Functional and morphological evaluation of radiation nephropathy and ureteral injury in the dog

Intraoperative radiotherapy (IORT) may provide a therapeutic advantage in the treatment of certain intraabdominal malignancies. However, before the therapeutic potential of innovative modalities can be assessed adequately, the in vivo radiobiological effects and responses of normal tissues to clinical doses of irradiation must be determined. In this study, the reactions of normal canine kidneys, ureters, and major vessels wee assessed following IORT, fractionated x-irradiation, or a combination of these modalities. Radiographically derived morphological endpoints, including kidney size and cortical width, were monitored for one year following irradiation. The renal parenchymal atrophy, vascular alterations and functional impairment that developed was directly related to the IORT dose, whether delivered alone or in combination with fractionated x-irradiation. The incidence of ureteral injury and secondary hydronephrosis increased with both the IORT dose and post-irradiation time. No ureteral changes were detected in dogs that received only fractionated x-irradiation (60-80 Gy). No significant arteriographic abnormalities could be detected in the caudal aorta during the one year follow-up period