Conformal radiotherapy of the dominant liver metastasis: a viable strategy for treatment of unresectable chemotherapy refractory colorectal cancer liver metastases.

OBJECTIVES: To evaluate the safety and efficacy of conformal radiotherapy (RT) of the dominant liver metastasis as palliative treatment of patients with unresectable colorectal cancer liver metastases.
METHODS: We retrospectively reviewed the hospital and RT records of 17 patients with unresectable colorectal liver metastases who had been treated with palliative RT to the dominant liver metastasis at our institution.
RESULTS: The median size of the dominant liver metastasis was 10 cm (range, 3-19 cm). Twelve patients (71%) had evidence of extrahepatic disease. A median of 2 (range, 0-4) prior chemotherapy regimens had been administered. Median radiation dose was 42 Gy (range, 7.5-72 Gy). Concurrent chemotherapy included celecoxib in 1 (6%), capecitabine in 6 (35%), and both agents in 9 (53%) patients. Frequencies of acute diarrhea, nausea, vomiting, fatigue, hand-foot syndrome, and neutropenia were 29%, 47%, 6%, 29%, 7%, and 0%, respectively (all grade 2 or lower; no grade 3 toxicities). No late toxicities were noted. With a median follow-up time of 9.2 months, the median actuarial overall survival time from RT was 12.6 months (95% confidence interval [CI]: 3.3-40.9 months). The actuarial in-field local control rate was 62% at 6 months. The median actuarial time to in-field, out-of-field hepatic and distant progression were 6.8, 3.9, and 4.1 month, respectively (95% CIs, 3.9-15.8, 1.8-6.3, and 1.8-11.5 months, respectively).
CONCLUSIONS: Conformal RT to the dominant liver metastasis as palliative therapy for unresectable colorectal cancer liver metastases has an acceptable toxicity profile and may improve survival. This approach merits further exploration.