basic film dosimetry - american association of physicists ... · basic film dosimetry indra j. das,...

Das/Cheng/AAPM/SLC/2001Das/Cheng/AAPM/SLC/2001

Basic Film DosimetryIndra J. Das,Indra J. Das, PhPh.D..D.

Department of Radiation OncologyUniversity of Pennsylvania

Philadelphia, PA

CheeChee--WaiWai Cheng, Ph.D.Cheng, Ph.D.Department of Radiation Oncology

Morristown General HospitalMorristown General HospitalMorristown, NJMorristown, NJ

&&


Basic Film Basic Film DosimetryDosimetry

WhatWhat is a film?is a film?

WhyWhy to use film ?to use film ?

HowHow to use film?to use film?

WhereWhere to use film?to use film?


Historical PerspectiveHistorical Perspective18261826 Joseph Joseph NiepceNiepce First PhotographFirst Photograph

18361836 J. M.J. M. DaguerreDaguerre Concept of developerConcept of developer

18891889 Eastman KodakEastman Kodak Cellulose nitrate base for emulsionCellulose nitrate base for emulsion

18901890 HurterHurter &&DriffieldDriffield Defined the term optical densityDefined the term optical density

18951895 RoentgenRoentgen First RadiographFirst Radiograph

18961896 Carl Carl SchlussnerSchlussner First glass plate for radiographyFirst glass plate for radiography

19131913 KodakKodak Film on Cellulose nitrate baseFilm on Cellulose nitrate base

19181918 KodakKodak Double emulsion filmDouble emulsion film

19331933 DupontDupont XX--ray film with blue baseray film with blue base

19421942 PakoPako Automatic film processorAutomatic film processor

19601960 DupontDupont Polyester base introducedPolyester base introduced

19651965 KodakKodak Rapid film processingRapid film processing

19721972 KodakKodak XTL and XV film for therapyXTL and XV film for therapy

19831983 FujiFuji Computed radiography systemComputed radiography system

19941994 3M3M Dry process laser imagingDry process laser imaging


Film Film DosimetryDosimetrykk Silver halides Silver halides

vv Radiographic filmRadiographic film��Available in various sizesAvailable in various sizes

��Radiation range (Radiation range (mGymGy--GyGy))��Wet chemical processingWet chemical processing��Strong energy dependenceStrong energy dependence��DensitometerDensitometer-- anyany

kk Self DevelopingSelf Developingvv RadiochromicRadiochromic, , Gafchromic Gafchromic filmfilm

��Relatively smaller film (10x10 cmRelatively smaller film (10x10 cm22))��Radiation range (Radiation range (GyGy--100Gy)100Gy)��No processingNo processing

��Little energy dependenceLittle energy dependence��DensitometerDensitometer-- Specialized (light sensitive)Specialized (light sensitive)


Radiochromic Film

NiroomandNiroomand--Rad Rad et al, et al, Radiochromic Radiochromic film film dosimetry: Recommendations of AAPM dosimetry: Recommendations of AAPM Radiation Therapy Committee Task group Radiation Therapy Committee Task group 55, 55, MedMed. Phys. 25(11), 2093. Phys. 25(11), 2093--2115, 19982115, 1998


FilmFilmkk Base (Cellulose nitrate or Polyester) (typically 200 Base (Cellulose nitrate or Polyester) (typically 200 µµm)m)

kk Emulsion (10Emulsion (10--20 20 µµm; 2m; 2--5 mg/cm5 mg/cm33))

vv Gelatin (derivative from bone)Gelatin (derivative from bone)

vv grain (size: 0.1grain (size: 0.1 --3 3 µµm diameter)m diameter)uu AgBrAgBr (cubic crystal with lattice distance of 28(cubic crystal with lattice distance of 28 nmnm

uu AgIAgI

uu KIKI

�� There are 10There are 1099--10101212 grains/cmgrains/cm22 in xin x--ray filmsray films

kk CoatingCoating

vv Very sensitive which may determine X & Y Very sensitive which may determine X & Y direction uniformitydirection uniformity

BaseBaseEmulsionEmulsion


Photographic ProcessPhotographic Process

kk Silver halides (Silver halides (AgBrAgBr,, AgClAgCl,, AgIAgI) ) are sensitive to radiation.are sensitive to radiation.

kk Radiation event (latent image) Radiation event (latent image) can be magnified by a billion fold can be magnified by a billion fold (10(1099 ) with developer.) with developer.


Emulsion of Film/RadiographEmulsion of Film/RadiographThe heart of film is emulsion which contains grains The heart of film is emulsion which contains grains

(crystals of silver halides) in gelatin(crystals of silver halides) in gelatin

Gelatin is suitable due toGelatin is suitable due to

vv it keeps grains well dispersedit keeps grains well dispersed

vv it prevents clumping and it prevents clumping and sedimentation of grains sedimentation of grains

vv it protects the unexposed grains it protects the unexposed grains from reduction by a developerfrom reduction by a developer

vv it allows easy processing of it allows easy processing of exposed grainsexposed grains

vv it is neutral to the grains in it is neutral to the grains in terms of fogging, loss of terms of fogging, loss of sensitivitysensitivity

Electron micrograph of grain in gelatinElectron micrograph of grain in gelatin


Film ProcessingFilm Processingkk Developing Developing [([(MetolMetol; methyl; methyl--pp--aminophenol sulphateaminophenol sulphate oror

PhenidonePhenidone; 1phenol 3pyrazolidone)]; 1phenol 3pyrazolidone)]

vv Converts allConverts all AgAg++ atoms toatoms to AgAg. The latent . The latent image image AgAg ++ are developed much more are developed much more rapidly.rapidly.

kk Stop BathStop Bath

vv dilute acetic acid stops all reaction and dilute acetic acid stops all reaction and further developmentfurther development

kk Fixer, Hypo Fixer, Hypo (Sodium(Sodium ThiosulphateThiosulphate))

vv it dissolves all undeveloped grains.it dissolves all undeveloped grains.

kk WashingWashing

kk DryingDrying


Latent imageLatent imagekk The change which causes the grains to be The change which causes the grains to be

rendered developable on exposure is rendered developable on exposure is considered to be the formation of latent image. considered to be the formation of latent image.

kk It is composed of an aggregate of a few silver It is composed of an aggregate of a few silver atoms (4atoms (4--10).10).

kk On average 1000On average 1000 AgAg atoms are formed per xatoms are formed per x--ray quantum absorbed in a grain. ray quantum absorbed in a grain.

kk Gurney &Gurney & MottMott provided a clear picture of provided a clear picture of latent imagelatent image

Ref.Ref. HerzHerz, 1969, 1969


GrainGrain

SilverSilver

SpeckSpeck

XX--rayray


HurterHurter && DriffieldDriffield (1890)(1890)Optical Density (OD)Optical Density (OD)

OD= logOD= log1010((IoIo/I)/I)

OD=logOD=log1010 (T) where T is transmittance(T) where T is transmittance

T=T=eeanan

a= average area/grain; n is number of exposed grains/cma= average area/grain; n is number of exposed grains/cm22; ; N is number of grains/cmN is number of grains/cm22

OD = log (T) = an logOD = log (T) = an log1010e = 0.4343 ane = 0.4343 an

n/N = an/N = aΦ ; Φ ; where where Φ Φ electron fluenceelectron fluence

OD = 0.4343 aOD = 0.4343 a22NNΦΦ

OD is proportional to OD is proportional to Φ Φ and hence dose and and hence dose and square of grain areasquare of grain area..


Characteristic curveCharacteristic curveH&D CurveH&D Curve

Gradient, gamma, slope = Gradient, gamma, slope = (D(D22--DD11)/Log(E)/Log(E22/E/E11))

Speed (sensitivity)= Speed (sensitivity)= 1/Roentgens for OD equal to unity1/Roentgens for OD equal to unity

Latitude (Contrast): Latitude (Contrast): range of log exposure to give range of log exposure to give an acceptable density rangean acceptable density range

Log (exposure)Log (exposure)

Opt

ical

Den

sity

Opt

ical

Den

sity

basebase

slopeslope

shouldershoulder


5.55.500 0.50.5 1.01.0 1.51.5 2.02.0 2.52.5 3.03.0 3.53.5 4.04.0 4.54.5 5.05.000

0.50.5

1.01.0

1.51.5

2.02.0

2.52.5

3.03.0

3.53.5

4.04.0

Opt

ical

Den

sity

Opt

ical

Den

sity

Log Relative ExposureLog Relative Exposure

Haus Haus et al 1997et al 1997

Characteristic curves of various filmCharacteristic curves of various film

DxDx

RxRx


Characteristics of Commercially Available Radiographic FilmsCharacteristics of Commercially Available Radiographic Films

FilmFilm Optimum DoseOptimum Dose GammaGamma LatitudeLatitudeCEA CEA TVSTVS 6060 4.44.4 0.350.35

CEA TLFCEA TLF 1919 3.63.6 0.40.4

Agfa Ortho Agfa Ortho STG2STG2 4.74.7 3.63.6 0.40.4

Agfa Agfa HTAHTA 3.53.5 2.72.7 0.30.3

Agfa Agfa RP1RP1 1.51.5 2.62.6 0.50.5

AgfaAgfa MR3MR3 4.24.2 2.12.1 0.60.6

Du PontDu Pont CronexCronex 4.04.0 2.62.6 0.50.5

Du Pont UVDu Pont UV 1.51.5 1.91.9 0.50.5

Fuji MIMAFuji MIMA 6.36.3 2.82.8 0.50.5

Fuji HRGFuji HRG 6.26.2 2.82.8 0.50.5

Kodak XVKodak XV 5050 2.92.9 0.60.6

Kodak TL 44 2.02.0 0.50.5

Kodak XLKodak XL 1.71.7 2.02.0 0.60.6

Kodak Kodak MinRMinR 12.312.3 1.81.8 0.40.4

Kodak TMATGKodak TMATG 2.52.5 2.52.5 0.40.4

Kodak Kodak OrthoOrtho 4.54.5 2.32.3 0.40.4

Konica MGHKonica MGH 5.05.0 2.72.7 0.40.4


TabularTabular

CubicCubic

3D3D

Eastman Kodak Company, 2001Eastman Kodak Company, 2001


Kodak, XV CEA, TVS

Cheng & Das, Cheng & Das, MedMed. Phys. 23, 1225, 1996. Phys. 23, 1225, 1996


Kodak MinKodak Min--RR Kodak ECLKodak ECL

Unusual silver halide grain morphologiesUnusual silver halide grain morphologiesHausHaus, 2001, 2001


Developed grain showing filamentary silver


00 1.01.0 2.02.0 3.03.0 4.04.0 5.05.0

Optical DensityOptical Density

00

1.01.0

2.02.0

3.03.0

4.04.0

5.05.0

6.06.0

7.07.0C

ontr

ast

Con

tras

t

RangeRange

Optimum Optical DensityOptimum Optical Density


8484 8686 9090 9292 9494 9696 9898 100100 1021028888

0.40.4

0.60.6

0.80.8

1.01.0

1.21.2

1.41.4

1.61.6

Developer Temperature (degree F)Developer Temperature (degree F)

Opt

ical

Den

sity

Opt

ical

Den

sity

DupontDupontKodak MRMKodak MRMFujiFujiKodak MR5Kodak MR5

Temperature Dependence of Various FilmsTemperature Dependence of Various Films


Bogucki Bogucki et al, Med.Phys., 24, 581, 1997et al, Med.Phys., 24, 581, 1997

Cha

nge

in O

D p

er D

egre

e Pr

oces

sor T

empe

ratu

reC

hang

e in

OD

per

Deg

ree

Proc

esso

r Tem

pera

ture

(( δδO

DO

D// δδ

TT))

9191 9292 9393 9494 9595 9696 9797 9898 9999

0.00.0

.02.02

.04.04

.06.06

.08.08

.10.10

Processor Temperature (degree F)Processor Temperature (degree F)

Kodak FilmsKodak Films

Min R MMin R M

Ektascan Ektascan HNHN

TT--Mat G/RAMat G/RA

Ektascan Ektascan IRIR

OD=KOD=K00T +KT +K11TT22


00 0.50.5 1.01.0 1.51.5 2.02.0 2.52.5 3.03.0 3.53.5 4.04.0

0.00.0

.02.02

.04.04

.06.06

.08.08

.10.10

Optical DensityOptical Density

Cha

nge

in O

D p

er D

egre

e Pr

oces

sor T

empe

ratu

reC

hang

e in

OD

per

Deg

ree

Proc

esso

r Tem

pera

ture

(( δδO

DO

D// δδ

TT))

Kodak FilmsKodak Films

Min R MMin R M

Ektascan Ektascan HNHN

TT--Mat G/RAMat G/RA

Ektascan Ektascan IRIR

Bogucki Bogucki et al, Med.Phys., 24, 581, 1997et al, Med.Phys., 24, 581, 1997


91 F91 F33 C33 C

95 F95 F35 C35 C

99 F99 F37 C37 C

103 F103 F39 C39 C

0.160.16

0.180.18

0.200.20

0.220.22

2.82.8

3.03.0

3.23.2

3.43.4

3.63.6

--2020

00

2020

4040

BaseBase

++

FogFog

ContrastContrastAverageAverageGradientGradient

SpeedSpeed% change% change

TemperatureTemperature

Standard Processing CycleStandard Processing Cycle


Various types of plots for film responseVarious types of plots for film response

Opt

ical

Opt

ical

Den

sity

Den

sity

Log (exposure)Log (exposure)

(a)(a)

Opt

ical

Opt

ical

Den

sity

Den

sity

Exposure, DoseExposure, Dose

(c)(c)

Log

(Opt

ical

Log

(Opt

ical

Den

sity

)D

ensi

ty)

Log (exposure, dose)Log (exposure, dose)

(b)(b)

OpticalOptical DensityDensity

Exp

osur

e, D

ose

Exp

osur

e, D

ose

(d)(d)

DXDX

TxTx

H&

DH

&D

Con

tras

tC

ontr

ast

Sens

itom

etri

cSe

nsito

met

ric

Cal

ibra

tion

Cal

ibra

tion


D = DoseD = DoseDr = Dose rateDr = Dose rateE = EnergyE = EnergyT = type of radiation (xT = type of radiation (x--rays, electrons etc)rays, electrons etc)d = depth of measurementd = depth of measurementFS= Field SizeFS= Field SizeΘΘ = Orientation: parallel or perpendicular= Orientation: parallel or perpendicular

Optical Density = OD(D, Dr, E, T, d, FS, Optical Density = OD(D, Dr, E, T, d, FS, ΘΘ))


Film Film Dosimetry Dosimetry in therapyin therapy

kk 1954,1954, GrankeGranke et al; tissue dose studies with 2 MV xet al; tissue dose studies with 2 MV x--raysrays

kk 1969,1969, DutreixDutreix et al; highlights of the problems in film et al; highlights of the problems in film dosimetrydosimetry

kk 1981, Williamson et al; Provided solution to the film 1981, Williamson et al; Provided solution to the film dosimetry problemsdosimetry problems

kk 1996, Cheng & Das; CEA film, better film for 1996, Cheng & Das; CEA film, better film for dosimetrydosimetry

kk 1997, Burch et al & 1997, Burch et al & YeoYeo et al; lateral scatter filteringet al; lateral scatter filtering


Optimum propertiesOptimum properties

kk Linear with dose (dose dependence)Linear with dose (dose dependence)

kk Linear with dose rate (dose rate Linear with dose rate (dose rate independence)independence)

kk Radiation type (independent of photon and Radiation type (independent of photon and electron)electron)

kk Energy independentEnergy independent

kk Uniformity in x & y (coating artifact)Uniformity in x & y (coating artifact)

kk Processing conditionProcessing conditionvv FadingFadingvv Delayed processingDelayed processingvv Atmospheric condition, temperature, humidityAtmospheric condition, temperature, humidity


Exposure, RExposure, R

Opt

ical

Opt

ical

Den

sity

Den

sity

1010--22 1010--11 101000 101011 101022 101033 101044 10105500

11

22

33

44

55

66

0.033R/sec0.033R/sec

1.31R/sec1.31R/sec

62R/sec62R/sec

1100R/sec1100R/sec

Dose Rate DependenceDose Rate Dependence

EhrlichEhrlich, J.Opt., J.Opt.SocSoc.Am. 46,801, 1956.Am. 46,801, 1956


00 1010 2020 3030 4040 5050 6060 7070 8080Dose (cGy)Dose (cGy)

00

0.50.5

1.01.0

1.51.5

2.02.0

2.52.5

Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

28 28 keVkeV 44 44 keVkeV

79 79 keVkeV

97 97 keVkeV

142 142 keVkeV

1.711.71 MeVMeV

Muench Muench et al, et al, MedMed. Phys. 18, 769, 1991. Phys. 18, 769, 1991

Kodak XV FilmKodak XV Film

Energy Dependence of Radiographic FilmEnergy Dependence of Radiographic Film


1010 100100 10001000

0.10.1

1.01.0

1010

100100

unfilteredunfiltered

filteredfiltered

Photon Energy, (Photon Energy, (keVkeV))

Rel

ativ

e re

spon

seR

elat

ive

resp

onse

RR.H. .H. HerzHerz, The photographic action, 1969, The photographic action, 1969

Energy response balancing with filter Energy response balancing with filter used in personnel monitoringused in personnel monitoring


00 2020 4040 6060 8080 100100

Dose (cGy)Dose (cGy)

0.00.0

1.01.0

2.02.0

3.03.0

4.04.0

5.05.0

Opt

ical

Den

sity

Opt

ical

Den

sity

Energy Dependence of CEA Energy Dependence of CEA TVS TVS filmfilm

CsCs--137137CoCo--60604 MV4 MV6 MV6 MV10 MV10 MV18 MV18 MV


Gamma raysGamma rays XX--raysrays

ODODγγ = 0.054 Dose= 0.054 Dose

ODODxx = 0.047 Dose= 0.047 Dose


0055 1010

5050

100100

Depth (cm)Depth (cm)

Dos

e (%

)D

ose

(%)

Air gapAir gapFilmFilm

00

0.250.25

0.500.50

0.75 mm0.75 mm

Effect of film air gap on depth doseEffect of film air gap on depth dose

Dutreix Dutreix et al, Ann NY et al, Ann NY Acad SciAcad Sci, 161, 33, 1969, 161, 33, 1969


Air gapAir gap FilmFilm

0055 1010

5050

100100


Dos

e (%

)D

ose

(%)

00

22

5 mm5 mm

Effect of film misalignment on depth doseEffect of film misalignment on depth dose




Effect of film under alignment on depth doseEffect of film under alignment on depth dose

55 1010


Air gapAir gap FilmFilm

00

5050

100100

Dos

e (%

)D

ose

(%)

0 mm0 mm

447 mm7 mm


Methods to eliminate problems with FilmMethods to eliminate problems with Film

kk To eliminate air trapped inside jacket, vacuum To eliminate air trapped inside jacket, vacuum packing could be used (CEA film).packing could be used (CEA film).

kk To keep identical position and pressure, RMI To keep identical position and pressure, RMI sells film cassettes for dosimetry.sells film cassettes for dosimetry.

kk Use film in water as suggested by van Use film in water as suggested by van Battum Battum et al, et al, RadiotherRadiother..OncolOncol. 34, 152, 1995. 34, 152, 1995

kk Special phantom; Special phantom; BovaBova, , MedMed. Dos. 15, 83, 1990. Dos. 15, 83, 1990


CEA Films (TLF, CEA Films (TLF, TVSTVS))

00 2020 4040 6060 8080 100100

Dose (cGy)Dose (cGy)

Opt

ical

Den

sity

Opt

ical

Den

sity

00

11

22

33

44Kodak TLKodak TL

120120

CEA TLFCEA TLFCEA CEA TVSTVS

Kodak XVKodak XV



OD Vs DoseOD Vs Dose

PDDPDD = [= [a+b(OD) +c(OD)a+b(OD) +c(OD)22]]dd // [a+b(OD) +c(OD)[a+b(OD) +c(OD)22]]maxmax

OAR=OAR=[[a+b(OD) +c(OD)a+b(OD) +c(OD)22]]x x // [a+b(OD) +c(OD)[a+b(OD) +c(OD)22]]caxcax

D = m(OD) thenD = m(OD) then

DD22/D/D11 = OD= OD22/OD/OD11

For limited range and linear filmFor limited range and linear film

Dose = a+b(OD) +c(OD)2


OD depth and field size dependentOD depth and field size dependent

OD(D, d) = ODOD(D, d) = ODss[1[1--1010--αα(d)D(d)D]]

αα(d) = (d) = αα(d(dmm)[1+)[1+ββ(d(d--ddmm)])]

ββ = 0.0182= 0.0182 CoCo--6060

ββ = 0.0150= 0.0150 4 MV4 MV

ββ = 0.0062= 0.0062 10 MV10 MV

Williamson et al , Williamson et al , MedMed. Phys. 8, 94, 1981. Phys. 8, 94, 1981



0.80.8

0.90.9

1.01.0

1.11.1

1.21.2

1.31.3

1.41.4

00 55 1010 1515 2020 2525 3030

Film

Den

sity

Film

Den

sity


Das/Cheng/AAPM/SLC/2001Das/Cheng/AAPM/SLC/2001Williamson et al , Williamson et al , MedMed. Phys. 8, 94, 1981. Phys. 8, 94, 1981

3030

4040

5050

6060

7070

8080

9090100100

110110120120

FilmFilmIon ChamberIon Chamber


3030

4040

5050

6060

7070

9595100100

9090

8080 FilmFilmIon ChamberIon Chamber



Sensitivity of film to scatterSensitivity of film to scatterkk Depth and field size dependence of ODDepth and field size dependence of OD

kk Van Van Battum Battum et al, film in wateret al, film in water

kk Burch et al, lead filterBurch et al, lead filter

kk Yeo Yeo et al , Lead filteret al , Lead filter

kk Skyes Skyes et al, against filter methodet al, against filter method

vv “although scatter filtering method appears to have “although scatter filtering method appears to have the desired effect it seems intuitively wrong to the desired effect it seems intuitively wrong to introduce a high Z filter in order to make an introduce a high Z filter in order to make an inadequate dosimeter, film, behave as if it is water inadequate dosimeter, film, behave as if it is water equivalent”equivalent”

kk Suchowerska Suchowerska et al MC simulation to prove scatter as et al MC simulation to prove scatter as a problema problem


00 55 1010 1515 2020 2525

9494

9696

9898

100100

102102

104104

106106

108108

4x44x4

10x1010x10

20x2020x20

30x3030x30


Opt

ical

Den

sity

(Nor

mal

ized

)O

ptic

al D

ensi

ty (N

orm

aliz

ed)

Van Van Battum Battum et al , et al , Radiother OncolRadiother Oncol, 34, 152, 1995, 34, 152, 1995

Effect of depth and field size on ODEffect of depth and field size on OD


00 22 44 66 20201818161614141212101088


Rel

ativ

e D

ose

(%)

Rel

ativ

e D

ose

(%)

00

2020

4040

6060

8080

100100

4x44x410x1010x10

20x2020x20

Van Van Battum Battum et al , et al , Radiother OncolRadiother Oncol, 34, 152, 1995, 34, 152, 1995

FilmFilmIon ChamberIon Chamber


2

34

5

6

23 4

56

Scattered photon, hν’

Primary Photon, hν

Scattered electrons

Compton Scattering

11


Yeo Yeo et al Med. Phys. 24, 1943, 1997et al Med. Phys. 24, 1943, 1997Burch et al, Med. Phys. 24, 775, 1997Burch et al, Med. Phys. 24, 775, 1997

FilmFilm Lead filterLead filter

PhotonPhoton

Parallel film OrientationParallel film Orientation

Movable positionMovable position

X, X, 6, 12, 19 mm6, 12, 19 mmt= 0.15, 0.30,t= 0.15, 0.30,.0.46, 0.76 mm.0.46, 0.76 mm


00 22 44 66 88

Energy (Energy (MeVMeV))

0.00.0

2.02.0

4.04.0

6.06.0

8.08.0

10.010.0

Rel

ativ

e Fl

uenc

e (%

)R

elat

ive

Flue

nce

(%)

MC simulation of photon spectrum at various depthsMC simulation of photon spectrum at various depths

30 cm30 cm

10 cm10 cm

1.5 cm1.5 cm

Suchowerska Suchowerska et al, Phys. et al, Phys. MedMed. . BiolBiol. 44, 1755, 1999. 44, 1755, 1999


00 55 1010 1515 2020 2525 3030 3535 404000

2020

4040

6060

8080

100100

120120

140140

160160

180180

200200

Dos

e (

Dos

e ( c

Gy

cGy ))


X=0 mmX=0 mm

Ion chamberIon chamber

X=6 mmX=6 mm

X=12 mmX=12 mm

4 MV, 25x25 cm4 MV, 25x25 cm22

0.76 mm 0.76 mm PbPb

Burch et al, Med. Phys., 24, 775, 1997Burch et al, Med. Phys., 24, 775, 1997


No No PbPb

Ion ChamberIon Chamber

Film+.46 mm Film+.46 mm PbPb


00 55 1010 1515 2020 2525 3030 3535 4040

00

2020

4040

6060

8080

100100

120120

4 MV, 25x25 cm4 MV, 25x25 cm22

No No PbPb

Film+.46 mm Film+.46 mm PbPb

Ion ChamberIon Chamber

Burch et al, Med. Phys., 24, 775, 1997Burch et al, Med. Phys., 24, 775, 1997

00 55 1010 1515 2020 2525 3030 3535 4040

00

2020

4040

6060

8080

100100

120120

Dos

e (

Dos

e ( c

Gy

cGy ))


4 MV, 6x6 cm4 MV, 6x6 cm22

Effect of Effect of Pb Pb filter on depth dosefilter on depth dose

Das/Cheng/AAPM/SLC/2001Das/Cheng/AAPM/SLC/2001Danciu Danciu et al, et al, MedMed. Phys. 28, 972, 2001. Phys. 28, 972, 2001

2.02.000 0.50.5 1.01.0 1.51.5

Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

0.00.0

1.01.0

1.51.5

2.02.0

2.52.5

3.03.0C0C0--6060KodakKodak

Dose (Dose (GyGy))

0.5g/cm0.5g/cm33

4 g/cm4 g/cm33

9 g/cm9 g/cm33

DepthDepth

Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

Dose (Dose (GyGy))00 0.50.5 1.01.0 1.51.5

0.00.0

1.01.0

1.51.5

2.02.0

2.52.5

3.03.06 MV6 MVKodakKodak

0.5g/cm0.5g/cm33

4 g/cm4 g/cm33

9 g/cm9 g/cm33

DepthDepth

2.02.0

00 0.50.5 1.01.0 1.51.50.00.0

1.01.0

1.51.5

2.02.0

2.52.5


0.5g/cm0.5g/cm33

4 g/cm4 g/cm33

9 g/cm9 g/cm33

DepthDepth

2.02.000 0.50.5 1.01.0 1.51.50.00.0

1.01.0

1.51.5

2.02.0

2.52.5


0.5g/cm0.5g/cm33

4 g/cm4 g/cm33

9 g/cm9 g/cm33

DepthDepth

2.02.0

Dose (Dose (GyGy)) Dose (Dose (GyGy))

Sensitometric Sensitometric curves for 15x15 cmcurves for 15x15 cm22 fieldfieldwith perpendicular film exposurewith perpendicular film exposure


Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

Depth (cm)Depth (cm)1414 161600 22 44 66 88 1010 1212

Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

1.01.0

1.51.5

2.02.0

2.52.5

3.03.0

3.53.5CoCo--6060

AgfaAgfa

KodakKodak

ParallelParallelPerpendicularPerpendicular

1414 161600 22 44 66 88 1010 1212

Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

1.01.0

1.51.5

2.02.0

2.52.5

3.03.0

3.53.515 MV15 MVAgfaAgfa

KodakKodak



1414 161600 22 44 66 88 1010 12121.01.0

1.51.5

2.02.0

2.52.5

3.03.0

3.53.56 MV6 MVAgfaAgfa

KodakKodak



Net

Opt

ical

Den

sity

Net

Opt

ical

Den

sity

1414 161600 22 44 66 88 1010 12121.01.0

1.51.5

2.02.0

2.52.5

3.03.0

3.53.545 MV45 MV

KodakKodak



Danciu Danciu et al, et al, MedMed. Phys. 28, 972, 2001. Phys. 28, 972, 2001


Net Optical Density0 0.2 0.4 0.6 0.8 1.0 1.2

0

5

10

15

20

25

30

Dos

e (c

Gy)

6x6, 5 cm depth6x6, 5 cm depth25x25, 5 cm depth25x25, 5 cm depth6x6, 15 cm depth6x6, 15 cm depth25x25, 15 cm depth25x25, 15 cm depth

Sykes et al, Med.Phys., 26, 329, 1999Sykes et al, Med.Phys., 26, 329, 1999


eewweewweeww

PP PP

eewweeww

eeff

filmfilm# # eeww<< #<< # eef f

ODODperpendicular perpendicular << ODODparallelparallel

PerpendicularPerpendicular ParallelParallel

PhotonsPhotons

electronselectrons

((eeww))nn ((eeww))nn+(+(eeff))mm


Gantry AngleGantry Angle

8080 8282 8484 8686 8888 9090

Nor

mal

ized

Res

pons

eN

orm

aliz

ed R

espo

nse

.96.96

.98.98

1.001.00

1.021.02

1.041.04

1.061.06

1.081.08

1.101.10

1.121.12

Kodak XV FilmKodak XV Film

SpectralSpectral

Spectral + air gapSpectral + air gap

Suchowerska Suchowerska et al. et al. PhyPhy. . MedMed. . BiolBiol. 46, 1391, 2001. 46, 1391, 2001


403530252015100.82

0.84

0.86

0.88

0.90

0.92

0.94

0.96

0.98

1.00

1.02

1.04

1.06

V-1

V-3V-2

CEA-1

V-4

CEA-2

V-5

Variation of cone factor, St, using film

Cone Diameter (mm)

Con

e Fa

ctor

(St)

Das et al, J. Das et al, J. RadiosurgRadiosurg. 3, 177, 2000. 3, 177, 2000


Electron beam film & isodoseElectron beam film & isodose


Densitometer: Densitometer: Device that measures Device that measures optical densityoptical density

kk Visual type densitometer (Visual type densitometer (DobsonDobson, Griffith & , Griffith & Harrison, 1926)Harrison, 1926)

kk Photoelectric typePhotoelectric type

vv light densitometer (wide spectrum)light densitometer (wide spectrum)�� Standard:Standard: McBethMcBeth,, XriteXrite, Nuclear Associate etc, Nuclear Associate etc

�� VidarVidar scanning systemscanning system

vv laser densitometer (single wavelength)laser densitometer (single wavelength)�� LumysisLumysis scanning systemscanning system


Film

Incident light

Transmitted light

Diffuse

Specular

Double diffuse


Disadvantage of film dosimetryDisadvantage of film dosimetrykk Chemical processing (except Gafchromic films)Chemical processing (except Gafchromic films)

vv OD depends on:OD depends on:�� developer temperaturedeveloper temperature�� drying conditionsdrying conditions

kk Strong energy dependence (high sensitivity to low Strong energy dependence (high sensitivity to low energy photons due to photoelectric interactions in energy photons due to photoelectric interactions in grainsgrains))

kk Sensitivity to environmentsSensitivity to environmentsvv high temperature and humidity crating fadinghigh temperature and humidity crating fading

vv Storage stabilityStorage stability

�� 0.050.05--0.1 OD in (60.1 OD in (6--60mR) among various 60mR) among various films films (ref (ref Soleiman Soleiman et al et al MedMed. . PhyPhy. 22, 1691, 1995). 22, 1691, 1995)

kk Microbiological growth in gelatinMicrobiological growth in gelatin

kk SolarizationSolarization: at extremely higher doses, OD decreases: at extremely higher doses, OD decreases

kk Absolute dosimetry is difficultAbsolute dosimetry is difficult


Advantage of film dosimetryAdvantage of film dosimetrykk Unrivaled spatial distribution of dose or energy Unrivaled spatial distribution of dose or energy

imparted.imparted.

kk Repeated reading of same film: permanent Repeated reading of same film: permanent recordrecord

kk Wide availability: Kodak,Wide availability: Kodak, AgfaAgfa, Fuji,, Fuji, DupontDupont, , CEA etc.CEA etc.

kk Large area dosimetry: Especially for electron Large area dosimetry: Especially for electron beambeam

kk Linearity of dose (over a short dose range, OD Linearity of dose (over a short dose range, OD can be treated linear with dose for most films)can be treated linear with dose for most films)

kk Dose rate independenceDose rate independence


ConclusionsConclusionskk Film is ideal for spatial dose mapping and relative Film is ideal for spatial dose mapping and relative

dose measurementsdose measurements

kk Proper storage is neededProper storage is needed

kk Proper processing is needed: QA on processorProper processing is needed: QA on processor

kk Use calibration factor (Use calibration factor (Sensitometric Sensitometric curve) from curve) from same batch of filmsame batch of film

kk Note for energy and dose rate dependenceNote for energy and dose rate dependence

kk Use same optical densitometer that has been used Use same optical densitometer that has been used for for sensitometric sensitometric curvecurve


--ConclusionsConclusionskk When exposing film; use proper methods to When exposing film; use proper methods to

eliminate air trapped in the jacket if vacuum packed eliminate air trapped in the jacket if vacuum packed films are not availablefilms are not available

vv Use identical pressure on film (invest in Use identical pressure on film (invest in pressure gauge)pressure gauge)

vv Use 2Use 2--3 degree angle when exposing parallel 3 degree angle when exposing parallel filmfilm

kk Keep film orientation sameKeep film orientation same

vv Parallel films gives higher OD than Parallel films gives higher OD than perpendicular orientationperpendicular orientation


--ConclusionsConclusionskk Select proper film for a dosimetric applicationSelect proper film for a dosimetric application

kk Be aware of differences in electron and photon OD Be aware of differences in electron and photon OD for same dosefor same dose

kk Keep identical exposure, processing and reading Keep identical exposure, processing and reading conditionsconditions


--Conclusions:Conclusions:

Accuracy in film dosimetryAccuracy in film dosimetry

2% 2% On the same filmOn the same film

3%3% Films processed simultaneouslyFilms processed simultaneously

5%5% Films processed separately but Films processed separately but identical processing conditionsidentical processing conditions

10%10% On films of different batches On films of different batches


[1] Attix, F.H. Introduction to Radiological Physics and Radiation Dosimetry. New York: John Wiley & Sons; 1986.

[2] Avadhani, J.S., Pradhan, A.S., Sankar, A. and Viswanathan, P.S. Dosimetric aspects of physical and dynamic wedge of Clinac 2100C linear accelerator [see comments].Strahlenther. Onkol. 173: 524-8, 1997.

[3] Bartlett, D.T. and Creasey, F.L. Latent image fading in nuclear emulsions. Phys.Med. Biol. 22: 1187-1188, 1977.

[4] Becker, K. Solid State Dosimetry. Boca Raton, Fl: CRC Press; 1973. [5] Bogucki, T.M., Murphy, W.R., Baker, C.W., Piazza, S.S. and Haus, A.G. Processor

quality control in laser imaging systems. Med. Phys. 24: 581-584, 1997. [6] Bova, F.J. A film phantom for routine film dosimetry in the clinical environment.

Med. Dosim. 15: 83-85, 1990. [7] Butson, M.J., Cheung, T. and Yu, P.K. Radiochromic film dosimetry in water

phantoms. Phys. Med. Biol. 46: N27-31, 2001. [8] Butson, M.J., Cheung, T. and Yu, P.K.N. Radiochromic film dosimetry in water

phantoms. Phys. Med. Biol. 46: N27-N31, 2001. [9] Butson, M.J., Mathur, J.N. and Metcalfe, P.E. Radiochromic film as a radiotherapy

surface-dose detector. Phys. Med. Biol. 41: 1073-1078, 1996. [10] Cadman, P. Use of CEA TVS film for measuring high energy photon beam dose

distributions. Med. Phys. 25: 1435-1437, 1998.

ReferencesReferences


--ReferencesReferences[11] Cheng, C.W. and Das, I.J. Dosimetry of high energy photon and electron beams with

CEA films. Med. Phys. 23: 1225-1231, 1996. [12] Cheng, C.W., Das, I.J. and Chen, D.J. Technical note: dosimetry in the moving gap

region in craniospinal irradiation. Br. J. Radiol. 67: 1017-22, 1994. [13] Danciu, C., Proimos, B.S., Rosenwald, J.C. and Mijnheer, B.J. Variation of sensitometric

curves of radiographic films in high energy photon beams. Med. Phys. 28: 966-974, 2001.

[14] Dobson, G.M.B., Griffith, I.O. and Harrison, D.N. Photographic Photometry. Oxford: The Clarendon Press; 1926.

[15] Dutreix, J. and Dutreix, A. Film dosimetry of high-energy electrons. Ann. N Y Acad.Sci 161: 33-43, 1969.

[16] Ehrlich, M. Characteristic curves for X-ray exposures at various dose rates. J. Opt. Soc. Am. 46: 801-, 1956.

[17] el-Khatib, E., Antolak, J. and Scrimger, J. Evaluation of film and thermoluminescentdosimetry of high-energy electron beams in heterogeneous phantoms. Med. Phys. 19: 317-323, 1992.

[18] Evans, M.D. and Schreiner, L.J. A simple technique for film dosimetry. Radiother.Oncol. 23: 265-267, 1992.

[19] Francescon, P., Cora, S., Cavedon, C., et al. Use of a new type of radiochromic film, a new parallel-plate micro-chamber, MOSFETs, and TLC 800 microcubes in the dosimetry of small beams. Med. Phys. 25: 503-511, 1998.

[20] Granke, R.C., Wright, K.A., Evans, W.W., Nelson, J.E. and Trump, J.G. The film method of tissue dose studies. Am. J. Roentgenol. 72: 302-307, 1954.


--ReferencesReferences[21] Hale, J.I., Kerr, A.T. and Shragge, P.C. Calibration of film for accurate megavoltage

photon dosimetry. Med. Dosim. 19: 43-46, 1994. [22] Haus, A.G. Advances in Film Processing Systems Technology and Quality Control in

Medical Imaging. Madison, Wi: Medical Physics Publishing; 2001. [23] Haus, A.G., Dickerson, R.E., Huff, K.E., et al. Evaluation of cassette-screen-film

combination for radiation therapy portal localization imaging with improved contrast.Med. Phys. 24: 1605-1613, 1997.

[24] Herz, R.H. The Photographic Action of Ionizing Radiations. New York: Wiley; 1969. [25] Kellermann, P.O., Ertl, A. and Gornik, E. A new method of readout in radiochromic

film dosimetry. Phys. Med. Biol. 43: 2251-2263, 1998. [26] Klein, E.E., Gerber, R., Zhu, X.R., Oehmke, F. and Purdy, J.A. Multiple machine

implementation of enhanced dynamic wedge. Int. J. Radiat. Oncol. Biol. Phys. 40: 977-85, 1998.

[27] Li, Z., Wen, D., Chen, D., et al. A study of dosimetric characteristics of GAF DM-1260Radiochromic films. Radiat. Phys. Chem. 57: 103-113, 2000.

[28] Ma, L., Li, X.A. and Yu, C.X. An efficient method of measuring the 4 mm helmet output factor for the Gamma knife. Phys. Med. Biol. 45: 729-733, 2000.

[29] Mayer, R., Williams, A., Frankel, T., et al. Two-dimensional film dosimetry application in heterogeneous materials exposed to megavoltage photon beams. Med. Phys. 24: 455-460, 1997.

[30] McLaughlin, W.L., Soares, C.G., Sayeg, J.A., et al. The use of a radiochromic detector for the determination of stereotactic radiosurgery dose characteristics. Med. Phys. 21: 379-388, 1994.


--ReferencesReferences

[31] McLaughlin, W.L., Yun-Dong, C., Soares, C.G., et al. Sensitometry of the response of a newradiochromic film dosimeter to gamma radiation and electron beams. Nucl. Instr. Meth. Phys. Res. A302: 165-176, 1991.

[32] Muench, P.J., Meigooni, A.S., Nath, R. and McLaughlin, W.L. Photon energy dependence of the sensitivity of radiochromic film and comparison with silver halide and LiF TLDs used for brachytherapy dosimetry. Med. Phys. 18: 767-775, 1991.

[33] Niroomand-Rad, A. Film dosimetry of small elongated electron beams for treatment planning. Med. Phys. 16: 655-62, 1989.

[34] Niroomand-Rad, A., Blackwell, C.R., Coursey, B.M., et al. Radiographic film dosimetry: Recommendations of AAPM Radiation Therapy Committee Task Group 55. Med. Phys. 25: 2093-2115, 1998.

[35] Niroomand-Rad, A., Gillin, M.T., Kline, R.W. and Grimm, D.F. Film dosimetry of small electron beams for routine radiotherapy planning. Med. Phys. 13: 416-21, 1986.

[36] Ramani, R., Lightstone, A.W., Mason, D.L.D. and O'Brien, P.F. The use of radiochromic film in treatment verification of dynamic stereotactic radiosurgery. Med. Phys. 21: 389-392, 1994.

[37] Robar, J.L. and Clark, B.G. The use of radiographic film for linear accelerator stereotactic radiosurgical dosimetry. Med. Phys. 26: 2144-2150, 1999.

[38] Shiu, A.S., Otte, V.A. and Hogstrom, K.R. Measurement of dose distributions using film in therapeutic electron beams. Med. Phys. 16: 911-915, 1989.

[39] Spunberg, J.J., Kessaris, N.D. and Chang, C.H. Film dosimetry of multiple electron beam ports with wedges. Int J Radiat Oncol Biol Phys 6: 379-380, 1980.

[40] Suchowerska, N., Hoban, P., Butson, M., Davison, A. and Metcalfe, P. Directional dependence in film dosimetry: radiographic and radiochromic film. Phys. Med. Biol. 46: 1391-1397, 2001.


--ReferencesReferences[41] Suchowerska, N., Hoban, P., Davison, A. and Metcalfe, P. Perturbation of radiotherapy beams by

radiographic film: measurements and Monte Carlo simulations. Phys. Med. Biol. 44: 1755-1765, 1999.

[42] Sykes, J.R. and Williams, P.C. An experimental investigation of the tongue and groove effect for the Philips multileaf collimator. Phys. Med. Biol. 43: 3157-3165, 1998.

[43] van Battum, L.J. and Heijmen, B.J. Film dosimetry in water in a 23 MV therapeutic photon beam.Radiother. Oncol. 34: 152-159, 1995.

[44] van Battum, L.J. and Huizenga, H. Film dosimetry of clinical electron beams. Int J Radiat Oncol BiolPhys 18: 69-76, 1990.

[45] van Bree, N.A., Idzes, M.H., Huizenga, H. and Mijnheer, B.J. Film dosimetry for radiotherapy treatment planning verification of a 6 MV tangential breast irradiation. Radiother. Oncol. 31: 251-255, 1994.

[46] Williamson, J.F., Khan, F.M. and Sharma, S.C. Film dosimetry of megavoltage photon beams: a practical method of isodensity-to-isodose curve conversion. Medical Physics 8: 94-98, 1981.

[47] Wu, A. and Krasin, F. Film dosimetry analyses on the effect of gold shielding for iodine-125 eye plaque therapy for choroidal melanoma. Med. Phys. 17: 843-846, 1990.

[48] Yeo, I.J., Wang, C.K. and Burch, S.E. A filtration method for improving film dosimetry in photon radiation therapy. Med. Phys. 24: 1943-1953, 1997.

[49] Yeo, I.J., Wang, C.K. and Burch, S.E. A new approach to film dosimetry for high-energy photon beams using organic plastic scintillators. Phys. Med. Biol. 44: 3055-3069, 1999.

[50] Yorke, E., Harisiadis, L., Wessels, B., Aghdam, H. and Altemus, R. Dosimetric considerations in radiation therapy of coin lesions of the lung. Int. J. Radiat. Oncol. Biol. Phys. 34: 481-7, 1996.

[51] Zhu, Y., Kirov, A.S., Mishra, V., Meigooni, A.S. and Williamson, J.F. Quantitative evaluation ofradiochromic film response for two-dimensional dosimetry. Med. Phys. 24: 223-231, 1997

basic film dosimetry - american association of physicists ... · basic film dosimetry indra j. das,...

Documents