Boron Neutron Capture Therapy (BNCT) is a binary treatment modality based on the nuclear reaction after irradiation of the boron localized preferably within the neoplastic cells by low-energy (thermal) neutrons. The interaction of 10B and the neutron leads to splitting of the 10B nucleus, releasing an alpha particle and lithium nucleus. Both the alpha particles (4He) and lithium nucleus have path lenghts for energy transfer of less than 10 µm giving thus rise in approximately one cell diameter to closely spaced ionizing events, eventually leading to cell death. The increasing interest in the method worldwide dating back to 1950‘s and 1960‘s in the USA and Japan could be attributed to unsatisfactory results in the treatment of glioblastoma multiforme with the plethora of modalities whereas the theoretical principles of BNCT, which is rather a biologically than physically targeted modality, seem to be promising in affecting the tumour cells providing their sufficient 10B concentration and delivered neutrons. This paper aims at reviewing the historical background of the method, its principles and contemporary clinical situation in the world.

        Key words: boron neutron capture therapy, boron compound, thermal neutrons, nuclear reaction, history and contemporary situation