Comparison of Single- and Five-fraction Regimens of Stereotactic Body Radiation Therapy for Peripheral Early-stage Non–small-cell Lung Cancer: A Two-institution Propensity-matched Analysis

We compared the outcome of peripheral early-stage non–small-cell lung cancer treated with single- and 5-fraction stereotactic body radiation therapy regimens. A total of 163 eligible lesions and a propensity score-matched 92 lesions were analyzed. No statistically significant differences were observed between these regimens, and both approaches are reasonable. Purpose: To evaluate differences in local control (LC), disease-specific (DC), and overall survival (OS) of patients with early-stage non–small-cell lung cancer (NSCLC) treated with single- (SF) versus 5-fraction (FF) stereotactic body radiation therapy (SBRT) at 2 institutions. Patients and Methods: Peripheral early-stage NSCLC cases treated with a median dose of 30 Gy in SF or a median dose of 50 Gy in FF were included per institutional practice. Kaplan-Meier and Cox models were used to assess survival. A matched-pair analysis was performed to account for imbalances. Toxicities including Common Terminology Criteria for Adverse Events (CTCAE) grade 3 pneumonitis, chest wall pain requiring long-acting narcotics, and hospitalization for respiratory events 6 months posttreatment were recorded. Results: A total of 163 lesions were treated between 2007 and 2015; 65 received SF SBRT and 98 received FF SBRT. Most tumors were T1 (n = 92) and T2 (n = 34) lesions and had adenocarcinoma (n = 77) and squamous cell carcinoma (n = 46) histologies, respectively. In the matched cohort, there were no differences in OS, LC, DC, or progression-free survival between the groups. LC and OS at 1 year in the matched cohort was 95% and 88%, and 87% and 84% in the SF and FF cohorts, respectively. There was 1 grade 3 pneumonitis in the FF group, and 9 total hospitalizations post-SBRT, 3 (5%) in the SF group and 6 (6%) in the FF group. Conclusions: No statistically significant differences were seen in LC or DC following SF or FF SBRT in this matched cohort of peripheral lesions. No grade 4 or higher toxicities were reported.