Comparison of Survival Outcomes of Single- and Five-Fraction Schedules of Stereotactic Body Radiation Therapy for Early-Stage Central or Peripheral NSCLC

SIMPLE SUMMARY: Patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT) often receive different treatment regimens based on the location of the tumor to minimize the risk of severe side effects. The aim of our study was to examine survival outcomes of patients treated with single-fraction SBRT for peripheral tumors and five-fraction SBRT for central tumors. In a cohort of 265 patients with NSCLC, we found no differences in patients treated for peripheral versus central tumors in progression-free survival, overall survival, local failure, nodal failure, or distant failure. These findings were confirmed upon propensity score matching. Our study demonstrated survival outcomes of patients treated with SBRT for early-stage NSCLC were equivalent for central and peripheral tumors. ABSTRACT: Background: The treatment of early-stage non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT) frequently involves different fractionation schemes for peripheral and central tumors due to concerns with toxicity. We performed an observational cohort study to determine survival outcomes for patients with peripheral and central NSCLC treated with SBRT. Methods: A single-institutional database of patients with early-stage NSCLC treated with SBRT from September 2008 to December 2018 was evaluated. Outcomes were progression-free survival (PFS), overall survival (OS), local failure (LF), nodal failure (NF), and distant failure (DF). Cox multivariable analysis (MVA), Kaplan–Meier plotting, Fine–Gray competing risk MVA, and propensity score matching were performed. Results: A total of 265 patients were included with a median follow-up of 44.2 months. There were 191 (72%) and 74 (28%) patients with peripheral and central tumors treated with single-fraction SBRT to a dose of 27 Gy and five-fraction SBRT to a dose of 50 Gy, respectively. On Cox MVA, there was no difference in OS (adjusted hazards ratio (aHR) of 1.04, 95% CI of 0.74–1.46) or PFS (aHR of 1.05, 95% CI of 0.76–1.45). On Fine–Gray competing risk MVA, there were no differences in LF, NF, or DF. Propensity matching confirmed these findings. Conclusion: The survival outcomes of patients treated with SBRT for early-stage NSCLC were equivalent for central and peripheral tumors.