Enhancement of tumor dose via neutron beam filtration and dose rate, and the effects of these parameters on minimum boron content

Calculations are made of the minimum boron content in tumor necessary for neutron capture therapy. These estimations are made for various neutron beams, on the basis of therapeutic gain produced by effective dose (absorbed dose x relative biological effect). The effects of repair are evaluated, in anticipation of boronated biomolecules having selective and long-term binding to tumor cells, thus allowing protracted irradiations. Pure epithermal neutron beams (free of significant fast neutron and γ contamination) are found to offer major advantages, particularly when the effects of repair are included. The various boron compounds being investigated for NCT are evaluated on the basis of necessary minimum boron content in tumor