Comparative efficacy of reactor vs. accelerator-based boron neutron capture therapy in U87MG glioblastoma models

Boron neutron capture therapy (BNCT) has emerged as a promising treatment for cancer, utilizing the interaction between thermal neutrons and boron-10 to selectively target and destroy cancer cells. This study evaluates the efficacy of BNCT using 4-borono-L-phenylalanine (BPA) in two different systems: reactor-based BNCT at Kyoto University Reactor (KUR) and accelerator-based BNCT at the Aomori Prefectural Quantum Science Center (QSC). The QSC cyclotron accelerator (HM-20V; Sumitomo Heavy Industries, Japan) operates a lower neutron generation capacity compared to the cyclotron accelerators (HM-30; Sumitomo Heavy Industries, Japan) used in clinical settings at Kansai BNCT Clinical Center in Osaka Medical Pharmaceutical University and Southern Tohoku Hospital. Using U87MG glioblastoma-bearing mouse models, we compared the therapeutic outcomes of both systems. This result may be partially attributed to the higher gamma-ray dose delivered by the QSC accelerator compared to KUR, which may enhance cytotoxic effects and help compensate for the lower neutron dose. Additionally, possible differences in overall neutron spectra delivered by the two different sources (KUR and QSC) used in the work described here could also have contributed to the observed outcomes.