On the eptihermal neutron energy limit for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT): Study and impact of new energy limits

Background and purpose: Accelerator-Based Boron Neutron Capture Therapy is a radiotherapy based on compact accelerator neutron sources requiring an epithermal field for tumour irradiations. Neutrons of 10 keV are considered as the maximum optimised energy to treat deep-seated tumours. We investigated, by means Monte Carlo simulations, range from eV in order optimise function depth. Methods: A Snyder head phantom was simulated mono-energetic neutrons with 4 different incident energies were used: eV, 100 1 keV. 10B capture rates absorbed dose composition every tissue calculated describe compare effects lowering energy. The Therapeutic Gain (TG) estimated considering whole brain volume. Results: For tumours seated at cm depth, provided respectively 54%, 36% 18% increase TG compared neutrons. between higher than up 6.4 depth inside head. size does not change these results. Conclusions: Using lower AB-BNCT irradiation could improve treatment efficacy, delivering more therapeutic while reducing healthy tissues. This lead new Beam Shape Assembly designs BNCT irradiation.