[Boron neutron capture a a new radiotherapy model].

The boron neutron capture therapy is based on the reaction occurring with certain probability, if a thermal neutron meets the boron 10 isotope. The low energy slow neutron is captured by the nucleus and it disintegrates into Li-nucleus and He-nucleus (alpha particle). If this physical reaction occurs in a living cell that will be destroyed. If the boron neutron capture reaction could be achieved selectively in malignant cells of tumor patients, that could be an effective therapeutical modality to treat the locally growing cancers. For boron neutron capture therapy to be successful two basic conditions must be fulfilled, an appropriate neutron source must be available and the sufficient number of 10B must be delivered possibly selectively into the tumor cells by a boron compound. At present both part of this binary system are under intensive investigation, the development of the neutron source, the synthetisation and experimental testing of boron delivery agents. The development of the dosimetry, microdosimetry, the work out of the powerful tools of detection the cellular, subcellular 10B distribution, the continuous improvement of the planning system and the optimization of the boron neutron capture therapy are the main point of the research area on boron neutron capture therapy. Clinical studies and clinical application of boron neutron capture therapy are under way for the treatment of melanoma malignum and for brain tumors, with the two boron compound has been clinically tested up to now, in Japan, at two Centres in USA, and recently has been started in Europe. The authors give an overview about the principles of boron neutron capture therapy, about the result of the research on neutron sources and boron compounds, moreover about the possible application area of this new radiation modality.