Outcomes of microwave ablation for colorectal cancer liver metastases: A single center experience

BACKGROUND AND OBJECTIVES: Surgical management of colorectal cancer liver metastases continues to evolve to optimize oncologic outcomes while maximizing parenchymal preservation. Long-term data after intraoperative microwave ablation are limited. This study investigates outcomes and patterns of recurrence in patients who underwent intraoperative microwave ablation. METHODS: A retrospective analysis of 33 patients who underwent intraoperative microwave ablation of colorectal cancer liver metastases from 2009 to 2013 at our institution was performed. Perioperative and long-term data were reviewed to determine outcomes and patterns of recurrence. RESULTS: A total of 49 tumors were treated, ranging 0.5-5.5 cm in size. Median Clavien-Dindo classification was one. Median follow-up was 531 days, with 13 (39.4%) patients presenting with a recurrence. Median time to first recurrence was 364 days. In those patients, 1 (7.8%) presented with an isolated local recurrence in the liver. Only 1 of 7 ablated tumors greater than 3 cm recurred (14.3%). Overall survival was 35.2% at 4 years, with a 19.3% disease-free survival at 3.5 years. No perioperative variables predicted systemic or local recurrence. CONCLUSION: Intraoperative microwave ablation is a safe and effective modality for use in the treatment of colorectal cancer liver metastases in tumors as large as 5.5 cm in size.