FRACTIONATED-IRRADIATION OF THE REGENERATED RAT-LIVER

Fractionated radiation therapy after liver resection for metastatic ca ncer has traditionally been a palliative procedure. Here, we consider that radiation may be an appropriate adjuvant therapy for cure after l iver resection for metastases. This pilot study in rats establishes a model for evaluating the effects of fractionated irradiation posthepat ectomy. Sixty Sprague-Dawley rats were randomized to four groups. The groups underwent laparotomy, laparotomy and radiation, hepatectomy, an d hepatectomy and radiation. We found that the rats treated with radia tion had statistically significant (P < 0.0001) clinical radiation cha nge by liver function tests at 6 months. This damage was resolved to n ormal at 1 year regardless of hepatectomy. In fact, we demonstrate the possibility of a protective effect from radiation damage in the regen erated liver. We also demonstrate statistically significant histologic change at 8 months (P < 0.01) in the radiation-treated rats which doe s not resolve at 1 year. (C) 1995 Academic Press, Inc.