Purpose: To report the effects of boost dose radiation on palliation, survival, and toxicity in patients undergoing palliative treatment for hepatic metastases from colorectal cancers and to assess the potential benefits of higher doses of radiation to partial liver volumes. Materials and Methods: Forty-five patients with hepatic metastases from colorectal cancers were treated with a course of palliative irradiation, Eligible patients included those with radiographically or histologically proven liver metastases. All patients but one received chemotherapy, either pretreatment (one patient) and/or concurrently with radiation (43 patients) via intravenous or hepatic intraarterial infusion. Patients were divided into two groups based on whether or not boost radiation was given. Thirty-three of the 45 patients (group 1) received whole-liver irradiation at doses that ranged from 8 to 31 Gy at 2.0 to 3.0 Gy per fraction (median dose, 21 Gy), The remaining 12 patients (group 2) received liver irradiation to 20 to 30 Gy followed by ct boost dose to the area of dominant disease for a total dose of 33 to 60 Gy, The extent of liver involvement was similar between the two groups. Palliation, overall survival, and toxicity were analyzed with respect to radiation dose, Results: There was no increase in acute effects observed in treating partial liver volumes to higher doses in conjunction with systemic chemotherapy. No cases of radiation-induced hepatitis or nephritis were documented, Hematologic toxicity (greater than or equal to grade 3) was observed in four patients with thrombocytopenia, three with leukopenia, and two with anemia, Pain was relieved in 71% and hepatomegaly in 59% of group 1 patients, as compared with 100% and 89%, respectively, of group 2 patients. Other symptoms such as nausea, fever, fatigue, and jaundice were palliated in 35% of group 1 and 90% of group 2 patients. The median survival time for group 1 patients was 4 months (range, 1 week to 26 months), which is consistent with that reported in the literature. The median survival time for group 2 patients was 14 months (range, 2 to 32 months) (P = .01), Conclusion: Standard hepatic irradiation followed by boost radiation to partial liver volumes in combination with chemotherapy is well tolerated without significant acute/late morbidity. Higher radiation doses to partial liver volumes offers improved palliative benefit and may prolong survival without an increase in morbidity. (C) 1996 by American Society of Oncology.
