Image-guided Radiofrequency Ablation for Treatment of Stage I Non-Small Cell Lung Cancer in 111 High-risk Patients: Analysis of Prognostic Variables.

Objective: Surgical resection is the standard treatment for stage 1 non-small-cell lung cancer (NSCLC). Radiofrequency ablation (RFA) is an option in high-risk patients who cannot undergo surgical resection of stage I NSCLC, but prognostic factors and long-term oncologic results have not been fully evaluated. We evaluated outcomes after image-guided RFA in high-risk patients with stage I NSCLC, and factors associated with survival.

Methods: We evaluated the outcomes of image-guided-RFA performed by thoracic surgeons, for biopsy-proven stage I NSCLC in high-risk patients over a 17-year period. The primary endpoint evaluated was overall survival (OS) studied using Kaplan-Meier analysis. Covariates associated with OS were analyzed with univariate proportional hazards regression and multivariate cox regression.

Results: One-hundred-eleven patients (median age 74 years) underwent image-guided RFA. After a median follow-up of 30 months, estimated OS was 86% at 1 year (95% CI 80%-93%) and 54% at 3 years (95% CI 46%-64%). During follow-up, local progression in the treated lesion occurred in 44 patients (40%). Covariates associated with improved OS in multivariate analysis included size < 2 cm (p=0.043) and adenocarcinoma histology (p=0.013).

Conclusions: While surgical resection remains the standard, image-guided RFA is effective for high-risk patients with stage I NSCLC who are not surgical candidates. Analysis of covariates associated with survival showed that size and histology of the lesion are important prognostic factors. Prospective studies of RFA are required to further define patient selection in this high-risk group.