Efficacy and safety of thermal ablation in patients with liver metastases

Thermal ablation is safe and effective for the treatment of hepatocellular carcinoma. However, it remains problematic with respect to liver metastases. Here, we aimed to evaluate the efficacy and safety of thermal ablation in patients with liver metastases.

Eighty-nine patients with 132 liver metastases measuring 0.8-5.0 cm were treated with microwave ablation (MWA) or radiofrequency ablation (RFA). The primary lesions were colorectal cancer in 38 cases and others in 51, respectively. Local tumor control, complications, and long-term survival were analyzed.

Complete ablation was achieved in 117 of 132 (88.6%) nodules. Seventeen of the 117 (14.5%) successfully treated nodules developed local recurrence. In a univariate analysis, a significant trend toward a lower local recurrence rate with MWA was observed (8.6% for MWA vs. 20.3% for RFA, P=0.072). Multivariate analysis showed that number of cycles of chemotherapy was the significant prognostic factor for overall recurrence (P=0.015), whereas disease-free interval was the significant prognostic factor for distant recurrence (P=0.030). Ablation modality showed potential prognostic significance for local recurrence (P=0.053). Major complications occurred in 1.1% of patients. No procedure-related mortalities were observed. The 1, 2, 3, and 5-year overall survival rates after the initial ablation were 84.9, 59.6, 48.8, and 36.3%, respectively.

Thermal ablation is a safe and effective treatment for patients with liver metastases. MWA has the potential to result in less local recurrence than RFA.