Tetrahedral Organ Model in Geant4 Based Particle Therapy Simulation Framework

Monte Carlo simulation for radiation therapy needs a computational model of patient geometry. Voxel model has been so far used for this purpose. However, tetrahedral model is more suitable for representing organ's shape. In this paper, we report on the development of tetrahedral organ model in Geant4 based particle therapy system simulation framework (PTSIM). Several organ geometries have been successfully constructed with the tetrahedral model in PTSIM. The performance in the simulation is discussed by comparing the tetrahedral model with the voxel model.