Radiographic Film Dosimetry

Radiographic 

Indra J. J Das, , Ph hD, , FACR 

Film Dosimetry 

Department of Radi iation Oncology 

Indiana University of School of 

Medicine & Midwe est Proton 

Radiation Therapy Institute (MPRI) 

Indianapolis, IN 

ID/AAPM- 

SS-Film/09

Learning OObjectives 

As describedd 

in TG-66 

ID/AAPM- 


Historical Pe 

erspective 

1826 Joseph Niepce First Photogrraph 

1836 J. M. Daguerre Concept of ddeveloper 

1889 Eastman Kodak Cellulose nittrate 

base for emulsion 

1890 Hurter & Driffield Defined the tterm 

optical density 

1895 Roentgen First Radiograph 

1896 Carl lSchlussner hl First i glass l plllate 

l for f radiography di h 

1913 Kodak Film on Celllulose 

nitrate base 

1918 Kodak Double emullsion 

film 

1933 Dupont X-ray X ray film w with blue base 

1942 Pako Automatic fiilm 

processor 

1960 Dupont Polyester base 

introduced 

1965 Kodak Rapid film pprocessing 

1972 Kodak XTL and XVV 

film for therapy 

1983 Fuji Computed raadiography 

system 

1992 CEA Vacuum paccked 

TLF AND TVS film 

1994 3M DDry 

process llaser imaging i i 

2000 Kodak Extended doose 

range (EDR) film 

ID/ARS/09

Radiograpphic 

Film 

� Base (Cellulose nitrate oor 

Polyester) 

(t (typically i ll 200 �m) ) 

� Emulsion (10-20 �m; 2--5 

mg/cm3 ) 

�� Gelatin (derivative fr 

rom bone) 

� grain (size: 0.1�3 �mm 

diameter) 

o AgBr (cubic crystal with llattice 

distance of 28 nm 

o AgI 

o KI 

� There are 109-1012 grrains/cm2 

in a x-ray films 

� Coating 

� Very sensitive whichh 

may determine X & 

Y direction uniformit ty 

ID/ARS/09 

Emulsion 

Base

Photographhic 

Process 

�� Sil Silver halides h lid (A AAgBr, AAgCl, Cl A AgI) ) are 

sensitive to radiaation. 

� Radiation event ( (latent image) can be 

magnified by a billion 

fold (10 

developer. 

9 ) with 

ID/ARS/09

Emulsion of Fiilm/Radiograph 

The heart of a film is emulsion whichh 

contains grains (crystals of silver 

hhalides) lid ) in 

gelatin l i 

Gelatin is suitable due to 

� it keeps grains well dispersed 

� it prevents clumping and sedimentatioon 

of grains 

�� it protects the unexposed grains from 

reduction by a developer 

� it allows easy processing of exposed 

grains 

� it is neutral to the grains in terms of 

fogging, loss of sensitivity 

Electron micrograph of grain in gelatin 

ID/ARS/09

Unusual Grain Morpho ologies of Films 

Eastman Kodak Company, 2001 

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

ID/AAPM- 


Latennt 

image 

�� The change which c 

auses the grains to be 

rendered developablle 

on exposure is 

considered to be the 

formation of latent 

image. 

�� IIt iis composed d of fann 

aggregate of fa few f 

silver atoms (4-10). 

� On average 1000 Agg 

atoms are formed per 

x-ray quantum absorrbed 

in a grain. 

� Gurney & Mott provvided 

a clear picture of 

ID/ARS/09 

latent image

Gurney & Mott Theory 

of Latent Image 

Speck 

Grai in 

Silv ver 

X-ray ray 

ID/AAPM- 


Film Proocessing 

�� Developing [(Metol; methyl 

1phenol 3pyrazolidone)] 

� Converts all Ag + at 

Ag + toms to Ag. The latent image 

Ag are developed 

d much more rapidly. rapidly 

� Stop Bath 

�� dilute acetic acid st 

tops all reaction and further 

development 

� Fixer, , Hypo yp (Sodium ( Thios 

� it dissolves all undeeveloped 

grains. 

� Washing 

� Drying 

l-p-aminophenol l p aminophenol sulphate or Phenidone; 

sulphate) p ) 

ID/ARS/09

Opti cal Dens sity 

1.6 

1.4 

1.2 

1.0 

0.8 08 0.8 

0.6 

0.4 

Temperature Dependenc ce of Various Films 

Dupont 

Kodak MRM 

Fuji j 

Kodak MR5 

84 86 88 90 92 

94 96 98 100 102 

Developer Tempera ature (degree F) 

ID/AAPM- 


Ch Ch hange in OD O OOD 

per De egree Proc Proc essor Tem mperature 

((�� OD/ OD/��T) T) 

.10 Ko 

.08 OD=K OD=K0T T +K +K1T2 .06 

.04 

.02 02 

0.0 

91 92 93 94 

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

odak Films 

Processor Temperatu ure (degree F) 

Min R M 

Ektascan HN 

T-Mat Mat G/RA 

Ektascan IR 

95 96 97 98 99 

ID/AAPM- 


Optical Density D (OOD) 

3.0 

2.5 

20 2.0 

1.5 

1.0 

05 0.5 

0.0 

XV, 100 cGy 

EDR, 400 cGy 

XV XV, 40 cG cGy 

EDR EDR, 80 cGy 

Srivastava & Das Med Phys 34:2445-46, 2007 

Temperaturee 

Dependence of Kodak films 

y = 0.0244x + 0.13 

R²=0.8782 R 0.8782 

y = 0.0176x + 0.532 

R² = 0.8951 0 8951 

y = 0.0204x 0 0204x - 00.606 606 

R² = 0.8856 

y = 0.0046x - 0.035 

R² = 0.9653 

80 82 84 86 88 90 92 94 96 98 100 102 104 106 

Temperature 

(deg F) 

ID/AAPM- 


Speed S SSpeed d 

% change 

Contrast 

Average 

Gradient 

Base 

+ 

Fog 

40 

20 

0 

-20 20 

3.6 

3.4 

32 3.2 

3.0 

2.8 

0.22 

0.20 

0.18 

0.16 

Standard Process sing Cycle 

91 F 

33 C 

95 F 

35 C 

Tempe erature 

99 F 

37 C 

103 F 

39 C 

ID/AAPM- 


Hurter & Drriffield 

(1890) 

OD= log 10(Io/I) 

Optical D Density D (OD) 

OD=log10 (T) where T is transmittance 

T=e an 

a= average area/grain; n is 

N is number of grains/cm2 s number of exposed grains/cm2 ; 

2 

OD = log (T) = an log 110e 

e = 0.4343 0 4343 an 

n/N = a��where �� electron 

fluence 

OD 0 4343 2 OD = 0.4343 a N� 2N� OD is proportional to ��annd 

hence dose and square 

of grain area 

ID/ARS/09

Characteriistic 

curve 

H&D CCurve 

Gradient, gamma, sloppe 

= (D2-D1)/Log(E2/E1) Speed (sensiti (sensitivity)= it ) 1/RRoentgens 

for OD equal to unity 

Latitude (Contrast): raange 

of log exposure to 

give a an a acceptable density range 

base 

slop slope 

Log (exp posure) 

shoulder 

ID/ARS/09

Sensit tometric 

c 

(a) 

(c) () (c) 

Various types of plo ots for film response 

Log (exposure) 

Exposure, Dose 

(b) 

Log (exposure, dose) DX 

(d) 

ID/AAPM- 

SS-Film/09 

Tx

Optical Optical Density = OD( (DDr (D,Dr D,Dr, DDr, ETdFS ETdFS��) 

E, T, d, FS, ��) 

D D=Dose D = Dose 

Dr = Dose rate 

E E = Energy 

T = type of radiation (x (x-r rays, electrons etc) 

d = depth of measuremen nt 

FS= Field Size 

�� = Orientation: parallel or perpendicular 

ID/AAPM- 


Contras st 

7.0 

6.0 

5.0 

4.0 

3.0 

2.0 

1.0 

0 

Optimum Optic cal Density 

Range 

0 1.0 2.0 

Optica al Density 

21 film types yp 

3.0 4.0 5.0 

ID/AAPM- 


Fil Film 

Double diffuse 

Inciddent 

light 

Specular 

Transmi itted light 

ID/AAPM- 


Diffuse

Densitometerrs/ 

Digitizers 

� Visual type yp densitomeeter 

(Dobson, ( , Griffith & 

Harrison, 1926) 

� Photoelectric type 

� light densitometer (widde 

spectrum) 

� Standard: McBeth, Xriite, 

Nuclear Associate etc 

�� Light source coupled w with CCD digitizer 

� Fluorescent light sourcce 

– Vidar VXR-16 Digitizer 

� LED light source - Howtek 

MultiRAD 460 Digitizer 

� Laser densitometer (sinngle 

wavelength) 

� Lumysis scanning systtem 

ID/ARS/09

Digiti g izers 

� Scanning film Digitizeer 

Artifacts: 

� Drift in OD; warm-up eeffect 

of fluorescent lamp 

� Use first 20-30 minutes 

� Scanner spatial distortioon 

� Validated in both dimennsions 

using known test patterns 

� Interference artifacts - at tthe 

interface of film and the glass 

plate/film support. (Multiple 

reflection due to changes in 

the index of refraction) 

Reinstein et. al., Dempsey et.al. 

as warm-up time 

� Use of diffused glass or anttireflective 

coated glass 

ID/ARS/09

Optimum Film 

Properties 

� Linear with dose (dosee 

dependence) 

� Linear with dose rate (dose rate independence) 

� Radiation type (indepeendent 

of photon and 

electron) 

� Energy independent 

� Uniformity in x & y (ccoating 

artifact) 

� Processing condition 

� Fdi Fading 

� Delayed processing 

� Atmospheric conditiion, 

temperature, humidity 

ID/ARS/09

6 

5 

4 

3 

2 

1 

10 10-2 10 10-1 10 100 0 

10 

Ehrlich, J.Opt.Soc.Am. 46,801, 1956 

Dose Rat te Dependence 

10 1 

0 0.033R/sec 

Exp Expp 

posure, p , 

R 

62R/sec 

1.31R/sec 

1100R/sec 

10 102 10 103 10 104 10 105 ID/AAPM- 


Dose rattio 

110 1.10 

1.08 

1.06 

1.04 

1.02 

1.00 

0.98 

0.96 

0.94 

0.92 

6 MV, EDR Film 

18 MV, EDR Film 

Dose 

1 10 100 

Dose raate 

(cGy/min) 

1000 10000 

Srivastava and Das Med Phys 33:2089 , 2006 

rate (film) 

ID/AAPM- 


Net Optical O OOptical 

De ensity 

2.5 

2.0 

1.5 

1.0 

0.5 

Energy Dependence o of Radiographic Film 

0 

28 keV 

44 keV 

0 10 20 30 

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

79 ke eV 

97 7 keV 

142 keV 

Kodak XV Film 

40 50 60 

Dos Dosse 

se (cGy) 

1.71 MeV 

70 80 

ID/AAPM- 


Op ptical De ensity 

50 5.0 

4.0 

3.0 

2.0 

1.0 

0.0 

Energy Dependenc e of CEA TVS film 

OD OD�� = 0.054 Dose 

OD ODx = 0.047 Dose 

x 

0 20 40 


Gamma G rays y X-rays X rays 

Dose Dosee 

e(cGy) e (cGy) 

Cs Cs-137 137 

Co Co-60 60 

4 MV 

6 MV 

10 MV 

18 MV 

60 80 100 

ID/AAPM- 


100 

50 

0 

Effect of film air ga ap on depth dose 

0.50 

0.25 

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

0 

075 0.75 mm 

5 

Depth 

(cm) 

Air gap 


10 

ID/AAPM- 


Effect of film misalign nment on depth dose 

100 

50 

0 

0 

2 

5 mm 

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

5 

Depth h (cm) 

Air gap 

10 


ID/AAPM- 


Effect of film under align nment on depth dose 

100 

50 

0 

4 

0 0mm 0 mm 

7 mm 

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

5 

(cm) 

Air gap 

10 


ID/AAPM- 


Methods to eliminaate 

problems with Film 

�� To eliminate air trapped 

d inside jacket jacket, vacuum 

packing could be used (CCEA 

film) 

�� To keep identical positio 

on and press pressure, re RMI 

sells film cassettes for ddosimetry 

�� UUse fil film in i water t as sugggested 

tdb by van Battum Btt et t 

al, Radiother.Oncol. 34, 152, 1995 

�� Special phantom; Bova, 

Med. Dos. 15, 83, 1990 

� Modern films come withh 

vacuum packed 

ID/ARS/09

Optica al Density Densityy 

4 

3 

2 

1 

0 

CEA Film 

ms (TLF, (TLF TVS) 

Kodak TL 

CEA TLF 

0 20 40 


Do Doose 

ose (cGy) 

CEA TVS 

60 80 100 

Kodak XV 

120 

ID/AAPM- 


OD vs 

Dose = a+b(OD) +c 

PDD = [a+b(OD) +c(OD) ) 2 ] d / [a+b(OD) +c(OD) 2 ] max 

OAR=[a+b(OD) +c(OD) 2 ] x / [a+b(OD) +c(OD) 2 ] cax 

For limited range and l inear film 

D = m(OD) (OD) th then thenn 

D2/D /D1 = OD OD2/O /OOD 

Dose 

c(OD) 2 

OD 1 

ID/ARS/09

Sensitivity of 

�Depth and field size dependdence 

of OD 

�V �Van BBattum et al, l fil film in i wwater 

�Burch et al, lead filter 

�Yeo et al , Lead filter 

�Skyes et al, against filter mmethod 

film to scatter 

�“although scatter filtering method 

appears to have the desired 

effect it seems intuitively wrrong 

to introduce a high Z filter in 

order to make an inadequate 

dosimeter, film, behave as if it is 

water equivalent” 

�Suchowerska et al MC simuulation 

to prove scatter as a 

problem 

ID/ARS/09

30 

25 

20 

15 

10 

5 

0 

0 0.2 0.4 

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

6x6, 5 cm depth 


6x6, 6 66x6, 6 15 15 cm d depth th 


0.6 0.8 1.0 1.2 

Net Opptical 

Density 

ID/AAPM- 


Optica al al Densit Densitty 

ty (Norm malized) 

108 

106 

104 

102 

100 

98 

96 

94 

Effect of depth 

0 5 

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

and field size on OD 

10 15 20 

Depth (cm) 

(cm) 

30 30x30 30 

20x20 

10x10 

4x4 

ID/AAPM- 


25

Rel lative Do ose (%) 

100 

80 

60 

40 

20 

0 

0 2 4 6 8 

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

10 

12 

Dep Depp 

pth p (cm) ( ) 

Ion Chamber 


4x4 

10x10 

14 

16 

20x20 

18 

20 

ID/AAPM- 


Movable position 

t= 0.15, 0.30, 

.0.46, 0.76 mm 

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

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

Pho oton 


Parallel film Orientation 

X X, 6, 12, 19 mm 

Lead filter 

ID/AAPM- 


Relat tive dose (ratio) ( 

Film Film no filter 

Film with filter 

Ion Chamber 

-10 10 -5 

Ju et al, Med. Phys., 29, 351 351-355, 355, 2002 

1.2 1.22 

1.0 1.00 

0.8 0.88 

0.6 0.66 

0.4 0.44 

0.2 0.22 

0 5 10 

Distance from c central axis (cm) 

ID/AAPM- 


Relativ ve Fluen nce (%) 

MC MC simulation of of photon photon spe 

spe ectrum at at various various depths 

depths 

10.0 

8.0 

6.0 

4.0 

2.0 

0.0 

0 2 

15 1.5 cm cmm 

Suchowerska et al, Phys. Med. Biol. 44, 1755, 1999 

10 cm 

Energ gy (MeV) 

30 cm 

4 6 8 

ID/AAPM- 


200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

X=0 mm 

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

1997 

X=6 mm 

0 5 10 15 

Depth ( (cm) 

4 MV, 25x25 cm cm2 0.76 mm Pb 

X=12 mm 

Ion chamber 

20 25 30 35 40 

ID/AAPM- 


120 

100 

80 

60 

40 

20 

0 

Ion Chamber 

0 5 10 15 

Effect of Pb filte er er on depth dose 

dose 

4 MV, 6x6 cm cm2 No Pb 

Film+.46 mm Pb 

Depth (cm) 

(cm) 

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

20 25 30 35 

40 

120 

100 

80 

60 

40 

20 

0 

Ion Chamber 

0 5 10 15 

4 MV, 25x25 cm cm2 No Pb 

Film+.46 mm Pb 

Depth (cm) 

(cm) 

20 25 30 35 40 

ID/AAPM- 


Net Optical Density D 

3.0 

2.5 

2.0 20 2.0 

1.5 

1.0 

0.0 

3.0 

2.5 

2.0 

1.5 

1.0 

0.0 

0 

0 

Kodak 

Kodak 

Sensitometric curves fo for 15x15 cm 

with perpendicular 

perpendicular 

2 field 

r film exposure 

exposure 

C0 C0-60 60 

0.5g/cm 

4 g/cm g/cm3 9 g/cm g/cm3 Depth 

0.5 1.0 

Dose (Gy) 

1.5 

0.5g/cm 3 

18 MV 

0.5 1.0 1.5 

Dose (Gy) 

(Gy) 

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

Depth 

0.5g/cm 

4 g/cm g/cm3 9 g/cm g/cm3 p 

0.5g/cm 3 

2.0 

2.0 

Net Optical Density D 

3.0 

2.5 

2.0 20 2.0 

1.5 

1.0 

0.0 

3.0 

2.5 

2.0 

1.5 

1.0 

0.0 

0 

0 

Kodak 

Kodak 

6 MV 

0.5g/cm 

4 g/cm g/cm3 9 g/cm g/cm3 Depth 

g 

0.5 1.0 

Dose (Gy) 

1.5 

0.5g/cm 3 

45 MV 

Depth 

0.5g/cm 

4 g/cm g/cm3 9 g/cm g/cm3 p 

0.5 1.0 

D Dose (G (Gy) 

) 

1.5 

ID/AAPM- 


0.5g/cm 3 

2.0 

2.0

Net Op ptical Density 

Net Optical De ensity 

3.5 

3.0 

2.5 

2.0 20 2.0 

1.5 

1.0 

3.5 

3.0 

2.5 

2.0 

1.5 

1.0 

Agfa 

Co Co-60 60 

Kodak 

0 2 4 6 8 10 12 

Depth (cm) 

Agfa 

Parallel 

Perpendicular 

15 MV 

Parallel 

Perpendicular 

Kodak 

0 2 4 6 8 10 12 

Depth (cm) 

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

14 16 

14 16 

Net Op ptical Density 

Net Optical Den Den nsity 

3.5 

3.0 

2.5 

2.0 20 2.0 

1.5 

1.0 

3.5 

3.0 

2.5 

2.0 

1.5 

1.0 

Agfa 

6 6MV 6 MV 

0 2 4 6 8 10 12 

Depth (cm) 

Parallel 

Perpendicular 

Kodak 

45 MV 

Kodak 

0 2 4 6 8 10 12 

Depth (cm) 

ID/AAPM- 


14 16 

Parallel 

Perpendicular 

14 16

e w 

e w 

(e (ew) n 

P 

Perpendicular 

e w 

Pho otons 

elec ctrons 

fil lm 

#e # e ew< <

100 

95 

90 

80 

70 

60 

50 

40 

30 

Williamson et al , Med. Phys. 8, 9 94, 1981 

120 

110 

100 

90 

80 

70 

60 

50 

40 

30 

ID/AAPM- 


Ion Chamber 

Film

IMRT Verification 

ID/AAPM- 


Advantage of ffilm 

dosimetry 

� Unrivaled spatial distribuution 

of dose or energy 

imparted. 

� Repeated reading of samme 

film: permanent record 

� 2-D distribution with sinngle 

exposure 

� Small detector size 

� Wide availability: Kodakk, 

Agfa, Fuji, Dupont, CEA 

� Large area dosimetry: Esspecially 

for electron beam 

� Linearity of dose (over a short dose range, OD can be 

treated linear with dose ffor 

most films) 

� Dose rate independence 

ID/AAPM- 


Film Dosimeetry 

- Caution 

�� Strong energy depen 

ndence (high sensitivity to 

low energy photons due to photoelectric 

interactions in grains 

s) 

� Film plane orientatioon 

with respect to the beam 

direction 

� Emulsion differences 

amongst films of 

diff different t bbatches, t h fil film ms of fth the same batch b t hor 

even in the same filmm 

� Densitometer/Digitizzer 

artifacts 

ID/AAPM- 


-Cautioon 

� OD depends on: 

� Chemical processinng 

� developer chemistrry 

and temperature 

� Processing g time 

� drying conditions 

� Sensitivity to environnment 

�� High temperature & humidity creating fading 

� Storage stability 

� 0.05-0.1 OD in (6- ( -60mR) ) among gvarious 

films (ref 

Soleiman et al Med. Phyy. 

22, 1691, 1995) 

� Microbiological growwth 

in gelatin 

�� Solarization: At extre 

emely higher doses, doses OD 

decreases 

ID/AAPM- 


Summmary 

�� Film is ideal detecto 

or for relative dose 

measurement 

�� Best suited for plana 

ar dose distribution 

� Dependent on type, batch, exposure 

condition, diti beam b eneergy, 

ddose, ddose rate, t 

processor condition, 

digitizer etc. 

� Film is a dying techhnology 

with a uncertain 

future. It is being repplaced 

with electronic 

devices 

ID/AAPM- 


ID/AAPM-

Radiographic Film Dosimetry

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