Bezjak A, et al. - Researchers investigated the maximum tolerated dose (MTD), effectiveness, and toxicity of stereotactic body radiotherapy (SBRT) for centrally located non–small-cell lung cancer (NSCLC) in a phase 1/2 study (NRG Oncology/RTOG 0813). A dose-escalating, five-fraction SBRT schedule was employed in medically inoperable patients with biopsy-proven, positron emission tomography-staged T1 to 2 (≤ 5 cm) N0M0 centrally located NSCLC. Participants received 10 to 12 Gy/fraction (fx) over 1.5 to 2 weeks. Overall, 120 patients were included. Resulting in 7.2% dose-limiting toxicities (defined as any treatment-related grade 3 or worse predefined toxicity that occurred within the first year) and high rates of tumor control, the MTD was assessed as 12.0 Gy/fx. The observed outcomes were comparable with that of patients with peripheral early-stage tumors in this study sample of mostly elderly patients with comorbidities.