Comparison between voxelized, volumized and analytical phantoms applied to Radiotherapy simulation with monte carlo

The purpose of this paper is to provide a comparison between the different methods utilized for building up anthropomorphic phantoms in radiotherapy treatment plans. A simplified model of the Snyder head phantom was used in order to construct an analytical, voxelized and volumized phantom, throughout a segmentation program and different algorithms programmed in Matlab code. The irradiation of the resulting phantoms was simulated with the MCNP5 (Monte Carlo N-Particle) transport code, version 5, and the calculations presented in particle flux maps inside the phantoms by utilizing the FMESH tool, superimposed mesh tally. The different variables involved in the simulation were analyzed, like particle flux, MCNP standard deviation and real simulation CPU time cost. In the end the volumized model resulted to have the largest computer time cost and bigger discrepancies in the particle flux distribution.