Postirradiation sarcomas in Sprague-Dawley rats

A series of radiation-induced neoplasms occurred in Sprague-Dawley rats 4-8 months after irradiation of a single hind leg with Co-60 gamma rays, The rats were exposed to fractionated cumulative doses that ranged from 0 to 106 Gy. Osteosarcomas, malignant fibrous histiocytomas and fibrosarcomas developed in the radiation fields of a number of the rats in the higher-dose groups, Tumors did not develop throughout an 8-month observation period in rats that received doses of only 0 or 46 Gy. The most common postirradiation sarcomas in humans are osteosarcoma, malignant fibrous histiocytoma and fibrosarcoma, The Sprague-Dawley rat may serve as a good animal model in studying the development of sarcoma in humans after regional radiotherapy. (C) 1998 by Radiation Research Society.