A brief review on reactor-based neutron sources for boron neutron capture therapy

Neutron sources for boron neutron capture therapy (BNCT) have been based, until few years ago, on fission nuclear reactors; indeed only nuclear reactors were able to produce neutron flux with the right intensity in the range of thermal and/or epithermal energy. At present many centers are substituting reactor sources with accelerator-based neutron sources that can be easily installed in a hospital environment helping the BNCT diffusion as a standard cancer treatment. Although only few reactor-based BNCT sources are still active (Argentine, China, Japan, Taiwan), nonetheless the role played by nuclear reactors was essential for BNCT birth, and the current available reactors will continue to give a fundamental contribution to its further development. In this article we report a brief review of the fission reactor-based neutron sources for BNCT; we focus on the main requirements which this source had to fulfil to be suitable for BNCT applications, not pretending to be exhaustive due to the very broad topic. General requirements for reactor BNCT neutron sources, techniques to produce epithermal neutron beams starting from fission neutrons, and parameters for their performance evaluation will be briefly discussed.