The use of 10B to enhance the tumour dose in fast-neutron therapy

Abstract
Incorporation of 10B in tumours treated by fast-neutron therapy would increase the tumour dose via the reaction 10B(n, alpha )7Li which occurs with partially thermalised neutrons. The extent of the dose enhancement was measured for neutron beams with median energies of 2.4, 3.3, 7.0 and 9.0 MeV by two techniques: with a BF3 proportional counter in three beams and activation of 23Na in the fourth. The results obtained with the two techniques are in good agreement. The magnitude of the dose enhancement depends upon the depth, field size and neutron beam energy. The products of the reaction in 10B would have an RBE about twice that of the fast-neutron dose in the absence of boron.