A simulation study on proton accelerator-based sources for BNCT of shallow tumors

Abstract

Boron Neutron Capture Therapy (BNCT) is considered as a cancer treatment method with less damage to healthy tissue during tumor destruction. Accelerator-based neutron sources, including proton accelerators, have been considered as appropriate candidates in the BNCT of deep-seated tumors. However, there is less attention to using high-energy proton accelerators for the treatment of shallow tumors. The present work investigates the possibility of using proton accelerators to provide a neutron beam for the treatment of shallow tumors by using the MCNPX Monte Carlo code. An optimized Be target has been used to produce neutrons through the 9Be(p,n)9B reaction. Different materials were investigated to achieve an optimized Beam Shaping Assembly (BSA). After passing the beam through an arrangement of optimized materials, the neutron beam, checked against the in-air parameters recommended by IAEA, has been generated. Furthermore, a simulated phantom with realistic materials, including skin and the underlying soft tissue, has been used for dose evaluations. The beam performance has been examined through dose delivery in tumor compared with that in normal tissue using the simulated phantom. The results show that proton accelerator-based neutron sources have the potential to be considered as an appropriate candidate for the BNCT of shallow tumors. The results are encouraging to perform more detailed engineering and treatment planning studies to reach the clinical phase.