Boron Neutron Capture Therapy

Boron neutron capture therapy is a form of radiotherapy for locally invasive malignant tumors, including primary brain cancers, recurrent head and neck cancers and cutaneous melanoma. Patients are first injected with a tumor-seeking drug containing boron-10, an isotope with an exceptional capacity to capture low-energy thermal neutrons, and are then irradiated with epithermal neutrons that lose energy as they penetrate tissue and become thermal neutrons captured by the boron-10 atoms; the resulting nuclear reaction produces high-energy alpha particles and lithium-7 nuclei with a range of only five to nine micrometers, destroying the cancer cells while sparing nearby healthy tissue. The concept emerged soon after James Chadwick discovery of the neutron in 1932, and William Sweet ran the first clinical trial in 1951 using nuclear reactors, with Hiroshi Hatanaka later establishing an influential research program in Japan; accelerator-based neutron sources have since replaced reactors, and clinical trials continue in several countries, particularly for recurrent glioblastoma and head and neck cancer.