Stereotactic body radiotherapy versus percutaneous local tumor ablation for early-stage non-small cell lung cancer

Objectives: To compare patterns of care and overall survival (OS) between stereotactic body radiotherapy (SBRT) and percutaneous local tumor ablation (LTA) for non-surgically managed early-stage non-small-cell lung cancer (NSCLC). Materials and methods: The National Cancer Database (NCDB) was queried from 2004 to 2014 for adults with non-metastatic, node-negative invasive adenocarcinoma or squamous cell carcinoma of the lung with primary tumor size <= 5.0 cm who did not undergo surgery or chemotherapy and received SBRT or LTA. Patterns of care were assessed with multivariate logistic regression. After propensity-score weighting with generalized boosted regression, OS was assessed with univariate and doubly-robust multivariate Cox regression. Results: Of 15,792 patients, 14,651 (93%) received SBRT and 1141 (7%) received LTA. Increasing age (OR 1.01, p =.035), treatment at an academic institution (OR 2.94, p <.001), increasing tumor size (OR 1.05, p <.001), and more recent year of diagnosis (OR 1.43, p <.001) were predictive of treatment with SBRT, whereas comorbidities (OR 0.74, p =.003) and treatment at a high-volume facility (OR 0.05, p <.001) were predictive for LTA. At a median follow-up of 26.2 months, SBRT was associated with improved OS relative to LTA within a propensity-score weighted doubly-robust multivariate analysis (HR 0.71, p <.001). On weighted subgroup analyses, improved OS was observed with SBRT for tumor sizes > 2.0 cm (HR 0.72, p <.001) and for those treated at high-volume facilities (HR 0.71, p <.001). No OS difference was found with SBRT or LTA in tumor sizes <= 2.0 cm (HR 0.90, p =.227). Conclusion: Within the NCDB, SBRT was more commonly utilized and was associated with improved OS when compared to percutaneous LTA for patients with non-surgically managed early-stage NSCLC. Patients with small tumor volumes likely represent an appropriate population for future prospective randomized comparisons between SBRT and LTA.