Radiobiological Effects of Auger Electron Emitters In Vivo: Spermatogenesis in Mice as an Experimental Model

Abstract

Using spermatogenesis in mice as the experimental model, the efficacy of Auger electron emitters for inducing radiobiological effects in vivo is investigated. The utility of the model and its relevance to man are examined. Procedures and protocols necessary for the conduct and interpretation of these experiments are described. Sperm cell survival data are presented for the Auger electron emitters, 201Tl and 55Fe, localised in the testes of the animals, and compared with the effects caused by the respective beta emitting counterparts, 204Tl and 59Fe, distributed similarly in the organ. In both cases, the conventionally calculated (MIRD) average radiation dose to the organ from the Auger electron emitter is about three times more efficient in sperm killing than the beta ray dose. Dosimetric models which account for this efficacy are indicated.