Fig. 1

Boron neutron capture therapy. BNCT is based on the nuclear capture and fission reactions that occur when boron-10, a non-radioactive stable isotope, is irradiated with low-energy thermal neutrons or, alternatively, higher-energy epithermal neutrons, which become thermalized as they penetrate tissues. a The ¹⁰B(n,α)⁷Li capture reaction results in the production of high linear energy transfer (LET) alpha particles (stripped down ⁴He nuclei) and recoiling lithium-7 (⁷Li) atoms. b A sufficient amount of ¹⁰B must be delivered selectively to the tumor and, depending upon the depth of the tumor, this can range from ~ 20 to 50 µg/g (~ 10⁹ atoms/cell); a sufficient number of neutrons must be absorbed by the cancer cell to sustain a lethal ¹⁰B(n,α)⁷Li capture reaction. Since the destructive effects of the α particles are limited to boron-containing cells, BNCT can selectively kill malignant cells and spare surrounding normal cells