Clinical results of boron neutron capture therapy

It is concluded that if some 17 boron-neutron capture nuclear reactions occur within a single tumor cell, the cell will be destroyed. To attain this goal, one has to deliver a minimum of 2.5 x 1012 neutrons per gram of tumor when the average concentration of boron-10 is 25 μg 10B/g. Factors that may assist in achieving this objective are: (1) epithermal neutrons are an already well-known means to improve penetration of neutrons in the tissue; (2) the aperture of the neutron beam is important, if the aperture of the craniotomy bone window is large, the neutrons will reach deeper; (3) deuterium water, when it is used to replace tissue water or the cerebrospinal fluid in the spaces of the brain, will reduce attenuation of thermal neutrons and thus will facilitate a satisfactory penetration of neutrons. In conclusion the author says that physicians involved in malignant brain tumor treatment should start treating patients without waiting for the construction of an ideal epithermal beam because 500,000 people in the world are dying each year of malignant brain tumors and at least one-third of them could be saved without waiting for an epithermal beam