Boron neutron capture therapy is a type of radiation therapy that uses boron-10, which is a stable isotope of boron that can undergo nuclear fission when exposed to neutrons, to treat cancer. The document discusses the history and development of boron neutron capture therapy, including clinical trials that have been conducted to test it as a treatment for brain tumors. It also covers applications of boron chemistry to cancer treatment, such as using boron compounds as delivery agents to target cancer cells and the development of boron-enriched nanocomposites for this purpose.