Estimation of Contamination of the Photonics in Precision Electron Linear Accelerator Electron Beams

Authors

Abstract

During the radiation therapy with electron beam, due to electron interaction
and scattering from structures of the head of the medical linear accelerator,
unwanted photons are produced. In order to measure photon contamination
at the electron mode of the ELEKTA Precise linear accelerator, thermoluminescence
detectors (TLD700 & GR200) at two energies (10 & 15MeV)
in polyethylene phantom were applied. Our result shows the rate of
produced bremsstrahlung photons dose for points close to the phantom
which is located in radiotherapy room of the Arak Ayat-O-lah Khansari
hospital are in mSv range

Keywords


[1]    F.M. Khan; "The physics of radiation therapy"; 3rd ed, Philadelphia: Lippincott Williams &Wilkins (2003).
[2]   Eric E. Klein, Daniel,A. Low, James A. Purdy, Chang in electron beam dosimetry with a new scattering foil-appllicator system on a CL2100C, Int. I. Radiation Oncology Biol. Phys., Vol. 32, No. 2. pp. 483-490, 1995
[3]   D.W.O. Rogers, J. Cygler, and T.R. Mackie; "Monte Carlo investigation of electron beam output factors vs size of square cutout"; Med. Phys. 26, No. 5 (1999) 743–750.
[5]   Hassan Ali Nedaie, M.A. Mosleh-Shirazi, M. Shariary , H. Gharaati, M. Allahverdi,"Monte Carlo study of electron dose distributions produced by the elekta precise linear accelerator". Rep Pract Oncol Radiother, 2006; 11(6): 287-292
[6]  Yukio Fujita, Atsushi Myojoyama, Hidetoshi Saitoh, Bremsstrahlung and photo neutron production in a steel shield for 15-22MeV clinical electron beams, Radiation Protection Dosimetry (2014), pp. 1–12.
[7]   Bhaskar Mukherjee, Dariusz Makowski, Stefan Simrock. "Dosimetry of high-energy electron LINAC produced photo neutrons and the bremsstrahlung gamma-rays using TLD-500 and TLD-700 dosimeter pairs". Nuclear Instruments and Methods in Physics Research A 545 (2005) 830– 841.