STEREOTACTIC BODY RADIATION STEREOTACTIC BODY RADIATION THERAPYTHERAPY

Presented at the Presented at the Annual Meeting of the Annual Meeting of the

American College of Medical Physics American College of Medical Physics in Orlando, Florida, May 24, 2005in Orlando, Florida, May 24, 2005

STEREOTACTIC BODY STEREOTACTIC BODY RADIATION THERAPY(SBRTRADIATION THERAPY(SBRT))

Part 1: Part 1: Overview of SBRT Overview of SBRT (S.H. Benedict, Virginia Commonwealth University)(S.H. Benedict, Virginia Commonwealth University)• AAPM Task Group 101: SBRTAAPM Task Group 101: SBRT• ASTRO GuidelinesASTRO Guidelines

Part 2: Part 2: Treatments of the spine with SBRT Treatments of the spine with SBRT (Paul Medin, Ph.D., UCLA)(Paul Medin, Ph.D., UCLA)

Part 3: Part 3: SBRT in the “Conventional” Clinical SettingSBRT in the “Conventional” Clinical SettingBill Hinson, PhD, Wake Forest UniversityBill Hinson, PhD, Wake Forest University

Part 4:Part 4: KV and MV imaging in SBRTKV and MV imaging in SBRTMichael lovelock, PhD, MSKCCMichael lovelock, PhD, MSKCC

EXTRACRANIAL STEREOTACTICEXTRACRANIAL STEREOTACTICRADIOSURGERY – What’s in a RADIOSURGERY – What’s in a

name?name? ESRT is the use of external beams to treat lesions of the body ESRT is the use of external beams to treat lesions of the body

with “surgical” doses and high precision tumor identification with “surgical” doses and high precision tumor identification and relocalization employing “stereotactic” image guidance or and relocalization employing “stereotactic” image guidance or implanted fiducials.implanted fiducials.

Extracranial stereotactic …. Extracranial stereotactic ….

Radioablation / Radiosurgery / RadiotherapyRadioablation / Radiosurgery / Radiotherapy

Surgery vs. Ablation vs. Therapy vs. …Surgery vs. Ablation vs. Therapy vs. …

According to the chief CPT code developer it will be called:According to the chief CPT code developer it will be called:

Stereotactic Body RadiotherapyStereotactic Body Radiotherapy

SBRT REQUIRES:SBRT REQUIRES:

Higher confidence in tumor targeting Higher confidence in tumor targeting

Reliable mechanisms for generating focused, sharply Reliable mechanisms for generating focused, sharply delineated dose distributionsdelineated dose distributions

Reliable accurate patient positioning accounting Reliable accurate patient positioning accounting for target motion related to time dependent for target motion related to time dependent organ movementorgan movement

SBRT: why try it?SBRT: why try it?

Highly efficient and extremely potent form of Highly efficient and extremely potent form of radiation treatment applicable to a wide variety of radiation treatment applicable to a wide variety of tumor typestumor types

Safe and effective for patients with medically Safe and effective for patients with medically inoperable primary lung cancerinoperable primary lung cancer Timmerman R, et al. Timmerman R, et al. ChestChest, 2003., 2003.

Ongoing investigations for patients with primary Ongoing investigations for patients with primary liver cancer (hepatocellular carcinoma)liver cancer (hepatocellular carcinoma) Extremely common type of cancer worldwideExtremely common type of cancer worldwide These patients are often unfit for surgeryThese patients are often unfit for surgery

Non-invasive alternative to surgery, RFA, or Non-invasive alternative to surgery, RFA, or cryosurgery for selected patients with cryosurgery for selected patients with “oligometastases”“oligometastases” Especially relevant in era of improving systemic “targeted therapy”Especially relevant in era of improving systemic “targeted therapy”

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

SBRT: what is it?SBRT: what is it?

StereotacticallyStereotactically localized, ultra-high- localized, ultra-high-dose radiotherapy delivered to discrete dose radiotherapy delivered to discrete tumor nodules in the lung, liver, and tumor nodules in the lung, liver, and other extracranial locations in a other extracranial locations in a hypofractionatedhypofractionated regimen (typically 1-5 regimen (typically 1-5 treatments)treatments)

The goal is complete cancer cell kill The goal is complete cancer cell kill within the treated volumewithin the treated volume

Beginning in January, 2005, SBRT will be Beginning in January, 2005, SBRT will be a category III CPT code for billing a category III CPT code for billing purposespurposes

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

SBRT: who started it?SBRT: who started it?

Answer: Blomgren and Lax, Karolinska Institute, Stockholm, Sweden

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

SBRT: who started it?SBRT: who started it?

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

Conventional vs SBRTConventional vs SBRT

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

Linear Accelerators with Linear Accelerators with features especially suitable features especially suitable

for SBRTfor SBRT

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

SBRT : SBRT : Immobilization/RepositioniImmobilization/Repositioni

ngng

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

SBRT: how much is SBRT: how much is enough?enough?

Fowler JF, Tome WA, Welsh JS. Estimation of the Required Doses in Stereotactic Body Radiation Therapy. In Stereotactic Body Radiation Therapy, Kavanagh BD and Timmerman RD, eds. Lippincott Williams & Wilkins, 2005.

* Slide courtesy of Brian Kavanagh / * Slide courtesy of Brian Kavanagh / University of ColoradoUniversity of Colorado

Fowler JF, Tome WA, Welsh JS. Estimation of the Required Doses in Stereotactic Body Radiation Therapy. In Stereotactic Body Radiation Therapy, Kavanagh BD and Timmerman RD, eds. Lippincott Williams & Wilkins, 2005.

* Slide courtesy of Brian Kavanagh / University of Colorado* Slide courtesy of Brian Kavanagh / University of Colorado

AAPM Task Group 101:AAPM Task Group 101:Stereotactic Body Radiation Stereotactic Body Radiation

TherapyTherapy The AAPM RTC approved the following charges of the task group:The AAPM RTC approved the following charges of the task group:

Charge (1): To review the literature and identify the range of historical Charge (1): To review the literature and identify the range of historical experiences, reported clinical findings and expected outcomesexperiences, reported clinical findings and expected outcomes

Charge (2): To review the relevant commercial products and associated Charge (2): To review the relevant commercial products and associated clinical findings for an assessment of system capabilities, technology clinical findings for an assessment of system capabilities, technology limitations, and patient related expectations and outcomes. limitations, and patient related expectations and outcomes.

Charge (3): Determine required criteria for setting-up and establishing an Charge (3): Determine required criteria for setting-up and establishing an ESRT facility, including protocols, equipment, resources, and QA ESRT facility, including protocols, equipment, resources, and QA procedures.procedures.

Charge (4): Develop consistent documentation for prescribing, reporting, Charge (4): Develop consistent documentation for prescribing, reporting, and recording ESRT treatment delivery.and recording ESRT treatment delivery.

AAPM TG 101: SBRT - Table of AAPM TG 101: SBRT - Table of Contents:Contents:

1. 1. . Clinical Rationale for SBRT . Clinical Rationale for SBRT

2. Review of Clinical History and Current Use of SBRT (Volker Steiber)2. Review of Clinical History and Current Use of SBRT (Volker Steiber)

3. Patient Immobilization, Relocalization, and Verification 3. Patient Immobilization, Relocalization, and Verification

4a. Treatment Planning and Dosimetry 4a. Treatment Planning and Dosimetry

4b. Treatment plan evaluation and dose reporting 4b. Treatment plan evaluation and dose reporting

5. Dosimetry 5. Dosimetry

6. SBRT Treatment Delivery Technology 6. SBRT Treatment Delivery Technology

7. Clinical Implementation of SBRT7. Clinical Implementation of SBRT

8. Future directions8. Future directions

RADIATION THERAPY ONCOLOGY GROUP (RTOG) RADIATION THERAPY ONCOLOGY GROUP (RTOG) 0236:0236:A Phase II Trial of Stereotactic Body Radiation Therapy A Phase II Trial of Stereotactic Body Radiation Therapy (SBRT) in the Treatment of Patients with Medically (SBRT) in the Treatment of Patients with Medically Inoperable Stage I/II Non-Small Cell Lung CancerInoperable Stage I/II Non-Small Cell Lung Cancer

PI: Robert Timmerman, MDPI: Robert Timmerman, MD EligilibityEligilibity

Patients with T1, T2 (≤ 5 cm), T3 (≤ 5 cm), Patients with T1, T2 (≤ 5 cm), T3 (≤ 5 cm), N0, M0 medically inoperable non-small cell N0, M0 medically inoperable non-small cell lung cancer;lung cancer;

Patients with T3 tumors chest wall primary Patients with T3 tumors chest wall primary tumors onlytumors only

No patients with tumors of any T-stage in No patients with tumors of any T-stage in the zone of the proximal bronchial treethe zone of the proximal bronchial tree*. *.

SBRT dose: 20 Gy x 3 fractionsSBRT dose: 20 Gy x 3 fractions

RADIATION THERAPY ONCOLOGY GROUP (RTOG) RADIATION THERAPY ONCOLOGY GROUP (RTOG) 0236:0236:Dosimetry specificationsDosimetry specifications

““Zone of the proximal Zone of the proximal bronchial tree” (figure)bronchial tree” (figure)

Target dose Target dose homogeneity limitshomogeneity limits

Dose “isotropicity” Dose “isotropicity” limitation requiring limitation requiring falloff of approx 50% falloff of approx 50% within 2 cm of PTVwithin 2 cm of PTV

V20 < 10%V20 < 10% Spinal cord, heart, Spinal cord, heart,

esophagus, etc. limitsesophagus, etc. limits

SBRT PHYSICS AND SBRT PHYSICS AND TECHNOLOGYTECHNOLOGY

1. CT simulation1. CT simulation: : Assess tumor motionAssess tumor motion

2. Immobilization2. Immobilization: : Minimize motion, breathing effects Minimize motion, breathing effects

3. Planning3. Planning: : Small field dosimetry considerationsSmall field dosimetry considerations

4. Repositioning4. Repositioning: : High precision High precision patientpatient set-up: set-up: Fiducial systems, IR/LED Active and Passive markers, US, Video Fiducial systems, IR/LED Active and Passive markers, US, Video

5. Relocalization5. Relocalization: : Identify Identify tumortumor location in the treatment field: location in the treatment field: * MV/ KV Xray, Implanted markers and/or set-up fiducials* MV/ KV Xray, Implanted markers and/or set-up fiducials* Motion tracking and gating systems* Motion tracking and gating systems* Real-time tumor tracking systems with implanted markers* Real-time tumor tracking systems with implanted markers

6. Treatment delivery techniques6. Treatment delivery techniques Adapted conventional systemsAdapted conventional systems Specialized SRT: Novalis, Cyberknife, TrilogySpecialized SRT: Novalis, Cyberknife, Trilogy

Clinical Implementation of Clinical Implementation of ESRT – ESRT –

““These techniques are unusual in These techniques are unusual in the high technology realm of the high technology realm of radiation treatment in that they radiation treatment in that they require more specialized require more specialized training training of physicians and physicists rather of physicians and physicists rather than specialized than specialized equipmentequipment.” .”

* Timmerman et al, * Timmerman et al, Technology in Technology in Cancer Research and TreatmentCancer Research and Treatment – – 20032003

SUMMARY: Technical elements of QASUMMARY: Technical elements of QA

The physicist should be responsible for all The physicist should be responsible for all technical QA procedures: technical QA procedures:

• • Imaging equipment Imaging equipment • • Localization and simulation equipmentLocalization and simulation equipment• • Treatment planning and evaluation systemTreatment planning and evaluation system• • Treatment delivery equipmentTreatment delivery equipment• • Treatment verification equipmentTreatment verification equipment

SUMMARY: Clinical elements of SBRT SUMMARY: Clinical elements of SBRT

QAQA A physician A physician andand physicist should carry out all clinical QA physicist should carry out all clinical QA

procedures:procedures:

• • Consistent target volume and organs–at–risk delineation Consistent target volume and organs–at–risk delineation • • Quantitative assessment of target and organ motion during Quantitative assessment of target and organ motion during

imaging and treatmentimaging and treatment • • Quantitative assessment of setup variation during imaging Quantitative assessment of setup variation during imaging

and treatmentand treatment • • Patient–specific QAPatient–specific QA

NEED TO ESTABLISH TERMINOLOGY NEED TO ESTABLISH TERMINOLOGY AND REPORTING CONVENTIONSAND REPORTING CONVENTIONS Prescription considerations: GTV, margins, dose Prescription considerations: GTV, margins, dose

inhomogeneity/uniformity inhomogeneity/uniformity Biological evaluations: EUD, NTCP, etcBiological evaluations: EUD, NTCP, etc Dose and Fractionation strategy: (1 to 5 fractions, QOD, Dose and Fractionation strategy: (1 to 5 fractions, QOD,

QD, etc) QD, etc) next