Percutaneous Cryoablation for the Treatment of Primary and Metastatic Lung Tumors: Identification of Risk Factors for Recurrence and Major Complications.

PURPOSE: To identify risk factors for local recurrence and major complications associated with percutaneous cryoablation of lung tumors. MATERIALS AND METHODS: All cases between April 2007 and September 2014 at 1 institution were retrospectively reviewed. Procedures were performed using computed tomography guidance and a double freeze-thaw protocol. Tumor progression was determined via World Health Organization guidelines, and complications were classified using SIR reporting standards. Measures of efficacy were calculated via Kaplan-Meier analysis. Predictors of local progression and major complications were identified by Cox proportional hazards and logistic regression. RESULTS: There were 47 tumors (25 primary, 22 metastatic) treated with median follow-up of 11.1 months. Mean diameter before treatment was 2.4 cm, and an average of 2.1 cryoprobes were used per procedure. Major complications (most commonly, pneumothorax requiring chest tube) occurred in 12 (25%) cases, and minor complications occurred in 13 (27%) cases. Median time to local progression was 14 months (16 mo for primary tumors and 10 mo for metastatic tumors), and median overall survival was 33 months (43 mo for patients with primary tumors and 22 mo for patients with metastatic tumors). On multivariate analysis, tumor diameter > 3 cm was associated with local progression (hazard ratio = 3.2, P = .013), and use of multiple cryoprobes (relative risk [RR] = 7.2, P = .045) and previous local therapy (RR = 15, P = .030) were associated with major complications. CONCLUSIONS: Percutaneous cryoablation of lung tumors is technically feasible with a complication rate comparable to other percutaneous ablation techniques. Percutaneous cryoablation is more efficacious and has fewer complications when offered to patients with small, previously untreated lesions.