Neutrons in cancer treatment. Past, present and future. Review

For many decades, neutrons have been actively used in the treatment of various cancer diseases. In the light of recent advances in conventional photon therapy, interest in neutrons has almost faded, despite their unique biological features. At the same time, neutron-capture therapy is actively developing, the concept of which is based on the high precision of the treatment method, allowing to minimize the toxicity of the treatment. Another way of using neutrons deserves attention - as sources for contact brachytherapy. In Russia, various neutron therapy methods have been studied in depth, ranging from fundamental aspects to direct wide use in various clinical situations. Such capabilities were provided by the extensive research infrastructure of particle physics, and its accessibility to researchers and clinicians. In the modern clinical perspective, neutron therapy can be an effective treatment option for certain clinical indications. Such cases are traditionally referred to as radioresistant tumors, which are considered to be low sensitive to irradiation. This mini-review recall the history of the use of neutrons since their discovery and to the present days, as well it discusses their role in the further development of radiotherapy.