Brain MRI surveillance without prophylactic cranial irradiation improves cognitive outcomes in small cell lung cancer

by SWOG Cancer Research Network

edited by Sadie Harley, reviewed by Andrew Zinin

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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, South Korea.

"In the MAVERICK trial, MRI surveillance alone resulted in improved cognitive failure-free survival compared to a strategy of MRI surveillance plus PCI, with similar benefits observed in patients with both limited- and extensive-stage disease," said Chad Rusthoven, MD, of the University of Colorado, the principal investigator of the S1827 trial. "These results support MRI surveillance as the standard of care for patients with SCLC."

SCLC frequently spreads to the brain, and PCI was developed as a strategy to reduce the incidence of brain metastases. Older studies from the pre-MRI era demonstrated improved overall survival (OS) with PCI, which led to PCI becoming a standard therapy.

However, PCI may be associated with neurocognitive toxicity, and its use has become increasingly controversial in the era of routine brain MRIs. Regular MRI surveillance allows for earlier identification of and treatment for brain metastases, potentially eliminating the OS advantage previously observed with PCI.

The international SWOG S1827 MAVERICK trial enrolled 304 patients with limited-stage or extensive-stage SCLC who had completed initial therapy and had no brain metastases on MRI.

Patients were randomly assigned to MRI surveillance alone or MRI surveillance plus PCI. Brain MRI was performed every three months during the first year and every six months during the second year, with standardized cognitive testing at the same time points. Sixty-eight percent of patients had limited-stage disease.

After a median follow-up of 22 months among living patients, cognitive failure-free survival was significantly better with MRI surveillance alone (hazard ratio, 0.60; 90% CI, 0.46–0.78; P = 0.0005). Cognitive failure was defined as a decline in scores on any one of a battery of six standard cognitive tests given to patients. Cognitive failure-free survival was defined as the time from randomization to either cognitive failure or death.

The benefit was consistent across patients with limited-stage SCLC and those with extensive-stage SCLC and was not significantly affected by receipt of immunotherapy.

Preliminary analysis of OS after 128 deaths showed no apparent difference between the groups (hazard ratio for MRI surveillance alone, 0.90; 90% CI, 0.67–1.20). The final OS analysis will be performed after 190 deaths. Progression-free survival also did not differ significantly between the treatment groups.

The investigators concluded that these results support MRI surveillance alone for patients with SCLC, while noting that final overall survival analyses are pending.

Key medical concepts

Small Cell Lung CarcinomaOverall Survival

Clinical categories

Oncology Provided by SWOG Cancer Research Network Who's behind this story?

Sadie Harley

BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Full profile →

Andrew Zinin

Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →

Citation: Brain MRI surveillance without prophylactic cranial irradiation improves cognitive outcomes in small cell lung cancer (2026, September 15) retrieved 16 September 2026 from https://medicalxpress.com/news/2026-09-brain-mri-surveillance-prophylactic-cranial.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.