Small liver colorectal metastases treated with percutaneous radiofrequency ablation: local response rate and long-term survival with up to 10-year follow-up.

To determine the long-term (10-year) survival of patients with colorectal liver metastases treated with radiofrequency (RF) ablation and systemic chemotherapy with intention to treat. Institutional review board approval was obtained for this study. From 1997 to 2006, 99 consecutive patients with 202 small (0.8-4.0 cm; mean: 2.2 cm ± 1.1) metachronous colorectal liver metastases underwent ultrasonography-guided percutaneous RF ablation with internally-cooled electrodes in association with systemic chemotherapy. Patients ineligible for surgery (n = 80) or whose lesions were potentially resectable and who refused surgery (n = 19) were included. Patients were followed up with contrast agent-enhanced computed tomography and/or magnetic resonance imaging for a minimum of 3 years to more than 10 years after RF ablation (n = 99, 67, 49, and 25 for 3, 5, 7, and 10 or more years, respectively). Overall local response rates and long-term survival rates were assessed. For each of these primary endpoints, Kaplan-Meier curves were generated and log-rank tests were used to assess for statistically significant differences. Primary and secondary technical success rates were 93.1% (188 of 202) and 100% (14 of 14), respectively. Local tumor progression occurred in 11.9% (24 of 202) metastases, and 54.2% (13 of 24) of these were re-treated. Patient survival rates increased with re-treatment versus no re-treatment (P < .001). At follow-up, 125 new liver metastases were found, and of these 32.8% (41 of 125) were treated with RF ablation. Overall survival rates were 98.0%, 69.3%, 47.8%, 25.0%, and 18.0% (median: 53.2 months) at 1, 3, 5, 7, and 10 years, respectively. The major complication rate was 1.3% (two of 156), and there were no procedure-related deaths. At the time this article was written, 32.3% (32 of 99) of the patients were alive, and 67.7% (67 of 99) were deceased, with a median follow-up of 72 months. Adding RF ablation to systemic chemotherapy achieved local control in a large majority of metachronous colorectal liver metastases. The 3- to 10-year survival rates of this relatively large series of patients were essentially equivalent to those of most surgical series reported in the literature. © RSNA, 2012.