Is it necessary to use a CTV margin when treating limited stage small cell lung cancer? This multicenter, real world analysis included 946 patients with LS-SCLC who were treated with definitive radiation using a CTV (57.4%) or not (42.6%). After propensity matching, there were no significant differences with or without a CTV in median PFS (11.6 v 11.8 months), response rate (69.4% v 72.8%), and median OS (30.7 v 35.8 months). There was also no difference in local recurrence. However, omission of a CTV was associated with less grade 3+ pneumonitis (3.4% v 8.3%) and grade 3+ esophagitis (5.7% v 9.1%). Finally, among patients who received immunotherapy, there was a suggestion that omitting the CTV was associated with better PFS and OS. | Wang, Radiother Oncol 2026
