70 Outcomes Following Stereotactic Radiosurgery for Brain Metastases from Lung Adenocarcinoma: The Wessex Experience

Abstract Introduction Brain metastases (BM) from lung adenocarcinoma represent a major proportion of intracranial malignancies, with approximately 30% of patients developing BM during follow-up. Stereotactic radiosurgery (SRS) is the most common management strategy. This study evaluates treatment response, prognosis, and central nervous system progression-free survival (CNS-PFS) in relation to tumour and patient characteristics. Methods This is a retrospective observational study of patients with confirmed lung adenocarcinoma who received SRS for BM at a single UK tertiary neuro-oncology centre between December 2016 and June 2025. Data were collected using electronic patient records and a prospective treatment outcomes database. Statistical analyses were performed using the R language. Results A total of 157 patients, with 367 BMs in total (mean 2.1 per patient), were treated across 180 SRS episodes. Molecular subtypes included: 4.4% ALK-mutated; 11.1% EGFR-mutated; 46.6% PD-L1 <1%; 16.9% PD-L1 1%–50%; and 36.4% PD-L1 >50%. The median overall survival (OS) for the cohort was 12.5 months (95% CI: 10.0–17.0), and the median CNS-PFS was 7.1 months (95% CI: 6.3–9.3). Patient and tumour characteristics were assessed using univariate and multivariate models. The number of BM treated did not significantly affect OS (p = 0.75). However, increasing total irradiated tumour volume was associated with poorer survival (p < 0.05). OS differed by molecular subtype, with ALK-mutated tumours demonstrating improved outcomes. CNS-PFS did not differ significantly between molecular groups (p = 1). Conclusion Overall survival in this cohort aligns with published data. Treating multiple metastases did not independently worsen OS, whereas greater total irradiated tumour volume was associated with poorer prognosis. Although OS varied by molecular subtype, CNS-PFS remained similar across groups, suggesting that SRS provides effective BM control regardless of tumour biology.