations up to 5 mm can be observed for the representations of images of the upper skull (lowz-values). By defining the image stack manually in the upper region of the image stack, this shiftcan be reduced. In spite of superior resolution and contrast we have to keep in mind that due tophysical aspects (z-gradients, volume exciting direction, etc.) the 3D-sequences are much moresensitive to potential z-shifts than the corresponding 2D-sequences. For the treatment of multiplemetastases it is recommended to check the defined targets with a 2D-sequence or CT.

Hypofractionated stereotactic radiotherapy for lung tumors P1-23Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Rolf, Sauer (1); Oliver, Ganslandt (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology Erlangen, Germany

Purpose/Objective: Given the possibility of highly conformal dose application, extracranial stereo-tactic radiotherapy (eSRT) offers radiation dose escalation, which should be the primary intentionin curative treatment of unresectable lung cancer / lung oligometastases. Since 2/2003 our insti-tution performs eSRT at the Novalis® (BrainLAB, Heimstetten, Germany). This phase-II-study wasintended to find out feasibility, side effects and clinical response after eSRT. Materials/Methods:

213

Page 216: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

From 2/2003 to 05/2005, 20 pts. with up to 5 lung tumors (3 pts. with non small cell lung can-cer, 17 pts. with oligometastases, n=39 PTVs) received either 5x7 Gy or 5x8 Gy hypofractionat-ed stereotactic radiotherapy combined with abdominal pressure after ExacTrac® positioning andisocenter verification. Radiation dose was prescribed to the 90%-isodose, covering a median GTVand PTV of 8.43 and 35.34 cc. All but one (conformal beam) were treated by dynamic arc tech-nique. Results: The irradiation technique could perfectly fit the following RTOG-quality assuranceguidelines (med, mean, min, max): Homogeneity 1.16 1.16 1.02 1.36 Conformity 1.29 1.38 1.121.98 Coverage 97.82 % 96.64 % 86.60 % 100 % Median doses to the normal lung tissue(right/left lung) was per fraction 6%/12% of total lung volume >2Gy, 2%/6% >4Gy and 1%/3%>6Gy. 26 /39 cases showed grade-1 lung toxicity, 4 grade-2 after a median FU of 66 d, after 124d only 8 cases with grade 1 tox.. CR, PR, NC/PD was found in 25, 10, 4 cases with no significantdifference between dose concepts. Conclusion: Extracranial hypofractionated stereotactic radio-therapy with up to 5x8 Gy is a safe and effective treatment. Dose limiting toxicity was not reached.

Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose to the organs at risk: a treatment planning study compared to 3-D radiotherapy P1-24 Jean-Briac, Prévost (1); Joost, Nuyttens (2); John, Praag (1) (1) Erasmus MC-Daniel den Hoed Cancer Center - Radiation Oncology; (2) Erasmus MC - Radiotherapy Rotterdam, The Netherlands

Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose toorgans at risk: a treatment planning study compared to 3-D radiotherapy. Purpose: TheCyberKnife is a 6 MV linear accelerator, mounted on a multi-jointed robotic arm, allowing flexibledelivery of (non-)coplanar beams. This frameless stereotactic radiotherapy system enables auto-matic correction for respiratory motion based on synchronic respiratory tracking. To investigatethe capacity to deliver high doses to the tumor while respecting the tolerance dose of the organsat risk (OAR) we compared the treatment plans of the CyberKnife with three dimensional radio-therapy (3-D RT). Methods and materials: Ten patients with T1-2 N0 M0 lung cancer and previ-ously treated with 3-D RT were selected. All patients were replanned with the CyberKnife treat-ment planning system. The tumor was contoured as the GTV. The CTV was equal to the GTV +5mm margin in all directions and the PTV = CTV + 3 mm margin in all directions. The constraintswere set to minimize the dose to the lung and adjacent OAR. A total dose of 45 Gy in 3 fractionswas prescribed to the 80% isodose line. For the 3-D RT planning, a GTV was defined with a slowscan. A GTV mobile was determined by adding 5mm to the GTV slow. A margin of 10 mm wasadded to the GTV mobile to create the PTV. A dose of 60 Gy (20 fractions) was specified accord-ing to ICRU 50. The analysis of the treatment plan was performed using dose volume histograms(DVH) of PTV and OAR. To enable comparison, the doses of both treatment plans were calculat-ed to equivalent doses in 2 Gy fractions (EQD2) using the linear quadratic model with an a/b ratioof 3 Gy for the organs at risk and 10 Gy for the tumor. Results: The mean of the minimum EQD2administered to the PTV by the CyberKnife and the 3-D RT was respectively 95.5 Gy and 61 Gy(p<0.05). A mean of the maximum EQD2 of 134.6 Gy and 69 Gy was administered to the PTVby respectively the CyberKnife and 3-D RT. The V20 of the lung, calculated after substracting thePTV, of the CyberKnife and 3-D RT was respectively 8.3% and 6.8% (p=0.0001). The dose to theother OAR was below tolerance level. Conclusions: With the CyberKnife, a much higher biologi-

214

Page 217: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

cal dose can be administered to the PTV compared to 3-D RT, with respect of the tolerance doseto the OAR (e.g. V20). Current experiments in the tracking of lung tumors with the CyberKnife areconducted.

The combined stereotactic procedures for cystic cerebral metastatic tumors: A possible pitfall in ‘one day double procedures’ P1-25In-Young, Kim (1); Jung, Shin (2); Tae-Young, Jung (1); sam-Suk, Kang (1) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department ofNeurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea

Objectives Although surgery has been a predominant choice in cases of cystic metastatic tumors,stereotactic aspiration and consecutive stereotactic radiosurgery has also been tried for specificcases, Two procedures are considered to be convenient for both patients and physician, becausethey could be carried out in a day with one frame application. However, a possible pitfall in oneday double procedures is that they might not be very successful in reducing the tumor volume.Materials & Methods Two patients with cystic metastatic tumors underwent stereotactic aspirationand catheter insertion for postoperative cystic fluid drainage with the guidance of neuronavigation.On the same day, after the confirmation that there was no more cystic fluid into the drainage bag,computed tomography (CT) was performed to verify if there was no remained cystic fluid. Thegamma knife radiosurgery (GKR) was performed on the next day. The follow up MRI was under-taken three months after these procedures. Results The preoperative tumor volumes were 60.8,56.5, 13.4 mm3, respectively. The volumes after stereotactic aspiration and full drainage were44.7, 33.6, 9.8 mm3 according to the CT, and we found that some remained cystic fluid in the lowdensity areas in the targeted lesions. On the next day, we observed that there was an additionalcystic fluid drainage during the night. The amount of drained cystic fluid during the night wasabout 13 cc, 8 cc, 1 cc, respectively. GKR was performed after catheter removal. The volumes atthe time of GKR were reduced to 40.1, 31.1, 9.5 mm3, and the prescription doses were 12 Gy, 18Gy, 20 Gy, respectively. The magnetic resonance images after three months showed a remarkablemarked volume reduction of those tumors. Conclusion Considering the requirement of minimizedvolume of the cystic tumors at the time of GKR, the confirmation of the full drainage of cystic fluidprior to GKR is essential in the stereotactic cyst aspiration and consecutive GKR.

The benefit of Gama Knife radiosurgery in the treatment of thalamic and brainstem metastases P1-26Wolfgang, Kreil (1); Verena, Weigl (1); Josef, Luggin (1); Sandro, Eustacchio (1); Georg, Papaefthymiou (1);Oskar, Schröttner (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria

Introduction: The role of gamma knife radiosurgery (GKR) in the treatment of metastatic lesionslocated in the brainstem and thalamus is investigated in order to examine the risk benefit ratio ofthis method. Whereas surgical removal or fractionated radiation are associated with severe neu-rological deterioration of the patient, GKR has proved to be a favorable alternative treatment.Materials and methods: 22 patients with metastases in the brainstem area, treated by GKR

215

Page 218: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

between 1992 and 2002, are reviewed regarding their neurological outcome and the tumors´response to the treatment. Tumor locations included the thalamus (8), pons (7), midbrain(4) andmedulla oblongata (3). The median dose to the tumor margin was 17 Gy (range 12 – 25). Themedian follow up time in these patients was 7,1 months (range 1 – 30,5). Results andConclusions: Tumor progression was controlled in all patients. No patient died or developed anew neurological deficit from growth of a radiosurgically treated tumor. There was no evidenceof delayed adverse radiation effects in any patient. Up to now, at least in literature, little atten-tion has been paid to the management of patients with brainstem and thalamic metastasis, prob-ably because of their poor prognosis. But, regarding the local control rate in the tumors and theneurological outcome especially the Karnofsky Index, patients seem to achieve effective palliationby GKR of brainstem metastases.

Clinical impact of high-resolution MRI on stereotactic radiosurgery for patients with brain metastases P1-27 Julian, Perks (1); William, Hall (1); Conrad, Pappas (1); James, Boggan (2); Robin, Stern (1); John, Hartman (3);Claus, Yang (1); Richard, Latchaw (6); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation Oncology; (2) U.C. Davis - Neurosurgery; (3) U.C. Davis - Radiology Sacramento, USA

In the evaluation and treatment of intracranial metastatic disease, the radiosurgery team atUCDMC has at times found more metastatic lesions on the treatment day than noted in the workup process. To this end, over an 18-month period, the first 63 patients with metastatic lesionswere analysed. Patients were categorized by age, gender, KPS, control, primary, and previousradiotherapy. The number of lesions noted prior to the day of treatment, the number treated andwhether all present lesions could be treated were recorded. The MRI scan performed for the refer-ral was also categorized in terms of slice thickness and contiguity. The referral pattern matchedwell with general radiosurgery practice, in terms of primary, age range, control etc. Whole-brainradiotherapy was given prior in 23 cases. Nine patients had prior radiosurgery. On average,patients had two lesions (mean 2.08, range 1-8, median 1) at referral but had three treated(mean 2.95, range 0-13, median 2). Significantly, there were 11 cases (17%) where treatmentwas compromised as not all excess lesions could be treated with the original frame placementand further treatment was necessary. Analysis of all contributing factors shows that the resolu-tion (slice thickness) of the referral imaging study (not just the time interval between referral MRIand treatment) is the major determining factor for the number of lesions encountered. This dataclearly demonstrates an increase in the number of lesions treated compared to those shown atreferral. A full patient work up should determine as accurately as possible the number of metas-tases that will be encountered in order to optimally plan treatment, avoid patient distress and theneed for additional treatment. Our conclusion is that that the imaging study used for the referralis critical and should ideally match the parameters used on the day of treatment.

216

Page 219: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Evaluation of prognostic factors in patients affected by brain metastases from lung cancer treated with gamma knife radiosurgery P1-28 Piero, Picozzi (1); Alberto, Franzin (2); Silvia, Snider (2); Francesca, Marchesi (3); Luca, Attuati (2); Antonella,Del Vecchio (1); Vanessa, Gregorc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele- Neurosurgery Department; (3) Ospedale San Raffaele - Department of Oncology Milano, Italy

INTRODUCTION: standard treatments in patients with lung cancer brain metastasis are surgery,WBRT and radiosurgery. We analyzed our consecutive series of patients to assess the role ofGammaKnife Radiosurgery and evaluate the major prognostic factors in such population. MATE-RIALS AND METHODS: between December 1993 and April 2004, 227 (180 male and 47 female)patients were treated in our centre for brain metastasis from lung cancer with GammaKnife. Meanage at treatment was 61 years. In most of them (70%) histology samples of primary tumour wasadeno-ca. In 129 patients (56,8%) a systemic illness control was not obtained, otherwise in 40pts (17,62%) the tumour resulted stable, in 58 pts (25,55%) there was no strumental evidenceof illness. 82 pts were also affected by other metastasis. Every patient was ranked in RPA and SIRclassification. 35 resulted in RPA class I, 185 pts in class II, 7 in class III. 116 pts presented witha single lesion, the rest with multiple brain metastasis. Mean dose to tumour was 22.6 ± 3.5Gray to 50% isodose. Mean lesion volume was 4,6 mm3 ± 5,4. Survival curves were obtainedwith Kaplan-Meyer method, prognostic factors were assessed trough Cox proportional hazardratio. Univariate and multivariate analysis were performed to evaluate prognostic factors.RESULTS: Mean survival rate was 8.3 months. One, two and three years survival rate was 38%,15% and 7%. Local tumour control was not achieved in 103 pts, who underwent a second linetreatment (GammaKnife, surgery or WBRT). In univariate testing, KPS, age, SIR and RPA ranking,volume of metastasis are significantly associated with outcome. In multivariate analysis, only RPAhas shown to be affordable in predicting the outcome, with an independent Hazard Ratio of 1.75.This study supports the use of GammaKnife in this group of patients, especially those in goodgeneral condition.

Linac based sterotactic radiosurgery (SRS) of brain metasases - 10 years experience P1-29 Martin, Chorvath (1); Martina, Skoknova (2); Yaroslav, Parpaley (2); Augustin, Durkovsky (3); Miron, Sramka(2); Juraj, Steno (4); Elena, Boljesikova (1) (1) St. Elisabeth Cancer Institute - Department of Radiotherapy; (2) St. Elisabeth Cancer Institute -Department of Radiosurgery; (3) St. Elisabeth Cancer Institute - Department of Radiology; (4) Faculty Hospitalof the Comenius University - Department of Neurosurgery Bratislava, Slovakia

Purpose: SRS is a well-accepted method for treatment of brain metastases. We reported data ofpatients who underwent Linac based SRS in a period from 1992 - 2002 at Radiotherapy Dept.St. Elisabeth Cancer Institute as a retrospective study. Material and Methods: From 1992 to 2002we treated with SRS 80 patients with brain metastases. Five patients had more than three lesions.The follow-up for 15 patients was lost. 60 patients (34 male, 26 female) were included into sur-vival analysis with up to three lesions in brain. The age of patients varied between 30 - 81 years.

217

Page 220: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

The primary site of tumors were as follows: 14 pts with lung carcinoma 23,3%, 10 pts with renalcarcinoma 16,6%, 10 pts with unknown primary site 16,6%, 9 pts with colorectal carcinoma15%, 6 pts with mammary carcinoma 10%, 4 pts with malignant melanoma 6.6%. The volumeof metastases varied from 0.1 cm3 to 22,5 cm3. SRS was applied with Clinac 2100 Varian 6 MVX. The treatment dose was calculated on 80% isodose. The minimal tumor dose TD min. rangedfrom 12.0 Gy to 24.0 Gy, average 17.0 Gy. The maximal tumor dose TD max. ranged from 14.25Gy to 31.0 Gy, average 24.0 Gy. Cumulative survival of all patients was calculated by the methodof Kaplan - Meier. Results: Overall survival (OS) was 6.2. months for all patients. We observedshortest OS in patients with brain metastases of malignant melanoma: 3.8 months and unknownprimary site: 4.1 months. The longest OS we observed in patients with brain metastases frommammary carcinoma was 23 months. OS in patients with brain metastases of pulmonary and col-orectal carcinoma were 16 and 15 months respectively. No significant difference between OS ofpatients in the group with single metastases and in a group with two or three metastases wasobserved (log rank 0.5)Conclusions: SRS is an efficient, accessible and non-invasive methodreducing radiotherapy-induced side effects, with a promising potential to increase survival ofpatients with up to three metastases of malignant tumors in brain.

Gamma knife radiosurgery for brain metastasis. Analysis of survival and prognostic factors P1-30 Alberto, Franzin (1); Piero, Picozzi (1); Silvia, Snider (2); Camillo, Ferrari Da Passano (1); Lorenzo, Gioia (1);Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department; (2) Ospedale San Raffaele - Stereotactic Neurosurgery& Gamma Knife Department Milano, Italy

Introduction: Standard treatments for patients with brain metastasis are surgery, whole brainradiotherapy (WBRT) and stereotactic radiosurgery (RS). Single treatment is not alweays afford-able in case of large cystic tumors. This study asseses the role of stereotactic drainage followedby gamma knife radiosurgery (GKRS) in the treatment of large cystic brain metastasis. Patients andMethods: Inclusive criteria of the study were: no prior whole-brain radiation therapy or surgicalresection, a maximum number of 4 lesions on MRI, a tumour diameter <4 cm, one cystic lesion,KPS ? 60, minimum follow-up period of 6 months after GKRS. Between February 2001 and March2004, 15 patients with 33 tumours (18 cystic tumour and 15 solid), fulfilled the eligibility criteriaand were included in this study (9 male, 6 female; mean age 60 yrs; range 38-75 yrs). The pri-mary cancer was lung (NSCLC) in 8 pts (57%), breast in 2 pts (13%), parotid in 1 pt (6,5%),melanoma in 1 pt (6,5%), kidney in 1 pt (6,5%), colon in 1 pt (6,5%), unknown in 1 pt (6,5%).Before stereotactic drainage the mean cystic tumour volume was 19,95 ml (ranging between 3,8and 48 ml). At the end of stereotactic drainage, before GKRS, mean tumour volume was 9,59 ml(1,2–18 ml). Mean prescription dose to the tumour margin was 19,6 Gy (range 16 - 25 Gy); at50% isodose. MRI follow up was performed every three months. We analysed survival periodand local tumor control rate. Results: Mean follow-up period was 10 months. Local tumour con-trol was achieved always in the cystic tumours. Two patients died in the first month after the treat-ment: one for carcinomatosis meningitis and one for pulmonary embolia. Conclusions: This studysupports the use of stereotactic drainage approach in case of large-volume multiple and cysticbrain metastasis.

218

Page 221: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stereotactic drainage and gamma knife radiosurgery of cystic brain metastasis P1-31Alberto, Franzin (1); Micol, Valle (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department Milano, Italy

Introduction: Standard treatments for patients with brain metastasis are surgery, whole brainradiotherapy (WBRT) and stereotactic radiosurgery (RS). Single treatment is not alweays afford-able in case of large cystic tumors. This study asseses the role of stereotactic drainage followedby gamma knife radiosurgery (GKRS) in the treatment of large cystic brain metastasis. Patients andMethods: Inclusive criteria of the study were: no prior whole-brain radiation therapy or surgicalresection, a maximum number of 4 lesions on MRI, a tumour diameter <4 cm, one cystic lesion,KPS > 60, minimum follow-up period of 6 months after GKRS. Between February 2001 andMarch 2004, 15 patients with 33 tumours (18 cystic tumour and 15 solid), fulfilled the eligibilitycriteria and were included in this study (9 male, 6 female; mean age 60 yrs; range 38-75 yrs).The primary cancer was lung (NSCLC) in 8 pts (57%), breast in 2 pts (13%), parotid in 1 pt (6,5%),melanoma in 1 pt (6,5%), kidney in 1 pt (6,5%), colon in 1 pt (6,5%), unknown in 1 pt (6,5%).Before stereotactic drainage the mean cystic tumour volume was 19,95 ml (ranging between 3,8and 48 ml). At the end of stereotactic drainage, before GKRS, mean tumour volume was 9,59 ml(1,2–18 ml). Mean prescription dose to the tumour margin was 19,6 Gy (range 16 - 25 Gy); at50% isodose. MRI follow up was performed every three months. We analysed survival periodand local tumor control rate. Results: Mean follow-up period was 10 months. Local tumour con-trol was achieved always in the cystic tumours. Two patients died in the first month after the treat-ment: one for carcinomatosis meningitis and one for pulmonary embolia. Conclusions: This studysupports the use of stereotactic drainage approach in case of large-volume multiple and cysticbrain metastasis.

Recurrent metastases following whole brain irradiation: hope for patients in RPA class III? P1-32 Markus, Gross (1); Steffi, Pracht (2); Klaus, Hamm (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Helios-Kliniken Erfurt - Department ofstereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy andRadiooncology Department Marburg, Germany

Background: Radiosurgery is an effective therapy for brain metastases, but has failed to show asubstantial survival benefit in patients suffering from recurrent metastases after whole brainradiotherapy (WBRT) so far. Therefore, we evaluated the prognostic factors derived from the RTOGrecursive partitioning analysis (RPA) to identify patient subgroups deriving a benefit from thismethod. Patients and Methods: A total of 46 patients with 70 recurrent cerebral metastases pre-viously treated with WBRT underwent single-dose linac radiosurgery. All patients were classifiedinto the three RPA prognostic classes based on age, performance score, and presence of extracra-nial tumour manifestations. The impact of prognostic factors on survival of these patients and theprognostic value of RPA classes in this collective was determined. Results: In RPA class I(Karnofsky performance score ≥ 70, primary tumour controlled, no other metastases, age < 65years), radiosurgery resulted in a median survival of 11.5 months (n = 11) which was signifi-

219

Page 222: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

cantly longer than for RPA class III (Karnofsky performance score < 70) (n = 22, 3.7, p<0.005),or RPA class II (all other patients) (n=14, 4.0, p<0.05). No significant difference in survivalbetween RPA class II and RPA class III was seen (p>0.5). Significant favourable prognostic fac-tors affecting survival were Karnofsky performance score, absence of extracerebral tumour, lesionvolume < 4 ml, encompassing dose > 18 Gy, and neurological symptoms prior to radiosurgery.Conclusion: Radiosurgery in patients with recurrent cerebral metastases results in a substantialsurvival benefit preferably in patients in with a low systemic and cerebral tumour burden.However, there was even a survival of about 4 months in patients of RPA class III, therefore jus-tifying radiosurgery for these patients, as well.

Gamma knife radiosurgery for the cavernous sinus metastases and invasion P1-33 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Masaki, Yoshimura (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

Background: We evaluated the efficacy of gamma knife radiosurgery for cavernous sinus metas-tases and invasion. Method: We treated and followed 21 patients with cavernous sinus metas-tases and invasion using gamma knife radiosurgery. Nine of these patients had nasopharyngealcancer and 12 had distant metastases from other cancers. The volume of tumors ranged from 2.9to 50.0 ml (median: 9.9 ml) and the radiation dose to the tumor margin was 10 to 21 Gy (medi-an: 14 Gy). Results: The median follow-up period was 9 months. Clinical symptoms wereimproved in 48 % of the patients after treatment, and tumor growth control was obtained in 67% of the patients at their final follow-up. The actual one - year and two - year tumor growth con-trol rates were 68% and 43%, respectively. The mean survival time was 13 months. No patientsuffered radiation injury. Conclusion: Gamma knife radiosurgery is a very useful therapeuticoption for the treatment of cavernous sinus metastases and invasion, either as initial treatmentor as an adjunct treatment for recurrences even in preirradiated patient.

Fatal intratumoral hemorrhage immediately after Gamma Knife radiosurgery for brain metastasis: Case report P1-34 Masahiro, Izawa (1); Mikhail, Chernov (1); Motohiro, Hayashi (1); Yuichi, Kubota (1); Hidetoshi, Kasuya (1);Tomokatsu, Hori (1) (1) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan

OBJECTIVE: Radiosurgical treatment of brain tumors is sometimes considered free from significantacute complications or adverse effects. We report a rare case of fatal intratumoral hemorrhageimmediately after gamma knife Radiosurgery (GKR) for brain metastasis. CASE PRESENTATION: A61-year-old woman with lung cancer complicated by systemic dissemination, experienced anacute episode of headache, speech disturbances, and right-side hemiparesis. She had no historyof arterial hypertension or coagulation disorders. CT and MRI disclosed 2 brain metastases. Thelargest tumor had a diameter of 4 cm and was located in the left frontal lobe, whereas the otherone with a diameter of 1.5 cm was located in the left cerebellar hemisphere. The supratentorialneoplasm was removed microsurgically without any complications. GKR for infratentorial lesionwas done in overall 3 weeks after manifestation of the cerebral disease. Marginal dose corre-

220

Page 223: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

sponded to 50% prescription isodose line and constituted 22 Gy, maximal dose was 44 Gy. Nocomplications were marked during frame fixation, treatment by itself, or frame removal. Fifteenminutes after the end of GKR session the patient acutely fell into deep coma with cardiac arrest.Immediate resuscitation resulted in recovery of the cardiac rhythm, and urgent CT disclosed mas-sive intracerebellar hemorrhage in the vicinity to radiosurgically treated tumor. The family reject-ed surgical treatment. Despite intensive therapy the patient remained deeply comatose and died4 days later. Autopsy confirmed hemorrhage in the brain metastasis and herniation syndrome.CONCLUSION: GKR for metastatic brain tumors should not be considered as absolutely risk freeprocedure. As shown in the described case, while rare, even fatal complications can occur, andtheir probability should be discussed with a patient and his or her family members during obtain-ing the informed consent for radiosurgical treatment.

Gamma knife radiosurgery for metastatic alveolar soft part sarcoma : a case report P1-35 Jang, Jae-Won (1); In-Young, Kim (1); Jung, Shin (2) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department ofNeurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea

Objectives Brain metastasis from alveolar soft part sarcoma (ASPS) is very rare, and there has beenno report on the radiosurgery for the cerebral metastasis of ASPS. We used gamma knife radio-surgery (GKR) as a palliative treatment, and report the results. Materials & Methods A 32-year-old female visited our hospital due to progressive headache. Two years ago, she had underwentan operation to remove the parietal mass, and the histological diagnosis had turned out to beASPS. The 3000cGy whole brain radiation treatment had been performed postoperatively. Afterthe admission the magnetic resonance images (MRI) showed multiple lesions, and the first GKRwas performed to the largest five lesions. The second GKR was performed three months later tothe new largest six lesions at the time. The latest follow-up imaging was computed tomographyten months after first GKR. Results The mean diameter of the tumors was 16.8 mm (range 9.1-30.7 mm). The prescription doses ranged from 12 Gy to 16 Gy. In ten tumors out of eleven, localtumor control was observed: size reduction 7, no increase in size 3. The size increase wasobserved only one tumor, but we had already observed the size reduction in that tumor sixmonths after first GKR. The patient has been followed up regularly for one year, and the Karnofskyperformance status became worse to 60 because of a number of newly developed cerebrallesions and systemic metastasis. Conclusion We report the experience of GKR in cerebral metasta-tic ASPS which is very rare. Similar to other cerebral metastatic tumors including sarcomas, thepalliative effect of GKR is thought to be satisfactory in cerebral metastatic ASPS.

221

Page 224: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Radiosurgery for the treatment of brain stem metastases: relationship between clinical status and survival P1-36José, Lorenzoni (1); Daniel, Devriendt (2); Nicolas, Massager (3); Françoise, Desmedt (1); Stéphane, Simon (4);Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme -Neurochirurgie; (4) Institut J. Bordet - Physique Brussels, Belgium

Objective: To study results and survival of patients with brain stem metastases treated with radio-surgery. Material & Methods: Among 160 patients treated for brain metastases betweenDecember 1999 and December 2003, there were 15 patients (9.4%) with 17 brain stem metas-tasis. Volume of the lesions ranged from 0.012 to 2.4 cc (mean 0.56 cc). Treatment was per-formed with Leksell gamma knife C, with a median peripheral dose of 18 Gy (ranging from15 to24 Gy) at a median isodose of 50% (ranging from 50 to 68%). Stratification of patients was doneusing the Recursive Partitioning Analyze (RPA), the Score Index for Radiosurgery in BM (SIR) andthe basic score for brain metastases (BS-BM). Results: The primary tumor was lung in 8 patients,breast in 4, and other in 3. Nine lesions were located in the pons, 5 in the mesencephalon, and3 in the medulla. All patients were followed clinically; radiological follow-up was available in 10patients (67%). Tumor control was achieved in all but one followed lesion. There were no com-plications related to treatment. Median survival of patients with brain stem metastasis was 10.8months, and was not different than the median survival of patients with metastases in other brainlocations (13,3 months, p= 0.15). BS-BM score differentiates 2 groups of patients with differentsurvival; RPA and SIR had borderline p values. Conclusions: Radiosurgery is an effective treatmentof brain stem metastases. As for other intracranial locations, survival is determined by the clinicalstatus at the time of treatment.

Stereotactic irradiation (STI) boost for multiple brain metastases P1-37 Hisato, Nagano (1); Takashi, Shuto (2); Yuji, Nakayama (2); Inomori, Shigeo (2) (1) Yokohama Rosai Hospital - Radiationoncology; (2) Yokohama Rosai Hospital - Neurosugery Yokohama Kanagawa, Japan

Combination of whole brain irradiation (WBI) and Stereotactic irradiation (STI) is still a hot argu-ment especially when a patient has more than five metastatic brain tumors. UncomplicatedControl (UC); (k-NTCP)*TCP, which was advocated by Gerald J. Kutcher (1996), will give a way outof this difficulty. NTCP (normal tissue complication probability) was calculated by Flickinger’s inte-grated logistic formula, and TCP (tumor control probability) was derived from Colombo’s formulato make account of dose inhomogeneity of STI. One shot was set in the phantom brain and UCwas calculated in two conditions, with WBI and without WBI. Then additional shot was set andcalculation was performed. Another shot would add till the value of UC with WBI became largerthan that of UC without WBI. This number of shots was gained with every collimator of gammaknife; 8, 14, 18mm collimator. When constant k was assumed 0.39 and the dose of WBI was30Gy/10fxs/2wks, more than 16, 4, 3 shots made the UC value larger than the value withoutWBI, if the collimator size was 8, 14, 18mm respectively. This means that when tumors of patientwere more then one centimeter in size and number of the tumors was more then five, WBI shouldbe delivered concomitantly with STI. Combination of WBI and STI boost should be recommend-ed in these conditions.

222

Page 225: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Localized therapy for limited metastatic disease to the brain:A Phase II study of surgery, stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) in favorable patients P1-38Lucien, Nedzi (1); John Wilson, Walsh (2); Roy, Weiner (3); Bryan R., Payne (4); Ellen, Zakris (1); Robert,Sanford (5); Timothy, Pearman (6); Paul, Rosel (7); Raja, Mudad (3); Anna, Hall (8); Judy, Weber (9) (1) Tulane University - Radiation Oncology; (2) Tulane University Medical Center - Department ofNeurosurgery; (3) Tulane University - Department of Hematology/Oncology; (4) LSU School of Medicine atNew Orleans - Department of Neurosurgery; (5) Tulane University - Radiation Oncology; (6) Tulane University- Psychology; (7) Tulane University - Radiology; (8) Tulane University Hospital and Clinic - Radiation Oncology;(9) New Orleans Regional Gamma Knife Center - Nursing New Orleans, USA

Background: Surgery, SRS and SRT are local therapies for selected patients with a limited numberof brain metastases. Occasional patients are treated with a combination of these therapies, butthis has not been studied prospectively. Purpose: To determine the feasibility and efficacy of sur-gery, SRS and SRT in favorable patients with 1-4 brain metastatses. Materials and Methods: In2001-2004, 23 patients with 1-4 intraparenchymal brain metastases and KPS>= 70%wereenrolled in an institutional review board approved clinical trial. Treatment for each lesion wasdetermined based on tumor size. Tumors <=2cm received SRS; tumors >2cm received eitherSurgery+SRT(25Gy/5) or SRS+SRT(25Gy/5), depending on patient and physician preference.Patients were followed with MRI scans every three months. Additional brain metastases detect-ed in follow-up were treated on study if KPS>=70% at the time of detection. Results: Five outof 23 patients were found to be ineligible: two for >4 metastases at treatment; two for extra-parenchymal location; one for no metastasis at treatment. Primary site was as follows: 8 breast;6 lung; 2 unknown; 1 anal; 1 kidney. Median KPS was 80% (70-100%). Eight (44%) had a soli-tary metastasis, eight (44%) had no extracranial disease and four (22%) had radiographically pro-gressive metastases more than three months following whole brain radiotherapy (WBRT). Forty-seven lesions in 18 patients were treated on study: 42 SRS; 2 SRS+SRT; 3 SRT. No lesion wastreated surgically. Median SRS tumor volume was 0.3cc (0.02-12). Median SRS dose was 20Gy(16.2-24) prescribed to the 65% (45-80) isodose. The median minimum target dose was 21.6Gy(13.7-33.2). Among 10 SRS targets >1cc, the median conformity index was 1.5(1.1-2.5). Themedian SRT target volume, dose and isodose were 28.3cc (8.7-59.6), 25Gy and 85% (80-89),respectively. The median SRT conformity index was 1.4 (1.3-1.7). With a median follow-up of 6.2months (0.6-20.5), 12 patients have died: 11 with progressive disease, one from a steroid-relat-ed GI bleed. There have been six intracranial failures: three local failures, two treated off studywith surgery and one treated off study with SRS+surgery; two elsewhere brain failures treatedon study with SRS; one leptomeningeal failure. Conclusions: SRS and SRT are prospectively fea-sible in patients with 1-4 brain metastases and KPS>=70%. A clinical trial remains ongoing.

223

Page 226: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Gamma knife (GK) radiosurgery for small brain metastases P1-39 Ouzi, Nissim (1); Daniel, Devriendt (2); Nicolas, Massager (3); Philippe, David (4); Françoise, Desmedt (1);Olivier, Coussaert (1); Stéphane, Simon (5); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme -Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Physique Brussels, Belgium

Introduction: With the advent of high-resolution magnetic resonance (MR) imaging and tighterfollow up, small and often multiple brain metastases (BM) are detected. Radiosurgery plays animportant role, together with conventional microsurgery and whole brain radiotherapy, in a com-prehensive treatment strategy for these patients. Here, we evaluate the efficacy of GK radio-surgery in controlling small BM while considering the potential effect of various maximal radia-tion doses on response. Methods: Between 2000 and 2004, 281 patients harboring BM weretreated with GK radiosurgery. A subgroup of 134 small lesions (56 patients) measuring up to 100mm_ in volume, received maximal doses of 24.5 to 53.3 Gy (18 to 24 Gy to the 45- 85% iso-dose line). Follow-up with sequential MR, MR spectroscopy and positron emission tomography(PET) imaging evaluated changes in tumor size. Results: Sixty-four lesions were followed up, 3-43 (median 10) months after treatment. The one year tumor control rate was 91% (43 % reduc-tion and 48% stabilization in size). Increased lesion volume was recorded 4-10 months post treat-ment in 3 patients. One had two lesions, inactive by PET scan. In another patient, one lesionexpanded initially and later decreased in volume. A second lesion enlarged 7 and 10 months aftertreatment. MR spectroscopy suggested inactive tumor. In a third patient, 3 lesions expanded 4and 6 months after treatment. All melanoma patients responded to treatment but difference inresponse could not be attributed to other pretreatment parameters or to maximal dose delivered.Conclusions: GK radiosurgery for patients with small BM can achieve high tumor control rate irre-spective of the maximal dose delivered. It can be administered in one session, treating simulta-neously lesions of different size and location, and serves as an important adjunct to multi-modal-ity treatment of these patients.

Fractionated gamma knife radiotherapy for huge metastatic tumor P1-40 Ushikubo, Osamu (1) (1) Kasai cardiology and neurosurgery hospital - neurosurgey Tokyo, Japan

OBJECT; The purpose of this study was to evaluate the safety and efficacy of gamma knife radio-therapy for the treatment of huge metastatic brain tumor. Methods; Fifteen lesions of ten patientsharboring metastatic brain tumors were treated GKRT . As for one, primary lesion was not clearin them. Tumor max diameter was more than 3cm in 11lesions. One lesion was recurrence of pre-viously irradiated lesion. Two tumors were located in near brainstem. The tumor volume rangedfrom 1900 to 28600 mm3. (median 20800 mm3) The peripheral dose to the tumor margin was10Gy and the whole tumor was covered. The treatment went three times every 2weeks. Thetumor control rate was 73%. We had to do craiotomty for one patient whose tumor was receivedpreviously irradiation. Pathology was tumor necrosis. Three lesions of two patients progressedfollowing therapy. Conclusions; It was investigation phase, but it was suggested that one of the

224

Page 227: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

therapies for giant metastatic brain tumor could get possible to be optional by this fractionatedgamma knife radiotherapy.

Stereotactic radiosurgery boost for metastatic brain tumors receiving WBRT P1-41 George, Pissakas (1); V, Georgolopoulou (2); K, Doukaki (3); S, Mourgela (4); E, Andriotis (5); M, Kalogeridou(3); S, Kosmidou (3); G, Arhontakis (4); E, Pappas (2); I, Kouvaris (6); A, Sotiropoulou (3) (1) Alexandra Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3)St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Neurosurgery; (5) St.Savvas Hospital -Radiology; (6) University of Athens - Radiation Oncology Athens, Greece

Purpose: Stereotactic radiosurgery (SRS) is nowadays an option for increasing the dose receivedby patients with brain metastases after WBRT has been completed. This study presents the expe-rience of our institution from applying linac based SRS as a boost treatment to selected patientsundergoing WBRT. Materials/Methods: Between March 2000 and February 2004, forty-ninepatients with metastatic tumors were selected to undergo an SRS boost after their WBRT. Criteriawere 1 to 3 lesions, age 18 years or older and good performance status (KPS>70). For stereo-tactic treatments we use the 6 MV beam of an Elekta SL18 linac to which a floorstand isocentricsubsystem is attached. The WBRT was given at 250 cGy/fraction to 3750 cGy in 3 weeks or at300 cGy/fraction to 3000 cGy in 2 weeks. The single fraction SRS dose followed one month aftercompletion of radiotherapy and was tumor-size dependent ranging from 1300 to 2000 cGy. Ourseries comprised of 36 male and 13 female patients, ages ranging from 34 to 79 years (median:54) with a median KPS of 90 (range: 70-100). Lesion volume ranged from 0.134 to 11.1 cc (medi-an 1.66cc) and solitary tumors were present in 67% of our cases. Follow-up time ranged from 2to 34 months (median: 6). Results: The one-day SRS procedure, involving frame fitting under localanesthesia, CT scan with a localizer and irradiation after a few hours of waiting for image fusionand treatment planning to be prepared, was received well by all patients without any complica-tions. Patient follow-up, 4 months after treatment, indicated elimination of lesions in 32% of ourcases, stable size in 8% and volume reduction in 60%. 7 months after treatment, these rates werereduced to 27%, 7% and 51%, respectively, since 3% of our patients showed local relapse at thetreated area and 8% developed new lesions. The remaining 4% of our cases, that initially showeda reduction in tumor size, recurred at subsequent follow-ups with increasing lesion volume.Conclusion: SRS is a useful method for boosting the dose received by metastatic brain tumors andachieving good local control rates.

225

Page 228: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stereotactic irradiation for metastatic brain tumors from hepatocellular carcinoma P1-42 Masao, Tago (1); Kenshiro, Shiraishi (1); Keiichi, Nakagawa (1); Keisuke, Maruyama (2); Hiroki, Kurita (3);Masahiro, Shin (4); Atsuro, Terahara (4); Shunsuke, Kawamoto (5); Kuni, Ohtomo (1) (1) University of Tokyo Hospital - Department of Radiology; (2) University of Tokyo Hospital - Department ofNeurosurgery; (3) Kyorin University Hospital - Department of Neurosurgery; (4) Toho University OmoriHospital - Department of Radiology; (5) Dokkyo University School of Medicine - Department of Neurosurgery Tokyo, Japan

Introduction: We retrospectively analyzed the outcomes of stereotactic irradiation (STI) formetastatic brain tumors from hepatocellular carcinoma (HCC). Materials and Methods: Elevenpatients with 22 metastatses from HCC were treated by STI at our hospital since 1991. We eval-uated nine patients (eight males and a female) with 20 tumors who have undergone at least onefollow-up visit. The median and mean tumor sizes were 13.8 mm and 14.6 mm, respectively(range: 2.0 - 27.7 mm). Thirteen tumors were treated by stereotactic radiosurgery using 15 to 25Gy to the margin, the remainder were irradiated between 34 and 38 Gy in 5 fractions at the mar-gin (all received 40 Gy in 5 fractions at the isocenter). Results: The median clinical follow-up peri-od was 5.2 months (range: 1.7 - 19.7 months). Six patients died, and three were alive at the lastfollow-up. The median survival was 5.8 months after STI. The actuarial 1-year survival rate was42 %. The median radiological follow-up period was 2.2 months (range: 0.7 - 15.4 months). 16of 20 tumors (80%) were controlled at the last imaging study. The actuarial 1-year control ratewas 57 %. Progression in four tumors was observed between three and four months after thetreatment, which were irradiated lower biological effective doses. Conclusions: STI provides rea-sonable effect for brain metastases from HCC. Higher dose may be necessary for long-term tumorcontrol.

Radiosurgical treatment of “radioresistant” cerebral metastases P1-43Charles, Valery (1) (1) Hopital de la Pitie-Salpetriere - Service de neurochirurgie Paris, France

Treatment of secondary cerebral lesions that were previously considered as radioresistant (RR)with fractionated regimen is now possible using radiosurgery. We reviewed datas of patientstreated between 1994 -2002 for kidney or melanoma brain metastases. Median follow-up was10 months . Among the 35 patients presenting 85 secondary melanoma lesions, mean age was52 (25-73), initial cancer was controled in 46% of the cases. The score index (SIR) was of 1 in 4cases, of 2 in 19 cases, of 3 in 12 cases. Median volume of lesions was 1,58 cm3 (0.04-63.6),minimum delivered dose was 14.4 Gy (10-19.4) and maximum dose was 22.8 Gy (13.7-47.8).Among the 31 patients presenting 70 secondary lesions of kidney, mean age was 58 (38-75), ini-tial cancer was controled in 22.6% of the cases. The SIR was of 1 in 3 cases, of 2 in 20 cases, of3 in 8 cases. Median volume was 1.36 cm3 (0.02-31.6), minimum delivered dose was 14.8 Gy(10.8-19) and maximum dose was 22.1 Gy (14.3-39.5). Kaplan-Meier analysis showed a medi-an survival of 200 days for melanoma and of 266 days for kidney. Local control at 3, 6 and 12months was 98, 92, 75.3% respectively for melanoma, and 98, 89.6, 89.6% respectively for kid-ney. The rate of grade>2 RTOG complications was 6%. Survival predicting factors for RR lesionswere : histology (p=0.05) and SIR index (p=0.01). Multivariate analysis of survival predictors

226

Page 229: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

performed separately for each histology showed no significant factors for melanoma. Age(p=0.04), disease control (0.01) and SIR (p= 0.01) were found significant for kidney. No factorwas found for prediction of the risk of relapse in a univariate analysis. Additional WBRT (35%cases) did not influence cerebral control (p=0.5). Radiosurgery alone is a safe, non invasive andefficient technique for patients presenting radioresistant cerebral metastases.

Repeated in-situ recurrence of brain metastases after radiosurgery and resection: dural contact as a risk factor P1-44 Dirk, Van Den Berge (1); Guy, Soete (1); Christine, Collen (2); Recai, Ates (3); Katrijn, Van Rompaey (4); Jean,D'Haens (4); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ-VUB - Radiotherapy; (3) AZ VUB - Neurochirurgie Brussels, Belgium

The widespread use of stereotactic radiotherapy as well as the improvement of systemic treat-ments has changed the passive and fatalistic attitude towards patients with metastasis to thebrain. In a small subgroup of patients impressive survival times in excellent quality of life can nowbe achieved, but al but a few patients ultimately succumb to their disease either due to extracra-nial progression, development of new intracranial disease or repeated recurrence of previouslytreated brain metastases. In this retrospective study we looked in our database covering the lastdecennium for repeated in-situ recurrence of brain metastases in patients surviving more than oneyear. The presence of contact with, or frank invasion of the dura was almost universal in thisgroup of patients. In some cases multiple metastases recurred selectively in lesions withmeningeal contact and not in others. This data suggest that, especially in patients with otherwisegood prognostic factors, measures should be taken to treat such lesions more aggressively bycombining modalities, taking larger resection / irradiation margins or increasing dose.

Paradigm shift in management of patients with multiple brain metastases: From whole brain radiotherapy to gamma knife radiosurgery P1-45 Masaaki, Yamamoto (1); Bierta, Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Gamma knife (GK) radiosurgery is now the primary treatment in an increasing number of patientswith brain metastases (METs), both radiosensitive and radioresistant, single and multiple. New, notyet widely known, concepts pertaining to GK radiosurgery for brain METs are presented based onour personal series of 1206 patients (1596 procedures, 10,557 tumors) with brain metastases whounderwent GK treatment (1992 – 2004). The most common primary tumor was lung (61.5%), fol-lowed by breast (10.1%), colon-rectum (8.7%), kidney (5.1%), stomach (2.9%) others (8.8%) andunknown (2.9%). In our experience, GK is a safe and effective treatment even in patients with 30-40, or more, tumors. Though lesion size is a limitation, high tumor control rates are possible whenlesions are irradiated with at least 18 Gy. Recurrence and radiosurgical complications are rare insuch cases. Symptomatic complications, i.e. radionecrosis of normal brain tissues, are slightly morecommon in long-surviving cases. However, in more than 85% of patients, death is due to diseasesbrain metastatic. Thus, most do not survive long enough for complications to manifest. Therefore,good brain function is generally maintained till death. Factors predicting longer survival are youth,

227

Page 230: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

better performance status, fewer tumors and absence of active non-brain disease. Although someinvestigaters report re-treatment for new lesions to be less frequent when whole brain radiother-apy (WBRT) is combined with surgery or GK radiosurgery, in our experience neither survival norlocal recurrence rates improve significantly with WBRT. Advantages of GK over WBRT include briefhospitalization, higher control rates, earlier symptom palliation, all MRI-detected lesions can betreated, other treatments (e.g. radiotherapy) can be postponed, GK-irradiation can be repeated, theincidence of radiation-induced dementia is far lower and more tumors (30+) can be treated in onesession. We advocate meticulous MRI follow-up to detect recurrence and assess tumor necrosis.All detectable tumors should be irradiated, in any patient wishes to continue receiving treatment.

Repeated radiosurgery for local recurrences of brain metastases after gamma knife radiosurgery P1-46 Kazuhiro, Yamanaka (1); Yoshiyasu, Iwai (1); Yasuhiro, Matsusaka (1); Kazuhito, Nakamura (1); Toshihiro,Yasui (1); Masaki, Komiyama (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

We evaluated the treatment results of repeated radiosurgery for recurrences of brain metastasesafter gamma knife radiosurgery (GKS). Fifty one patients with 63 brain metastases were treatedrepeatedly because of recurrent tumors after GKS. The mean age of these patients was 60 (range:37 - 76). The most common primary site was the lung (76%). The mean tumor volume was 5.9ml (0.02 - 20.8 ml) and the mean delivered dose to the tumor margin was 19.3 Gy (range: 12 -25 Gy) in the first GKS. The interval between the first and the second GKS was 9.9 months. Inprinciple, methionine-PET was carried out before repeated GKS. The mean follow up period was8.2 months (1 - 42 months) after second GKS. The median survival time was 24 months after thefirst GKS and 12 months after the second GKS. Twenty seven patients died and the causes ofdeath were 8 (30%) brain tumors, 13 (48%) systemic extracranial disease, and 2 (7%) meningealcarcinomatosis. Thirty eight lesions (62%) were controlled after the second GKS and the cumula-tive 50 % control duration was 12 months. Symptomatic radiation injury including transientepisodes appeared in 9 (14.8%) patients. Repeated GKS for recurrences of brain metastases afterGKS was useful especially for limited survival patients.

Gamma knife radiosurgery for large volume brain metastases:Acceptable volume response rate with marginal increase in toxicity P1-47C.P., Yu (1); Joel Y. C., Cheung (1); Josie F. K., Chan (2); Samuel, Leung (3); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Center; (2) Canossa Hospital - Gamma Knife Center; (3) Queen ElizabethHospital - Department of Neurosurgery Hong Kong, Hong Kong

Objective: To analyze the volume response rate and toxicity of large volume brain metastases(LVBM) treated by gamma knife radiosurgery. Methods: We arbitrarily defined LVBMs as lesion(s)larger then 8 cc. We treated LVBMs prospectively with a separate protocol: 18 Gy margin dosewith a very high central dose at 45-60 Gy, assuming the more hypoxic and necrotic centre wasmore radio-resistant. For comparison, we treated the small volume lesions (<8 cc) using a mar-gin dose of 18 Gy with central dose at 36 Gy. We performed sequential MR volume mapping at

228

Page 231: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

3 months interval to assess tumor volume response and regular clinical follow up for outcomeassessment. Results: Between 1995 and 2004, 137 patients harboring 568 brain metastasesunderwent gamma knife surgery. We only included those patients with at least 3 MRI follow-upsfor this analysis. 68 patients with 316 lesions formed the database of this study. 42 lesions from31 patients were larger than 8 cc and were treated according to the LVBM protocol. Mean vol-ume of these lesions was 16.9 cc +/- 8.4. During follow up, we observed tumor volume shrink-age in 36 out of 42 (86%) lesions. 28 (66.6%) showed progressive and permanent shrinkage. 8(19%) developed increase in volume after an initial decrease. 3 of these were local recurrence at12 months, 23 months, and 36 months, all proven by open surgery. The other 5 were diagnosedas radiation necrosis. In comparison, all small lesions responded with volume shrinkage. 49(18%) developed radiation necrosis or local recurrence. Median survival of patients harboringLVBM was similar to those with small volume lesions. 6 patients with LVBMs (16 patients withsmall lesions) survived more than 2 years. Conclusion: Although patients harboring LVBMs aretraditionally excluded for radiosurgery, many patients are not candidates for open surgery.gamma knife radiosurgery remains a viable treatment option. 86% of the lesions responded withvolume shrinkage (versus 100% for small lesions). Incidences of radiation necrosis plus tumorrecurrence were comparable between the LVBMs and small lesions. Survival figures were alsosimilar. gamma knife surgery can be recommended to patients with LVBMs who were unsuitablefor open resection, despite a slightly lower response rate when compared to small lesions.

A comparison of Whole Brain Radiation Therapy (WBRT) and radiosurgery (RS) for the treatment of brain metastases: If the volume is prognostic factor influencing survival? P1-48Edyta, Wolny (1); Aleksandra, Grzadiel (2); Andrzj, Tukiendorf (3); Leszek, Miscyk (1)(1) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Radiotherapy Department; (2) Center ofOncology-MSC Memorial Institute Branch in Gliwice - Treatment Planning Department; (3) TechnicalUniversity of Opole - Mechanical Faculty

Gliwice, Poland

PURPOSE: The comparison of radiosurgery and whole brain radiotherapy of patients with brainmetastases and evaluation of tumor volume impact on survival. MATERIALS AND METHODS: 155patients (102 men and 53 women, age 32-81) suffering from brain metastases, treated withWBRT and RS between April 2001 and April 2004. 70 patients were treated with WBRT alone,61 with RS, and 24 with WBRT and RS boost. The most frequent primary tumor was histologi-cal confirmed lung cancer [96 patients - 62% (55 non-small-cell and 41 small-cell-cancer)], 22patients (14%) had lung tumor without histological confirmation,18 patients (12%) had non evi-dence of primary tumor,12 patients (8%) suffered from breast cancer and 7 (4%) from renal can-cer. Solitary brain metastases had 33 (21%) and multiple 117 (79%) patients RS was performedusing linear accelerator (peripherial dose range was 12-20 Gy) and WBRT was performed usingfive fractions delivered to total of 20 Gy. The volume of the largest treated lesion varied from 0.5cm_ to 65 cm_. The performance status in ZUBROD scale was estimated and varied from 0 to 3.RESULTS: The tumor volume increase of about 1cm_ enhanced failure risk of 1,2% (SD 0,54%).The increase in ZUBROD score about one degree enhanced failure risk of 41%.(SD 18%). Theestimation of survival time median (weeks) is:

229

Page 232: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

for lung tumor: 17.9(SD3.8) - WBRT, 15.8(SD4.2) - RS, 35.4(SD11.4) - WBRT+RS;

for lung cancer: 41.1(SD9.8) - WBRT, 35.9(SD9.2) - RS, 81.2(SD 27.6) - WBRT+RS;

for breast cancer: 37.8(SD13.9) - WBRT, 32.9(SD12.1) - RS, 74.6(SD32.9) - WBRT+RS;

for renal cancer: 42.1(SD20.8) - WBRT, 36.9(SD18.7) - RS, 81.4(SD41.8) - WBRT+RS;

for unknown primary site: 32.9(SD10.5) - WBRT, 28.3(SD7.4) - RS, 3.7(SD21.3) - WBRT+RS.

CONCLUSION: WBRT in combination with radiosurgery seems to be most effective brain metas-tases treatment modality. Clinical success appears to be dependent on the total intracerebraltumor mass and performance status.

Gamma knife radiosurgery for skull base chordomas: What is an adequate dose level? P1-49 Marc, Goldman (1); Georg, Noren (1); Stephen C., Saris (1); Carla, Bradford (1); Melissa, Remis (1) (1) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA

PURPOSE: Given the critical location and locally aggressive nature of skull base chordomas, theypose a formidable management challenge. Other studies have demonstrated the need to deliverhigh doses of radiation to affect the growth of chordomas. Gamma knife radiosurgery was usedas sole treatment after either subtotal surgical resection or diagnostic biopsy to control thegrowth. We compared the efficacy of different dose levels in this and other studies. MATERIALSAND METHODS: We evaluated five patients with chordomas who underwent gamma knife radio-surgery as sole adjunct to subtotal surgical resection (three patients) or diagnostic biopsy (twopatients). Patient age was 27-57 years (mean 40). The treated tumor volumes were 2.3 to 29.3cm3 (mean 13.1 cm3) with tumor margin dose range 10-25 Gy (mean 19.2 Gy) and a maximumtumor dose mean of 43 Gy. The follow-up time was 24-84 months (mean 50.4 months). Postradiosurgery tumor volume was calculated from serial MRI imaging performed at regular inter-vals. Patients were seen in follow-up to assess for any focal neurological findings related to eithergamma knife treatment or tumor progression. RESULTS: Four patients had stable disease or tumorshrinkage. Only one patient had tumor progression, which was out-of-field. This patient had aprescription dose of 10 Gy to the tumor margin due to proximity of the optic apparatus.Remarkably, this patient also developed cranial nerve deficits. The remaining four patients had aminimum of 20 Gy to the tumor margin and had improvement or no change in pretreatmentsymptoms. CONCLUSION: Skull base chordomas over a wide range of volumes may be effective-ly treated with gamma knife radiosurgery following biopsy or subtotal resection with low risk ofside effects. Precise target definition and planning and a minimum dose of 20 Gy seem to be nec-essary to achieve these results.

230

Page 233: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stereotactic radiosurgery in the management of glomus jugulare tumors P1-50Francisco, Mascarenhas (1); A, Gonçalves Ferreira (2); H, Carvalho (3); M, Santos (4); A, Almeida (5); M, Vacas(6); M, Sá da Costa (7); S, Germano (8) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal- Neurosurgery Dpt; (3) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (4) Hospital de SantaMaria- Lisboa-Portugal - Radiotherapy Dpt; (5) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt; (6)Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (7) Hospital de Santa Maria- Lisboa-Portugal -Radiotherapy Dpt; (8) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt Lisboa, Portugal

ABSTRACT Purpose: This retrospective study evaluate the efficacy and toxicity of stereotacticradiosurgery (SRS) in the management of the glomus jugulare tumors (GTJ). Methods: Fifteenpatients were submitted to SRS with a 6 MV linac at the Hospital Santa Maria in Lisbon betweenJuly 1997 and February 2005. Median age was 55.4 years (range 30 to 77) of twelve femalesand three males. Six pts have failed to previous treatment modalities. Reasons to treating withSRS included residual or recurrent tumors after surgery and embolization(6), geriartric/medicallyunsuitable for surgery (5) and patient preference (4). The tumor volume ranged from 2.3 to 10.4cc (mean, 6.3 cc). The median marginal dose was 13.8 Gy (range, 12 to 15 Gy) prescribed to80% isodose line. Results: The median time from date of SRS to the last follow-up was 47.3months (range 2 to 92 months) including 6 and 9 pts with more than 60 and 36 months respec-tively. Improvement of the symptoms and cranial nerve disfuntions were presented in all patients.After surveillance magnetic imaging eight tumors were reduced and the others were stable beingconsidered a local control in all pts. No acute or late toxicity was documented. Conclusions: Ourexperience in this series presenting excellent tumor control rate and a favorable toxicity profilesupport the effectiveness of SRS for patients with glomus jugulare tumors.

Dramatic short term response of tumors of the pineal region to the Gammaknife radiosurgery P1-51 Mazdak, Alikhani (1); Mohammad Ali, Bitaraf (1) (1) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Tehran, Iran

The optimal management of lesions arising from th pineal region has been a subject ofdebate.Fifteen cases of pineal region tumors were treated by stereotactic radiosurgery in a 15months period in Iran gammaknife center . The tumor diagnosis was confirmed by biopsy,tumormarkers and MRI imaging.All th patients had a history of increased ICP and V-P shuntinsertion.The mean radiation dosage was 20 Gy at 50% isodose.Follow-up data was availablefor 7 patients at 6 months follow-up period . Five patients had more than 90% decrease in tumorvolume and 2 patients had stable tumor size.Six patients experienced an improvement in clinicalsigns and symptoms.Four patients became symptom free with no neurological deficit. One patientdeveloped intradural seeding of tumor to the spine despite a decrease in tumor size and clinicalimprovement.Our results indicate that gammaknife radiosurgery might be regarded as an impor-tant treatment modality as adjunct or primary management of pineal region tumors.

231

Page 234: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Cyberknife radiosurgery in recurrent head and neck cancer P1-52 Seong Yul, Yoo (1) (1) Radiation Oncology DepartmentSeoul, South Korea

Purpose : Locally recurred head and neck cancer after radiation therapy with presentation of grossdisease in the field of previous radiotherapy has no effective option of treatment when the sal-vage surgery has limited. In this study cyberknife radiosurgery was used in the treatment oftumors for the palliative aim to remove gross tumor again in expectation of local control.Materials and Methods : Among the 53 patients, a total of 71 sites were treated by radiosurgeryat KIRAMS. Squamous cell carcinoma was 59 sites in 41 patients. Distribution of the region was23 nasopharynx, 15 metastatic neck, 12 paranasal sinuses, 8 oropharynx, 2 parotid and so on.14 sites received single irradiation with dose of 12 to 23 Gy. 57 sites received 15 to 39 Gy dev-ided by 3 fractions. Median GTV was 18 cm3(0.4 – 457.1 cm3). Results : Median follow-up peri-od is 8 months (3 – 27 months). Including the number of patients showing partial response whoalive more than 6 months until the time of evaluation, the total number of response was 44 sites(62.0 %) out of 71. Response rate by site was 73.9 % in nasopharynx (17/23), 86.7 % inmetastatic neck (13/15), 66.7 % in PNS (8/12) and 37.5 % in oropharynx (3/8), etc. Responserate by volume was 82.4 % (28/34) when the tumor is smaller than 3 cm in diameter and 37.8% (14/37) in larger than 3 cm. No difference of response was found between squamous cell car-cinoma and non-squamous cell carcinoma, and between single and 3 fractions treatment. Grade3 and 4 complication of normal tissue damage was in 2 (4.6%) in responded sites and 6 (21.4%)in non-responded sites. The patients with NED state until now are 17 (32.1%) in number fromthe total of 53 patients. For the 36 patients failed to be controlled, local recurrence or no responsewas in 26 (49.0 %), local recurrence and distant metastasis in 1, and distant metastasis only in5. Conclusion : Radiosurgery is a reliable palliative treatment to the patients who recurred at thesite of previous irradiation in head and neck region. Recurrences in the neck and nasopharynxwhich show the tumor size of less than 3 cm in diameter are good candidate.

Radiosurgery for glomus jugulare: late results P1-53Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil

Glomus Jugulare is a slow growing hypervascular tumor with a complex localization that hasbeen treated to date with microsurgery alone or associated with radiation therapy. In the lastdecade radiosurgery has been employed to control tumor grow. Objective: The objective is toanalyze the late results of radiosurgery alone in the treatment of glomus jugulare. Material andMethods: Three patients with complex glomus jugular tumor were submitted to radiosurgery asprimary therapy, 2 men and one woman, with 78, 60 and 23 yeas old. The volume of the lesionswere 3.06, 4.92 and 19.6 cc. The primary symptoms were pain and there was no cranial nervedysfunction. The patients received 20, 18 and 16Gy at 90 % isodose line, using a LINAC withconformal shaped bean collimator. Results: All tree patients had important relief of the pain (nomore medication necessary) and a follow up of 47, 43 and 53 month showed slight reduction ofthe lesion in all thee patients. The women developed a new glomus jugular in the contralateralside and were submitted again to radiosurgery. Conclusion: Despite of the small number of cases,

232

Page 235: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

long term follow-up showed that radiosurgery is safe and effective control tumor grow andreduce pain associated with glomus jugulare.

Early Experience with a CyberKnife Stereotactic Radiosurgical P1-54Program Michael, Schulder (1); Brian, Beyerl (1); Richard Hodosh (1); Edward, Zampella (1); Elsbieta, Masur (1); LouisDchwartz (1)(1) New Jersey Medical School, Newark NJ, Overlook Hospital, Summit NJNewark, USA

INTRODUCTION: We report our neurosurgical experience after a year of Cyberknife radiosurgery(CKR). METHODS: A Cyberknife stereotactic radiosurgery unit (Accuray Inc.) was installed atOverlook Hospital (Summit, NJ) in August 2004. Data were collected retrospectively for allpatients with intracranial and spinal tumors that have undergone CKR. Seventy-seven patientswith 84 tumors were treated. Diagnoses included 32 patients with metastatic tumors (including8 in the spine), 16 with acoustic neuromas, 15 with meningiomas and 14 with high grade astro-cytomas. RESULTS: Treatment planning was done using MRI registered to CT scans. The prescrip-tion isodose line ranged from 75% to 85%. Intracranial tumor volumes ranged between 0.058and 34 cc (median 1.4 cc) with dosing between 1500 and 2500 cGy (median 2000cGy). Spinaltumor volumes ranged between 11 and 99 cc (median 56 cc) with dosing between 1800 and2500 (mean 2100 cGy). The number of treatment fractions ranged from 1 to 5 for patients withmalignant tumors (mean 2.4) and 2 to 5 fractions (mean 4.6) for those with benign lesions. Twenty-seven of the patients with 30 tumors have been followed for more than 6 months (meanof 7 months). Imaging has demonstrated tumor control in 64% of patients with malignant tumorsand all with benign tumors. CONCLUSION: We were able to treat patients with a wide variety ofintracranial and intraspinal pathology in our first year of CKR, including patients with large tumorvolumes. A higher number of fractions were used to treat patients with benign tumors.

Final design, integration and testing of the dedicated proton SRS/SRT beamline at the NPTC P1-55 Marc R, Bussiere (1); Isaac, Mendelson (1); Hanne, Kooy (1); Jay, Flanz (1); Miles, Wagner (1); Bernie, Gotchalk(2); Paul, Chapman (3); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Harvard University - PhysicsDepartment; (3) Massachusetts General Hospital - Pediatric Neurosurgery Department Boston, USA

Since the start of the NPTC clinical operation in November 2001 the demand for treatment slotshave gradually increased. Foreseeing further demand for the facility prompted the design of anadditional horizontal beamline to be used in conjunction with the proven reliability and precisionof the STAR patient positioner. Planning for the new beamline started in October 2002 with anoriginal goal of clinical operation in fall 2004. Design and integration has primarily been done in-house resulting in longer turnaround than anticipated. Design guidelines for the system include:a single scattering system with an SAD of 450 cm, maximum penetration of 20 g•cm-2 and max-imum field radius of 5 cm with dose uniformity of ± 2.5%. The scattering system integrates rangeand modulation control using a lamination approach. This system is designed with simplicity androbustness in mind. A binary absorber stack provides fine and course steps to achieve flat SOBP.

233

Page 236: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

The nozzle incorporates a retractable axial x-ray tube, monitor chambers, light field device as wellas a retractable and rotating nozzle. The nozzle provides a mount compatible with either colli-mating cones or the Radionics Inc. mMLC. The integration and testing of the nozzle and scatter-ing system are discussed

Three year radiosurgery experience at the Northeast Proton Therapy Center P1-56 Marc R, Bussiere (1); Hanne, Kooy (1); Paul, Chapman (2); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Massachusetts General Hospital- Pediatric Neurosurgery Department Boston, USA

Massachusetts General Hospital (MGH) physicians have been treating patients using proton radi-ation therapy since 1961. Until November 2001 proton radiation was delivered at the HarvardCyclotron Laboratory (HCL). Prior to the transition from the HCL to the Northeast Proton TherapyCenter (NPTC) program patient throughput at the Harvard facility were around 24 daily-fraction-ated cases, 5 daily-fractionated ocular cases and an average of two weekly radiosurgery cases.The NPTC treatment day is eight hours with a current throughput of 42 daily-fractionated cases,5 daily-fractionated ocular cases and one weekly radiosurgery case. The reduction in protonradiosurgery cases has been dictated by the reduction in proton SRS treatments slots due to thehigh demand for fractionated proton treatments. The MGH is fortunate to have been able toabsorb the radiosurgery workload through its Linac based radiosurgery program. The protonradiosurgery program’s current capacity issues will soon be history with the implementation of adedicated proton SRS/SRT beamline that is currently being commissioned. Despite the reductionsin proton radiosurgery cases there have been over 170 patients treated with proton radiosurgeryusing the gantries at the NPTC. The program’s diagnosis profile is discussed and compared to thatof the HCL. Treatments using the NPTC gantry system have provided us with an opportunity toexpand on the radiosurgery techniques used at the HCL. Treatment techniques and rational arediscussed. A variety radiosurgery cases treated at the NPTC, including some extra-cranial casesare presented. Intra-cranial cases include pituitary adenomas, acoustic neuromas and AVMs.Extra-cranial targets have included solitary lesions contained in the L, T spinal bodies as well asa lung lesion.

History of proton beam radiosurgery P1-57 Mehryar, Mashouf (1); Elham, Bidabadi (2) (1) Guilan university of medical sciences - Department of neurosurgery; (2) Guilan university of medical sci-ences - Pediatric neurology Rasht, IRAN

In 1946, Wilson first proposed the clincial use of charged-particle beams because of their uniquecharacteristics. Lars Leksell adressed the theoretical and many practical aspects of stereotacticradiosurgery in 1951.9Using the Uppsala University cyclotron Leksell and Borje Larsson, a radio-biologist, used a cross fired proton beam in intial experiments in animals and in the first treat-ments of human patients. In 1954, John Lawrence began to use the Berkely cyclotron's Braggpeak to irradiate the pituitaries of patients with metastatic breast cancer for hormonal suppres-sion.. In 1961 Raymond Kjellberg began treating patients using the Bragg peak of protons from

234

Page 237: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

the Harvard Cyclotron Laboratory. This was soon followed by similar efforts led by V.S. Koroshkovin Moscow. Stereotactic treatment of arteriovenous malformations began in 1963 and was basedon a stereotactic guidance device and angiograms.6 Some tumors including skull base lesionscould be adequately localized by pneumoencephelography. Leksell performed the first such treat-ment, radiating a vestibular schwannoma in 1969.

Radiosurgery damage probability in target volume. - A proposal for a biological response model P1-58Vinicio, Toledo-Buenrostro (1); Gabriel, Rodriguez-Hernandez (2) (1) Hospital San Javier - Radiation Oncology; (2) Hospital San Javier - Medical Physics and Radiation Protection Guadalajara, Mexico

Introduction Radiosurgery is not commonly used as a fractionated modality in the treatment ofintracranial lesions, some experience is emerging in relation to fractionation in various types ofintracranial lesions and had been reported, however the lack of statistically significant morbidityinformation limits the widening of the practice outside of clinical trials. Material and methods Celldeath mechanisms and predictive assays were reviewed before mathematically modeling late tox-icity for fractionated radiosurgery. As had been referred the effect is dose-volume dependent andhierarchical and non hierarchical tissues had different latency period for functional and morpho-logical changes. We assumed then these variables can predict end point tissue toxicity. Dp =[(df/v) á/â ] / N / i Damage probability (Dp), df (dose per fraction), v (volume), á/â (alfa/beta ratiofrom QLM), N (number of fractions administred) and i (interval between fractions). HypothesisRadiation induced damage probability in gross tumor volumes and his surrounding tissues inradiosurgery could be higher than estimated in most clinical settings, with equal volumes andequal conformal index, for fractionated radiosurgery there should be a minor probability of toxi-city than one fraction radiosurgery. Assuming for healthy tumor surrounding tissues á/â ratio tobe equal to 3 (1 to 6, late responding tissues) and 10 for tumor cells (early responding). Themodel compares one fraction radiosurgery with fractionated treatments. No equivalent doseresponse has been developed in interfractionation schemes between single, two and three frac-tions, tables for Biological Equivalent Dose in damage probability in alfa/beta ratio 3 and 10 weredeveloped following our proposal for comparison. Conclusion The dose standardization is thegoal in whatever instrumentation and technique are applied, mathematical models simplifies thedecision making process in identified benign intracranial diseases to be treated with RS. Weassume Dp model can be appied and clinically correlate with outcome in patients, results willencourage investigation in valid clinical settings for developing intercomparative treatmentschemes in one and multiple fraction radiation administration with radiosurgery.

235

Page 238: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Distal region cephalothorax map of Crayfish Procambarus clarkii.Magnetic resonance atlas for experimental gamma radiosurgery P1-59 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, Ponce de Leon (1); M.P., Torres Garcia (2);J.L., Bortolini Rosales (3); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); E, Muñoz Mancilla (5); Miguel,Perez Pastenes (1); JA., Viccon Pale (7) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico -Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) MetropolitanAutonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico

Uncoupling of the present circadian rhythm in pairs organs has been an effective instrument toobtain information about its behavior. In the crayfish of genus Procambarus the possibility has beenopened to obtain this uncoupling in the circadian rhythm of the chelipeds motor activity, by meansof the gamma surgery in one of the protocerebrum hemiganglia. By that, it was necessary to pre-viously establish the histological map and magnetic resonance of the distal region cephalothoraxwas selected as a target. In order to obtain the map with resonance: crayfish at time to be immo-bilized for its cephalothorax using stereotactic device for radiation and this one introduced to theresonance camera (Sigma eco-speed, Platform 9.1, teslas 1.5), were obtained from the stereotac-tic atlas in two sequences of axial cuts, T1 and T2. After, these images were amplified to 200 µmand it shows a map and is compared with the obtained one through conventional histology.

Distal region cephalothorax map of Crayfish Procambarus clarkii.Cerebroid ganglion and adjacent structures histological map: basic model for gamma radiosurgery P1-60 Ramiro, Del Valle (1); Daniel Salvador, Ruiz Gonzalez (1); Salvador, De Anda Ponce de Leon (1); Miguel, PerezPastenes (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); E, Muñoz Mancilla (6); Manuel, Martinez Lopez(1); L., Mendoza Vargas (4); JA., Viccon Pale (9); Juan, Ortiz Retana (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico -Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) MetropolitanAutonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico

Astacid´s central nervous system, is compound of a cerebroid ganglion and paired longitudinalventral nerve cord, under digestive tract, in the cephalothoracic region, connected to the sube-sophageal ganglion. Anatomical differences exist with other species of decapods like the acces-sory lobes, that in Procambarus they are the bigger structures in the central nervous system andrecognized like the centers of sensorial integration. Of there the importance to know the anato-my and histology these structures to understand roll that plays within all the organization of thenervous system. Objective of this research is to establish the normal histological frame of the cere-broid ganglion and adjacent structures of P. clarkii. Adult organisms were fixed with Davidson´sand RF´s solutions by 48-72 hours, later were dissected and including in paraffin (56-58 °C melt-ing point), obtaining cross and longitudinal sections with a 7 µm thickness of cerebroid ganglionregion. Slides were stained by Hematoxylin-Eosin, Lendrum, Mallory and Masson techniques. Thedifferent cellular types were observed that they conform to nervous system in the anterior regionof cephalothorax and adjacent tissues. Photomicrographs on light field was taken in MicroscopeOlympus Provis AX70.

236

Page 239: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Modulation of dose rate effects to minimize normal neural tissue toxicity while maximizing tumor control probability P1-61 Steven, Howard (1); James, Welch (1); Ian, Robbins (2); Wolfgang, Tome (1) (1) University of Wisconsin Medical School - Human Oncology Department; (2) University of WisconsinMedical School - Medical Oncology Madison, USA

Radiotherapy delivered below standard dose-rates reduces normal tissue toxicity and can inducesignificant tumor regression in some tumor types but not others. Early clinical studies suggestedthat fractionated reduced dose-rate external beam radiotherapy can achieve an improved thera-peutic ratio. The factors and mechanisms that determine the response of normal cells and tumorsto low dose-rate irradiation remain largely unknown. In conventional radiotherapy a dose of 2 Gyis delivered at a dose rate of 4-6 Gy/min, which means that the delivery of this dose requires onlya few minutes. By reducing the effective dose-rate and increasing the treatment time, it becomespossible for repair processes to be active during irradiation. This reduction in dose-rate can resultin a therapeutic advantage because repair of sub-lethal damage is greater for late complicationsthan for tumors and there may be some accumulation of tumor cells in a sensitive phase of thecell cycle such as G2. A low dose-rate can either be obtained by using a continuous low dose-rate irradiator which is economically not very feasible, or by dividing the standard 2 Gy fractioninto a number of equal sub-fractions that are delivered in a pulsed manner separated by a fixedtime interval. Thus, allowing for repair during each sub-fraction. This pulsed approach will pref-erentially protect normal tissue and have almost the same effect in terms of tumor cell kill becauserepair capacity is greater in late responding normal tissues than tumors. We have developedmodel-based methodology using reduced dose-rate external beam radiotherapy in the re-treat-ment of recurrent glioma patients that have received prior radiotherapy. Re-treatment will bedelivered using daily 2 Gy fractions administered in 20 cGy pulses at a dose rate of 100 MU/minevery three minutes for a time averaged dose-rate of 6.67 cGy/min. The model, its background,clinical implementation and preliminary clinical results will be discussed.

Vascular changes in the rat middle cerebral artery after Gamma Knife irradiation (preliminary results) P1-62José, Lorenzoni (1); Gyorgy, Szeifert (2); Isabelle, Salmon (3); Françoise, Desmedt (1); Jacques, Brotchi (4);Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) National Institute of Neurosurgery - Department ofNeurosurgery; (3) Hôpital Erasme - Department of Pathology; (4) Hôpital Erasme - Neurochirurgie Brussels, Belgium

Purpose: To study the effect of a single dose of gamma irradiation in a great intracranial vessel inrats at different doses and intervals. Material & Methods: 125 male Wistar rats were irradiated ina gamma knife using a stereotactic frame designed for small animals. The target was the rightmiddle cerebral artery and coordinates were calculated according to Paxinos rat brain atlas. Dosesdelivered to the artery were 15, 30, 50, 70, 90, 120 and 160 Gy. And rats were sacrificed at 24hours, 7 days, 21 days, 2 months, 6 months, 1 and 2 years. Others non irradiated rats served ascontrols. Basic staining were used, as well as specific ones for endothelial layer, smooth musclecells, fibroblasts, and apoptosis. Results: Vasoconstriction was detected at 24 hours until 7 days;this phenomenon affected in a diffuse way the vessels of the polygon and was observed even at

237

Page 240: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

low doses. In a second step there was a damage of the endothelium that was dose dependentand finally appeared changes in the vessel wall. Apoptotic markers were employed trying to cor-relate apoptosis induction by radiation and structural changes observed. Conclusions:Radiosurgery is able to induce changes in great intracranial vessels in rats. Most of these changesseem to be dose and time dependent. This animal model could be useful in estimating vascularrisk in radiosurgical treatments, especially those using high dose irradiation.

Comparison of late radiobiological effect of the brachytherapy and LINAC radiosurgery modalities on the normal brain tissue P1-63 Arpad, Viola (1); Jeno, Julow (1); Tibor, Major (2) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Oncologyand Radiation Therapy, Budapest, Hungary - Department of Radiation Therapy Budapest, Hungary

Purpose: The goal of this study was the comparison of the dose distributions, the radiological effi-ciency of 125 Iodine brachytherapy and the LINAC radiosurgical procedure. Methods and mate-rials: For the irradiation of the 37 brain tumors we prepared plans of 125 Iodine brachytherapyand plans for LINAC radiosurgical irradiation. For each of the brachytherapy plans, we determinedthe amount of normal tissue in relation to a given percentage of the target volume, whichreceived doses of 8, 12, 20-100 Gy. For the equivalent volumes, we found dose values referencedback to the LINAC plan. We recounted the LINAC doses into brachytherapy doses according tothe dose-time formula of the linear quadratic (LQ) model. We attributed two brachytherapy dosesto each volumetric value, this gave a comparison of late radiobiological effect of the brachyther-apy and LINAC plans on the normal tissue. Results: At higher doses brachytherapy is significant-ly more advantageous regarding the normal tissues than LINAC irradiation. Better conformalityhas been achieved at the plans for brachytherapy than at the plans for LINAC irradiation, with nosignificant difference. In dose homogeneity, LINAC has proved to be significantly better thanbrachytherapy (p<0.01). Conclusion: In order to achieve a balance between better tumor controland protection of the normal tissues, the comparison of the results of stereotactical irradiationmethods may be useful.

Treatment of acoustic neurinoma with stereotactic radiosurgery P1-64 Leoncio, Arribas Alpuente (1); ML, Chust (1); A, Menendez (1); V, Crispin (1); JL, Guinot (1); JL, Mengual (1);PP, Escolar (1) (1) Instituto Valenciano de Oncología - Radiation Oncology Valencia, Spain

Acoustic neurinoma is a benign tumor arising from Schwann cells, usually located in the vestibu-lar portion of the vestibulocochlear nerve. Surgery has been the classical treatment but, despitethe advances developed recently in surgical approaches, a significant rate of complications per-sits for a majority of patients. Radiosurgery has been used during last years as an effective andnon invasive treatment for small and medium sized acoustic neuromas achieving an excellentlocal control with less complications than surgery .We analize retrospectively patients with diag-nosis of acoustic neuroma treated with stereotactic radiosurgery in our deparment. Methods andmaterials Since February 1998 to October 2003, the treatment of 86 patients was revised ( medi-an follow-up 51 months ; range 13-87 ). All of them have been diagnosed according to MRI and

238

Page 241: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

CT images and audiogram. Thirty- five patients were men and fifty-one women with a medianage of 65 years old ( range 19 – 87 ). Unilateral hearing loss was the most common symptomfollowed by tinnitus and dizziness. Radiological images showed that the tumor was intracanalic-ular in 14 patients, in 65 had both intracanalicular and cerebellopontine angle components, in 4patients tumor was cystic and in 3 we had to make an angiography in order to differenciate frommeningioma. Pretreatment clinical hearing evaluation was performed according to Gardner-Robertson classification: class I, 4 patients; class II, 23; class III, 23; class IV, 6; class V, 15. Facialneuropathy was also evaluated ( House- Brackmann ): minimal 6 patients; moderate 4 and palsyin 1 patient. Five patients had trigeminal neuropathy ( decrease sensation or paresthesias ).Fourteen patients had hydrocephalus before treatment with stereotactic radiosurgery and five ofthem needed surgical derivation. Radiosurgery was the first treatment in 74 patients; in elevenpatients surgery was previously performed and one patient received external beam radiotherapyand radiosurgery. We used Professor Barcia-Salorio’s stereotactic frame. MRI and CT were per-formed to determinate radiosurgery target volume. Planning was made with PLATO 3D LINE sys-tem. Treatment was delivered in LINAC , 6 Mv photons using a noncoplanar multiple arcs tech-nique witn circular collimators. The median dose at isocenter was 18 Gy ( range 9 Gy- 30 Gy );median marginal dose 12 Gy (range 6 Gy- 16 Gy); median isodose prescription 80% ( range 40%-100%). Results Forty-seven patients remained with stable desease; 31 showed tumor sizedecreased and in four patients complete response was achieved. Three patients experiencedenlargement of tumor sie. Absolute local control was 96.4%. Five years actuarial local control was95%. Two out of three patients who failed to radiosurgery recieved salvage surgery achievingultimate local control. In the third patient a second radiosurgery was performed with tumor pro-gression 9 months later, receiving than salvage surgery. Acute complications: two patients devel-oped transient trigeminal neuropathy , one minimal transient facial neuropathy and 1 patientheadache. Cronic complications: four patients developed LCR cyst and in two of them surgerywas required. Seven patients presented hydrocephalus . Treatment with derivation was per-formed in three of them. Postreatment hearing evaluation was made in 48 patients: 16 / 23 withgrade I-II previous to radiosurgery (69%) and 13/25 with previous level III / IV (20%) remainedstable or improved their functional level. Conclusion Streotactic radiosurgery achieve a rate oflocal control with a low rate of complications and a high probability of preserving functional hear-ing. We have more incidence of cyst an hydrocephalus than is reported in the literature perhapsbecause in almost fifty per cent of this patients the tumor size was greater than 3 cm and theywere older than 70.

Vestibular schwannomas (VS): intracanalicular extension and associated hearing loss. Volumetric analyses P1-65 Ouzi, Nissim (1); Nicolas, Massager (2); Carine, Delbrouck (3); Philippe, David (4); Daniel, Devriendt (5);Françoise, Desmedt (1); Jacques, Brotchi (2); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - CentreGamme Knife; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Radiothérapie Brussels, Belgium

Introduction: While tumor size affects the ability to achieve hearing preservation during micro-surgery for VS, no clear association exists between tumor size and the degree of hearing loss (HL).It has been previously reported that parameters related to internal acoustic canal (IAC) extension

239

Page 242: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

are predictors of severity of hearing deficit, but in their analyses investigators have largely reliedon two dimensional measurement of tumor size. Utilizing our gamma knife (GK) workstation forVS treatment planning, considerable inter-individual variability in the shape of the IAC wasobserved. With the capability to define and measure IAC bony and tumor volumes we attemptedto identify predictors of degree of HL. Methods; Between 2000-2005, 150 patients with VS weretreated at our GK center. There were 57 females and 93 males aged 11 to 89 (median 55) years.Prior to treatment, Gardner Robertson class (GRc) scores were evaluated and patients underwentcomputed tomography (CT) and magnetic resonance (MR) imaging (T1 with and without gadolin-ium and T2, 1 mm contiguous sequences). There were 33% GRc I, 23% GRc II, 20% GRc III, 2%GRc IV and 22% GRc V patients.Using the workstation software, intra and extracanalicular tumorand bony IAC volumes and dimensions were measured and the IAC tumor to canal volume ratiowas calculated. Results; Tumor volume ranged from 46-8300 (median 1100) mm3 . The intra-canalicular component measured 22-732 (median 174.5) mm3 and the canal volume was 110-862 (median 243) mm3. The canalicular tumor to canal ratio ranged from 0.15-1.0 (median 0.79).Preliminary analysis suggests an association between Grc and canalicular tumor/canal volumeratio and not with absolute tumor volumes. Conclusion; The results suggest that in consideringdisease progression and the possible adverse effects VS have on hearing, relative intracanaliculartumor size and growth rather than absolute tumor size should be evaluated.

Radiosurgery of cerebellopontine angle tumors. Optimization of treatment and outcomes evaluation P1-66 Yaroslav, Parpaley (1); Miron, Sramka (1); Augustin, Durkovsky (2) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Departmentof Radiology Bratislava, Slovakia

Statement of study purpose Radiosurgery of cerebellopontine angle tumors during last 10 years isusing strict dose parameters, showing good results in tumor control and neurological deficit pre-vention in multiple studies. However further improvement of planning, precise evaluation of tumorchanges as also tracing cranial nerve function are needed. Methods After tumor and brainstem 3Dvisualization we did planning with surface dose 12-14 Gy (70%-80% of maximum) and conform-ity factor 1,2-1,8. We use 2 to 6 ovoid isocenters, control dose at risk structures and maximumdose location. For evaluation of tumor control we use volumetric study with full tumor contouringon T1 2 mm MRI scans 6 months and annually after radiosurgery, fused with MRI from planning.For evaluation of V, VII and VII cranial nerves function we used questionnaire based on House-Brackman and Gardner-Robertson scales, clinical neurological investigation, audiometry and elec-tromyography. Results We evaluated patients after LINAC radiosurgery on our institution from1993 to 2005 with acoustic neuromas (79) and cerebellopontine meningiomas (76). Mean fol-low-up 56 months. Clinical results was evaluated by 56 patients with acoustic neuromas and 36patients with meningiomas with 52 monts mean follow-up. Tumor control rate is 93,8% by neu-romas and 84,5% by meningiomas. Hearing preservation rate was 92,7% and facial nerve preser-vation 94,5%. Cases with postoperative facial nerve neuropathy and hearing loss correlated withhigher maximum dose in tumor tissue. Tinnitus appeared in 4% of patients, trigeminal neuralgian. V. in 2% of cases. Conclusions LINAC radiosurgery of common cerebellopontine angle tumorsis providing high percent of tumor control by rare cranial nerve complications also by long-term

240

Page 243: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

evaluation. Improvement of planning technique and automated isocenter positioning opens newhorizons for LINAC radiosurgery with cylindrical collimators. 3D volumetric study is precise tool fortumor control evaluation giving early information about continuing growth of tumor.

Gamma knife radiosurgery for vestibular schwannomas P1-67 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

The aim of this study is to evaluate the efficacy of gamma knife radiosurgery on vestibular schwan-nomas. We reviewed the records of 110 patients with more than 2 years of follow-up. There were61 (55%) female and 49 (45%) male with median age 49. Mean volume of the tumours was 7.3cc. Mean marginal dose to the tumor was 12.96 Gy. In 12 patients there were no hearing beforegamma knife treatment. In 30 (33%) patients the hearing level was decreased after treatment.Only 1 patient had temporary facial paresis. The tumor growth control rate was found to be 98%.gamma knife radiosurgery is an effective treatment for vestibular schwannomas.

Limitation of size for the radiosurgical treatment of vestibular schwannomas.Comparison between 2D and 3D informations P1-68 Pierre-Hugues, Roche (1); Jean, Regis (2) (1) CHU La Timone - neurochirurgie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France

When managing vestibular schwannomas (VS), tumor size is an important limitation for the radio-surgical treatment. Considering that each posterior fossa is of individual morphology, the relation-ship between the tumor volume (TV) and posterior fossa volume (PFV) is a relevant parameter toindividually evaluate the tumor mass effect. Stereotactic fused CISS MR and CT scan images wereobtained from 58 adult patients harbouring an unilateral VS. Tumors were classified as Koos II in25, Koos III in 21 and Koos IV in 12 cases. Using a Gammaplan working station, the followingparameters were screened: intracisternal anteroposterior, transverse, craniocaudal and maximumdiameters of the VS. The computarized TV, the parenchymal volume, the cisternal volume werealso calculated. Correlations between the actual tumor volume and the tumor diameters wereassessed with the Spearman’s correlation coefficient. The prediction of brain compression follow-ing the aforementioned measured parameters was studied using the ROC anlysis. The simplestmethod to approximate the tumor volume was the maximum intracisternal diameter of the VS(Spearman’s Rho = 0.94). The simplest measurement to predict the brain compression was thetransverse intracisternal tumor diameter. Using a 80% threshold value for the sensitivity andspecificity, neuroagressiveness could be predicted for a TV cut-off value of more than 1997 cubicmillimeters, and for a more than 14.5 mm transverse diameter cut-off value. This study indicatesthat sophisticated 3D measures like the ratio TV/PFV are not more accurate to predict brain shiftthan the intracisternal transverse diameter of the VS. Since it is our believe that radiosurgical treat-ment is not the first stair option for large VS, these study provide quantitative informations regard-ing the limitation of tumor size for the gamma knife radiosurgical treatment.

241

Page 244: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Linac radiosurgery for acoustic neuromas: experience at the CHU of Liège P1-69 Isabelle, Rutten (1); Bruno, Kaschten (2); Snezana, Kotolenko (3); Achille, Stevenaert (2); Jean-Marie,Deneufbourg (1) (1) CHU Liège - Radiothérapie; (2) CHU Liège - Neurochirurgie; (3) C.H. de Luxembourg - Radiotherapy Liège, Belgium

We present a retrospective analysis of the results of linac radiosurgery performed on 27 patientswith an acoustic neuroma between 1995 and 2001. We focused on tumour control, preservationof hearing, and of function of trigeminal and facial nerves. The median follow-up was 51 months(range 16-96 months). Only evolutive tumours were treated. Their median size was 18 mm(range 9-30 mm). Patients were immobilized with a BRW model headframe. Treatment planningwas performed with a Radionics X-knife v. 4. An arc technique was used with a 6 MV Linac.Single doses were 12-14 Gy at the 80% isodose. Results can be summarized as follows.

Early detection of tiny vestibular schwannoma by FIESTA MR Images and treated with gamma knife radiosurgery P1-70 Chain-Fa, Su (1); Tzu-Wen, Loh (1); Chou Chin, Lee (2); Wen-Lin, Hsu (3); Shinn-Zong, Lin (1) (1) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Neurosurgery; (2) Buddhist Tzu-ChiMedical Center, Tzu-Chi University - Department of Radiology; (3) Buddhist Tzu-Chi Medical Center, Tzu-ChiUniversity - Department of Radiation Oncology Hualien, Taiwan

Purpose: Gamma knife radiosurgery (GKRS) has been proven as an effective treatment for vestibu-lar schwannoma less than 3 cm in diameter. In addition, Fast Imaging Employing STeady-stateAcquisition (FIESTA) image of brain MR can present the fine anatomical structures in the internalacoustic canal without contrast enhancement. We report our preliminary experience in GKRS afterearly detection of tiny vestibular schwannoma by FIESTA MR images. Materials and Methods:Between January and December of 2004, FIESTA images were routinely added to all patients forMR study of brain in Tzu-Chi Medical Center, Hualien, Taiwan. Sixteen patients (11 women and5 men, age ranged from 45 to 85 years with a mean of 61) were diagnosed as tiny vestibularschwannoma (less than 0.5 c.c. in tumor volume). Tumors were calculated between 0.013 c.c.and 0.4 c.c. with a median volume of 0.155 c.c. Fourteen patients had serviceable hearing beforeGKRS. In GKRS, only 4 mm collimators were used. The median marginal dose was 12.5 Gy (range:11-14) at an isodose line 50-70 %. Results: In this short-term follow-up (mean 8.9 mos, range:3.9-15.6 mos), no tumor progression, no hearing deterioration and no new cranial neuropathycould be detected. Conclusions: With the application of FIESTA image, tiny vestibular schwanno-ma can be early detected. Because the low dose (12-14 Gy) GKRS was proven to be effective forlong-term control of tumor with preservation of hearing function, it is worthy to use FIESTA todetect the tiny vestibular schwannoma and treated by GKRS. Long-term follow up is still needed.

242

Page 245: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Wednesday 14/09/05

POSTER SESSION 2 10h30 - 11h30

PHYSICS, MOLECULAR IMAGING, MENINGIOMAS,FUNCTIONAL RADIOSURGERY, SPINAL RADIOSURGERY,PITUITARY TUMORS

Stereotactic neurosurgery for central pain P2-1Yong-sheng, Hu (1); Yong-Jie, Li (2) (1) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital Universityof Medical Sciences; (2) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan WuHospital, Capital University of Medical Sciences Beijing, China

Objective: A study on Stereotactic Neurosurgery for the treatment of central pain. Methods: 12patients with central pain have been investigated clinically including 6 cases of thalamus or pon-tine infarction, 2 cases of thalamus haemorrhage, one case of thalamus necrosis and 3 cases ofspinal pathology. The mesencephalotomy and bilateral anterior cingulotomy was co-performed in8 patients with central pain. Other targets included the mesencephalon tract, the ventralis pos-terolateralis nucleus of thalamus (VPL) and the cingulate gyrus respectively. The visual analogscale (VAS) and the McGill pain questionnaire (MPQ) were evaluated for preoperative and post-operative pain status of each patient. The visual analog scale (VAS) and the McGill pain question-naire (MPQ) were used for preoperative and postoperative evaluation of the pain status of eachpatient. Statistical analyses were conducted using paired-samples t test. Results: The short-term(1 month) follow-up results indicated a significant reduction in patients’ pain scales (p<0.05).The daily narcotic dosage of all patients decreased obviously. In the long-term follow-up period,the relieve pain effect of the co-operation of mesencephalotomy and bilateral anterior cinguloto-my was better than the lesion of mesencephalon, the ventralis posterolateralis nucleus of thala-mus and the cingulate gyrus respectively. There were no serious complication and surgery-relat-ed mortality. Conclusion: Stereotactic neurosurgery procedure is effective in relieving central pain.The co-operation of mesencephalotomy and bilateral anterior cingulotomy is more beneficial tothe patients with central pain.

Cyberknife radiosurgery for hypothalamic harmatoma in patientwith medically intractable epilepsy and precocious puberty P2-2Kyung Jin, Lee (1); Kyung-Sool, Jang (2) (1) St Mary's Hospital - Department of Neurosurgery; (2) St.Mary's hospital - Neurosurgery Seoul, Republic of Korea

Background: hypothalamic harmatoma represent well-known cause of central precocious puber-ty and gelastic epilepsy. Although Conventional microsurgical resection is used in hypothalamicharmatoma, often associated with morbidity. In this case present, cyberknife radiosurgery wasapplied as a safe and noninvasive to obtain seizure control. Methods : A 6-year-old boy present-

243

Page 246: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

ed with medically intractable gelastic epilepsy and increased episodes of secondary generalizedseizures. Abnormal violent behavior and precocious puberty were also presented. Magnetic res-onance imaging of brain revealed hypothalamic harmatoma measured 10 and 12mm. Cyberkniferadiosurgical treatment was performed with marginal dose of 14 Gy 73 % of isodose areas.Results : After follow-up periods of 6 months, progressive decreased in both seizure frequencyand intensity was noted. After 10 months, seizure was disappeared. This patient was able tolearn. Follow-up Magnetic resonance imaging has slight decresed changes in size of the lesions.Conclusions : Cyberknife radiosurgery can be an more effective and safe than conventional micro-surgery for achieving good seizure control in patient with hypothalamic harmatoma.

LINAC radiosurgery for hypothalamic hamartoma epilepsy P2-3Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil

Radiosurgery for the treatment of hypothalamic hamartoma epilepsy has achieved very goodresults with low rate of complications in the literature. At our institution we performed radio-surgery in three patients with classical epilepsy secondary to hypothalamic hamartoma. Toachieve the best dose distribution, according to the structure of the lesion, using a LINAC, con-ventional or shaped beam collimator was used. Objective: Describe three cases of LINAC radio-surgery for hypothalamic hamartoma epilepsy. Material and Methods: Three male patients, 3, 8and 21 years, with medically untreated epilepsy secondary to hypothalamic hamartoma, anddaily typical gelastic, were submitted to LINAC radiosurgery. The fist and the second patientswere previously operated with partial resection and showed no change in the epilepsy profile.Results: After four months a remarkable reduction on the number of crisis was noted on all threepatients. At the end of the 8th, until the 30th follow-up month, complete control of the epilepsywas achieved on the fist patient, with no more medications. The second and the third patientswith a follow up of 22 and 12 months still present rare seizure, less then one per month. Therewas no neurological deficit secondary to radiosurgery. Conclusion: Hypothalamic hamartomaepilepsy can be successfully treated with LINAC radiosurgery.

Gamma knife radiosurgery for intracranial meningiomas: Relationship between shrinkage and symptom relief P2-4 Jeremy, Ganz (1); Amr, El Shehaby (1); Hafez, Ayman (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt

Objective: It is a common assumption that clinical relief following radiosurgery accompaniestumour shrinkage. A prospective study was undertaken to see if this assumption was valid.Materials and methods: From June 2001, 151 consecutive patients underwent gamma knifeSurgery (GKS) for a total of 163 meningiomas. The mean follow up has been 13.4 months (range3 to 36 months). One hundred and twenty-seven tumours (84%) were basal and 24 (16%) werenon basal. The commonest location for basal meningiomas was in and around the cavernoussinus (43%). The commonest location for non-basal meningiomas was parasagittal (50%). Themean age was 49 years (range 20 to 75 years). The male : female ratio was 1:3. The prescrip-tion dose used was 12 Gy for all cases except three. The mean tumour volume was 9.5 cm3 (range

244

Page 247: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

0.58 - 43.2 cm3). The mean conformity index was 1.15. The mean prescription isodose was 48%(range 30% to 75%). The mean percentage cover was 90% (range 54 to 100%). A cover of lessthan 90% was used in 22 patients in 21 of whom it was used to protect vision. Results: The var-ious ways of defining shrinkage are also discussed. Clinical improvement was significantly relat-ed to tumour shrinkage (p<0.0005). However 40% of tumours which had not shrunk demon-strated clinical improvement, Almost all the symptoms which improved were related to basalmeningiomas. There were changes of visual function in 13 patients. In 11 it improved and in twothere was deterioration. Diplopia improved in 22 patients and was unchanged in 11. Headacheimproved in 15 patients and was unchanged in 5. Three patients had tumour swelling with tem-porary neurological deficit which was easily managed with dexamethasone with no permanentsequelae. Epilepsy was present in 9 basal and 11 non basal locations. Improvement of the epilep-sy had no relation to location or previous surgery. The most usual factor associated with lack ofimprovement following GKS was the patient not taking the medication as instructed (p < 0.01).The mean follow up of tumours which have shrunk was 17 months while for this which had notit was 12.4 months (p < 0.005). Conclusion: The findings are in keeping with those publishedelsewhere. However, there are three interesting new observations. Clinical improvement canoccur without tumour shrinkage in a fair number of patients. Reduction in volume seems to beginconsistently after about 15 months. Lack of improvement of epilepsy may often be due to thepatients’ mismanagement of their medication. This should be considered when the effects of anytreatment are measured against epilepsy control.

A prospective multicenter study about tumor volume reduction after stereotactic radiotherapy of skull base meningiomas P2-5 Martin, Henzel (1); Markus W, Gross (1); Klaus, Hamm (2); Gunnar, Surber (3); Gabriele, Kleinert (3); Gerd,Strassmann (1); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg, Germany - Dept. of Radiation Oncology; (2) Helios Klinikum Erfurt, Germany- Dept. for Stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy andRadiooncology Department Marburg, Germany

Introduction: Fractionated stereotactic radiotherapy (SRT) is well established in the treatment ofskull base meningiomas. Data for radiological regression are very heterogenous according to dif-ferent definitions. Therefore, aims of this prospective study are to analyse tumor volume (TV)shrinkage and to calculate determinant factors. Methods: 94 patients suffering from a WHO I°meningioma were examined under equal conditions before and every 6 months after SRT. Fat sat-urated axial T1-weighted contrast-enhanced MRI scans with a 1-3 mm slice thickness were used.After image fusion TV was drawn in each slice for analysing TV shrinkage 3-dimensionally by theplanning system. Prognostic factors like histological subtypes, prescribed dosis, age, gender, pre-operations and initial TV were calculated. Results: Initially the mean TV was 12.8 ml (median 8.5ml). A decreasing mean TV shrinkage was seen 6, 12, 18 and 24 months after SRT: 18.1%(p<0.0001), 26.2% (p<0.0001), 30.3% (p<0.0001) and 39.4% (p=0.05). Patientsyounger/older than 55 years revealed a significant mean shrinkage of 29.7%/20.0% (p<0.05).Smaller TV tented to an increased shrinkage: TV < 8.5 ml 26.5% and TV >8.5 ml 23.7% shrink-age (p=0.11). There was no correlation between TV shrinkage vs. improvement of the symptoms,vs. prescribed dosis vs. histological subtypes. Conclusion: SRT is a very effective method for the

245

Page 248: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

treatment of skull base meningiomas. More than 30% TV shrinkage is seen 2 years after irradia-tion. Younger age and previous operations are determinant factors. Smaller TV and females tentto an increased shrinkage. Prescribed dosis or histological subtypes do not affect TV shrinkage.

Fractionated stereotatic radiotherapy of base of skull meningiomas: a preliminary comparison in the delineation of the gross target volume between 4 medical specialities P2-6Carine, Mitine (1); Laurent, Gilbeau (2); Frederic, Dessy (2); Christelle, Pirson (2); Jean-Francois, Rosier (2);Marie-Therese, Hoornaert (2); Ludovic, Harzee (2); Anne, Doneux (2) (1) Jolimont hospital - Radiotherapy; (2) Hôpital de Jolimont - Radiotherapie Haine St Paul, Belgium

Purpose: To study the interobserver variability of base of skull meningiomas delineation on com-puted tomography. Methods and materials: A group of 8 physicians working in the same centre(2 neurosurgeons, 2 neuroradiologists, 2 radiation oncologists and 2 medical oncologists) wereasked to delineate the gross tumour volume of two patients on sequential CT slices. All observerswere provided with the same clinical information. Results of the delineation by the 4 specialitiesare compared to each other. The mean of the volumes delineated by all observers are calculated.To determine the variation in the anatomical position of the target volume, a 3D comparisonbetween an arbitrary point determined in the tumour and the most distant point of the tumourin the three directions. For the interobserver variability, the coefficient of variance is used. Results:Large differences are observed between the 8 physicians both for the estimation of the tumourvolume and its anatomical position: the ratio of the largest to the smallest defined volumes variesby factors 8.8 for the first patient and 3.3 for the second. This ratio becomes 1.19-1.66 for themedical oncologists, 1.07-1.57 for the neuroradiologists, 1.07-1.08 for the neurosurgeons and1.14-6.5 for the radiation oncologists. The intersecting volumes (on which all physicians agree)represented only 32 % and 34 % of the mean volume for the two patients. Compared to radia-tion and medical oncologists, neurosurgeons and neuroradiologists tend to delineate slightlysmaller volumes; the results for the radiation group need to be taken cautiously because of thelarge delineation of one of the two observers. Lowest COVs, indicator of a smallest interobserv-er variation, are found for the group of neurosurgeons and neuroradiologists. Conclusions: Thefirst step of 3D treatment planning, the delineation of base of skull meningiomas tumour, neces-sitates a good cooperation with a multidisciplinary team by using different imaging modalities asNMR and methionine PET. Difference between radiation oncologists and other specialities couldbe unconscious integration of geometrical uncertainties relevant in radiotherapy as the set-upvariation, organ motion…

246

Page 249: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stereotactic radiation therapy for optic meningioma; an experience of Ramathibodi Hospital P2-7 Chomporn, Sitathanee (1); Mantana, Dhanachai (1); Putipan, Puataweepong (1); Lojana, Tuntiyatorn (1);Anuchit, Poonyathalang (2); Veerasak, Theerapanchareon (3) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - Ophthalmology; (3) Ramathibodi Hospital Mahidol University - Neurosurgery Department Bangkok, Thailand

Background and objective: To report on technique and results of 12 patients with optic menin-gioma treated with stereotactic radiotherapy or stereotic radiosurgery at Ramathibodi Hospital.Patients and methods: Between November 1998 and January 2005, 12 patients (10 females, 2males; age 25-67) with optic meningioma were treated with stereotactic radiation therapy. Fivepatients had no vision before starting radiation, 6 had impaired vision with or without proptosisor decreased facial sensation, and 1 had proptosis and lateral rectus palsy. All except one weretreated with fractionated stereotactic radiotherapy (SRT) with an average dose of 51.6 to 59 Gy(mean 55.7), 1.8 Gy/fraction, prescribed at 90% isodose, delivered in 5-6 weeks. Stereotic radio-surgery (SRS) was used in one patient who had no vision. The dose of SRS was 15 Gy prescribedat 80% isodose. Results: After a median follow-up of 30 months (range 3-66), no tumor progres-sion was observed. There was no visual improvement in all 5 patients who were blind beforeradiation. Vision remained stable in 2, and improved in 4 patients. Vision became worse in onepatient who had uncontrolled DM and hypertension. This patient developed vitreous hemorrhage2 years after radiation and underwent surgery. Proptosis was stable or improved as well as facialsensation. One patient had decreased vision 4 months after radiation completion but fully recov-ered after steroid treatment. No complication was observed in other patients. Conclusion:Stereotactic radiation therapy is an effective treatment option for patients with optic meningioma.It results in good tumor control and improved or stable vision in the majority of patients who stillhave useful vision before treatment without serious complication.

Long-term follow-up of sellar and para-sellar meningiomas treated with stereotactic radiosurgery and fractionated stereotactic radiotherapy using the UCLA grading system P2-8 Carlos, Mattozo (1); Leonardo, Frighetto (2); Alessandra, Gorgulho (3); Cynthia, Cabatan-Awang (3); TimothyD., Solberg (4); Michael, Selch (5); Antonio, DeSalles (6) (1) UCLA Medical Center - Neurosurgery; (2) University of California Los Angeles - Neurosurgery; (3) UCLAMedical Center - Department of Neurosurgery; (4) UCLA Medical Center - Department of Radiation Oncology;(5) UCLA - Radiation Oncology; (6) UCLA Medical Center - Neurosurgery Los Angeles, USA

Objectives: To evaluate the long-term follow-up of sellar and para-sellar meningiomas treatedwith Stereotactic Radiosurgery (SRS) and Fractionated Stereotactic Radiotherapy (SRT) accordingto the UCLA grading system. Materials and Methods: Treatment outcomes of 35 patients submit-ted to SRS and SRT at UCLA for sellar and parasellar meningiomas were retrospectively analyzedaccording to the UCLA grading system. Grade I meningiomas were limited to the cavernous sinus(Total: 4, SRS: 4), Grade II extended to the clivus or petrous bone (Total: 3, SRS: 3), grade III hadcompression of the optic structures (Total: 17 SRS: 7, SRT: 10), grade IV compressed the brain-stem (Total: 9, SRS: 7, SRT: 2)and Grade V had bilateral extension to the cavernous sinuses (Total:

247

Page 250: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

2, SRT: 2). There were 9 males (25.7%) and 26 females (74.3%) with a median age of 52 years(31-78). The median follow-up was 92.5 (57-141) for SRS and 60.5 (48-89) for SRT. Mediandoses were 1600 cGy (1200-2000) for SRS prescribed to the 50% (50-90) isodose line and 4680cGy (2380-5040), prescribed to the 90% (50-95) for SRT. Results: Tumor control was 100%(14/14) for SRT patients and 85.7% (18/21) for SRS (p=.329, Pearson Chi-Square), for a totalcontrol of 91.4%. Two patients submitted to SRS presented with decrease in vision (9.5%). Allother side-effects were minor and included 6 cases (28.5%) treated with SRS (assymptomaticbrain edema in one, facial hypoesthesia in 3 and stroke related to carotid stenosis in other two).Only one patient submitted to SRT presented with asymptomatic brain edema (7.1%). Side-effectsoccurred in 6 high grade tumors (66.6%), comparing to three low-grade tumors (I and II). Therewere more side-effects in high grade tumors treated with SRS (p= 0.056, Fischer exact test).Conclusion: The current results suggest a trend towards increase in safety when SRT is used inhigh grade sellar and parasellar meningiomas.

Decision tree software: stereotactic radiation X conventional surgery P2-9 Alessandra, Gorgulho (1); Antonio, De Salles (1); Martin, Pellinat (2) (1) UCLA Medical Center - Department of Neurosurgery; (2) Idego Methodologies - VisionTree Healthcare Los Angeles, USA

Introduction: Currently, multiple treatment options and physician bias to the most familiarapproaches require a tool to help patients organize information and take appropriate decision.Materials and Methods: Seventeen patients facing the dilemma stereotactic radiation(SR) vs con-ventional surgery(CS) used VisionTree Healthcare software. SR and CS had been recommendedwhen they used the decision-making software. Diagnosis was: cranial nerve neuroma(6), supra-tentorial tumor(4), pituitary adenoma(2), trigeminal neuralgia(2), chordoma/glomusjugularis/spinal tumor(1 each). Mean age was 58.68±12.73 (39-77) years, 12 male.Effectiveness/complications/recovery time/number of visits/specific relevant issues were rated bya physician, using literature data and personalized risks factors. Priorities were graded from 1-10(10=best). Personal values (like death/sequelae/fear) were included. Evaluation survey wascompleted by 1-5 scale (5=best). Software calculates a normalized score (0-100%) reflectingpatient’s priorities, likelihood/willingness ratings (scale:0–10) for options. This score represents towhat degree (in percentage) the option met the patient’s rated criteria. Results: Scores in order ofpreference were obtained. For the analysis between stereotactic radiation and open surgery, onlythe first and last scores were compared. Intermediate scores concerning other minimally invasiveoptions (SRSxSRT, SRSXradiofrequency) were not considered. The mean score for first option was87±9 versus 43.4±18.43 for last option. Survey mean rates were: 4.7±0.6 for friendliness nav-igation, 4.5±0.8 for recommendation to others, 4.41±0.9 for satisfaction. Treatment optionrankings were the expected in all but one patient who was unable to make a decision. All butthis patient took the first treatment option. All first options had a score above 70. Conclusions:Decision-making software use is an innovative concept to help patients maximizeexpectations/priorities. Patients expressed satisfaction. VisionTree was particularly helpful evalu-ating therapeutic options in a clear/organized fashion. All available options are presented andpatients are able to objectively review, evaluate and confirm their option. Data is stored electron-ically as record of the patient’s informed consent.

248

Page 251: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Quality of life after interdisciplinary treatment of cavernous sinus meningiomas P2-10 Markus, Gross (1); Ahmed, Farhoud (2); Martin, Henzel (1); Stefan, Heinze (2); Ulrich, Sure (2); Helmut,Bertalanffy (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Philipps University Marburg - Departmentof Neurosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany

Background: Despite advances in microsurgical techniques, meningiomas involving the cav-ernous sinus often require multidisciplinary treatment including stereotactic radiotherapy either asa primary treatment, or to control residual or recurrent tumors after previous surgery. Goal of thisstudy was to evaluate quality of life (QOL) after different interdisciplinary tumor treatment.Methods: 104 patients (20 men, 84 women) harboring cavernous sinus meningiomas were ret-rospectively analyzed to evaluate post-treatment QOL, as well as morbidity and outcome. QOLwas assessed by Short Form 36 (SF36), measuring 8 different health domains. Follow-up wasachieved in 96 patients. In operated patients it was 44 months, in patients treated by radiother-apy alone 24 months. The study group was divided into 3 therapeutic categories: patients treat-ed surgically only (group I, 22 patients), patients treated with stereotactic fractionated radiother-apy (group II, 34 patients), and patients who were treated with both modalities, surgery andradiotherapy (group III, 40 patients). Results: 75% of tumors in group I could be excised totally.There was no mortality in this series. Post-operative cranial nerve impairment occurred in 47% ofsurgical patients, 12% remained permanent, one patient suffered from angular gyrus infarction.After irradiation acute toxicity was seen rarely (3%). Clinically significant late morbidity and newneurological palsies were not encountered. No tumor progression or regrowth was observed ingroup I and III, in group II one tumor progress occured. No statistically significant difference inQOL was found between the 3 groups and compared with values of normal USA population.However, patients in group II had the best QOL in all but one health domains. Conclusion: Grosstotal excision provides a long-term recurrence free survival with acceptable morbidity. Quality oflife (QOL) after stereotactic radiotherapy is excellent, as well, therefore offering an important alter-native treatment option.

Stereotactic radiosurgery for atypical and anaplastic meningiomas P2-11 Hideyuki, Kano (1); JUn, Takahashi (2); Norio, Araki (3); Masumi, Hiraoka (3); Naohiro, Horii (4); Kasumi, Araki(1); Tetsuya, Ueba (1); Kosuke, Yamashita (1); Nobuo, Hashimoto (2) (1) Kishiwada City Hospital - Neurosurgery; (2) Kyoto University Graduate School of Medicine - Neurosurgery;(3) Kyoto University Graduate School of Medicine - Radiation Oncology Department; (4) Kishiwada CityHospital - Radiation Oncology Kishiwada, Osaka

Introduction: Atypical and anaplastic meningiomas frequently recur in the relatively short-termafter surgery, even if they are radically resected. We have followed such postoperative cases byshort-interval repeated MRI and have performed stereotactic radiosurgery (SRS) toward progres-sive tumors as a salvage therapy. The objective of this report was assessment of the degree oftumor control, the risk of complications, and the presence of variables that predict outcome inpatients treated with SRS for high-grade meningiomas. Methods: We reviewed 12 high-grade

249

Page 252: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

meningioma patients with 30 lesions treated by Linac-based SRS at Kyoto University Hospitalbetween 1997 and 2002, all of which underwent initial surgery and received SRS for tumor pro-gression. They included 10 atypical meningiomas and 2 anaplastic ones according to the WHOclassification. A mean tumor volume was 6.35cc and a mean marginal dose of SRS was 18.0Gy(12-20Gy). Results: After a mean follow-up period of 37.3 months (6-84 months), 13 lesions hadtumor progression within the SRS field and 6 lesions had out of the SRS field. Nine of 16 lesions,which were treated by SRS with marginal dose of less than 20Gy, had local recurrence in the radi-ation field with the median time to progression (TTP) of 6 months. In contrast, the mean TTP was21 months in 14 lesions treated with marginal dose of 20Gy. The marginal dose less than 20Gywas a statistically significant factor for a short-term progression in high-grade meningiomas(P<0.0139). Five-year progression-free survival ratio in lesions treated with SRS below 20Gy and20Gy were 29.4% and 63.1%, respectively. Conclusion: High-grade meningiomas were recom-mended to receive SRS with marginal dose of more than 20Gy. And MRI follow-up in the closeinterval will be effective on growth inhibition of high grade meningiomas because SRS can beachieved toward small-sized targets.

Long-term experience of gamma knife radiosurgery for benign skull base meningiomas P2-12 Wolfgang, Kreil (1); Verena, Weigl (1); Sandro, Eustacchio (1); Josef, Luggin (1); Georg, Papaefthymiou (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria

Objectives. As most of the Gamma knife reports are related only to short- or mid-term results wehave evaluated the effectiveness and toxicity of radiosurgical treatment for benign skull basemeningiomas in 200 patients with a follow-up of 5 to 12 years in order to define the role of GKRSfor basal meningiomas and to provide further data for comparison with other treatment options.Methods. Ninety-nine patients were treated with a combination of microsurgical resection andGKRS. In 101 patients GKRS was performed as the sole treatment option. Tumour volumes rangedfrom 0.38 ccm - 89.8 ccm (median 6.5 ccm) and doses of 7 Gy to 25 Gy (median 12 Gy) weregiven to the tumour borders at covering isodose volume curves (range: 20 % - 80 %, median 45%). Results. The actuarial progression-free survival rate was 98.5 % at 5 years and 97.2 % at 10years. Passing radiation-induced oedema occurred in two patients (1 %). The neurological statusimproved in 83 cases (41.5 %), remained unaltered in 108 patients (54 %) and deteriorated in 9cases (4.5 %). Worsening was transient in 7 patients (3.5 %) and unrelated to tumour or treat-ment in one single patient (0.5 %). Repeated microsurgical resection was performed in fivepatients following GKRS (2.5 %). Conclusions. GKRS has proved to be an effective alternative tomicrosurgical resection, radiotherapy and Linac-based radiosurgery for adjunctive and primarytreatment of selected patients with basal meningiomas. Due to the excellent long-term tumourcontrol rate and low morbidity associated with GKRS this treatment option should be used morefrequently in the therapeutic management of benign skull base meningiomas.

250

Page 253: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Gamma knife radiosurgery for the treatment of skull base meningiomas P2-13 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - RadiationOncology Istanbul, Turkey

The aim of this retrospective study is to show the efficacy of the gamma knife radiosurgery forskull base meningiomas. We reviewed the records of 190 meningioma patients treated withgamma knife radiosurgery between 1997 and 2001. Skull base meningiomas were 64% (122cases) of all meningioma patients. Cavernous sinus were (60 cases) the prominent localisationand the remaining skull base meningioma areas were mostly petrous apex, petroclival region,sphenoid wing and tentorium. Patient age ranged from 18 to 80 years and the follow-up periodfor patients ranged 4 to 8 years. We used median 9 isodose area and median dose at the tumor50% isodose line was 14 Gy (ranged between 12 to 20 Gy). The tumor growth control wasachieved in 110 cases (90%) and only 12 cases' tumors carried on growing. Subclinical, neuro-radiologically seen neural tissue changes revealing after medical therapy were seen in 6 patients.Gamma knife radiosurgery is an effective and safe treatment modality for skull base locatedmeningiomas especially the ones invading cranial nerves and vascular structures.

Stereotactic LINAC-radiosurgery for meningiomas P2-14 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

Object: To present the experience treating 63 patients with meningiomas using stereotactic Linac-Radiosurgery Material and methods: We presented our experience in the management of 63patients with meningiomas which were treated using stereotactic Linac-radiosurgery technique.During the first 60 months of operation of the first radiosurgical unit in Venezuela since February2000, 430 patients with vascular malformations, tumors and trigeminal neuralgia were treated.Of these, 63 patients ( 48 women and 15 men, age 21 to 86 years) had meningiomas. The meanfollow-up period was 38 months (range 4 to 54 months). The tumor volume was 8.49 cc (range1.14 – 47.71 cm3). The mean prescription dose was 14.5 Gy (range 12 – 18.75 Gy). The meanperipheral isodose was 80%. Results Tumor control was obtained in 58/59 patients. Fifty ninepatients were evaluated with serial post-operative MR images performed at 6, 12, 18, 24, 36,48 months, etc., by protocol after radiosurgery. Eighteen tumors showed a loss of central contrastenhancement on MR images. We saw no change in the size of 35 tumors; twenty one tumorsdecreased in size. Patients were clinically stable without evidence of any new neurological deficitsand 27 patients improved. One patient died in the course of follow-up due to another conditionnot related to his treated meningioma. No immediate post-operative complications or periopera-tive seizures occurred. Temporary new neurologic deficits developed in 2 patients at 14 and 18months. They presented transient trigeminal hypoesthesia. Conclusion: Stereotactic Linac-Radiosurgery in our experience has proved to be a safe and effective therapy for patients withsubtotal resected or recurrent meningiomas. Linac-Radiosurgery is also an effective primary alter-native treatment for patients with advanced age, deteriorated medical conditions or high-risktumor location that preclude a microsurgical approach

251

Page 254: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

LINAC radiosurgery in the management of parasagittal meningiomas P2-15 Roberto, Spiegelmann (1); Jacob, Zauberman (2); Janna, Menhel (3); Rafael, Pfeffer (3); Dror, Alezra (3) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Neurosurgery; (3) ShebaMedical Center - Department of Oncology Ramat Gan, Israel

Parasagittal meningiomas have a relatively high incidence of recurrence after conventional sur-gery due to their attachment to the sagittal sinus. Patients frequently require repeat operationsthroughout their life. Radiation treatment has been effective in the past to control meningiomas.Radiosurgery is an appealing alternative to avoid radiation exposure of normal brain. At our cen-ter, 49 parasagittal meningiomas were managed by radiosurgery during a 10-year period (1993-2003). They represented 18% of our meningioma series. Thirty eight patients had one or sever-al previous microsurgical resections. The mean dose to the tumor margins was 1400 cGy. Twopatients with malignant tumors died early after treatment. Eight patients were lost to follow-up.The remaining 39 patients were available for analysis after a mean follow-up of 39 months (12-132). 22 tumors were smaller, 10 were stable, and 5 had grown. Three of the latter requiredrepeat surgery. Of 6 patients with histologically-proven aggressive tumors (atypical/malignant)only 1 was controlled at 2-year follow-up. The actuarial tumor control rate for the series is 87%.MRI changes compatible with radiation injury were observed in 6 patients (15%); five were symp-tomatic. Only 2 patients remained with persistent deficits. Conclusion: LINAC radiosurgery washighly effective in the control of benign parasagittal meningiomas in this series. Failures wereobserved outside of the treatment margins. Better definition of intrasinusal components will like-ly improve tumor control.

Optic nerve sheath meningioma : Comparison of 3D-conformal radiotherapy (3D-CRT), stereotactic radiotherapy (SRT), and intensity modulated radiotherapy (IMRT) P2-16 Pornpan, Yongvithisatid (1); Porntip, Thamwinitchai (2); Paitoon, Tawsagul (1); Mantana, Dhanachai (1);Sawwanee, Asavaphatiboon (3); Chumpoj, Kakanaporn (2); Wichan, Prasertsilpakul (1); Chirapha,Tannanonta (1); Jiraporn, Laothamatas (1); Prasert, Assavaprathuangkul (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Siriraj Hospital - Radiology; (3)Ramathibodi Hospital Mahidol University - Radiology Bangkok, Thailand

Purpose: To assess the efficacy of different radiotherapy planning techniques (3D-CRT, SRT, andIMRT) in patients with optic nerve sheath meningioma Methods: Twelve cases with optic nervesheath meningioma who were treated with SRT technique during 1995-2004 were replannedusing the 3D-CRT and IMRT planning system. Contrast-enhanced computed tomography(CT) datawith 1.5-mm slice thickness was used. Plans from the three techniques were compared withrespect to dose conformity, dose uniformity, dose volume histogram(DVH), dose to organs atrisk(OAR), and dose distribution. The prescribed dose was 50 Gy in 25 fractions. Results: IMRTplan was superior to 3D-CRT and SRT in terms of target dose conformity and uniformity. Therewas no major difference of the target coverage among the three techniques. Regarding the spar-ing of OARs, IMRT was not different from SRT and both were better than 3D-CRT. Conclusion:IMRT and SRT gave lesser dose to the surrounding normal organs compared with 3D-CRT in

252

Page 255: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

patients with optic nerve sheath meningioma. Further studies are needed to establish the trueclinical advantage of each technique.

Does diffuse white matter change often seen after WBRT also occur after GK for multiple brain METs? P2-18 Masaaki, Yamamoto (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan

Does diffuse white matter change often seen after WBRT also occur after GK for multiple brainMETs? Masaaki Yamamoto , Bierta Barfod, Yoichi Urakawa Katsuta Hospital Mito GammaHouseWe assessed whether diffuse white matter change (DWMC), often seen after WBRT and consid-ered to represent a possible risk for future dementia, occurs after GK treatment for patients withmultiple brain METs. Among the more than 1200 patients who have undergone GK radiosurgeryfor brain METs in our facility since 1998, we selected 60 (the original tumor was lung cancer in40) with 5 or more lesions for this study. Follow-up MR images were obtained more than 6months after treatment in these 60 patients. The mean and maximum tumor numbers were 13and 48, respectively. There were 40 females and 20 males. Mean age at the time of radiosurgerywas 60 years, range 35 to 82. MR images obtained 7-56 (mean; 14) months after treatmentdemonstrated no DWMC in any of the 60 patients. For comparison with WBRT for brain METs,we also analyzed 45 (the original tumor was lung cancer in 29) patients referred to us who hadundergone WBRT during the same period. There were 22 females and 23 males. Mean age atthe time of radiosurgery was 58 years, range 19 to 83. MR images obtained 6-42 (mean; 16)months after WBRT demonstrated DWMC in 21 (47%) of these 45 patients. DWMC occurred in8%, 50%, 63% and 84% of the patients, respectively, 6, 12, 18 and 24 months after WBRT. Theincidence of DWMC was higher in elderly (_„60 years, 50%) than in younger patients (33%),though the difference did not reach statistical significance. Although DWMC incidence correlatedsignificantly with irradiation doses in younger patients (p_ƒ.0001), this was not the case in theelderly group (p__.5541). In conclusion, it is reasonable to assume that GK radiosurgery for mul-tiple METs would not have an adverse effect on mental function in long-term survivors.

Stereotactic irradiation for choroidal melanoma in the elderly P2-19 Stéphanie, Bolle (1); Isabelle, Rutten (1); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie Liège, Belgium

Aim: To evaluate the role of stereotactic radiotherapy (SRT) in the management of choroidalmelanoma in the elderly. Methods: A retrospective study of 4 patients with choroidal melanomaineligible for enucleation or brachytherapy for reason of large tumor size, poor general status, med-ical contraindication to anaesthesia or important visual deficit treated with SRT during 1996 and1997. Median age was 79 years. Three patients presented medium-size choroidal melanoma andthe last one large-size. The prescribed dose was one to three fractions of 10-12,5 Gy (one frac-tion/week). Median follow-up was 43 months. Results: No acute side effect was observed exceptslight conjunctival irritation related to eye fixation by the ophtalmologist. Three patients had par-tial tumor response and one a complete response. No enucleation was required for recurrence or

253

Page 256: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

complication. No radiation induced late effect was detected. At last ophtalmological follow-up,lack of pain and absence of tumor progression was observed; visual acuity was reduced of 2 lines.Side effects of radiation and their impact on visual function were difficult to estimate regardingother pre-existing ophtalmologic diseases (macular degeneration, cataract, glaucoma, retinaldetachment). Three deaths occured respectively at 7, 50 ant 79 months and were not tumor relat-ed. Conclusions: SRT for choroidal melanoma in the elderly is feasible, well tolerated and tumorcontrol can be obtained by such a method. However, the available data are not sufficient to eval-uate long term side effects and future clinical studies are necessary to optimise dose and fraction-ation. Currently, we believe that SRT can at least be proposed as palliative treatment for the elder-ly who are unsuitable for enucleation or conservative treatment owing to medical reasons.

Conformal stereotactic radiotherapy in the management of the orbital hemangioma P2-20 F, Mascarenhas (1); M, Santos (1); I, Monteiro Grillo (1); A, Almeida (2) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal- Radiology Dpt Lisboa, Portugal

Background: Surgical resection and corticosteroid therapy have been the most commonly usedmethods of treatment in the management of orbital hemangioma. Conventional external radio-therapy has been traditionally deferred face to those modalities by the high incidence of late ocu-lar complications. The modern techniques of conformal stereotactic radiotherapy (CSR) canachieve high local control rate and substantial clinical improvement with a minimal radio-inducedmorbidity. Material and Methods: A case of recurrent orbital hemangioma previously submittedto surgery and corticoesteroid therapy is described. The clinical presentation, diagnostic charac-terization and treatment protocol are reviewed. Comparative evaluation previous and 2 yearsafter treatment are presented. The patient was treated with 6 Mv photons CSR receiving a totaldosis of 20 Gy in 10 fractions. Results: This recurrent lesion causing marked symptoms as rightorbital pain, diplopia and proptosis had a complete clinical improvement 3 to 4 weeks after treat-ment. The follow-up 30 months after CSR has revealed a significant and persistent reduction ofthe lesion with no moderate or severe radiation-induced secondary effects. Conclusions: This caseis illustrative from the efficacy of CSR and supports this modality as an alternative treatment inthe unresectable orbital hemangioma preserving the organ and its function and providing thelocal tumor control and a better quality of life with minimal morbidity.

254

Page 257: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Accuracy in ophthalmic radiosurgery - eye fixation, imaging, dosimetry P2-21 Josef, Novotny Jr. (1); Josef, Novotny (2); Roman, Liscak (3); Vaclav, Spevacek (4); Jan, Hrbacek (5); Pavel,Dvorak (6); Tomas, Cechak (7); Josef, Vymazal (8) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na HomolceHospital - Stereotactic and radiation neurosurgery; (4) CTU in Prague, Faculty of Nuclear Science and PhysicalEngineering - Dosimetry and application of ionizing radiation; (5) CTU in Prague, Faculty of Nuclear Scienceand Physical Engineering - Dosimetry and application of ionizing radiation; (6) CTU in Prague, Faculty ofNuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (7) CTU in Prague,Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (8) NaHomolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic

Following issues concerning the accuracy of the ophthalmic radiosurgery were addressed: stabil-ity and reliability of eye fixation, accuracy of stereotactic imaging, absolute and relative dosime-try. Stability and reliability of eye fixation was checked by two subsequent magnetic resonanceimaging (MRI) performed in at least two hours interval. Accuracy of stereotactic imaging wasassessed by a special phantom for image distortion evaluation. Since patient is usually treated inprone position comparison between MRI done in prone and supine patient position was done aswell. Special water filled head phantom was used for measurements to assess accuracy ofabsolute and relative dosimetry in eye lesion. Altogether six different treatments were simulatedand evaluated. Polymer-gel dosimeter evaluated by nuclear magnetic resonance was used toassess the accuracy of relative dosimetry. Small ion chamber was used to assess the accuracy ofabsolute dosimetry. Clinically important inaccuracies were observed neither in eye fixation nor inMRI of the eye. Typical image distortion for selected MRI sequence was not higher than 1.0 mm(mean value 0.5 mm). Deviations observed between two subsequent MRIs done in at least twohours interval as well as for MRIs done in prone and supine patient position were typically with-in 0.5 mm. A comparison of calculated dose profiles from the treatment planning system andthose measured by the polymer-gel dosimeter in all three axes demonstrated a very good agree-ment. Typical deviations between measured and calculated absolute dose were within 5 % fordepths larger than 10 mm. For depths smaller than 10 mm there was observed up to 15-20%deviation compare to the treatment planning system calculations.

Combined positron emission tomography and magnetic resonance imaging in the dosimetry planning of radiosurgery using Leksell gamma knife for intracranial tumors in children. Preliminary experience P2-23 Benoit, Pirotte (1); Serge, Goldman (2); Philippe, David (3); Daniel, Devriendt (4); Jacques, Brotchi (1); Patrick,Van Bogaert (5); Marc, Levivier (6) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neuroradiologie; (4)Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Paediatric Neurology; (6) Hôpital Erasme - CentreGamme Knife Brussels, Belgium

Objective. To evaluate the integration of Positron Emission Tomography (PET) images into theradiosurgical treatment planning of intracranial tumors in children. Methods. Between 2000 and2005, PET images using [18F]fluorodeoxyglucose (FDG) and [11C]methionine (Met) were com-

255

Page 258: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

bined to magnetic resonance (MR) images in the dosimetry planning of radiosurgery of intracra-nial tumors in 8 children at Erasme Hospital, Brussels, Belgium. All radiosurgical procedures usedthe Leksell gamma knife° (LGK) model C. These 8 children (5 males/3 females; aged from 2 to 12years) presented tumor residue that were judged inaccessible for surgical excision (2 ependymo-mas, 2 pilocytic astrocytomas, 3 glioblastomas and one choroid plexus carcinoma). The frame fix-ation, the images acquisition and the radiosurgical procedures were performed the same dayunder general anesthesia and under the attendance of a senior anaesthesiologist in all cases.Both PET and MR images were then acquired in frame-based stereotactic conditions according toa methodology previously described for PET-guided neurosurgical procedures. FDG-PET was usedin one case, Met-PET in 6 and PET with both tracers in one). Level and distribution of PET traceruptake in the tumor were analyzed to define tumor contours allowing to build a PET volume. PETvolume was subsequently projected on MR images and compared to MR data (MR volume) inorder to define a final target volume for the dosimetry planning of radiosurgical treatment.Maximal tumor volume was irradiated in each case, with the intention to treat the entire abnor-mal metabolic area comprised in the radiosurgical planning. Pre- and post-operative analysis ofMR and PET images evaluated whether integrating PET data in the radiosurgical planning con-tributed to improve the tumor volume definition and the radiosurgical treatment. Conclusions.Independent and complementary metabolic data on tumor heterogeneity or extent were usefulfor planning the radiosurgical treatment. In all procedures, PET data helped to assess tumorextent and contributed to define a final target volume different from that obtained with MR alone.These preliminary results are promising and suggest that PET-guidance could help to optimize thetumor volume definition and to target radiosurgical treatment to tumor portions which presentthe highest evolving potential.

Integration of CT-PET and MRI images in stereotactic procedures using hardware coregistration P2-24 Piero, Picozzi (1); Luca, Attuati (2); Alberto, Franzin (2); Lorenzo, Gioia (2); Claudio, Landoni (3); V.V, Dolenc (4)(1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele- Neurosurgery Department; (3) Ospedale San Raffaele - Dept. of Nuclear Medicine; (4) University ofLjubljana, Clinical Center - Department of Neurosurgery Milano, Italy

INTRODUCTION: Metabolic information could be an useful instrument to further improve theaccuracy of stereotactic procedures, nevertheless integration of PET data in stereotaxy is cumber-some, as the current version of GammaPlan does not accept them. We developed a method thatneeds only the CT indicator box to co-register PET images within CT study and integrates thisinformation with MRI imaging. MATERIALS AND METHODS: The study was performed using aPET/CT scanner. A standard CT bed adapter was attached to the scanner couch, on which thepatient, with the stereotactic frame fixed, was positioned. Images can be acquired using anyradioisotope. CT and PET images were exported in DICOM 3 standard and then reconstructedfrom spiral acquisition data (FOV 35 mm): • CT: 512x512 matrix (pixel size 0.9766 mm, 5 mmslice thickness, 4.25 mm gap). • PET: 128x128 matrix (1.9531 mm, 4.25 slice thickness, Hannand Ramp filters). A homemade software, based on MatLab, was created to fuse PET and CTstudies. From PET images, pixels showing an intensity value less than 30% of the maximum werethreshold to zero to exclude “background” noise. In a new study, PET remaining pixels, belong-

256

Page 259: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

ing to the brain, were overwritten to the correspondent ones in CT images. So, CT head struc-tures were replaced with the corresponding PET ones, maintaining the stereotactic markers.Accuracy of hardware co-registration was checked to be ~ 1 mm by a quality control: maximalvalue of misalignment was 0.8 mm (20 cm from FOV centre). The new study was then transferredto our Gamma Plan analysis workstation. RESULTS: Using CT indicator box simplifies the proce-dure and needs no operator interaction during matching. No radioactive spilling is necessary. Thismethod was tested on a phantom and on patients. Localization accuracy of the PET images is lim-ited by the slice thickness.

Role of positron emission tomography in stereotactic radiosurgery with gamma knife P2-25 Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Naoki, Hayashi (1); Yuta, Shibamoto (2); Jun, Yoshida (3) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiologyand Radiation Oncology; (3) Nagoya University School of Medicine - Department of Neurosurgery Nagoya, Japan

We usually use magnetic resonance imaging (MRI) and/or computed tomography (CT) for doseplanning of stereotactic radiosurgery because MRI and CT precisely show us anatomical structuresincluding brain lesions. On the other hand, positron emission tomography (PET) and single pho-ton emission CT (SPECT) give us valuable functional information, though spatial resolution ofthese images is not good. FDG (18F-fluolo-2-deoxy-D-glucose)-PET is useful to evaluate tumorextension in skull base tumors. In a patient with renal cell carcinoma FDG-PET showed a petrousbone metastasis as a remarkable uptake area in the cold surrounding structures. During follow-up after radiosurgery we sometimes have difficulties in differentiating tumor recurrence from radi-ation necrosis, because both types of lesions look alike on MRI as regrowing irregular-shapedwell-enhanced areas. PET images provide additional metabolic information in such cases. Wetreat the regrowing lesions again by repeat radiosurgery in three cases of brain metastasesbecause high uptake of FDG implied viable recurrent tumors. After repeat radiosurgery they wereshrunk successfully. In glioma cases PET provides complementary information that contribute tothe optimization of the treatment of tumors. Metabolic and functional information of PET can beused for diagnosis, guidance of therapies, and treatment monitoring in stereotactic radiosurgerywith gamma knife.

Tomotherapeutic intensity-modulated radiosurgery (IMRS): improving dose gradients and maximum dose after inverse optimization using ActiveRx P2-26 Martin, Fuss (1); Bill J., Salter (2) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA

Intensity-modulated radiosurgery (IMRS) for brain metastases and AVM using the Nomos Peacocksystem has been delivered in >150 cases in our institution over the last 4 years. A new softwaretool provided within the Corvus planning software (ActiveRX)allows for post inverse planning re-optimization and individualization of the dose distribution. We analyzed this tool with respect toincreasing the steepness of the dose gradient and dose inhomogeneity while maintaining doseconformity. Fifteen radiosurgery plans for solitary brain metastases that were clinically delivered

257

Page 260: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

during the last two months were analyzed. All plans were copied and ActiveRX, a tool availableduring plan review, was opened. The toolset in ActiveRX includes an eraser, a pencil to redefineisodose lines and a drag and drop tool, allowing reshaping of isodose lines. To assess changesin the steepness of the dose gradient and dose homogeneity, the 100%, 90%, 50% and 25% iso-dose volume, the volume of the target, maximum dose and mean dose to the target were sam-pled. Target volumes ranged from 0.6 to 14.1 cm3 (mean/median 3.9/1.8 cm3). Mean RTOG con-formity index (CI) of plans delivered was 1.23±0.31, and mean homogeneity index (HI) was115±5%. Using ActiveRX, the mean CI was slightly improved to 1.14±0.1, with associatedincrease in HI to 141±10%. The respective average Ian Paddick CI for the 100%, 90% 50% and25% isodose lines were 0.79 vs.0.83, 0.44 vs. 0.59, 0.12 vs. 0.19, and 0.04 vs. 0.07 (allp<0.05), with significant improvements using ActiveRx post-optimization. A post inverse plan-ning optimization tool for IMRS plans allowed for statistically significant improvements in thesteepness of the dose gradient, and increased maximum and mean target doses compared toclinically delivered plans that were already considered excellent. Gains were especially pro-nounced in the reduction of normal brain tissue included into the 90%, and 50% isodose lines.We have since made this process part of the clinical routine for all cranial IMRS procedures.

Radiosurgery, staged radiosurgery and fractionated radiosurgery:experiences of gamma knife and CyberKnife P2-27 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan

The technical development of radiosurgery expanded treatment indications for cranial andextracranial lesions. Benefits of gamma knife and CyberKnife are reported based on own experi-ences. Gamma knife provides 201 focused beams at a point. High dose treatment to small lesionsis sharp and rapid. No hair loss appears even in the treatment of multiple metastases more than10 lesions. Fractionation (3 times of low-dose radiosurgery) is also possible during 3 to 5 days offrame fixation (Stereotact Funct Neurosurg, 1995). Small lesions, multiple lesions and functionaldisorders are good indications for gamma knife. CyberKnife is based on frame-less stereotaxy andhas large collimators to 60mm. 50 to 100 beams are usually used for a lesion by conformal doseplanning. Staged or fractionated radiosurgery for large lesions is able to perform painlessly.Intensity modulated radiation therapy is also possible for malignant invasive tumors. Largelesions, invasive lesions and peripherally situated pathologies are good indications forCyberKnife. It is concluded that development of radiosurgery may provide further indications,improved results and minimal complications.

Today’s technology and application of a dedicated neuro-radiosurgery systems P2-28Franz, Krispel (1) (1) American Radiosurgery, Inc. - Research and Development San Diego, USA

Radiosurgery as a Neurosurgical procedure has established itself over the last 40 years. Even thatthe basic principle is still the same today, the advances in technology for diagnosis and therapyhas driven this procedure to a very high precision. The increased knowledge in detailed Neuro

258

Page 261: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

anatomy and physiology allows now to fully utilize this precision to the benefit of the patient. TheGamma ray based rotating system “GammaART-6000™ “ employs newly patented technologies,taking full advantage of today’s precision diagnostic. Together with the advanced “4 D” comput-er planning system, this neuro-radiosurgical Instrument marks the latest innovation in this field.30 needle beams rotate around the target in non overlapping circles. The sources are arrangedin one hemispheric sector and can be turned off at any time during treatment. This new techniqueallows “a-symmetric” application of radiation, leading to better conformance and smaller targets.Very small lesions as well as un- symmetric larger targets can be treated with high precision. Thefirst machine of this kind is now operational since 1 _ years in USA. The technology is protectedby US patent US 6,512,813B1, US 5,528,653 and US 5,757,886. Clinical results are givenelswhere at this conference. A descriptions of the system and its relation to small structureNeuroanatomy is given.

Dynamic patient positioning using Leksell gamma knife P2-29 Stefan G, Scheib (1); Stefano, Gianolini (2); Friederike, Reich (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3)Unitversity of Applied Science Remagen - Department of Medical Engineering and Sports-MedicalEngineering Zürich, Switzerland

In order to investigate the potential benefit of dynamic patient positioning within the radiationfocus using the gamma knife, which is not possible with the current version of the APS, a proto-type of a triple axis scanner was build and used together with gamma knife B. The stereotacticframe is fixed to this scanning system, which is able to move the frame whilst the patient couchremains in the treatment position. Each of the three orthogonal linear axes can be operated inde-pendently. The system is connected to a PC where all parameters are visualised in real time. Thepositioning reproducibility is less than 1/10 mm and the range of the axes enable the wholestereotactic space to be covered. The scanning speed for each axis can be chosen up to 2.5 mm/s.The frame can be moved in 3D either by using constant velocities for each axis (drive mode), byvarying velocities for each axis (dynamic mode), or by stepping a given increment along each axis(stepping mode). Dedicated dose distributions can be applied using appropriate dose optimisa-tion algorithms. This could comprise homogeneous dose distributions throughout the target,intended dose inhomogeneities in selected areas within the target, or selected dose gradients atperipheral target regions. Using the scanning device in the drive mode together with the 4 mmcollimator allows the application of homogeneous dose distributions. In order to produce 3D opti-mised dose distributions a dose optimisation algorithm is implemented. The flexibility of the scan-ning system allows to explore the potential benefit of a scanning gamma knife. Calculated andmeasured dose distributions are compared to those using standard gamma knife technique.

259

Page 262: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Extracranial stereotactic IMRT - A study of set-up reproducibility P2-30Meg, Schneider (1); Robert, Smee (1); Lyn, Emanuel (2); John, Way (3); Karl, Chan (4) (1) Prince of Wales Hospital - Department of Radiation Oncology; (2) University of New South Wales - Princeof Wales Hospital - Department of Radiation Oncology; (3) Prince of Wales Hospital - Physics Department ofRadiation Oncology Randwick, Australia

INTRODUCTION: Three patients with vertebral body lesions were treated with a stereotactic IMRTtechnique. Accuracy and reproducibility in the set-up are paramount, as all three patients hadreceived previous radiation, with the spinal cord being the organ at risk. METHODS: All patientswere set-up using the Body Fix System (Radionics/Medical intelligence). This system comprises afull body vacuum bag attached to an indexed carbon fibre base-board, to which a stereotacticlocaliser is attached. It also allows the use of a double vacuum system, which is intended toachieve a high level of reproducibility and restriction of internal organ motion. Xknife RT 3 plan-ning software was used for planning, and a set of DRR’s (pa and lateral) was calculated for eachpatient. At treatment, a pa and lateral port film were taken second daily, which were then com-pared to the DRR’s that were produced by the planning system. Deviations in three dimensionswere then measured (AP, LAT and Vertical) and evaluation was then recorded. These results willbe presented. The time required to produce the initial mould was measured, as well as set-upand treatment times. RESULTS: The initial results are encouraging, but data is still being collect-ed. Results will be presented and discussed. CONCLUSION: The production of the vacuum bagwas no longer than other immobilisation modalities used in radiotherapy. With experienced RT’s,it was actually quicker and simpler than production of a thermoplastic mask, which is a common-ly used technique in head and neck irradiation. Treatment set-up times compared favourably withother conformal radiotherapy techniques.

Implementation of A 6D robotic couch-top for the automation of image-guided brain SRS and spinal SRT P2-31 Almon, Shiu (1); Eric, Chang (2); Conjung, Wang (1) (1) The University of Texas M.D. Anderson Cancer Center - Radiation Physics; (2) The University of Texas M.D.Anderson Cancer Center - Radiation Oncology Houston, USA

This study is focused on the implementation of a 6D Robotic couch-top for the image-guidedbrain SRS and spinal SRT. A robotic couch-top is replaced the existing couch-top on our LINAC/CT-on-rails unit. This couch-top consists of two platforms, are connected by six linear, lengthadjustable cylinders. The system is capable of moving the upper platform relative to the lowerone in all three axes in space. The couch-top movements can be directed via the tracking andpositioning software and the dead-man switch on the control panel. The software along with 3infrared LED cameras system allows positioning the couch-top automatically. To automaticallysetup the patient accurately, first, the 3 cameras were calibrated to ensure the cameras covered1 m2 area near isocenter. Setup the MIS to ensure the lasers aligned with the radiation isocenter.Then the calibration cube was used to define the daily isocenter. Finally, the localizers for bodyframe, CRW frame, and couch-top leveling device with sphere markers were created for the spine,brain and conventional treatments, respectively. The body frame localizer with sphere markerswas tested first without the patient to assess the accuracy of positioning the couch-top automat-

260

Page 263: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

ically. The accuracy in positioning at AP-, LAT-, and SI-direction is within 0.2 mm. Two spinalpatient’s setup on L4 –L5 and T11-T12 were also evaluated. The accuracy in positioning theupdated isocenter in all directions is less than 0.5mm. The CRW head frame localizer with spheremarkers was also evaluated with a head phantom. The accuracy of positioning the target isocen-ter to coincide with the radiation isocenter at different couch positions is less than 0.5mm. Usingthe leveling device, the couch-top could be leveled to be within 0.1 degree in tilt, yaw and rolldirections for the patients received the treatment at the various anatomic sites.

Targeting accuracy of a novel image guided gating system for stereotactic body radiotherapy P2-32 Stephen, Tenn (1); Paul, Medin (1); Timothy D., Solberg (1) (1) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA

INTRODUCTION: Targeting accuracy was evaluated for a novel image guided gating system(BrainLAB AG, Heimstetten, Germany) for stereotactic body radiotherapy (SBRT). METHOD: A solidwater phantom containing five 2mm lead BBs was imaged with CT and reconstructed with 3mmslice thickness. CT data was used for planning and generation of digitally reconstructed radi-ographs (DRR). For irradiation, the phantom was placed on a platform capable of 2-dimensionalmovement (1.8cm superior-inferior and 1.2cm anterior-posterior) mimicking thoracic tumormotion. Infra-red reflecting spheres placed on the phantom were used by the system to trackphantom movement. The moving phantom was localized at 3 different positions (10%, 50% and90% anterior-posterior peak-to-peak amplitude) in the simulated breathing cycle using digitalstereoscopic kV radiographs triggered appropriately by the gating system. Localization was doneby fusing BBs in the kV radiographs with those in DRRs. Film was placed horizontally inside thephantom and exposed by our linac using a 5mm SRS cone under gated conditions. Fiducial pinmarks in the films allowed the position of the gated fields to be compared to those of fieldsexposed in a non-moving phantom positioned by the same stereoscopic kV radiography system.The effect of both fast (3.6 second period) and slow (5.7 second period) motions on accuracy wasinvestigated. RESULTS: Difference in average superior-inferior position between the static fieldsand the gated fields are as follows: 0.7mm for 10% level and slow motion, 1.1mm for 10% leveland fast motion, 0.1mm for 50% level and slow motion, 0.1mm for 50% level and fast motion,0.2mm for 90% level and slow motion, and 0.0mm for 90% and fast motion. The standard devi-ation of the difference is 0.1mm for all measurements. CONCLUSION: Our study demonstratesvery high accuracy of this system which is necessary for SBRT of moving targets.

Comparison of five radiosurgery treatment planning techniques: Is it a case of "six of the one, half a dozen of the other?" P2-33 Hester, Burger (1); Audrey, Pentz (1) (1) Netcare Group of Hospitals - Medical Physics Division Johannesburg, South Africa

Introduction: Planning comparison studies assess theoretical differences in treatment plans. Thevolume of normal tissue included in and immediate adjacent to the prescription isodose line, inte-gral dose to the brain, dose inhomogeneity and dose to critical structures may all contribute tothe risk of complications. Five techniques were evaluated: Circular arc (collimators), conformal

261

Page 264: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

static beam, conformal arc, dynamic conformal arc and intensity modulated radiosurgery (micro-multileaf collimator). Methods: Eight cases were selected, based on shape and diameter: Roughlyspherical < 3 cm, complex < 3 cm, complex > 3 cm and multiple lesions. Two were plannedwith all five techniques and the remainder with the conformal techniques only. A target volumewas drawn in by the oncologist. Plans were renormalized to deliver 18 Gy to at least 99% of thetarget volume, with the exception of plan 5 (95%). The PITV, VNT50%, VNT25%, MDPD andDVHs were calculated. Plan 5 was rated by 31 oncologists and planners, indicating whether iso-dose data, DVH data or RTOG indices were used for evaluation. Results: Apart from the expect-ed difference in MDPD between multiple and single isocenter techniques, only small differenceswere observed, mainly with regard to VNT50% and VNT25%. Analysis indicated that 42% ofoncologists based their assessment primarily on DVH data, 40% on isodose distributions and only18% on RTOG criteria. Conclusion: Limited information can be obtained with the RTOG criteriaalone. More detailed radiobiological analysis, combined with training, coordinated follow-up andobservation of actual complications is required. A project has been launched to register allpatients within the Netcare Group in South Africa on a national database to record predicted vs.actual complications. Cognitive testing using the Brain Resource Centre’s IntegNeuro system willassist in the assessment of cognitive function.

Feasibility of implanted fiducial markers for patient positioning for cranial radiotherapy P2-34Rosa, Cañon (1); Ignacio, Azinovic (2); Mario, Lobato (2); Francisco, Garcia-Cases (2); Maricarmen, Heredia(2); Jose, Navarro (3); Jose, Martinez (2) (1) Hospital San Jaime - Oncology Platform, Radiation Oncology; (2) Hospital San Jaime - Oncology Platform,Radiation Oncology; (3) Hospital San Jaime - Neurosurgery Torrevieja, Spain

Purpose: To assess the feasibilty and reliability of fiducial marker implantation for precise set-upand real-time positioning in patients with brain tumours treated with external beam radiothera-py. Methods and Materials: Between October 2003 and October 2004, 12 patient (p) withintracranial tumors were treated with external radiotherapy using implanted cranial gold markers.The procedure consisted in the insertion of 3 gold markers of 2 mm in diameter in the skull. Beforetreatment planning, immobilization with a thermoplastic mask was performed . Routine CT scanwith intravenous contrast and Magnetic Resonance Imaging registration was used to identify thetarget volume. Before each fraction the patient was positioned on the treatment table and 2orthogonal portal images were performed using an amorphous silicon panel to localize the 3 goldseeds and the target position was calculated using a comerzialized computer program (ISOLOCsoftware, MED-TEC). This program provides the couch movements required to move the target tothe isocentre. Results: Gold markers were implanted in 12 patients (5 women and 7 men, medi-an age 50,5 years range 28 – 74). Tumor histology was: 6 (50%) gliomas (primary 4 and 2relapse after surgery, chemotherrapy and radiotherapy, then 2 re-irradiations), in 5 (41.7%) caseswere brain metastases and 1 acoustic neurinoma. Patients were treated using 6 MV photons with5 (3 – 7) non-coplanar beams, with conventional fractions in 4p (33,3%), hypofractionation in 6p(50%) and hyperfractionation in 2 p. When the setup error was corrected using the coordinatesof the 3 markers, the final movements has been less than 2 mm in all cases. No serious compli-cations related to the gold markers insertion were noted. One patient treated with simoultaneous

262

Page 265: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

intracarothid chemotherapy suffered an unilateral aseptic meningitis, with complete resolutionafter the treatment. Conclusions: The use of 3 implanted fiducial is an optimal technique for pre-cise set-up in patients with brain tumors treated with external radiotherapy. This commercial sys-tem is highly suitable for fractionated stereotactic irradiation. Final adjustments are low using thecurrent methodology based in anatomical references.

Dynamic extracranial robotic radiosurgery by means of a real-time motion correction system: Analysis of the reduction of the planning target volume compared to the static technique P2-35Franco, Casamassima (1); Giovanni, Ambrosino (2); Paolo, Francescon (3); Carlo, Cavedon (3); Joseph,Stancanello (3); Stefania, Cora (3); Michele, Avanzo (3); Paolo, Scalchi (3) (1) University of Firenze - Department of Fisiopathology - section of Radiotherapy; (2) S. Bortolo Hospital -Vicenza - Italy - General Surgery Department; (3) S. Bortolo Hospital - Vicenza - Italy - Medical PhysicsDepartment Firenze, Italy

Introduction: Spatial accuracy in extracranial radiosurgery is affected by organ motion. Static tech-niques require to enlarge the planning target volume (PTV) in order to guarantee tumour cover-age; PTV enlargement however implies irradiation of bigger volumes of organs at risk (OAR). Twopossible solutions exist: 1) gated techniques, which allow smaller volumes to be irradiated butnegatively affect treatment times; 2) dynamic strategies that can reduce irradiated volumes andpreserve treatment times. In this work we report on initial experience in the use of the Synchronydynamic device, an extension of the Cyberknife system. Method: We selected 7 extracranial treat-ments (2 liver, 4 lung, and 1 pancreas) performed before use of Synchrony for which we delin-eated the tumor volume in CT scans acquired in inspiration and expiration phases. We fused thetwo datasets and we delineated the PTV after join of the two contours. After acquisition of theSynchrony system we revaluated the plans by taking into account only one of the contours andwe calculated 1) PTV volume differences, 2) 50% isodose volume differences and 3) difference inNTCP for organs at risk, using the Lyman model with correction for fractionation. Results: Volumereductions were 38% (average) for liver lesions, 43.9% (average) for lung targets and 8.5% forthe pancreas treatment. Volumes of 50% isodose surfaces underwent similar percentage reduc-tion. NTCP reduction depends on the type of OAR. For lung NTCP was reduced from 2.5% to0.1% (average), while for liver cases NTCP varied from 32% to 21% (average). Differences for thepancreas case were negligible. Conclusion: Significant volume reduction is obviously attained fortargets located in proximity of the diaphragm. Reduced dose to OARs can be achieved by meansof a real-time motion correction device, which opens the way to dose escalation. We estimatedan advantage for OARs with parallel architecture, even if major differences could be expected forserial organs.

263

Page 266: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Monte Carlo simulation for stereostatic treatment with multiple fields P2-36 Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology Shatin, Hong Kong

The stereostatic treatment plans from Radionics Xknife RT3.0 are compared with Monte Carlo sim-ulation. The arc treatment is simulated by using multiple fields. Different cone sizes , Jaws andNon-jaws algorithm will be compared. Measurement results will be presented as well. The MonteCarlo code called MCBEAM from Fox Chase Cancer Centre in USA is used in this project. MCBEAMis EGS4 based code modified from BEAM code of NRCC. A computer program has been written togenerate the multiple fields for the arc. Beam can be placed every 0.25°, 0.5° or 1.0° of the gantry.In this study, half-degree intervals was found to be a good approximation of the arc treatment.

The study of dose enhancement close to platinum implants for 4, 8, 14 and 18 mm collimator helmets in the Gamma Knife surgery P2-37 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong

Introduction: Platinum objects are sometimes implanted into a human brain, such as theGuglielme Detachable Coil system, the Auditory Brainstem Implant, and the Deep BrainStimulation. For patients who undergo gamma knife Surgery and who have platinum implantsinside their brains within the treatment target, no specific guidelines or recommendations to min-imize the undesired effects to the surrounding critical structures were given. In this work, we cal-culated the dose enhancement close to a 4 mm diameter platinum implant when a single shotirradiation was made using the 4, 8, 14 and 18 mm collimator helmets. Methodology: The PRES-TA (Parameter Reduced Electron-Step Transport Algorithm) version of the EGS4 (Electron GammaShower version 4) MC computer code was employed. The platinum implant was placed at theunit centre point (UCP) and the single shot isocentre targeted at the UCP. Energy depositions sur-rounding the implant were scored and gave the absorbed dose. Results and Discussion: For the8, 14 and 18 mm collimator helmets, the dose enhancements obtained are similar, which can beexplained by the similar beam profiles with and without the platinum implant in the region fromthe maximum down to the platinum-phantom interface. On the other hand, the dose enhance-ment for the smallest 4 mm collimator helmet is higher than those using the 8, 14 and 18 mmcollimator helmets, which can be explained by the rapid fall-off of the steep gradient of the doseprofile without the platinum implant.

264

Page 267: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stochastic target approximation by auto-computation of spatial units for stereotactic radiosurgery P2-38 Kyoung-Sik, Choi (1); Seongjong, Oh (2); Hyun-Tai, Chung (3); Moon-Chan, Kim (4); Bo-Young, Choe (5); Suh,Tae-Suk (6) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (2)The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (3) SeoulNational University Hospital - Department of Neurosurgery; (4) Kangnam St. Mary's Hospital - Neurosurgery;(5) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (6)The Catholic University of Korea, School of Medicine - Biomedical Engineering Seoul, Korea

An optimization plan can be generated using approximation algorithm with an improved tech-nique commonly applicable in a Linear accelerator and gamma knife for stereotactic radiosurgery.The two modalities in the radiosurgical plan were optimized by the conjunctions of many beamparameters in three dimensional space. In stereotactic radiosurgery, the dose distribution toadjust an intracranial tumor is produced from the spheres set on the unit isocenter or shot. Thiswork mainly focused on two beam parameters of the isocenter location, the collimator size andpoints. One used a small collimator size considering the irregular boundary regions between thetumor and the normal tissue. In the other, an irregularly shaped tumor was approximated as arectangular coverage and cubic structure to find the statistical distribution based on a 1„e1„e1mm3 voxel. The results of applying the four imaginary targets fully acceptable to a radiosurgicalplan conforming to Radiation Oncology Therapy Group (RTOG) guidelines; the prescription iso-dose line surrounding the targets was included in a more than 50% isodose curve. The dose con-formity was ordinarily acceptable and the dose homogeneity was always satisfied for various tar-gets (less than 2.0). This approach using stochastic algorithm is a useful radiosurgical plan with-out restrictions in the various tumor shapes and the different modalities.

Comparison of dose calculations and dose measurements near heterogeneities in gamma knife radiosurgery P2-39 Françoise, Desmedt (1); Stéphane, Simon (2); Bruno, Vanderlinden (2); Christophe, Vandekerkhove (2);Thierry, Gevaert (1); Bob, Schaeken (3); Daniel, Devriendt (4); Nicolas, Massager (5); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Physique; (3) AZ Middelheim - Physique; (4)Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neurochirurgie Brussels, Belgium

Purpose. The software used in gamma knife radiosurgery (Leksell GammaPlan®) doesn’t takeinto account the presence of heterogeneities in the skull. A linear attenuation coefficient of 0.063cm-1 (water) is applied in dose calculation. But sometimes, targets are located close to bonestructures or sinus cavities. The purpose of this study is to estimate if dose calculations are ingood agreement with measurements in such areas. Methods. Measurements were performed onthe head of an anthropomorphic phantom in stereotactic conditions. A CT scan was preliminarydone and TL and Alanine detectors were placed in intracranial holes close to bone and aeric cav-ities. Different doses were prescribed on these areas, which were then irradiated in the gammaknife. Results. Preliminary measurements with TL dosimeters near bone structures give a meas-ured dose of 0.974 +/- 0.087 Gy for a prescribed dose of 1 Gy on a volume equivalent to TLdetectors. The same measurements were performed with Alanine detectors for a prescribed dose

265

Page 268: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

of 10 Gy also near bone structures. The measurements give a dose of 11.304 +/- 0.127 Gy.Conclusion. Preliminary results show that TL measurements are in good agreement with dose cal-culations. Contrary to TL detectors, Alanine dosimeters are tissue equivalent which gives a betterchoice for phantom measurements. It is therefore interesting to perform an experimental compar-ison between these detectors. Temporarily, dose measurements with alanine are less close todose calculations but more measurements have still to be performed and also close to aeric struc-tures. It might be also interesting to compare not only absolute doses but also the shape of cal-culated isodoses and measured isodoses on Gafchromic® films near heterogeneities.

Dynamic arc: useful or expensive toy for meningiomas treatment? P2-40 Frederic, Dessy (1); Carine, Mitine (2); Laurent, Gilbeau (1); Marie-Therese, Hoornaert (1) (1) Hôpital de Jolimont - Radiotherapie; (2) Jolimont hospital - Radiotherapy Haine Saint Paul, Belgium

Purpose: To quantitatively compare treatment techniques: static, conformal fields and dynamic arcin stereotatic fractionated radiotherapy for meningiomas. Materials and methods: we report acase of a temporo-parietal meningioma (WHO grade 2) which occurred in a 64-year-old women.She was treated by fractioned radiotherapy using a Linac after a subtotal resection. The mediantarget volume is 95, 6 cm3 and the dose delivered 57.6 Gy by fractions of 1.8 Gy five times week-ly. Stereotatic fractionated radiotherapy is delivered by a Varian clinac 2100C/D with a 120 leafsMLC photon beam 6 MV. The planning software is BrainScan 5.3. The drawing of all the struc-ture is made in Iplan 2 from BrainLab.Before the treatment of a patient using such a technique,we also realise a quality control of the dynamic arc module of the BrainScan 5.3 software. Usingthe IMRT Omnipro phantom form scanditronix and Kodak EDR-2 film. The planning is mapped tothe phantom filled with slab of film, treated and the film was compare to the calculated doseusing the Gamma factor as evaluation method. The dose distribution is planned in order to coverat least 95% of the target’s volume with the prescription isodose. The patient will be plannedwith the three different options (static filed, conformal arc and dynamic arc). In the fixed-fieldoption and conformal arc, the MLC leaves remain static during the irradiation and in the dynam-ic arc technique, the leaves are dynamically moving to match the changing shape of the targetprojection. We will study the difference in DVH for the total irradiated volume, PTV and criticalorgans (brainstem, chiasma, cranial nerves) and also use the of conformity index, minimum tar-get dose for different plan corresponding to the following specification. We also study the influ-ence of the prescription isodose (50 %, 80 % and 90%) on the different PTV.

Simultaneous SRS for multiple intracranial lesions with single isocenter using micromultileaf collimator P2-41 Junichi, Fukada (1); Etsuo, Kunieda (1); Osamu, Kawaguchi (1); Satoshi, Seki (1); Naoyuki, Shigematsu (1);Minoru, Uematsu (1); Atsushi, Kubo (1) (1) Keio University - Department of Radiology Tokyo, Japan

Introduction: Most of multileaf collimator devices consist of only one layer of leaves so that it isdifficult to produce multiple “holes” in one treatment field. Micromultileaf collimator (MMLC))which has two banks of leaves perpendicular to each other is capable of producing a treatment

266

Page 269: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

field with multiple “holes” corresponding to multiple targets, though it has limitations to someextent. Therefore, it is possible to treat multiple lesions adjacent to one another with one isocen-ter. We report some cases in which multiple close lesions were treated with stereotactic radio-surgery simultaneously with a single isocenter. Cases and methods: 4 cases with multiple lesionswere treated with a single isocenter. They included three cases of metastatic brain tumors andone case of atypical meningioma. One case of metastatic brain tumor and one case of meningo-ma had undergone surgical removal previously. A 6-MV linear accelerator (Linac, ML15MV:Mitsubishi Electric Corp. Tokyo, Japan) was used to produce the x-ray beam. An MMLC module(AccuLeaf: Alayna Enterprises Corporation, Paris, France) was mounted on the linac gantry-head.MMLC has leaves arranged on two levels perpendicular to each other. The effective leaf width ofthe inner pairs is 2.6mm at the isocenter while it is 4.5mm for the outer pairs. We treated 2lesions simultaneously in one case of metastatic brain tumor and postoperative meningioma. Wetreated 3 lesions with a single isocenter in two cases of metastatic brain tumors. Estimated tar-get volume of 4 cases are 8.91cc, 3.27cc, 3.49cc, 0.90cc. We simulated planning, treating eachtarget independently, measuring the distance from one target center to another, and evaluatingthe homogeneity and conformity indices. Results: All treatments were completed with no adverseevents. The treatment time can be shortened. Distance between one target center and anotherranged form 41.7 mm to 8.1mm. Simultaneous SRS showed acceptable results in homogeneityand conformity, though lower conformity was observed in the simultaneous SRS for 3 lesions.Conclusion: If multiple lesions are adjacent to one another, simultaneous SRS were able to com-plete safely with MMLC and achieve sufficient conformity. With simultaneous SRS, we can treatin shorter time and reduce patients burden and deal with multiple lesions. From that aspect,simultaneous SRS has clinical efficacy.

A new tool for quantitative evaluation of plan quality in Fractionated Stereotactic Radiotherapy P2-42 Janna, Menhel (1); Dror, Alezra (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel

Objective: To evaluate differences between IMRT and Dynamic Arcs (DA) for FractionatedStereotactic Radiotherapy (FSR) using a novel approach for plan evaluation. Methods: 17 casesof cavernous sinus meningioma were evaluated. In all cases the tumor compressed the opticpathways, the major organ at risk (OAR). DA consisted of 4 dynamic arcs and IMRT included 12beams (BrainLab ver. 5.21). Optic pathway dose was aimed to be limited to 2 Gy/fraction. Thecomparison analysis included both dose and volume–related target coverage (dTC and vTC), PITV(RTOG, 1993), Conformity Index (CI, Lomax) and Conformation Number (CN, Van't Riet) values.We developed and implemented a novel evaluation criterion, Critical Organ Scoring Index (COSI),defined as: [1-VTol/vTC], where VTol is the partial volume of OAR receiving over tolerance dose.This parameter approaches unity when the critical structure is completely spared, and target cov-erage is 100%. Deviations will yield lower values of COSI. We present a new 2D graphical rep-resentation of COSI versus CI, which improves our ability to assess trade-offs of the different plansin a simple visual way. Results: For optic pathway volume, receiving over 50Gy average COSI val-ues for DA and IMRT were 0.889 and 0.896 respectively. There were no significant differences inany scoring indices between the two approaches. However, COSI-CI plots revealed that IMRT was

267

Page 270: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

superior in 47% and inferior in 17.5% of cases. For the remainder, both treatment approacheswere equivalent. Conclusions: For all conformity score functions plan quality was acceptable forboth DA and IMRT approaches. The novel COSI method we developed proved to be consistentwith other conformity score functions, and was highly efficient in assessing specific structure spar-ing. COSI-CI plots can be expanded to include multiple OARs, as relevant for a particular treat-ment site, enabling reliable visual assessment of different plans.

Characterization of lung lesion doses in Stereotactic Body Radiation Therapy (SBRT) via Monte Carlo P2-43 Premavathy, Rassiah (1); Martin, Fuss (2); Bill J., Salter (3) (1) UTHSC San Antonio - Radiology; (2) UTHSC San Antonio - Radiation Oncology; (3) Cancer Therapy &Research Center - Medical Physics San Antonio, USA

Stereotactic Body Radiation Therapy (SBRT) represents an exciting new delivery paradigm inwhich hypofractionated, extremely conformal dose distributions is delivered. Determining theoptimal dose and fractionation scheme, requires an understanding of the true delivered radiationdose and, thus, an accurate understanding of the dosimetry in the inhomogeneous and very low-density-environment of the lung. This study attempts to accurately characterize the doses receivedby static targets located in the lung, as well as doses to critical structures for the serial tomother-apeutic intensity-modulated delivery method used for SBRT in our clinic. 76 NSCLC patients havebeen treated with SBRT between 2001–2004 with, a standard prescription dose for lung metas-tases of 36 Gys in 3 fractions delivered every 48 hours and primary lung neoplasms (stage 1NSCLC) between 3 times 16 Gy to 3 times 20 Gy. Dose distributions previously planned on a con-ventional planning system were recalculated using a Monte Carlo (Peregrine pre-release version)which is accurate to better than .3% in an anthropomorphic phantom. 10 of the 76 SBRT patientdata sets are presented here. The mean CTV volume of the lesions presented here is 40.1 cm3(4.7 cm3 –99.8 cm3). The conventional algorithm overestimates the mean dose to the CTV forall lesion volumes by an average of 14.1 % of prescribed dose (range: 6.6 %- 25.1 %) comparedto MC calculation. This overestimation is greater for small lesions, where the 25.1 % of over-pre-diction corresponds to the smallest lesion (4.7 cm3), demonstrating that an accurate modeling ofelectronic equilibrium conditions is most important for small lesions. The largest discrepanciesexist for both the Maximum and Minimum doses to critical structures (lungs, spinal cord, esoph-agus and the major airways), with mean doses in better agreement. Statistical analysis of all 76patients is underway and will be presented.

In SRS treatment what factors affect the normal tissues receiving doses much less than prescription doses? P2-44 Ramaswamy, Sadagopan (1); Narayan, Sahoo (2) (1) M.D. Anderson Cancer Center - Radiation Oncology; (2) M.D. Anderson Cancer Center - Radiation Physics Houston, USA

In this study, we investigate two factors that influence the volume of normal tissues receiving lowdoses, specifically, 70,50 and 30% of the prescription dose. The two factors that studied were thetarget volumes and the average depth of the target. A plastic head phantom filled with water wasused with speherical targets of various sizes simulating the typical metastatic lesions seen in

268

Page 271: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

radiosurgery treatments. Treatment plans were done using Radionics treatment planning soft-ware resulting in four 90 degree arcs at four different couch angles. The planning process usedis simillar to that employed in our clinic, aiming for minimum achievable TVR, isodose coveragewith atleast 80% dose with respect to isocenter. However, the presence of critical structures isignored in this study. As expected, our study indicated that the volumes of tissues receiving 70,50 and 30% prescription dose is correlated directly with tumor volume and the relationship is notlinear. A fourth order polynomial seems to fit all 70,50 and 30% dose volume with target volumewith a coefficient of variation ( r^2) 0.998 or better. The volumes of normal tissues receiving lowdoses did not vary with the average depth of target as it varied from 8cm to 4cm.

Dosimetric verification of an IMRS dose delivery of the Novalis system P2-45 Dong-Joon, Lee (1); Moon-Jun, Sohn (1); Sung Rok, Han (1); Sang Won, Yoon (1); Gee Taek, Yee (1); C. Jin,Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery Goyang, Korea

INTRODUCTION IMRS(Intensity Modulated Radiosurgery) is an effective treatment option that hasbeen applied in OAR(Organ At Risk) closed lesion. We evaluate the dosimetric accuracy in theprocess of IMRS commissioning of Novalis (BrainLAB AG, Heimstetten, Germany) METHODS Asmall water phantom(SWP) include well shape target lesion was designed for evaluate the dosedelivery and distributions of the prescribed IMRS plan. To verify the dose delivery, special dosime-ters were placed at the OAR region and 20 Gy dose was delivered to the isocenter. Farmer typeionchamber (0.6cc) and 9 number of TLDs were irradiated to determine the absorbed dose in afew typical points. And the monochromic films(GAFCHROMIC Dosimetry Type MD-55, Victoreen,USA) were irradiated in the SWP to verify the 3D dose distribution. And MapCheck 1175 2D-diode array was used for the planned 9 beam fields to verify the dose distributions. The severaltreatment plan techniques including IMRS were adopted and compared for this study. Non-copla-nar 9 beams were used for IMRS treatment and the intensity modulated beams were deliveredthrough the sliding window technique using mMLC. RESULTS The experimental set up of SWPallows to evaluate the dose delivery and dose distribution. Spatial localization accuracy wasfound to be smaller than ±1.0 mm and the dose delivery difference of measured dose and cal-culated dose was within ±1.5 %. And dose–difference distribution of superimposed isodose(measurement-calculation) values were within ±5.0 %. CONCLUSION For the comparison ofusing other treatment plan technique, only the IMRS treatment plan can save the OAR complete-ly. And dosimetric accuracy of the IMRS plan using single slice delivery showed that dose distri-bution was good agreement in high dose and low dose gradient regions.

Multiple isocentric plan with Brain Lab microMLC for eight brain mets P2-46 Dinesh, Tewatia (1); S.K., Rout (1) (1) Indraprastha Apollo Hospital - Medical Physics New Delhi, India

In this paper we have evaluated the possibility of treating multiple brain mets with the help ofBrainLab microMLC(52 leaf). The patient after receiving 40Gy of whole brain dose came with mul-

269

Page 272: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

tiple brain mets(eight) for irradiation. The treatment of choice for the patient was SterotacticConformal beams(SRT) with the help of BrainLab M3 system. Treatment plan for the patient gen-erated with combination of both coplanar and noncoplanar beams. The goal treatment planningwas to encompass 90% dose to PTV while minimizing dose to other critical structers and normalbrain.The following parameters are evaluted: target conformity,target homoginiety,normal tissuereceieving doses>80%,>50%,and >20%.The plan showed a good confomity of the dose dis-tribution with all brain mets.In this study static conformal beam showed significant dosimetricinprovement than conformal dynamic arc planning.

An analysis of the impact of intrafraction internal anatomy motion on delivery of radiation therapy: A dosimetry analysis using a dynamic phantom system P2-47 Chung, Jin-Beom (1); Suh, Tae-Suk (2); Chung, Won-Kyun (3) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (2) The Catholic Universityof Korea, School of Medicine - Biomedical Engineering; (3) Seoul Health College - Radiation Science Seoul, Korea

Respiratory motion in the thorax and abdomen is an important limiting factor in high-precisionradiation therapy. The lung tumor and tumors (liver, pancreas, stomach) in abdomen therefore areinternal motion due to breathing. We will perform to measurement and analysis of a delivereddose distributions for these moving tumors. In preliminary study, we investigated the displace-ment of moving tumors in the abdominal regions such as liver, lung with previously reportedpapers. With analytical motion model described by Lujan et al., internal motion of organ wasreproduced with phantom and moving control device (MCD), which appear three dimensional (3-D) motions such as x, y and z axis. The Dynamic phantom system was used to assess the deliv-ered dose distribution of organ with and without internal motion under similar condition,although there are not the same internal organ motion. In this study, Kodak X-Omat film was usedto measure dose distributions. Difference of dose distribution to motion of internal organ wasobserved. Little difference appeared in maximum doses. But minimum doses of difference in dosedistribution irradiated on moving tumor are apparently higher than 10%. The dose distributionfor moving organ was also increased more than 10 mm of the penumbra region during respira-tion. In future, we will obtain the exact evaluation of dose distributions if improved in programedsoftware of moving control device and measure precise internal motion using image modalitysuch as fluoroscopy, simulator in based on this study.

Dynamic field shaping arc versus circular cones for treatment of AVM: a comparative study P2-48 Carole, Gallez (1); Dirk, Verellen (2); Koen, Tournel (3); Nadine, Linthout (4); Tom, Wauters (5); Jean, D'Haens(6); Guy, Storme (7) (1) VUB - ETRO; (2) AZ VUB - Physique; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy; (5) AZ-VUB -Radiotherapy; (6) AZ-VUB - Neurosurgery; (7) AZ VUB - Radiothérapie Brussels, Belgium

Background and Purpose: To investigate the influence of beam collimation in linac-based stereo-tactic radiosurgery (SRS) of arteriovenous malformations (AVM) comparing circular cones andmicro multileaf collimation (mMLC). Material and Methods: A comparative planning study

270

Page 273: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

(BrainSCAN v 5.2, BrainLAB, Germany) has been performed on 2 types of AVM: (a) a sphericallesion (0.78 cm3) and (b) an irregular shaped lesion (11.11 cm3). A prescription dose of 20 Gy(80%) has been defined to encompass the target volume. A single isocentric dynamic field shap-ing arc therapy (DFSAT) technique using a mMLC has been compared to single and multi-isocen-tric arc techniques (2,3,4 and 5 isocenters, with varying cone diameters) using circular cones(CCT). A linac dedicated for radiosurgery (NOVALIS system, BrainLAB, Germany) has been used forall planning simulations. The total amount of Monitor Units (MU), Conformity Index (CI: definedas the ratio of target volume encompassed by the 80% prescription isodose with the total volumeof tissue encompassed by the 80% prescription isodose) and Dose Heterogeneity (DH: defined asthe ratio of the difference of the maximum dose and the minimum dose to the target volume tothe median dose to the target volume) have been evaluated. Results: For the spherical lesion,comparable results have been obtained between both treatment techniques with a slight advan-tage for CCT (respectively for CCT and DFSAT: CI 4.70 and 5.34; DH 0.10 and 0.16; 3499 MU and3550 MU). For the irregular shaped lesion, the CI seemed superior for CCT compared to the DFSAT(on average 1.31 compared to 3.25) due to underdosage of the lesion (minimal target dosebetween 10.75Gy and 16.50Gy for CCT versus 20.50Gy for DFSAT). This is confirmed in the DH:ranging between 0.88 and 1.14 for CCT and 0.26 for DFSAT. The latter is also reflected in the max-imum dose: ranging between 37.25Gy and 49.00Gy for CCT versus 26.75Gy for DFSAT. The sin-gle isocentric DFSAT required 3360 MU whereas a 5 isocenter CCT required 15026 MU for thesame target dose. Conclusions: For spherical lesions the CCT and DFSAT yield comparable resultswith a slight advantage for the CCT. The CCT is significantly inferior compared to DFSAT for theirregular shaped lesion, both with respect to treatment efficiency and target coverage.

Gamma knife surgery for functioning pituitary adenomas extending into cavernous sinus: Advantages in robotized micro-radiosurgery with advanced MR iImaging P2-49 Motohiro, Hayashi (1); Masahiro, Izawa (1); Taku, Ochiai (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1);Kintomo, Takakura (1); Jean, Regis (2) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service deNeurochirurgie Tokyo, Japan

Rationale: Tumors which are extending into the cavernous sinus (CS) are difficult to be safelyremoved by microsurgery. Gamma knife surgery (GKS) has played important role as an alternativetreatment for CS tumors without any significant complication. Since 1999, new gamma knife sys-tem with APS (Automatic Positioning System) has been refined with advantages. Additionally,sequences of MRI have developed dramatically, that 0.5-1.0mm thickness with the highest qual-ity can be possible to perform, and provided us to complete more accurate dose planning for pitu-itary functioning adenomas to suppress tumor progression and activity. Method: Frame applica-tion should be parallel to the optic pathway. We should select some original sequences of MRIdedicated to the pituitary adenomas extending into the CS. In the treatment of functioning ade-nomas, precisely tumor visualization must be the most important, and relationship to the vitalstructures should be also elucidated. Adenomas should be involved perfectly within 50% isodoseline with highly conformity/selectivity in avoidance to the excessive irradiation dose to the notonly optic pathway, but also normal pituitary glands and lateral wall of CS with 0.1mm level

271

Page 274: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

adjustment. Consequently, we should pay attention for the occupied percentage of 80% isodoseline area to be as much as possible to expect tumor shrinkage and improve /normalize endocrino-logically. Results: We have treated 50 cases with pituitary adenomas using only new GKS withAPS. 26 adenomas, including 16 functioning adenomas, could be evaluated at least 1 year fol-low-up. Tumor control rate achieved in 100%, and observed much shrinking in 62.5%. 75%patients experienced endocrinological improvement, and observed nearly normalization (onlybase line value) in 43.8%. In particular, the patients with Cushing disease experienced more effec-tive than before, in spite of quite short time follow-up. No patient has complained any complica-tion. Conclusions: We have demonstrated to establish the optimal dose planning with APS. Ofcourse, longer term follow-up should be need. But, we already experienced some satisfied resultswith the treatment concept and strategy as “Robotized Micro-radiosurgery”.

Efficacy of gamma knife radiosurgery in patients with recurrent or residual functioning and non functioning pituitary adenomas P2-50 Mercedes, Heureux (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Nicolas, Massager (3); Marc, Levivier (4);Bernard, Corvilain (1) (1) Hôpital Erasme - Endocrinology; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neurochirurgie; (4)Hôpital Erasme - Centre Gamme Knife Brussels, Belgium

The goal of this study was to examine the potential benefit of gamma knife radio surgery (GKS) inpostoperative patients with recurrent or residual functioning and non functioning pituitary adeno-mas. 20 cases of residual pituitary adenoma visualised by RMN and/or PET with 11C-methionine(PET-Met) and treated with GKS were analysed. 5 were non functioning adenomas, 6 adrenocor-ticotropic adenomas, 7 prolactinomas, 1 somatotropic adenomas and 1 plurihormonal adenomas(GH+PRL). The treatment was justified either by the persistence of uncontrolled hypersecretion orby the regrowth of the residual tumour. PET-MET was combined with MRI for GKS targeting. Themean tumour volume was 2.76 ± 2.32 cm3 (range 0.15-6.7). The mean dose was 18.6 Gy(range14-20) for non functioning pituitary adenomas and 28.2 Gy (range 18-35) for functioningpituitary adenomas. The mean follow-up duration was 36 ± 17months (range 15-57). Weassessed the effects of GKS on (1) tumour growth (2) control of hormone hypersecretion (3) occur-rence of pituitary insufficiency. Adequate follow up was unavailable in 2 patients. Tumour growth(defined as no further growth) was controlled in 94.1 % of the cases and tumour shrinkage(defined as tumour decreased) occurred in 76.4%. Reduction of hormonal hypersecretion wasobserved in 69.2 % of the cases and 14.2 % of cases were considered as cured. The results werenot different according to the type of hypersecretion. 2 patients had panhypopituitarism beforeGKS. After irradiation, patient endocrine function was studied every 12 months. Some level ofpituitary insufficiency was observed in 7/16 patients (43.7 %). This was mainly observed inpatients treated for large residual pituitary tumours. In this small series, the most vulnerable axisis the somatotropic axis, followed by the gonadotropic, the corticotropic and thyrotropic axis. Noother adverse effects were observed. In conclusion, this study suggests that GKS is a safe andeffective therapy in selected patients with residual and recurrent pituitary adenomas. Longer fol-low-up is required for a more complete assessment of late toxicity and treatment efficacy.

272

Page 275: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Clinical results of LINAC-based stereotactic radiosurgery and Fractionated Stereotactic Radiotherapy for pituitary adenomas P2-51Putipun, Puataweepong (1); Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1);Somjai, Dangprasert (1); Jiraporn, Laothamatas (1); Veerasak, Theerapancharoen (2); Suchart,Phuthichjaroenrat (3); Pornpan, Yongvithisatid (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital MahidolUniversity - Department of Surgery; (3) Prasat Neurological Institute - Pathology Bangkok, Thailand

ABSTRACT Objective : To evaluate the clinical results of stereotactic radiosurgery (SRS) and frac-tionated stereotactic radiotherapy (FSRT) for pituitary adenomas with regard to tumor control andcomplications of the treatment. Methods: There were 51 patients with pituitary adenoma whounderwent SRS or FSRT between November 1997 and October 2003. Of these, 12 received SRSand 39 received FSRT. The median tumor volume was 1.6 ml for SRS and 11.3 ml for FSRT. Tenof the SRS and 11 of the FSRT patients were hormonally active at the time of the initial diagno-sis. Both SRS and FSRT was performed using a Linac-based radiosurgery system. Median averagedose was 15.8 Gy for SRS and 54.6 Gy for FSRT. Result : Median follow-up time was 4.7 (1.5-7.4) years. The five-year overall tumor control rate was 96% (92% for SRS and 97% for SRT). Twopatients with ACTH secreting adenomas had local failure, one had an endocrinologic and radio-logic recurrence 15 months after SRS and subsequently had repeat surgery followed by FSRT. Theother one had endocrinologic recurrence 20 months after FSRT which required additional bilater-al adrenalectomy. Hormonal normalization was achieved in 61%. Both SRS and FSRT showedsimilar responses with the average time to hormonal normalization of 12 months. There were nolate severe complications except for pituitary deficiency. The incidence of endocrinologic adverseeffects was similar in the two groups. The 3- year rate of freedom from newly initiated hormon-al replacement was 80%. Conclusion : Both SRS and FSRT achieved a similar high local controlrate without severe complication.

Gamma surgery in the treatment of nonsecretory pituitary macroadenomas P2-52 Jason, Sheehan (1); Ladislau, Steiner (2); Vincezo, Mingione (3); Edward R., Laws Jr. (1); Mary Lee, Vance (2);Chun-Po, Yen (2); Melita, Steiner (2); Matei, Stroila (2) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Neurosurgery; (3)University of Vienna - Department of Neurosurgery Charlottesville, USA

Objective: A retrospective analysis of the imaging and clinical outcomes following Gamma sur-gery in 100 nonsecretory pituitary macroadenomas is presented. Methods: From June 1989 toMarch 2004, 100 consecutive patients with nonsecretory pituitary macroadenoma were treatedat the Lars Leksell Center for Gamma Surgery at the University of Virginia. Ninety-two tumors weremacroadenoma residuals following one or multiple surgical procedures; in 8 patients, the Gammasurgery was the primary treatment. Ten patients received conventional fractionated radiotherapybefore gamma knife. Sixty-nine patients had replacement therapy for one or more hormonaldeficits. Peripheral doses between 5 to 25 Gy (mean 18.5 Gy) were given. The dose to the visu-al pathway never exceeded 8 Gy. Results: Imaging and endocrine follow-up was available in 90patients ranging from 6 to 142 months (mean 44.9 months) and 6 to 127 months (mean 47.9

273

Page 276: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

months), respectively. Tumor volume decreased in 59 patients (65.6%), remained unchanged in24 (26.7%) and increased in 7 (7.8%). The minimum effective peripheral dose was 12 Gy.Peripheral doses above 20 Gy did not seem to provide additional benefit. The median time forshrinkage of the tumor was 9 months. Following Gamma surgery, of 69 patients with a partiallyor fully functioning pituitary gland, 12 (19.7%) developed new hormonal deficits. For patientswith endocrine follow-up longer than 2 years, the rate of new deficits was 25%. Conclusions:Present experience suggests that Gamma surgery is an appropriate management in aggressivenonsecretory pituitary macroadenoma residuals or recurrences following microsurgery and as aprimary treatment in selected patients.

Results of steretoactic radiosurgery in patients with functional pituitary adenomas P2-53 Fabiola, Flores Vazquez (1); Pomponio, Lujan Castilla (2); Fiacro, Jimenez-Ponce (3); Francisco, Velasco (4);Mario, Enriquez (5); Luis, García (6); Eduardo, Arana (7) (1) Hospital General de Mexico - Radiotherapy; (2) Hospital General de Mexico - Radiotherapy; (3) HospitalGeneral de Mexico - Neurosurgery; (4) Hospital General de Mexico - Neurosurgery; (5) Hospital General deMexico - Radiotherapy; (6) Hospital General de Mexico - Neurosurgery; (7) Hospital General de Mexico -Radiotherapy Mexico City, Mexico

Oversecretion of hormones from pituitary adenomas result in significant morbidity and reduce lifeexpectancies for affected patients. surgical resection , is able to normalize hormone levels rapid-ly for 57 a 91% of patients. Unfurtunately, patients with persistent or recurrent endocrinopathiesafter surgical resection achieve biochemical remission less frecuently after repeated surgery. frac-tioned external beam radiation therapy results in clinical remission of symptoms for many patienswith hormone secreting tumors. nevertheless, radiotherapy frecuently causes hypothalamopitu-itary dysfunction, and is associated with the risk of radiation - induced neoplasms. methods:between 2000 - 2002, 14 patients with functional pituitary adenomas underwent radiosurgery:11 patients with tumors that produced prolactina, and 3 with growth hormone producing tumors.in the prolactinoma patients, the mean target volume was 2.7 cm. In the acromegalic patients,the mean target volume was 2.9 cm.The mean patient age was 36 years. 100% had undergonesurgery earlier. the median follow up period after radiosurgery was 36 months. Results: endocrinenormalization or "cure", was definided as the finding of normal or below normal hormone levels.In 10 patients there was normalization of hormones secretion within the first 12 months, all thispatients had prolactinoma tumors, 4 mores patients improved and normalized within the next sixmonths. The mean radiation dose directed to the tumor was 20 Gy. calculated dose to the adja-cent optic apparatus was less 8 Gy . after 36 months of follow up 6 patients, with prolactinomasless than 40 mm in diameter underwent an elevation from hormone levels. A new anterior pitu-itary deficiency developed in3 patientes (21%). Conclusions: surgical resection should remain theinitial primary treatment for the majority of patients with hormone productin pituitary adenomas.Nonetheless, radiosurgery provides biochemical remission for many patients with persistent orrecurrent hormone oversecretion syndromes caused by tumors size or location.

274

Page 277: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Gamma knife radiosurgery for secretory and non-secretory pituitary adenomas P2-54 Aditya, Gupta (1); Sandeep, Vaishya (1); S S, Kale (1); V S, Mehta (1) (1) All India Institute of Medical Sciences - Neurosurgery Department New Delhi, India

Gamma knife Radiosurgery is widely used for the treatment of a variety of brain lesions. In thisstudy we evaluated the efficacy of gamma knife Radiosurgery for primary and adjunctive treat-ment of pituitary adenomas, both hormonally secretory as well as non-secretory. 150 patientswith pituitary adenomas were treated starting 1997 May. Of these, 40 were treated primarily andthe rest (except one) had undergone surgical decompression prior to gamma knife. Non-function-ing adenomas constituted the largest group, with 60 patients. The secreting adenomas weretreated with a mean margin dose in the range of 27-35 Gy whereas the nonfunctional ones weregiven margin doses in the range of 10-12 Gy. RESULTS: In the Non-functional group, follow upwas available for 36 patients, of whom 19 had reduction or disappearance of tumor with thetumor remaining stable in the rest 17 patients. In the GH secreting tumors, the endocrine followup was available for 26 patients of which all had decline or normalization in levels except 2. Theradiologic follow up in this group was available for 14 patients, 9 of which showed a shrinkingor disappeared tumor. In the Prolactinoma group, endocrine follow up was available for 18patients of which 10 demonstrated significant decrease or normalization. Radiologic follow upwas available for 15 patients all of whom showed a decrease in size or disappearance. In theACTH group, follow up was available for 4 patients, 2 of which demonstrated both a decline inACTH levels as well as tumor size. The 2 remaining patients had a stable tumor size with highACTH levels. No significant side effects or radiation induced complications were seen in anypatient. CONCLUSIONS: gamma knife Radiosurgery provided safe and effective treatment for bothsecretory and non-secretory pituitary adenomas treated primarily or adjunctively.

The radiosurgery for nonfunctioning pituitary adenomas P2-55 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Katsunobu, Yoshioka (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan

Object: We evaluated the effectiveness of gamma knife radiosurgery in the treatment of nonfunc-tioning pituitary adenomas. Methods: We treated 34 patients with nonfunctioning pituitary ade-nomas between January 1994 and December 1999. Thirty-one of these patients were followedfor greater than 30 months. The mean age was 52.9 years. All patients underwent resection priorto radiosurgery. In four patients, treatment was performed with staged radiosurgery. The treat-ment volume was 0.7 to 36.2 cm3 (median 2.5 cm3). The treatment dose ranged from 8 to 20Gy (median 14.0 Gy) to the tumor margin. In 15 patients (48.4%), the tumor either compressedor was attached to the optic apparatus. The maximum dose to the optic apparatus was from 2 to11 Gy (median 8 Gy). Results: Patients were followed for 30 to 108 months (median 59.8months). The tumor size decreased in 18 patients (58.1%), remained unchanged in 9 patients(29.0%), and increased in four patients (12.9%). The 5-year actual tumor growth control rate was93%. Among patients with tumor growth, two cases were secondary to cyst formation. Twopatients (6.5%) required adrenal and thyroid hormonal replacement during the follow-up periodafter radiosurgery due to radiation-induced endocrinopathy. None of the patients suffered from

275

Page 278: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

new cranial nerve deficits, which included optic neuropathy. Conclusion: In this series, radio-surgery had a high tumor growth control rate during the long-term follow-up period.Furthermore, we observed a low morbidity rate with endocrinopathies and optic neuropathies.This low rate even included cases in which the tumor compressed or was attached to the opticapparatus. We emphasize the necessity of long-term follow-up to evaluate late complications.

LINAC stereotactic radiosurgery for pituitary adenomas P2-56 Martin, Malacek (1); Juraj, Steno (2); Ludmila, Trejbalova (3); Augustin, Durkovsky (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) Faculty Hospital of the ComeniusUniversity - Department of Neurosurgery; (3) Faculty Hospital of the Comenius University - Department ofEndocrinology; (4) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia

Material/methods: 54 patients underwent the LINAC radiosurgery (LRS) for pituitary adenoma(PA): 23 endocrine-inactive PA, 19 growth hormone secreting PA (GH-PA), 8 adrenotorticotropichormone secreting PA (ACTH-PA = 6 Cushing’s diseases, 2 Nelson’s syndromes) and 4 prolactin-omas during 12 years. In 17 cases with GH-PA we irradiated residual tumor (after pituitary sur-gery), 2 patients underwent primary radiosurgery, one of them without complete irradiation ofthe target volume. Thus only 18 cases with GH-PA are discussed. In other patients, we irradiat-ed residual tumor. The mean marginal dose was 17.8 (12–28) Gy, the irradiation of visual path-ways never exceeded 8 Gy. The mean follow-up was 62.3 months. During the clinical examina-tions, radiological changes of tumor, elevated hormone-response rate (RR), pituitary function andvision were observed. Results: The tumor growth was controled in 96.3% of patients. Threeworsenings of previously deteriorated vision and 5 deteriorations of postsurgically preserved pitu-itary function were found during the follow-up period. Complete GH-RR or a partial one with“safe” GH serum levels (under 2 ng/ml) were found in 38.9 % (7patients) and the partial GH-RRonly with “unsafe” GH serum levels (more than 2 ng/ml) in 61.1 % (11patients). One LRS had tobe repeated (finally with complete GH-RR). Only partial ACTH-RR has been achieved in all caseswith Cushing’s disease. Their overall follow-up was shortened due to two deaths. The prolactine-RR was also only partial. Conclusion: LRS is safe supplemental treatment of pituitary surgeries.The tumor growth control is good. 39.9 % of partial GH-RR with “safe” GH serum levels, 100%of partial ACTH-RR and prolactine-RR are less satisfactory. Some elevation of marginal dosescould improve our results.

Using a small diode detector for a quick quality assurance (QA) test of the Cyberknife system P2-57 Anthony K., Ho (1); Steven D., Chang (2); John R., Adler Jr. (3); Cristian, Cotrutz (4); Iris, Gibbs (5) (1) Stanford University - Radiation Oncology; (2) Stanford University - Neurosurgery; (3) Stanford University- Neurosurgery; (4) Stanford University - Radiation Oncology; (5) Stanford University - Radiation Oncology Stanford, USA

INTRODUCTION: Routine QA is done regularly for our Cyberknife System, using both thermolumi-nescence detectors (TLD) and Gafchromic films. Although both methods do a good job, it takes afew hours to perform the procedure. As a result, a faster method is needed for testing the wholesystem. METHODS: A small diode approximately 3 mm length and 3 mm diameter is used in thisstudy. A hole was drilled in a small tissue equivalent cube (6.35cm x 6.35cm x 6.35cm) to accom-

276

Page 279: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

modate the diode, and three fiducials were implanted in the cube for tracking purposes. A small5 mm collimator is used, and treatment planning is done with only 5 beams to deliver approxi-mately 100 cGy to the diode. RESULTS: Tests were first done to determine if this QA test is feasi-ble. 100 cGy was delivered to the approximate center of the diode. The block that housed thediode was then moved 1 mm from that center. The diode readings for those points 1 mm awayfrom the center were about 90% of the reading at the center. This indicates that it is possible touse the setup to determine the accuracy of delivery the dose to within about 1 mm. Since diodesensitivity decreases with cumulated dose, a jig is used to calibrate the diode every time this QAprocedure is done, with a 60 mm collimator. The readings using the mini phantom are normal-ized. CONCLUSIONS: The present study shows that this particular diode can detect system accu-racy to within 1 to 2 mm, and the QA procedure can be done in less than 10 minutes. This methodof using a small diode can be used for routine or quick check of the entire Cyberknife system. Thisone procedure checks treatment planning, the robot, imaging system, and dose delivery.

Influence of different inhomogeneities on the geometric distortion in stereotactic magnetic resonance imaging P2-58 Josef, Novotny Jr. (1); Josef, Vymazal (2); Pavel, Chuda (3); Dusan, Urgosik (4); Josef, Novotny (5); Roman,Liscak (6) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Stereotactic and radiation neuro-surgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neu-rosurgery; (5) Na Homolce Hospital - Medical physics; (6) Na Homolce Hospital - Stereotactic and radiationneurosurgery Prague, Czech Republic

Aim of this study was to evaluate influence of different inhomogeneities on the geometric imagedistortion in the stereotactic brain magnetic resonance imaging. Cylindrical perspex phantomsecured to the base of the Leksell stereotactic frame with special insert consisting of glass solidrods organised in a regular grid was used for the assessment of stereotactic MRI geometric accu-racy. Following inhomogeneities were studied as potential source of MRI stereotactic image geo-metric distortion: air, fat, bone, contrast agent, silver surgical clip, Yasargil surgical clip, ventricu-lar shunt and five different dental materials. The phantom was sequentially stereotactically inves-tigated according to normal imaging procedures done for patients. The images were transferredinto the treatment planning system and deviations between stereotactic coordinates based onMRI and real geometrical rod positions were evaluated for each study and further investigated asa function of presented inhomogeneity. Impact of inhomogeneities was studied in two ways: 1)entire stereotactic image geometric distortion (shift in fiducials) and 2) stereotactic image geomet-ric distortion in a volume of the immediate vicinity of the inhomogeneity location. Introducedinhomogeneities caused no additional distortion on the entire stereotactic MRI image and resultsfor these measurements reflected results performed with the phantom with no inhomogeneity(mean image distortion 0.2 mm). The influence on stereotactic image geometric distortion in avolume of the immediate vicinity of the inhomogeneity location was observed only for Yasargilclip and ventricular shunt. The image distortion was observed within about 15 mm distance fromthe inhomogeneity location in this case. No other studied inhomogeneities showed significanteffect on the image distortion.

277

Page 280: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Repositioning accuracy - evolution of a fractioned stereotactic system for the head and neck region P2-59John, Way (1); Margaret, Schneider (2); Robert Ian, Smee (2); Lyn, Emanuel (2); Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology; (2) University of New South Wales- Prince of Wales Hospital - Department of Radiation Oncology Shatin, Hong Kong

INTRODUCTION: Over three years more than twenty patients with head and neck lesions weretreated with a stereotactic IMRT technique. Accuracy and reproducibility in the set-up are para-mount. Analysis of the standard deviation of depth probe measurements was done during theevolution of the methods used to immobilise these patients. METHODS: All patients were set-upusing the HNL system [Radionics]. Initially the default Support frame assembly system was used.Some patients were uncomfortable with this system, so an alternative was devised. The Med-TecUni-frame system was used with the mask base supplied by Radionics. After a trial with standardmasks was done, thicker IMRT masks sometimes in combination with a mouthpiece (Precise Bite)were incorporated along with improved posterior support i.e. Accuform cushions or vac-bags.Changes to approaches used to immobilise patients warranted analysis. Standard deviation ofdepth probe measurements were calculated and displayed in graph form. RESULTS: By analysis ofthe standard deviation of depth probe measurements, changes to our methods of immobilisationresulted in more accurate repositioning. Results will be presented and discussed. This poster willcover some of limitations encountered with repositioning accuracy and the methods used to over-come these limitations. CONCLUSION: Radiation Therapists should strive to improve techniquesespecially where known limitations exist. Many past papers discuss these limitations. A combina-tion of methods is usually necessary due to the individual nature of each patient’s treatment.

Applications of polymer gel dosimetry in stereotactic radiosurgery P2-60 Panagiotis, Papagiannis (1); Pantelis, Karaiskos (2); Loukas, Sakelliou (1); Panagiotis, Sandilos (2); Michael,Torrens (3) (1) University of Athens - Physics; (2) Hygeia Hospital - Medical Physics; (3) Hygeia Hospital - Gamma KnifeNeurosurgery Department Athens, Greece

The advantages of the polymer gel – MRI method and particularly its ability to measure with highspatial resolution 3D dose distributions in a water equivalent material, make it ideal for SRS appli-cations. This work discusses the feasibility of adapting the method for tasks ranging from accept-ance testing to treatment plan verification and the calculation of correction factors in dosimetryusing conventional systems. Different polymer gel filled vials were accommodated in a in a cus-tom made head phantom and irradiated on a model 4C Leksell gamma knife® unit according toplans generated by the GammaPlan® software. These plans included single shot delivery at theunit center point (UCP) with each of the four collimators, a plan with multiple, different collima-tor shots resembling a highly conformal, single target treatment as well as a plan resembling thetreatment of four brain metastases with four 8 mm collimator shots using different prescriptionisodose lines and different prescription doses. Measurements were compared to correspondingGammaPlan® calculations in the form of relative dose profiles, planar distributions as well as 3Dplan evaluation criteria including the target volume DVH, target coverage and conformity indices.

278

Page 281: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

The comparison yielded agreement within experimental uncertainties which are also discussed.Relative dose distributions measured for the 4 mm and 8 mm collimators were averaged for grad-ually expanding cubic volumes centred at the UCP. This allowed for the calculation of appropri-ate volume averaging correction factors of conventional detectors used for output factor determi-nation of the available collimators. Preliminary results support the accuracy of gamma knife poly-mer gel dosimetry using two echo TSE MR sequences which achieve a 60-fold reduction in scantime relative to commonly used multi-echo CPMG sequences. Thus, results of this study combinedwith the availability of MR scanners in SRS departments support the introduction of the geldosimetry method in the clinical setting.

Radiosurgery for vertebral angioma. Steretactic body frame P2-61 Luis, Larrea (1); E, Lopez (1); J, Bea (1); M.C., Banos (1) (1) Hospital NISA Virgen del Consuelo - Oncologia Radioterapica Valencia, Spain

SBF Setup protocol Objectives: -High target doses -Treatment biologically aggressive -Accuratelocalization -Better inmovilisation -Better reproducibility -High levels of geometrical accuracy indose deliver CTV nearby or inside critical organs -Hypofractionated irradiation -Better biologicalresponse Treatment requirements: -Immovilitation -Reproducibility -3D coordinates system -3Dplanning sistem -Conformal beam delivery SBF characteristics Box -wood -Wooded bed (materi-al-rigid) -56*35*120 cm Thickness: very low attenuation Fiducials for CT Easy reproducibility (sta-tistical margin) Immovilisation devices -Diaphragmatic compressor -Vacuum pillow Marks forreposition -External and chest marks -Knee mark SBF Setup protocol Before each CT acquisitionsession: - Test of geometric and dosimetric parameters (isocenter scales and coordinate system,laser accuracy, CT numbers (HU) (Fig shows: Accuracy and reproducibility of Body Frame align-ment in CT unit, phantom repositioning in CT unit and also in Body Frame. Äz in CT unit is con-sidered as one-half CT-slice thickness.) Patient CT simulation and deviations may be know, wemake: -3 times CT scan in different days in one week -CTV*3 and surrounding tissues -Easyanatomical structures*3 PTV determination: GTV margins are determined as the addition of theincertitude of the following contributions: -Internal moving and breathing. -Repositioning ofpatient inside of BF -Repositioning of BF in the table unit -Incertainty evaluated from LINAC geo-metric parameters Incertainties are evaluated for each patient. GTV position and volume incert-tainties are considered. Breathing, patient repositioning and Body Frame alignment are also stud-ied. Treayement steps: 3D previous dosimetric planning (6 to 8 coplanar or non coplanar beams)On site verification of beams clearance Definitive 3D dosimetric calculation: - DVH in order toevaluate dose in CTV, PTV and risk structures, focusing in Y axis in order to stimate maximal spinaldose. - Exported DRR to i-view to estimate accuracy of isocenter Quality assurrance Periodic LINACchecks and specific test of geometrical and dosimetric parameters previous each treatment ses-sion Patient CT virtual simulation and deviations 3D planning On site verification for beams clear-ance Treatment delivery Find individual margins for PTV Standard beams DVH for tumour, PTVand critical organs Treatement protocol Spine-vertebra 12 Gy single dose SBF Clinical ExperienceHospital NISA Virgen del Consuelo. Valencia 5 patientes all with pain remision.

279

Page 282: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Dosimetric effect of intra-fraction motion during spinal radiosurgery P2-62Martin, J Murphy (1); Cihat, Ozhasoglu (2); Warren, Kilby (3); Derek, Olender (3);(1) Virginia Commonwealth University, Richmond VA; (2) University of Pittsburgh PA; (3) AccurayIncorporated, Sunnyvale CARichmond, USA

PURPOSE: Intra-fraction organ motion causes uncertainty in the delivery of all external beam radi-ation treatments. Radiosurgery has traditionally minimized motion with rigid fixation devices butskeletally-fixated stereotactic frames developed for spinal radiosurgery have not been widelyused. Instead the patient is usually restrained using combinations of head mask or frame, cervi-cal spine collar, and vacuum-formed body cast, depending on the target location. These devicesallow for potentially significant intra-fraction movement, which introduces to radiosurgery theissue of planning with a motion margin.In image-guided robotic radiosurgery the beam alignment is adjusted repeatedly during treat-ment to minimize the effect of intra-fraction movement. However, there is a residual uncertaintyfrom target motion occurring between corrections. This study has evaluated observed patterns ofmovement during spine radiosurgery and used these data to assess the dosimetric impact ofmotion on treatment delivery both with and without periodic motion correction.METHOD: The intra-fraction imaging records of 35+ image-guided spinal radiosurgery treat-ments were reviewed. The distributions of position changes were calculated for all six translation-al and rotational degrees of freedom. Statistical analysis was used to compare the offset distri-butions along each axis, and also the impact of intra-fraction motion correction. Records wereevaluated individually to determine the frequency of systematic offsets among the population(defined as a mean translational offset ≥ ±1 mm in at least one axis). Sample treatment planswere recalculated with each group of beams moved relative to the patient by an amount sam-pled from the observed offset distributions, both with and without motion correction. The dosi-metric effects of random, and combined random and systematic offsets, were evaluated. Theresulting treatment plans were compared in terms of target volume and spinal cord DVHs.RESULTS: The population offset data shows intra-fraction motion in all axes of translation androtation. The most significant translational motion was left-right and the most significant rotationwas about the superior-inferior axis. The effect of motion correction was to significantly (p<0.01)reduce the observed offsets for all six degrees of freedom. The mean radial translation wasreduced by a factor of approximately 2. Systematic offsets were detected in approximately 20%of cases without motion correction, reducing to zero when motion correction was applied. Thetreatment plan results show that the primary effect of uncorrected random intra-fraction motionis to reduce coverage of the target volume by the prescription isodose. This effect was significant-ly reduced when motion correction was applied. Uncorrected systematic motion was shown toalso potentially increase the dose delivered to the spinal cord. The magnitude of these effectsdepends upon the treatment geometry and the relative direction of motion.CONCLUSIONS: Intra-fraction motion correction removes systematic targeting offsets and reducesrandom offsets. Therefore, assuming equivalent patient immobilization and pre-treatment align-ment, image-guided robotic spinal radiosurgery can improve upon the targeting accuracy achiev-able with other techniques that do not correct for intra-fraction motion. The treatment plan resultsdemonstrate that this increased accuracy improves target volume coverage in all cases and

280

Page 283: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

reduces risk of spinal cord overdose in some cases. This study suggests that motion correctioncan reduce the required safety margin by approximately a factor of 3.

Implementation of helical tomotherapy for spinal radiosurgery P2-63 John, Fiveash (1); Richard, Popple (2); Jennifer, De Los Santos (2); James, Markert (3); Barton L., Guthrie (4);Chris, Dobelbower (2) (1) University of Alabama at Birmingham - Radiation Oncology; (2) University of Alabama at Birmingham -Radiation Oncology; (3) University of Alabama at Birmingham - Department of Neurosurgery Birmingham, USA

Purpose: To evaluate helical tomotherapy for single fraction spinal radiotherapy (radiosurgery).Materials and Methods: Treatment plans from four clinical cases of primary or metastaticparaspinal tumors were generated utilizing two different inverse treatment planning and deliverysystems: Eclipse/Helios with Varian 120-MLC (Varian Medical Systems, dMLC) and TomotherapyHi-Art2 (TOMO). Varian dMLC plans were developed using a standard, clinically proven techniquecomprised of seven posterior axial beams spaced 20 degrees apart. Tomotherapy Hi-Art2 helicaltomotherapy plans were generated utilizing a 1 cm beam width. The plans were normalized suchthat the prescription point received the same dose as the clinical plans. Optimization planninggoals were maximal spinal cord sparing in the high dose region and maximum dose less than140%. Plans that were not acceptable due to another organ at risk were rejected. The feasibilityof megavoltage CT imaging for determination of intrafraction motion was studied in a clinicaltomotherapy patient. Results: Dose heterogeneity was slightly better in the TOMO plans with amean maximum PTV dose of 133.6% vs 139.9% with dMLC. TOMO also produced plans with alower volume of spinal cord receiving the higher doses of RT. The average dMLC plan produceda 33% higher dose to 0.5 cc of spinal cord than TOMO. Pre and post treatment CT scans werefused without difficulty on the clinical TOMO console to determine intrafraction motion includingtranslation and rotation. Conclusions: The Tomotherapy Hi-Art system contains all the essentialelements for spinal radiosurgery: dose conformality, accurate image guidance for initial targetlocalization, and the ability to determine intrafraction motion, although not in real-time. Our pre-clinical studies suggest that there may be a dosimetric advantage for helical tomotherapy overother MLC delivery systems in some selected cases depending upon how plan quality is meas-ured. An ongoing clinical trial will determine intrafraction motion and then study the efficacy andtoxicity of single fraction radiosurgery in patients with paraspinal tumors.

Spinal radiosurgery: the consequences of “segmental image fusion technique” and its clinical experiences P2-64 Moon-Jun, Sohn (1); Dong-Joon, Lee (1); Yoon-Joon, Hwang (2); Sang-Ryong, Jeon (3); Ho-Yeon, Lee (4);Sang-Ho, Lee (5); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery; (2) Inje University Ilsan Paik Hospital -Department of Neuroradiology; (3) Asan Medical Center, College of Medicine, University of Ulsan -Department of Neurosurgery; (4) Wooridul General Hospital - Department of Neurosurgery Goyang, Korea

To investigate the optimum coordination method of image discrepancy affected by changes inbody position for image fusion and clinical results in spinal radiosurgery. Twenty patients withspinal tumors underwent image-guided spinal stereotactic radiosurgery and their clinical results

281

Page 284: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

were evaluated. To optimize the coordination of different diagnostic image sets, the segmentalimage fusion method was used. Thin multi- sliced MR images were obtained from the segmentsof interest in a perpendicular angle without spacing. Then, multiple segmented MR images werecorrelated onto the CT images integrated with stereotactic localizer by defining the objects asanatomical landmarks. The consequence of image fusion was evaluated by using volumetricmeasurements of targets on each image modality and by analyzing optimal dose planning andproper image fusion. : Differences of gross tumor volume (GTV) between CT and MR based plan-ning compared with GTV of CT-MR image fusion were 30.5 + 4.8 % and 14.5 + 3.3 %, respec-tively. Measured value of GTV in CT-MRI image fusion was 14.06 cm3 and GTV of CT versus MRbased planning was 11.64 cm3 vs. 11.72 cm3, respectively. Positional discrepancy of two imagesets was minimized with this segmental image fusion method. Mean tumor volume and pre-scribed dose of benign and metastatic spinal tumors were 3.54 cm3 vs. 24.47 cm3 and 17.6Gyvs. 26.4 Gy at 80% isodose line in 1.6 vs. 2.9 fractions, respectively. The pain was remarkablyreduced within two weeks. Most of the tumors were stable or reduced in their volume during fol-low-up period. : Image fusion was successfully performed using segmental fusion technique.Segmental image fusion method provides better identification of spinal structures and significantimprovement on precise radiosurgical treatment planning.

Non-invasive radiological evaluation of superior cerebellar artery after gamma knife radiosurgery for idiopathic trigeminal neuralgia: preliminary results of a cohort study P2-65 José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel, Devriendt (4); Françoise, Desmedt (1);Paul, Van Houtte (4); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme -Neurochirurgie; (4) Institut J. Bordet - Radiothérapie Brussels, Belgium

Objective: To study non-invasive radiological changes on Superior Cerebellar Artery (SCA) aftergamma knife radiosurgery on patients suffering Idiopathic trigeminal Neuralgia (ITN) using a dis-tal targeting treatment protocol. Material and Methods: A measure of the maximal dose receivedby SCA was performed studying the treatment planning for all patients treated radiosurgically forITN. In those patients with a dose received by the SCA was 10 Gy or more, a prospective cohortstudy was designed. This study considers high resolution MRI, including T1, T1 Gad, T2 , Protondensity, and 3D TONE based angio MRI sequences. The end points were the existence of anyinfarction in the SCA territory or any obstruction or stenosis of the SCA. Results: 16 patients havebeen included in this study. Mean dose received by the SCA was 57.5 Gy. (15 – 87 Gy.) And themean radiological follow up was 25 months, (12 – 42 months). Until now, no patient in the studyhave presented radiological changes, neither in the permeability of the SCA, nor in the cerebellarparenchyma. Conclusions: SCA can receive a high dose of radiation after a radiosurgical treatmentof ITN, and although this study hasn’t shown any vascular change at this level, it could be prudentto keep in mind a potential complication and to consider, perhaps, the SCA as one structure at risk.

282

Page 285: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

Stereotactic radiosurgery for trigeminal neuralgia using a non-dedicated linear accelerator P2-66 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA

Introduction: The authors evaluate the efficacy and safety associated with the use of StereotacticRadiosurgery for trigeminal neuralgia (TN) with a non-dedicated linear accelerator Methods:Between March 2003 and March 2005, 10 patients were treated with a non-dedicated linearaccelerator for trigeminal neuralgia. The median age was 55.1 y.o. (range 48-73 years). Allpatients had essential TN. Five patients had undergone previous surgical procedures. In one ofthem, five radiofrequency procedures were performed. Radiation doses were 80 Gy in 4 casesand 90 Gy in the other six patients. A 4-mm collimator was used in all treatments. A isodosescurve of 50% was used focusing the treatment on the entry zone. Results: Initial results showedpain relief in all cases. Pain relief was experienced at an average of 1.14 months (range 15 daysto 4 months) after the procedure. The mean follow-up period was 14 months (range 4 to 24months). At the last follow-up, 9 patients had sustained significant pain relief. Six patients werepain free without medication and three patients had a significant reduction in pain with lowdoses of medication. One patient had persistent pain. This patient had a concurrent facial hemis-pasm. No patient experienced new numbness post-radiosurgery or other complications.Conclusions: Stereotactic Radiosuregery using a non-dedicated linear accelerator is a safe, effec-tive and precise treatment for TN

The complication rates after gamma knife radiosurgery for facial pain are predicted by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures P2-67 Thomas, Ellis (1); Volker W., Stieber (2); Stephen, Tatter (1); Alan, deGuzman (2); Kenneth, Ekstrand (2);Michael, Munley (2); Daniel, Bourland (2); Kevin, McMullen (2); William, Huang (2); Lovato, James (3);Christopher, Balamucki (4); Charles, Branch (1); Edward G., Shaw (2) (1) Wake Forest University School of Medicine - Department of Neurosurgery; (2) Wake Forest UniversitySchool of Medicine - Department of Radiation Oncology; (3) Wake Forest University School of Medicine -Public Health Sciences; (4) Wake Forest University - School of Medicine Winston Salem, USA

Introduction: Facial pain is a spectrum of conditions of varying clinical behavior. Burchiel has sug-gested a pain classification scheme (BPC) for seven different types of facial pain. We analyzed thecomplication rates of 256 gamma knife radiosurgery procedures for facial pain based on their pre-treatment BPC. Clinical Material and Methods: Between 09/99 and 03/04, 326 GKRS proceduresfor patients with facial pain were performed. Typically the 50% isodose line was placed tangen-tial to the brainstem, with the shot isocenter targeted at the proximal trigeminal nerve root. Theradiation dose was prescribed at the 100% isodose line. Patients self reported pain control datavia a detailed questionnaire. Results: 6/7 types of BPC were represented (no patients had deaf-ferentation pain). 240 patients were treated with one 4 mm isocenter. 49%, 20%, and 25%,received 90 Gy, 85 Gy, or 80 Gy, respectively. Dose was prescribed at the 100 % isodose line.Patients with typical TN aka Type 1 experienced the lowest incidence of complications: 38%

283

Page 286: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Poster Abstracts

described facial numbness, 20% described tingling or prickling, and 4% described a burning sen-sation after treatment. Among patients with TN Type 2, 41%, 20%, and 19%, experienced theabove post-treatment symptoms, respectively. Among patients with somatoform pain disorder,35%, 40%, and 10%, experienced the above post-treatment symptoms, respectively. Amongpatients with multiple sclerosis, 38%, 25%, and 13%, experienced the above post-treatmentsymptoms, respectively. Among patients with neuropathic pain, 38%, 13%, and 24%, experi-enced the above post-treatment symptoms, respectively. The worst outcome was seen with pos-therpetic neuralgia patients, of whom 67%, 17% and 50%, experienced the above post-treat-ment symptoms, respectively. Conclusion: This study demonstrates that the pre-treatment BPCpredicts for post-GKRS complications. This allows the clinician to assess the risk-benefit ratio foreach sub-classification of facial pain.

The success of gamma knife radiosurgery for facial pain varies by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures for trigeminal neuralgia P2-68 Volker W., Stieber (1); Thomas, Ellis (2); Alan, deGuzman (1); Edward G., Shaw (1); Charles, Branch (2); Daniel,Bourland (1); Kevin, McMullen (1); Christopher, Balamucki (3); Michael, Munley (1); Kenneth, Ekstrand (1);Lovato, James (4); William, Huang (1); Stephen, Tatter (2) (1) Wake Forest University School of Medicine - Department of Radiation Oncology; (2) Wake ForestUniversity School of Medicine - Department of Neurosurgery; (3) Wake Forest University - School of Medicine;(4) Wake Forest University School of Medicine - Public Health Sciences Winston Salem, USA

Introduction: Facial pain is a spectrum of conditions of varying clinical behavior. Burchiel has sug-gested a pain classification scheme (BPC) for seven different types of facial pain. We analyzed theoutcomes of 256 gamma knife radiosurgery procedures for facial pain based on their pretreat-ment BPC. Clinical Material and Methods: Between 09/99 and 03/04, 326 GKRS procedures forpatients with facial pain were performed. Typically the 50% isodose line was placed tangentialto the brainstem, with the shot isocenter targeted at the proximal trigeminal nerve root. The radi-ation dose was prescribed at the 100% isodose line. Patients self reported pain control data viaa detailed questionnaire. Results: 6/7 types of BPC were represented (no patients had trigeminaldeafferentation pain). 240 patients were treated with one 4 mm isocenter. 49 %, 20 %, and 25%,received 90 Gy, 85 Gy, or 80 Gy, respectively. Dose was prescribed at the 100 % isodose line.Independently of prescription dose, a significant association between the type of facial pain andthe pain control rate after GKRS was observed in the study (Pearson; p<0.001). Patients with typical TN aka Type 1 (n=172) experienced the best results from GKRS: 90 % had pain relief, 80% reported improved quality of life, median time to improvement was 4 weeks, and pain recurredin only 19 % with a median pain-free interval of 1.25 years. The worst outcome was seen withpostherpetic neuralgia (n=6), with no patients experiencing pain relief or an improvement in theirquality of life. Conclusion: This study demonstrates that Burchiel classification of the facial painaffects facial pain outcome post-GKRS, allowing for proper patient selection, especially of “atypi-cal” facial pain types.

284

Page 287: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Sponsored Sessions Abstracts

LUNCH SEMINAR BRAINLAB 12/09/05

NOVALIS FOR FUNCTIONAL NEUROSURGERY Room NationChairman: Antonio AF, De Salles

Novalis for functional neurosurgery Antonio AF De Salles, MD, PhD; Alessandra Gorgulho, MD; Paul Medin, PhD; Nzhyde Agazarian, PhD; TimothySolberg, Ph.D.; Michael Selch, MDUCLA - Departments of Neurosurgery and Radiation Oncology, Los Angeles, USA

INTRODUCTION: Functional changes in the central nervous system (CNS) are possible via destruc-tion of pathways, nuclei or modification of cellular function. Precise, fast and homogeneous dosedelivery becomes important in modern Functional Radiosurgery.METHODS: From December 1997 to April 2005 several approaches to Functional Radiosurgerywere tested using the Novalis. Animal experimentation conducted for Parkinson’s disease,Epilepsy and Chronic Pain supported the clinical use of Novalis in Trigeminal Neuralgia (176patients), Cluster Headache (4 patients), Essential Tremor (3 patients), Chronic Pain (3 patients)and Epilepsy (5 patients). Homogeneous plans using the shaped-beam technique were devel-oped to completely envelope mesial temporal structures related to Temporal Lobe Epilepsy. RESULTS: Modification of cell function was observed electrophysiologically and histologically inanimal models for epilepsy and Parkinson’s disease. Obliteration of pathways and nuclei wereobserved when targeting the spinal dorsal root ganglion, the root entry zone of the trigeminalnerve, the thalamus, and the subthalamic nucleus. Functional changes related to pain improve-ment were observed in patients with cluster headache by observing symptomatic relief.Homogeneous plans to the level of 10% from the center to the periphery were observed in plan-ning for mesial temporal lobe structure modification.CONCLUSIONS:This experience shows that the Novalis technology is precise and capable of deliv-ering high doses (150Gy) for tissue ablation, as well as low doses (15 Gy) tightly, conformally,and homogeneously for functional modification without radiation necrosis.

LUNCH SEMINAR MEDTRONIC 14/09/05

THE COMPLEMENTARY ROLE OF INTRA OPERATIVE MRI AND RADIOSURGERY Room NationChairman: Jacques, Brotchi

ULB Erasme experience of treating patients with PoleStar and gamma knife Prof. J. BrotchiDept. of Neurosurgery, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium

Image-guided neurosurgery has gained broad acceptance as this technology has defined newstandards for minimally invasive procedures. However, accuracy issues still hamper success for

285

Page 288: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

Sponsored Sessions Abstracts

complex brain tumor resection interventions. The main confounding factor is due to anatomicaldeformations during the course of the surgery resulting from CSF leakage and retraction and abla-tion of tissue. As part of a phase 1 study on the integration of preoperative images used for navigation withiMRI controls, we have coupled the current PoleStar hardware with the addition of aStealthStation (Medtronic SNT, Boulder, Co) computer. The current PoleStar software interface isused for all scanning functions, while the StealthStation application is used to load preoperativeimages and merge them with the intra-operative images. Since June 2004, we have applied thisprotocol to 20 patients, aiming at the development of an image processing scheme for robust andaccurate registration between the image modalities. These cases demonstrate the benefits of theintegration of low field intra-operative imaging system with pre-operative imaging within thecontext of neuronavigation and its potential role as an adjunct for combined therapy with partialtumor removal followed by radiosurgery.

Complementary use of intra operative MRI technique and radiosurgeryDr. M. SchulderNew Jersey Medical School, Department of Neurosurgery, Newark NJ, USA

Introduction. Surgery and stereotactic radiosurgery (SRS) are often presented as mutually exclu-sive options for patients with intracranial tumors. However, many patients may be best served bya planned strategy of subtotal resection followed by planned adjuvant SRS. Intraoperative MRI(iMRI) may be used to ensure that in such cases the surgical goals have been reached – i.e. thatthe residual lesion is small enough for safe and effective SRS.Methods. In 20 twenty patients, iMRI-guided resection and adjuvant SRS was planned.Diagnoses included meningioma in 11 patients (9 skull base, 2 parasagittal), pituitary adenomain 6, schwannoma in 2, and craniopharyngioma in 1. IMRI was acquired with the PoleStar sys-tem (Odin/Medtronic Surgical Navigation Systems, Louisville CO, USA). Images were obtainedbefore surgery and when the surgical goals were though to be achieved. Surgical planning wasdone with the integrated infrared surgical navigation tool.Results. A complete resection was done in 3 patients. IMRI led to additional resection in 6patients, while in another 7 unnecessary dissection was avoided when images showed that thesurgical goals had been reached. In 13 patients, a suitable target for SRS remained after surgery. Five patients underwent SRS while8 chose observation and followup imaging. Progression was seen in only one patient who provedto have a malignant meningioma. Stereotactic radiation therapy was used to treat 2 patients and3D conformal RT for the remaining 2 patients.Conclusions. Images acquired with iMRI had an impact on 13/20 patients in whom the preoper-ative surgical plan was subtotal resection plus adjuvant SRS. In such patients, a complete surgi-cal resection remains ideal and should be pursued if safely possible. The appropriate timing ofSRS after subtotal resection is still uncertain, and observation remains an option for patients withbenign tumors.

286

Page 289: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen

The scientific committee, the local organising committee, the officers andthe board members of the ISRS 2005 congress wish to kindly acknowledge

the following companies for their confidence, their precious support and their active collaboration (listed by alphabetical order).

ISRS 2005 Major Sponsors and ExhibitorsBrainLAB

Elekta

Sponsors and ExhibitorsAccuray

American RadiosurgeryDixi medical / BioScanIBA Particle Therapy

Medtronic3D Line Medical Systems s.r.l.

ExhibitorsAlcis & Neuropace

Carl Zeiss Surgical GmBHFoundation Against Cancer, Belgium

inomed Medizintechnik GmBHMedical Intelligence

Nomos Radiation Oncology - A Division of North American ScientificOrfit Industries NV

PhilipsPTGR-GmbH

Radionics, a Division of Tyco Healthcare Belgium N.V.Siemens

TomoTherapy IncorporatedVarian Medical Systems

ContributorsCodali-GuerbetGE Healthcare

PfizerS. Karger AG

NV Schering SA

Academic SponsorsBelgacom

Bruxelles CapitaleCommunauté Française

FNRS

Additional thanks from the Local Organization Committeeto the Magritte Foundation and Brussels International.

Sponsors and ExhibitorsAcknowledgements

Page 290: FINAL PROGRAM AND BOOK OF ABSTRACTS€¦ · Concert of Toots Thielemans OS24 - Permeke/Rembrandt Spine OS17 - Permeke/Rembrandt Imaging Arteriovenous Malformations OS18 - Willumsen