Model for the occurrence of bone tumors in beagles

A three-stage model for the induction of bone tumors in beagles from single injections of Pu-239 is presented. The model involves branching with one o r two initiation steps controlled by radiation. It was applied to six group s of animals with graded injection levels between 0.38 and 33.6 kBq/kg body mass, assuming an endosteal dose rate constant in time and proportional to tile injected activity. The density of osteosarcoma survival times is Weibu ll with shape factor three and the scale factor being a function of the inj ected activity. The fraction of animals with bone tumors can be predicted u sing the survivor function of tile controls, but some systematic deviations occur between calculations and observed Fractions in an intermediate dosag e range. It is shown that for low levels of Pu-239 the fraction of animals with tumors is proportional to the injected amount of plutonium. (C) 2001 E lsevier Science Ltd. All rights reserved.