The Effects of Total-Body Fast Neutron Irradiation in Dogs

Abstract

A considerable body of information has been accumulated on the effects of neutrons on microorganisms, cells, and small animals. The relative biological effectiveness (RBE) of neutrons has been investigated extensively, by means of a number of biological end points, and a wide variety of values from 1 to 20 have been reported. These studies have been summarized previously (1, 2). Studies of the effects of single-exposure total-body neutron irradiation on mammals the size of the dog have not been attempted previously because of the lack of suitable source. With most neutron generators, a field large enough to accommodate the dog is associated with a flux density too low to be useful for acute exposures. The flux density from the 60-inch Crocker Laboratory cyclotron, however, was sufficiently high to permit lethal exposures in a period of a few minutes. The relative biological effectiveness in mice of neutrons from this source has been determined (3). The present report deals with acute effects in the dog after exposure to total-body fast neutron radiation, and comparison is made with dogs exposed to penetrating X-radiation.