BNCT

Boron neutron capture therapy (BNCT) is a biochemically targeted radiotherapy designed to destroy cancer cells while sparing surrounding normal tissue. The approach relies on delivering boron-10–containing compounds to tumor cells and then exposing the area to low-energy neutrons. When a boron-10 nucleus captures a neutron, it undergoes a nuclear reaction that produces alpha particles and lithium-7 nuclei, delivering highly localized, high-LET radiation within the boron-loaded cells.

The effectiveness of BNCT depends on achieving preferential boron uptake by tumor cells relative to normal cells and on delivering an adequate neutron dose to the tumor. The emitted alpha particles and lithium nuclei have a short tissue range, typically several micrometers, which confines most damage to boron-containing cells and minimizes exposure to surrounding healthy tissue. Boron delivery agents commonly studied include boronophenylalanine (BPA) and sodium borocaptate (BSH). Treatment planning uses imaging to estimate boron distribution and neutron dose.

Neutron sources for BNCT have traditionally been nuclear reactors, but accelerator-based neutron sources are increasingly used to expand accessibility. BNCT is still primarily investigative and not a standard-of-care therapy in most countries. It has been explored for glioblastoma and recurrent or challenging head and neck cancers, among others. Ongoing research focuses on improving boron delivery, optimizing neutron irradiation, and clarifying clinical benefits through prospective trials.