MRI Surveillance Without PCI Improved Cognition in SCLC

Brain magnetic resonance imaging (MRI) surveillance without prophylactic cranial irradiation (PCI) improved cognitive failure–free survival among patients with small-cell lung cancer (SCLC) in the phase 3 SWOG S1827 MAVERICK trial, according to SWOG Cancer Research Network. Preliminary results showed no apparent difference in overall survival (OS). The findings were presented at the IASLC 2026 World Conference on Lung Cancer.

The international randomized trial enrolled 304 patients with limited- or extensive-stage SCLC who had completed initial therapy and had no brain metastases on MRI. Participants were assigned to MRI surveillance alone or MRI surveillance plus PCI. MRI was performed every 3 months during the first year and every 6 months during the second year, with cognitive testing at the same intervals. Overall, 68% had limited-stage disease.

After a median follow-up of 22 months among living patients, cognitive failure–free survival—the primary endpoint—was significantly better with MRI surveillance alone (hazard ratio [HR], 0.60; 90% CI, 0.46-0.78; P=.0005). The endpoint was defined as time from randomization to cognitive failure or death. Cognitive failure was a decline on any 1 of 6 standard tests.

The benefit was consistent in limited- and extensive-stage disease and was not significantly affected by receipt of immunotherapy. A preliminary OS analysis after 128 deaths found no apparent between-group difference (HR for MRI surveillance alone, 0.90; 90% CI, 0.67-1.20). Progression-free survival also did not differ significantly.

Investigators concluded that the findings support MRI surveillance alone for patients with SCLC. However, the final OS analysis is planned after 190 deaths, leaving the survival comparison unresolved.

Source: SWOG Cancer Research Network. Brain MRI surveillance without PCI improves SCLC cognitive outcomes. News release. SWOG Cancer Research Network; September 14, 2026. Accessed September 20, 2026.