Abstract. This study was undertaken to evaluate long-term results of radiofrequency (RF) ablation in patients with colorectal lung metastases and to stratify patients benefitting from lung RF ablation. Lung RF ablation was performed in 78 patients with 198 colorectal lung metastases. Safety, local tumor progression, and survival were evaluated retrospectively. The mean follow-up period after the 140 lung RF ablation sessions was 24.6±7.6 months. Pneumothorax and pleural effusion requiring chest tube placement occurred respectively in 18 (12.9%, 18/140) and 2 (1.4%, 2/140) sessions. The respective 1-, 3-and 5-year local tumor progression rates were 10.1% (95% CI, 2.9-17.3%), 20.6% (95% CI, 8.9-22.2%) and 20.6% (95% CI, 8.9-22.2%). The 1-, 3-and 5-year survival rates were 83.9% (95% CI, 75.2-92.7%), 56.1% (95% CI, 41.7-70.5%) and 34.9% (95% CI, 18.0-51.9%), with median survival time of 38.0 months. Univariate analysis revealed maximum tumor diameter of 3 cm or less, single-lung metastasis, lack of extrapulmonary metastasis and normal carcinoembryonic antigen (CEA) level as better prognostic factors. The latter two were significant independent prognostic factors. The 1-, 3-and 5-year survival rates were 97.7% (95% CI, 93.3-100%), 82.5% (95% CI, 68.2-96.8%) and 57.0% (95% CI, 34.7-79.2%) in 54 patients with no extrapulmonary metastases and 96.9% (95% CI, 90.8-100%), 86.1% (95% CI, 71.1-100%) and 62.5% (95% CI, 36.3-88.6%) in 33 patients with negative CEA levels. Lung RF ablation is a safe and useful therapeutic option. These identified prognostic factors will help to stratify patients who benefit from lung RF ablation.
