Comparison of Electron-Beam Dose Distributions in a Heterogeneous Phantom Obtained Using Radiochromic Film Dosimetry and Monte Carlo Simulation

Document Type : Original Paper


1 M.Sc. in Medical Physics, Nuclear Engineering Dept., Shahid Beheshti University, Tehran, Iran

2 Assistant Professor, Radiotherapy Physics Dept., Tehran University of Medical Science, Tehran, Iran

3 Associate Professor, Nuclear Engineering Dept, Shahid Beheshti University, Tehran, Iran


Introduction: Nowadays new radiochromic films have an essential role in radiotherapy dosimetry. Properties such as high sensitivity, good reproducibility, high spatial resolution, easy readout and portability have made them attractive for dosimetry, especially in high-dose-gradient regions.
Material and Methods: In this study, electron-beam dose distributions in homogenous and heterogeneous phantoms were calculated using the MCNPX Monte Carlo code and compared with experimental measurements obtained by GAFCHROMIC® EBT film and p-type silicon diode dosimetry. Irradiation was carried out using an Elekta linear accelerator at two different electron energies (8 and 15 MeV), with a 10×10 cm2 applicator and at 100 cm source-to-surface distance.
Results: The results show good agreement (within 2%) between radiochromic film measurements and MCNP results.
Conclusions: The results show that the new radiochromic films can be used in electron dosimetry and that they are also reliable in presence of heterogeneous media.


Main Subjects

1. Khan FM. Physics of Radiation Therapy, 3rd ed. Baltimore: Lippincott Williams & Wilkins;2003.
2. Butson MJ, Yu PKN, Cheung T, Metcalfe P. Radiochromic film for medical radiation dosimetry. Mater
Sci Eng R. 2003; 41(35):
3. Soares CG. Radiochromic film dosimetry. Radiat Meas. 2006 Dec; 41:S100S116.
4. McLaughlin WL, YunDong
C, Soares CG, Miller A, Van Dyk G, Lewis DF. Sensitometry of the
response of a new radiochromic film dosimeter to gamma radiation and electron beams. Nucl Instrum.
Methods Phys. 1991 Apr;302(1):165–76.
5. Briesmeister JF. MCNP—a general Monte Carlo Nparticle transport code: version 4C. Report LA13709M.
Los Alamos, NM: Los Alamos National Laboratory, 2000.
6. NiroomandRad
A, Blackwell CR, Coursey BM, Gall KP, Galvin JM, McLaughlin WL, et al.
Radiochromic dosimetry: recommendations of the AAPM Radiation Therapy Committee Task Group
55. Med Phys. 1998 Nov;25(11):2093–115.