Monte Carlo simulation of 10 MV photon beams and beam profile validations

Abstract

In radiation therapy, various radiation energies have been used according to the size and depth of tumor for therapeutic purpose. The electron energies are used for superficial treatments, whereas photon energies such as 6 MV, 10 MV and 18 MV energy levels are utilized for the treatment of deeper tumors. The suitability of energy levels for treatment has been determined by dose distributions in water phantom. In this study, beam profiles of clinical linear accelerators for 10 MV photon beams in water phantom were obtained by using Monte Carlo Simulation Program (MCSP) developed. MCSP was carried out taking into account the interactions of photons with matter in MATLAB (The Mathworks, Inc.). Monte Carlo simulation results were calculated for 5x5, 10x10 and 20x20 cm2 field sizes at 5, 10 and 20 cm depths for the dose profiles. In order to validate the beam profiles, Monte Carlo results were compared with experimental results for 1 cm and 10 cm depths at all the field sizes. MCSP results have shown a good agreement with experimental results.