POSTIRRADIATION SARCOMAS IN SPRAGUE-DAWLEY RATS

A series of radiation-induced neoplasms occurred in Sprague-Dawley rat s 4-8 months after irradiation of a single hind leg with Co-60 gamma r ays, The rats were exposed to fractionated cumulative doses that range d from 0 to 106 Gy. Osteosarcomas, malignant fibrous histiocytomas and fibrosarcomas developed in the radiation fields of a number of the ra ts in the higher-dose groups, Tumors did not develop throughout an 8-m onth 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 r at may serve as a good animal model in studying the development of sar coma in humans after regional radiotherapy. (C) 1998 by Radiation Rese arch Society.