Impact of stereotactic body radiation therapy volume on surgical patient selection, short-term survival, and long-term survival in early-stage non-small cell lung cancer

Abstract

Objectives: Stereotactic body radiation therapy (SBRT) is increasingly used to treat non-small cell lung cancer. The purpose of this study is to analyze relationships between facility SBRT utilization and surgical patient selection and survival after surgery.

Methods: Data on patients with TI/T2N0M0 lesions and treatment facility characteristics were abstracted from the National Cancer Database, 2008 to 2017. Facilities were stratified using an SBRT/surgery ratio previously associated with short-term survival benefit for patients treated surgically, and by a previously identified surgical volume threshold. Multiple regression analyses, Cox proportional-hazard regressions, and Kaplan-Meier log rank test were employed.

Results: In total, 182,610 patients were included. Proportion of high SBRT:surgery ratio (≥17%) facilities increased from 118 (11.5%) to 558 (48.4%) over the study period. Patients undergoing surgery at high-SBRT facilities had comparable comorbidity scores and tumor sizes to those at low-SBRT facilities, and nonclinically significant differences in age, race, and insurance status. Among low-volume surgical facilities, treatment at a high SBRT-using facility was associated with decreased 30-day mortality (1.8% vs 1.4%, P < .001) and 90-day mortality (3.3% vs 2.6%, P < .001). At high-volume surgical facilities, no difference was observed. At 5 years, a survival advantage was identified for patients undergoing resection at facilities with high surgical volumes (hazard ratio, 0.91; confidence interval, 0.90-0.93 P < .001) but not at high SBRT-utilizing facilities.

Conclusions: Differences in short-term survival following resection at facilities with high-SBRT utilization may be attributable to low surgical volume facilities. Patients treated at high volume surgical facilities do not demonstrate differences in short-term or long-term survival based on facility SBRT utilization.

Keywords: non–small cell lung cancer; patient selection; stereotactic body radiation therapy; surgery.