Assessment of MRI brain at baseline in patients with mutation positive mNSCLC

Abstract

Introduction Mutation-positive metastatic non-small cell lung cancer (mNSCLC) is associated with a superior prognosis compared with mutation-negative mNSCLC. International guidelines advise staging MRI brain however the optimal timing of imaging remains unclear [1].We aimed to determine whether baseline MRI brain carries prognostic value. Patients with mutations tend to be better candidates for stereotactic radiosurgery (SRS); however, practice varies. We assessed whether baseline MRI brain influenced SRS intervention and prognosis. Methods We identified all patients with mutation-positive mNSCLC commenced on a TKI at Barts from 2018-2023 by searching our SACT applications iQEMO and ARIA.We identified those treated with SRS at our centre during this time period on ARIA. Baseline MRI brains (defined as <3 months before or after first outpatient oncology appointment) were identified on Powerchart and PACS. GraphPad Prism 10 and R v4.2.2 were used for statistical analyses. [Formula presented] Results We identified 237 patients with mNSCLC started on TKIs (Table 1). Median OS was 35 months. Older patients had a poorer prognosis (p = 0.006). There was no significant difference in OS in patients who had MRI at baseline or not, or whether they had brain metastases at baseline or not. Performing a baseline MRI brain is significantly associated with receiving SRS (p = 0.0099). There was no significant difference in OS between patients who received SRS compared to those who did not, stratified by age, sex, mutation, and TKI therapy. Conclusion This work explores the impact of baseline MRI brain in mutation-positive mNSCLC. Our findings suggest no OS benefit from routine baseline MRI brain or SRS. Important limitations include not accounting for performance status, comorbidities, number of lines of SACT, time to SRS, and presence of symptoms of brain metastases at baseline. Further work is needed to explore these. These results may have meaningful cost implications within public health systems and assist in guiding MDTs and clinicians who are considering attaining an MRI brain at baseline for patients with mNSCLC. Disclosure No significant relationship. Copyright © 2026 Elsevier B.V.