G4Linac_MT, an easy-to-use Geant4-based code for modeling medical linear accelerator

Abstract In this paper, we present G4Linac_MT, a simple-to-use open source code developed to facilitate the use of the Geant4 C++ toolkit for the simulation of a medical linear accelerator (linac). This multithreaded code encapsulates several well-developed C++ modules serving to handle the complexity of coding geometry and material, to easy plot histograms of various physics quantities, to auto-merge output data created by all working threads into a single file, to well-estimate the number of simulated primary particles required to achieve data with a statistical uncertainty 2 radiation field are showed in order to demonstrate the G4Linac_MT capabilities. Thus, comparisons between simulated dosimetric functions and measured ones in a water phantom have been established by using a gamma index method and the results show a good agreement within 2.6%-1 mm accuracy. In addition, after optimizing variance reduction techniques, the overall CPU time spent by this multithreaded code has been decreased by a factor of 7.