140 Repeat salvage stereotactic radiosurgery for brain metastases: safety and efficacy data of three treatments to the same lesion

Abstract Introduction Stereotactic radiosurgery (SRS) achieves durable local control for brain metastases, while improvements in systemic therapies have increased overall survival in patients with metastatic solid tumours, leading to a growing need for salvage SRS. Evidence on the safety and efficacy of salvage SRS is limited, and repeated salvage for a single lesion has not been described. We present outcomes of five patients who underwent repeat salvage SRS for progressive brain metastases. Method Demographic and clinical data were retrospectively collected for patients treated at a single SRS centre between January 2011 and January 2025. Patients who received more than one salvage SRS treatment for a brain metastasis were identified, and SRS treatment details for each procedure were collated. Outcomes included overall survival, measured from completion of the second salvage treatment, local control, and toxicity (radionecrosis, nausea, headache) graded according to Common Terminology Criteria for Adverse Events (CTCAE). Patients were followed up according to local SRS protocols. Results Five patients met inclusion criteria. After a median follow-up of 13 months (range 4–33), median overall survival was 20 months. Local control was maintained in three of five patients. One patient experienced grade 1 radionecrosis, headache, and nausea, and another experienced grade 1 radionecrosis. In this small cohort, no clinical or treatment-related factors were identified that correlated with increased toxicity or reduced local control. Conclusions To our knowledge, this is the first report describing repeat salvage SRS for progressive brain metastases. These preliminary data suggest that repeat salvage SRS is feasible, appears safe, and may provide meaningful local control in selected patients.