Neutron relative effectiveness factors in Boron Neutron Capture Therapy: estimation of their values from the secondary charged particles and evaluation of weighted kerma factors for a standard tissue

The average Relative Biological effectiveness (RBE) factors for neutron irradiation in the context of a BNCT treatment are studied. This research considers the various interactions and secondary particles of each process and estimates the RBE based on the damage induced in tissues by all of these particles. A novel concept of estimating the biological dose by means of weighted kerma factors is introduced. These weighted kerma factors include the RBE of each energy deposition based on an RBE-LET relationship for secondary charged particles and can be directly incorporated in weighted dose calculations from Monte Carlo simulations. Furthermore, the dependence of the neutron weighting factor on neutron energy for standard soft tissue is discussed.