Radiation-Induced Rectal Complications are not Influenced by Age: A Dose Fractionation Study in the Rat

Abstract Van den Aardweg, G. J. M. J., Olofsen-van Acht, M. J. J., van Hooije, C. M. C. and Levendag, P. C. Radiation-Induced Rectal Complications are not Influenced by Age: A Dose Fractionation Study in the Rat. Radiat. Res. 159, 642–650 (2003). Radiation-induced complications of the rectum are an important dose-limiting factor in radiotherapy of pelvic malignancies. In general, animal studies demonstrated no differences in acute and late normal tissue toxicity with age, but little is known about rectal complications in relation to age. For this purpose, an extensive histological and dose fractionation study was carried out on the rectum of young (12 weeks) and older (77–80 weeks) rats. In this paper, the results of dose fractionation are presented in relation to age at the time of irradiation. Young and older animals were irradiated with single and fractionated doses. After irradiation, rectal complications could lead to occlusion and stenosis, eventually resulting in the clinical symptoms of a megacolo...