Thermal Neutron Relative Biological Effectiveness Factors for Boron Neutron Capture Therapy from In Vitro Irradiations.

The experimental determination of the relative biological effectiveness of thermal neutron factors is fundamental in Boron Neutron Capture Therapy. The present values have been obtained while using mixed beams that consist of both neutrons and photons of various energies. A common weighting factor has been used for both thermal and fast neutron doses, although such an approach has been questioned.

Radiobiology data of melanoma cells after low-energy neutron irradiation and boron compound administration.

The cold neutron beam at the PF1b line at the Institut Laue-Langevin (ILL), without fast neutrons and a low contribution of gamma rays, is a very suitable facility to measure cell damage following low-energy neutron irradiation. The biological damage associated with the thermal and the boron doses can be obtained in order to evaluate the relative biological effectiveness (RBE) for Boron Neutron Capture Therapy. Three different experiments were carried out on the A375 melanoma cell line: the first one in a hospital LINAC, to obtain the reference radiation data, and the other two at the ILL, in which the damage to cells with and without boron compounds added was measured.