MRI Surveillance Alone Improves Cognitive Survival in SCLC

Results from the international phase III SWOG S1827 MAVERICK trial have shown that brain MRI surveillance alone can improve cognitive failure-free survival in patients with small-cell lung cancer (SCLC) compared to MRI surveillance plus prophylactic cranial irradiation (PCI). The findings, presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC), support MRI surveillance alone as the standard of care for SCLC.

For decades, PCI has been used after initial therapy for SCLC due to its effectiveness in reducing brain metastases and improving overall survival. However, the MAVERICK trial was designed to determine whether modern MRI surveillance could allow patients to avoid PCI and its potential cognitive and other toxicities without compromising survival.

The trial, which enrolled 304 patients with limited-stage or extensive-stage SCLC between January 2020 and December 2025, found that MRI surveillance alone significantly improved cognitive failure-free survival. The primary endpoint of the trial reduced the risk of cognitive failure or death by 40% compared to MRI plus PCI (hazard ratio [HR] 0.60; 90% confidence interval [CI] 0.46-0.78; p=0.001). The benefit was consistent among patients with both limited-stage and extensive-stage disease, and regardless of whether patients received immunotherapy.

At a median follow-up of 22 months among living patients, the study showed no apparent difference in overall survival between the two groups (HR for the MRI alone arm, 0.90; 90% CI 0.67-1.20). The final overall survival analysis, planned after 190 deaths, will provide more definitive results. Brain metastasis-free survival was also not significantly different between the two groups (HR 1.25; 90% CI 0.95-1.66).

Serious treatment-related adverse events were less frequent with MRI surveillance alone. Grade 3-5 adverse events occurred in 0.8% of patients receiving MRI surveillance alone compared to 7.9% of those receiving MRI plus PCI (p=0.004). One grade 5 encephalopathy event occurred in the PCI group.

The findings of the MAVERICK trial have significant implications for the treatment of SCLC. By reducing the need for PCI, the trial suggests a safer and more patient-friendly approach to managing the disease. This could lead to improved quality of life for patients and potentially lower healthcare costs.

The International Association for the Study of Lung Cancer (IASLC) is the only global organization dedicated solely to the study of lung cancer and other thoracic malignancies. The association's membership includes more than 10,000 lung cancer specialists across all disciplines in over 100 countries, forming a global network working together to conquer lung and thoracic cancers worldwide. The association also publishes the Journal of Thoracic Oncology, the primary educational and informational publication for topics relevant to the prevention, detection, diagnosis, and treatment of all thoracic malignancies.

The IASLC 2026 World Conference on Lung Cancer, attracting nearly 7,000 researchers, physicians, and specialists from more than 100 countries, aims to increase awareness, collaboration, and understanding of lung cancer and help participants implement the latest developments across the globe.