Local Efficacy and Survival after Microwave Ablation of Lung Tumors: A Retrospective Study in 183 Patients

Abstract

PurposeTo retrospectively evaluate local efficacy and survival after microwave (MW) ablation of lung tumors and identify predictors of prognosis. Materials and MethodsData from 183 consecutive patients (67 women; mean age, 61.5 y ± 13.4) with lung tumors who had undergone 203 lung MW ablation sessions from January 2011 to May 2013 were assessed. The χ2 test, independent-samples t test, Kaplan–Meier analysis, and Cox regression model analysis were used to estimate survival rates and evaluate significance of factors affecting rates of incomplete ablation, local progression, remote progression–free survival (RPFS), and cancer-specific survival (CSS). ResultsTechnical success rate was 100%. Incomplete ablation rate after 183 first MW ablations was 14.2% (26 of 183); maximum diameter of target tumors (P = .00001) was associated with incomplete ablation on univariate analysis. The local progression rate was 19.1% (35 of 183); emphysema (P = .020) and maximum diameter of target tumor (P = .000003) were associated with local progression. Median and 4-year RPFS were 15.0 months (95% confidence interval [CI], 11.1–18.9 mo) and 23.8%, respectively. Tumor stage (P < .01) and incomplete ablation (P = .002) were independent predictors of RPFS. Median and 4-year CSS were 24.9 months (95% CI, 19.9–29.9 mo) and 31.1%, respectively. Median and 4-year overall survival were 23.7 months (95% CI, 20.6–26.8 mo) and 29.6%, respectively. Tumor stage (P < .01) and maximum diameter (P = .009) were independent risk factors for CSS. ConclusionsMW ablation is effective for lung tumors, especially small lesions of early-stage primary lung cancer and solitary lung metastasis.