I Individualized Dosimetry with gamma camera planar images

131I Individualized Dosimetry with gamma planar images

Dra. RAQUEL BARQUERO SANZHOSPITAL CLINICO UNIVERSITARIO VALLADOLID

SACYL

JORNADA CIENTIFICA HOSPITAL PUERTA DE HIERRO 6 JUNIO 2016

Individualized Dosimetry with gamma camera

imagesDra. RAQUEL BARQUERO SANZ

HOSPITAL CLINICO UNIVERSITARIO VALLADOLIDSACYL


WHY INDIVIDUALIZED

DOSIMETRY?DOSIMETRY?Recent literature reviews show

correlations between absorbed dose and tumor response as well as normal

tissue toxicity


WHY INDIVIDUALIZED

DOSIMETRY?DOSIMETRY?Recent literature reviews show

correlations between absorbed dose and tumor response as well as normal

toxicity


MEDICAL PHYSICS MISSION

SUPPORT FOR ACTIVITY ESTIMATION IN PATIENT DOSIMETRY


MEDICAL PHYSICS MISSION

SUPPORT FOR ACTIVITY ESTIMATION IN PATIENT DOSIMETRY


CHANGES IN DIRECTIVE EU

(ProceduresDIRECTIVE 97/43

In radiotherapeutic should be directly implied a medical physics expert

In therapeutic standard practicesin nuclear medicine will be available a medical physicsavailable a medical physicsexpert

In other radiologic practices willbe

implied a medical physics expert


2013/59NEW!!!!!

CHANGES IN DIRECTIVE EU

Procedures)• DIRECTIVE 2013/50

in standardised therapeuticalnuclear medicine practices

….......

a medical physics expert shall beinvolved;

a medical physics expert shall beinvolved;


in radiotherapeutic practicesother than standardisedtherapeutic nuclear medicinepractices, a medical physicsexpert shall be closely involved;

STANDARDISED THERAPEUTIC?

I-131 HIPERTIROIDISMO (sodiumI-131 CARCINOMA TIROIDEO CDT (Y-90 LINFOMA NO HODKING (I-131 (tositumomab) + “surrogateLu-177 TUMORES NEUROENDOCRINOS (DOTOATE


Lu-177 TUMORES NEUROENDOCRINOS (DOTOATE NEUROLOGICOS (metaiodobenzilguanidinaESFERAS DE Y-90 PARA RADIOEMBOLIZACION HEPATICAMETASTASIS PROSTATICAS CON RAPOLICITEMIA VERA P-32 (phosphateSINOVIORTESIS Y-90 (ferric hidroxideTRAT.DOLOR METASTÁSICO CON SRSM-153 (ethylenediaminetetramethylenephosphonateRe-186 (hidroxyethylidenediphosphonato

STANDARDISED THERAPEUTIC?

sodium iodine)131 CARCINOMA TIROIDEO CDT (sodium iodine)90 LINFOMA NO HODKING (ibritumomab tiuxetan)

surrogate” 111-In ibritumomab tiuxetan177 TUMORES NEUROENDOCRINOS (DOTOATE octreotate)


177 TUMORES NEUROENDOCRINOS (DOTOATE octreotate)metaiodobenzilguanidina) MIBG I-131

90 PARA RADIOEMBOLIZACION HEPATICAMETASTASIS PROSTATICAS CON RA-223 (dicloruro de Radio)

phosphate)hidroxide macroaggregates FHMA)

TRAT.DOLOR METASTÁSICO CON SR-89 (Chloride),ethylenediaminetetramethylenephosphonate EDTMP)

hidroxyethylidenediphosphonato HEDP)

RADIOPHARMACEUTICAL THERAPYWhere absorbed doses are calculatedArt 7 BOE CCMNArt 7 BOE CCMN


•Tumor/lesión•Critical organs

RADIOPHARMACEUTICAL THERAPY

absorbed doses are calculated?

7 BOE CCMN7 BOE CCMN


Tumor/lesiónorgans/tissues

METHODOLOGY

ADLESION =QUANTITATIVE RADIOPHARMACEUTICAL BIODISTRIBUTION ->A


CUANTIFICACION

BIODISTRIBUTION ->A

LESIONTCRITICALO rAD / (~=

METHODOLOGY

SrA LESION )·(~S FACTOR: MASS, RADIONUCLIDE, TISSUE,…


CUANTIFICACION

TCRITICALOLESIONLESION S /)· →

INDIVIDUALIZED PATIENT CALCULATION: HOW?


DATA ACQUISITION

A(t)

IMAGEGC, SPECT, PET

Externa PROBECZT INa CI

INDIVIDUALIZED PATIENT CALCULATION: HOW?

Individualizedcalculation


Blood, urinesamples

MASSm

IMAGEGC, US, SPECT,

PET

DETERMINATION OF CURVE FITTING

The time dependence of activity


The time dependence of activitythe source region are determined

QUANTITTIVE MEASUREMENT THECHIQUES

DETERMINATION OF ÃCURVE FITTING

activity (time-activity curve) whitin


activity (time-activity curve) whitindetermined from a serial image data.

QUANTITTIVE MEASUREMENT THECHIQUES


ACTIVITY DATA COLECTION


QUANTITATIVE IMAGINGPLANAR SCINTILLATION

CAMERA OR TOMOGRAPHIC SPECT PET SYSTEMS?

• STANDARD: I-131, hipertiroidismo CDT: • MIRD 16 (1999) (the committee on medical internal

radiation dose)radiation dose)

• New therapy: SPECT PET• I-131: 131-I TOSITUMOMAB, 131I

RADIOINMUNOTHERAPHY• MIRD 24 (SPECT)

• Lu-177: MIRD 26 (SPECT)• Y-90: BTG/ AAPM (ENSAYO)• Ra-223: PLANAR (ENSAYO)


QUANTITATIVE IMAGINGPLANAR SCINTILLATION

CAMERA OR TOMOGRAPHIC SPECT PET SYSTEMS?

131, hipertiroidismo CDT: PLANARthe committee on medical internal

SPECT PETI TOSITUMOMAB, 131I-L19SIP

RADIOINMUNOTHERAPHY

90: BTG/ AAPM (ENSAYO)223: PLANAR (ENSAYO)


MIRD 16 METHODOLOGY


MIRD 16 METHODOLOGY


GC PLANAR MIRD 16MUST BE ACTUALIZED 1999!!!!

TWO PROBLEMS

SENSITIVITY


GC PLANAR MIRD 16MUST BE ACTUALIZED 1999!!!!

CORRECTION FOR SCATTED PHOTONS• Based in 99m-Tc imaging:

• Imaging from more than 80% directphotons

• Scatter and penetration components s+p• Scatter and penetration components s+pcan be estimated with Triple EnergyWindoe (TEW)

• Problems with 131-I:• Imaging from direct photons (d),

collimator Compton photons (s) and penetration photons (p):

d=51%; s=25%; p=24% CDR: Collimator detector response CDT críticaMonte Carlo should be used


310-332 405-427

MIRD 23: QuantitativeSPECT bforpatient specificdosimetry 3-D Dosimetry in internalRadionuclideTherapy, J NuclMed 2012; 53: 1310-1325

Triple energy window: TEW427

Bremsstrahlung:105-195 keV

SIMIND

Red= Scatter and penetrationsBlack= Total


MIRD 16: SENSITIVITY

• Sensitivity in Parallel-holerelatively independent of distance whithin a definedshould be as close as possible to the subject.

• The system calibration (count rate per unit activity) is obtained by counting a known activity for a fixed period of time within a standardized geometry in air relative to the scintillation camera using designated camera acquisition settings


MIRD 16: SENSITIVITY

hole collimators will be of source-to-collimator

defined region… the detector should be as close as possible to the subject.The system calibration (count rate per unit activity) is obtained by counting a known activity for a fixed period of time within a standardized geometry in air relative to the scintillation camera using designated camera acquisition settings


Norma ISO 16644 (Draft International Standard)

Measurement of activity in nuclear Measurement of activity in nuclear medicine using gamma camera planar image for thyroid treatments with

ISO/TC/85/SC2

WG22: 22 Dosimetry and related protocols in medical applications of ionizing radiation


Norma ISO 16644 International Standard)

Measurement of activity in nuclear Measurement of activity in nuclear medicine using gamma camera planar image for thyroid treatments with 131I

ISO/TC/85/SC2

and related protocols in medical applications of ionizing radiation


NORMA ISO 16644

SPANISH PROPOSAL

TEAMRaquel Barquero Servicio Radiofísica y PR. HCUV

Hugo Pérez García RFIR, Sº de Radiofísica y PR. HCUV

Alexander Cárdenas Solano, Físico Médico, Área de Medicina Nuclear, Hospital Nacional Edgardo Rebagliati


NORMA ISO 16644

SPANISH PROPOSAL

TEAMRaquel Barquero Servicio Radiofísica y PR. HCUV

Hugo Pérez García RFIR, Sº de Radiofísica y PR. HCUV

Alexander Cárdenas Solano, Físico Médico, Área de Medicina Nuclear, Hospital Rebagliati Martins, LIMA (PERU)


MEDICAL PHYSICS SPANISH SOCIETY:Patient dosimetry

• Raquel Barquero (coordinadora), HCUV, Valladolid• Natividad Ferrer, Hospital Ramón y Cajal, Madrid• Javier Luis Simón, Hospital Virgen del Rocío, Sevilla• Josep Martí, Clínica Universitaria Navarra, Pamplona• Josep Martí, Clínica Universitaria Navarra, Pamplona• Luis Carlos Martínez, Hospital Doce Octubre, Madrid• Carlos Montes, Hospital Universitario Salamanca,

Salamanca• Rafael Plaza, Hospital La Paz, Madrid• Mª Angeles Rivas, Hospital Lozano Blesa, Zaragoza• Pablo Mingez Gaviña, Hospital Cruces, Bilbao


MEDICAL PHYSICS SPANISH SOCIETY:in Nuclear Medicine

Raquel Barquero (coordinadora), HCUV, ValladolidNatividad Ferrer, Hospital Ramón y Cajal, MadridJavier Luis Simón, Hospital Virgen del Rocío, SevillaJosep Martí, Clínica Universitaria Navarra, PamplonaJosep Martí, Clínica Universitaria Navarra, PamplonaLuis Carlos Martínez, Hospital Doce Octubre, MadridCarlos Montes, Hospital Universitario Salamanca,

, Zaragoza


ISO16644STANDARDIZED:STANDARDIZED:

HOW TO OBTAIN ACTIVITY FORM DETECTED COUNTS IN PLANAR GAMMACAMERA IMAGING


ISO16644STANDARDIZED:STANDARDIZED:

HOW TO OBTAIN ACTIVITY FORM DETECTED COUNTS IN PLANAR GAMMACAMERA IMAGING


Calculation of activity in the patient uptake

( g

Sn

A =(


• ng Total (gross) photopeak events(counts)• nb Background counts• t Measuring time (Actual Frame Duration• S Sensitivity or calibration factor to calculate

cps/MBq• Z Depth of the centre of the tumor or

view, cm• μ Attenuation coefficient for 131I in soft tissue

Calculation of activity in the patient uptake

)z

b

eStn

⋅−⋅

−µ

/)


events(counts) in the specific region of the image (ROI)

Duration in DICOM image) , scalculate the count rate per unit of activity,

or tissue with activity uptake in the anterior

tissue of density 1 g/cm3, 0,11 cm-1

GAMMACAMERA 1) Absolute CALIBRATION

0ηε ⋅= G JORNADA CIENTIFICA HOSPITAL PUERTA DE HIERRO 6 JUNIO 2016

From countsto Activity

GeometricefficiencyFotones/s

Geométric

Counts/PhotonsIntrínsic

effciciency

GAMMACAMERA PLANARCALIBRATION

GeométricFactor

MCNPX

CALIBRATION

kk

bg

Gatnn

⋅−

=/)(

0η

tnnwtnn

eGtnn

a bgbg

zbg /)(

/)(/)(11.0

0

−⋅=−

=⋅⋅

−= ⋅− εη

[ ] )()()()( 22222

2

wuanunutwau relbg ⋅++⋅=


MCNPX SIMULATIONCollimator geometric


MCNPX SIMULATIONgeometric eficciency, G


RESULTS:GEOMETRIC FACTORS

dis-1

1e-4

3e-4

5e-4

1e-3• DETALED DESCIPTION OF:• I-131• Collimator• Uptake-collimator

distance• Uptake size


0

Phot

ons

cm-2

dis

1e-6

3e-6

5e-6

1e-5

3e-5

5e-5

SIEMENS E-CAM HE COLLIMATOR

Holes Shape HEX

Hole Lenght, L (mm) 50.8

Septal Thickness (mm) 2

Hole Diameter (mm) 3.4

RESULTS:GEOMETRIC FACTORS

Siemens e-cam

1e-4

3e-4

5e-4

1e-3

r=7 cmr=6r=5r=4r=3r=2.5r=2r=1


d (cm)

5 10 15 20 25 30 351e-6

3e-6

5e-6

1e-5

3e-5

5e-5

SENSITIVITY (each lesion each

= SS ROI


From patient image

From MCNPX

SENSITIVITY (cps/MBq) each patient

0η⋅⋅ GROI


MCNPX simulation

CALIBRATION Previus measurement

INTRINSIC EFFICIENCYAn independent measurement

1. A source (Petri dish) is filled with radioactive water in which the activity Ak

2. Positioned at 10 cm distance centre of the surface of the collimator in the

2. Positioned at 10 cm distance centre of the surface of the collimator in the direction of the axis of symmetry of the

3. Acquisition of DICOM image in GC4. The geometry factor in the acquisition with

reference phantom Gk is obtained from Figure


INTRINSIC EFFICIENCYAn independent measurement

A source (Petri dish) is filled with radioactive water of 131I is diluted

distance from the geometrical centre of the surface of the collimator in the

distance from the geometrical centre of the surface of the collimator in the direction of the axis of symmetry of the GCAcquisition of DICOM image in GCThe geometry factor in the acquisition with

is obtained from Figure


• How obtainng for to knowintrinsicefficiency


kk

bg

GAtnn

⋅−

=/)(

0η

know


SENSITIVITY (OBTAINED BY MONTE

Siemens e-cam

Sens

itivi

ty (c

ps/M

Bq)

202122232425262728293031323334353637383940


d (cm)

0 2 4 6 8 10 12 14 16

Sens

itivi

ty (c

ps/M

Bq)

56789

1011121314151617181920

FIGURE . Sensitivity S for Siemens e-cam system as a function of the activity radius and distance activity collimator d. Sensitivity varies from 7 to 36 cps/results can be seen for radius 1, 2, 3 and 4 (only these radius are included by simplicity).

SENSITIVITY (cps/MBq) OBTAINED BY MONTE CARLO

Siemens e-cam

r=7r=6r=5r=4r=3r=2.5r=2r=1SIMIND r=1SIMIND r=2SIMIND r=3SIMIND r=4


d (cm)

18 20 22 24 26 28 30

cam system as a function of the activity radius r . Sensitivity varies from 7 to 36 cps/MBq. SIMIND

results can be seen for radius 1, 2, 3 and 4 (only these radius are included by

EXAMPLEEXAMPLE10 PATIENTS UNDERGOING

DCT TREATMENT WITH 131DATA ACQUISITION: PLANAR GAMMA CAMERA


EXAMPLEEXAMPLE10 PATIENTS UNDERGOING

DCT TREATMENT WITH 131-IACQUISITION: PLANAR GAMMA CAMERA


QUANTIFICATION OF THE ACTIVITY UPTAKE IN IMAGE OF 10 PATIENTS UNDERGOING DCT

• rhTSH• Siemens e-cam 3/8” HEGP• 15 cm skin-collimator• 15 cm skin-collimator• 15% energy window, centered• Intrinsic effciency previously• Sensitivity [20.75-28.10] cps• ImageJ• HURRA FILTER


QUANTIFICATION OF THE ACTIVITY UPTAKE IN IMAGE OF 10 PATIENTS UNDERGOING DCT

3/8” HEGP

centered at 364 keVpreviously determined, 5.28·10-2

cps/MBq


PROCEDURE (1/5)PREVIOUS CONSIDERATION

Small uptake (Thyroid carcinoma) ?The following method is valid for sizesresolution of the GC.

Table System spatial resolution of E

Distance (cm)

5

7.5

10

15

20

25

30


PROCEDURE (1/5)PREVIOUS CONSIDERATION

) ?sizes near or sizes bellow the spatial

of E-CAM HE gamma camera

FWHM (cm)

1.11

1.22

1.5

1.84

2.28

2.53

2.91


PROCEDURE DATA ACQUISITION


DICOM image of the

PROCEDURE (2/5)DATA ACQUISITION


DICOM image of the LESION

PROCEDURE DATA ANAYSIS


Rectangular ROI to obtain central profile

PROCEDURE (3/5)DATA ANAYSIS


Rectangular ROI to obtain central profile


Plot profile


The collimator artefacts can be eliminated


profile values


eliminated with a process filter :

PROCEDURE DATA ANAYSIS


The ROI in small sizes is chosengeometric counts are obtainedis recommended.



chosen as the region in whichobtained and a diameter as the FWTM

2.97 2.59 2.96


DICOM IMAGES ACQUIRED 7 DAYS AFTER ADMINISTRATIONFROM 10 PATIENTS DCT TREATED WITH 131

(ADMINISTERED ACTIVITIES IN

2.96 2.96

2.96 4.07


DICOM IMAGES ACQUIRED 7 DAYS AFTER ADMINISTRATIONFROM 10 PATIENTS DCT TREATED WITH 131-I

(ADMINISTERED ACTIVITIES IN GBq)

3.70 3.334.81

DATA ANAYSIS

• IDENTIFICATION OF SOURCE REGIONS• SALIVARY NO• NUCLEAR MEDICINE PHYSICIAN

• TEMPORAL SAMPLING: SERIAL MEASUREMENTS• TEMPORAL SAMPLING: SERIAL MEASUREMENTS• 1 d after administration• 2 d “”• 3 d “”• 8 d “”


DATA ANAYSIS

IDENTIFICATION OF SOURCE REGIONS

NUCLEAR MEDICINE PHYSICIAN

TEMPORAL SAMPLING: SERIAL MEASUREMENTSTEMPORAL SAMPLING: SERIAL MEASUREMENTS


DOSIMETRY METHOD)( 00

efin

CAtA−

⋅⋅=λλ

λ


DOSIMETRY METHOD)( tt

ef

in inef ee ⋅−⋅− −⋅ λλλ


DOSIMETRY METHOD

T

A = 44,1~


DOSIMETRY METHOD

efin

ef

in

uTλλ

λλ

−

=ln

efTCA ⋅⋅⋅ 0044


DOSIMETRY METHOD


)()((%)·)·(·046,0

)( 00

gmdTCMBqA

GyD ef=

1. ACTIVITY AT 1 D, 2D, 3 D AND 8 D

2. FIT TO A SIMPLE EXPONENTIAL to know:

3. C0 AND λef (Tef )4. Mass (g)4. Mass (g)

a) Ratio of mass object of small size (pill) and FWTMpill

b) Proporcionallity(FWTM/2)lesion of eachlesion size (m=0,075 g) and (FWTM/2)pill (m, g)


RESULTSTREATMENT AADM (MBq)

1 40702 25903 29604 29605


5 40706 29607 37008 48109 3330

RESULTSm(g) D(Gy)

0,075 566,132

0,041 37,388

0,149 842,001

0,368 128,049


0,030 81,988

0,194 129,719

0,226 78,255

0,041 629,525

0,036 4655,675

No correlation between administered activities and absorbed dose

3500

4000

4500

5000

D(Gy) vs Aadm (MBq)

Bq≠


0

500

1000

1500

2000

2500

3000

0 1000 2000

Dose

(Gy)

Aadm (MBq)

correlation between administered activities and absorbed dose

D(Gy) vs Aadm (MBq)

≠ Gy


3000 4000 5000 6000

Aadm (MBq)

CorrelationAadm (MBq

4000

5000

6000

Aadm

(GBq

)Aadm (MBq) vs m(g)


0

1000

2000

3000

0,000 0,050 0,100

Aadm

(GBq

)

Correlation betweenMBq) and m(g)

y = -4619,8x + 3954,6R² = 0,1595

Aadm (MBq) vs m(g)


0,150 0,200 0,250

m (g))

Correlation betweenand

uptake 1 d

10

12

14

D(Gy) vs C0


0

2

4

6

8

0 500 1000 1500 2000

D(Gy

)

between D(Gy) and 1 día (%)y = 0,0025x + 0,6385

R² = 0,9041D(Gy) vs C0


2500 3000 3500 4000 4500 5000

Co

I Individualized Dosimetry with gamma camera planar images

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