Abstract
The Monte Carlo method is considered the most accurate method for dose calculation in radiotherapy. The Linear accelerator (Linac) is currently the most widely used in radiotherapy center machines. This study aims at validating the GAMOS code based on the Geant4 Monte Carlo toolkit. A Saturne43 LINAC of 12 MV photon beam was modeled for configuring a 10 × 10 cm2 radiation field. The electron beam parameters such as spot size and mean energy were tuned by comparing calculated dose distribution within homogenous water phantom with a measured one. The results obtained showed that the depth dose and lateral dose profiles are sensitive to the electron beam parameters studied. The best matching with measured was found when the appropriate mean electron energy and beam width were 11.8 MeV and 2 mm respectively.