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.