Treatment failure after percutaneous radiofrequency ablation for nonsurgical candidates with pulmonary metastases from colorectal carcinoma

Background: This study critically evaluated the local and overall treatment failure rates after percutaneous radiofrequency ablation (RFA) of pulmonary metastases from colorectal carcinoma. Methods: Fifty-five nonsurgical candidates underwent RFA of colorectal pulmonary metastases. The primary end points of this study were local progression-free survival (PFS) and overall PFS. Univariate and multivariate analyses were performed to identify significant prognostic parameters for local and overall PFS. Results: The local recurrence rate was 38%. For local PFS, univariate analysis demonstrated that the largest size of lung metastasis, the location of lung metastases, the post-RFA carcinoembryonic antigen level at 1 month, and the post-RFA carcinoembryonic antigen level at 3 months were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm and a post-RFA carcinoembryonic antigen level of >5 ng/mL at 1 month were independently associated with a reduced local PFS. The overall recurrence rate was 66%. For overall PFS, univariate analysis demonstrated that sex and the largest size of lung metastasis were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm was independently associated with a reduced overall PFS. Conclusions: RFA of colorectal pulmonary metastases may have a useful role in local disease control for nonsurgical candidates, but its efficacy in patients with a lung metastasis of >3 cm is limited.