Is SBRT More Effective Than CRT for Peripheral, Central Stage I NSCLC?

Background: Stage 1 non–small-cell lung cancer (NSCLC) treated by stereotactic body radiotherapy (SBRT) has an 85% to 95% local control rate. Historically, conventional radiotherapy (CRT) has not done nearly so well; 2 randomized trials comparing SBRT to CRT have not demonstrated superiority of SBRT. Objective: To examine whether SBRT would improve local control compared to hypofractionated CRT for stage I NSCLC. Design: Multicenter randomized trial. Participants: Patients from 16 Canadian centers who had medically inoperable N0 tumors that were ≤5 cm in size. Methods: Patients were stratified by tumor size (T1, ≤3 cm; T2a, >3 to 5 cm), location (whether they were within 1 cm of mediastinum or 2 cm of proximal bronchial tree), and the treating institution. Patients were randomized in favor of SBRT 2:1. Patients with peripheral tumors received 48 Gy in 4 alternate-day fractions. Those with central tumors randomized to SBRT received 60 Gy in 8 alternate-day fractions. CRT patients r more...