Repository hosted by TU Delft Library

Values of the relative biological effectiveness (RBE) of fast neutrons for effect on normal tissue depend not only on the neutron energy and the dose, but also on the type of tissue irradiated. Values of the RBE of 15 MeV neutrons are reviewed for rapidly proliferating rodent tissue, such as mouse bone marrow, mouse intestine and rat skin treated with single and fractionated irradiations. In addition, RBE values were obtained for rodent tissue with relatively long cell life times, such as the vascular endothelium, the spinal cord and the lung. In general, the normal tissue data indicate that for doses between 50 and 250 rad the RBE values range up to values of about 2, but depend on the fractionation regimen.