This work aims to focus on beam shaping assembly (BSA)'s design and optimization for boron neutron capture therapy (BNCT) facility based on a proton accelerator. The beam shape assembly optimization is simulated by MCNP Monte Carlo code. The beam shaping assembly is consists of a set of materials used as moderator, reflector, neutron filter and gamma filter. The output neutron beam characteristics are compared to that recommended by the international atomic energy agency (IAEA).
The dose components that contributed to the absorbed dose are simulated using MCNP code based on the neutron interactions mode and boron concentration values taking into account the Relative Biological Effectiveness (RBE) factors. The total effective dose in brain tumor and healthy tissues for different values of 10B concentration are compered to calculate the therapeutic gain (TG). The results indicated that The Healthy tissues at the skin surface, skull and beyond the tumor receive the lowest radiation dose. TG may be used as a fast evaluation of the impact of varying 10B concentrations on the therapeutic outcome, and treatment optimization