Dosimetric impact of the variation of the materials assigned in the simulation by the method of Monte Carlo in radiotherapy treatment

To perform Monte Carlo simulation must also assign to each voxel a material, whose effective sections shall be used for the transport of particles. The allocation is made on the basis of the mass density of each voxel and is not two-way, that several different materials may apply to a same density composition. So the assignment is not fixed and depends on the user. Our study focuses on the allocation of materials from the mass densities, and its impact on clinical dosimetry. (Author)