BNCT is biochemically targeted radiation therapy. Boron-10 (10B) atoms are selectively delivered to the tumor, followed by irradiation with low energy neutrons.
The stable boron isotope 10B has a large neutron capture radius. Thus, 10B is more likely to capture neutrons than many other elements that are present in biological environments (e.g., nitrogen and hydrogen). A fission reaction occurs upon neutron capture, and a lithium ion and an alpha particle are produced. These particles have high kinetic energies, but their range is only about 10 microns. This leads to very efficient cancer cell killing precisely at the site of boron accumulation.