Development of a quasi-monte-carlo generator for linac using geant4 code

The goal of this study is to evaluate the impact of using a Quasi-Monte-Carlo (QMC) generator on calculations of beam data, delivered by a 12 MV Saturne 43 LINAC photon beam. In this work, the Geant4.9.4.p04 is used to construct our Geant4-based application for Saturne 43 LINAC simulation. Both beam data calculations for two kinds of random generators (MC and QMC) have been compared to the measured ones using gamma index comparison tool. As known, that the least known parameters in a MC simulation of the treatment head, are often the properties of the initial electron beam. In previous study where a MC generator has been employed, we have found that the appropriate mean energy, sigma and its full width at half maximum were 11.5 MeV, 0.4 MeV and 1.177 mm with accuracy within 1.5%/ 1mm. Our results show that, both simulations share approximately the same value of CPU time, and its results have statistical uncertainly less than unity. The recent study emphasizes the electron beam configuration obtained from a MC generator and the accuracy of calculated beam data in a homogeneous water phantom has been improved to 1.31%/ 1mm.