[Chronic radiation sequelae in the rat rectum following intracavitary irradiation with different doses]

The dependence of chronic radiation damage of the rectosigmoid on dose, dose rate and irradiated volume after intracavitary irradiation with an oscillating iridium source was studied in rats. The incidence of large bowel stenosis increased with increasing dose, dose rate and volume. The nominal dose leading to 50% incidence of stenosis was 27 Gy at 2 Gy/min, 32.5 Gy at 0.2 Gy/min and 51 Gy at 0.05 Gy/min.