In the SWOG S1827 MAVERICK phase III randomized trial, patients with small-cell lung cancer (SCLC) who underwent regular brain MRI surveillance without prophylactic cranial irradiation (PCI) had significantly better cognitive failure–free survival (the primary endpoint of the trial), without an apparent difference in overall survival, according to results presented at the Presidential Symposium of the IASLC 2026 World Conference on Lung Cancer, hosted by the International Association for the Study of Lung Cancer, in Seoul, Republic of Korea.