Abstract Aims Since 2016, the University Hospital Southampton NHS Foundation Trust (UHSFT) has been commissioned by NHS England to deliver SRST to brain metastases. At UHSFT, all referrals are discussed at the Wessex Neurosciences multidisciplinary team meeting. Referrals that satisfy the criteria set by NHS England (estimated prognosis greater than 6 months, absence or controlled extracranial disease or potentially controllable extracranial disease with a Karnofsky Performance Status >70%) will be offered SRST. This retrospective study was performed to assess overall survival rates of patients with brain metastases treated with SRST with further tumour subtype analysis. We also benchmarked our results with other SRST centres. Method Retrospective data collection was performed for all the patients who have been treated with SRST. Patients who received SRST to a single metastasis, multiple metastases and/or to the resection cavity between 01/01/2017 to 30/09/2019 were included in this study. All treatment was delivered using a LINAC based SRST platform. Prescription doses ranged from 13.5 Gy to 21 Gy in a single fraction, 21 to 24 Gy in 3 fractions and 25 Gy in 5 fractions. Patients are treated using a stereotactic thermoplastic immobilisation shell and dynamic conformal arc therapy with ExacTrac TM and Cone Beam CT imaging. Dates of death were obtained from the NHS Digital Spine and survival analysis using median overall survival was performed using the Kaplan Meier Method. Results 277 patients were treated between 01/01/17 and 30/9/2019. The median overall survival from the Kaplan Meier Method was shown to be 14.7 months and the 6-month overall survival was 71% for all patients. Sub-group analysis of individual tumour sites showed: lung (n=110) median OS 12.1 months, melanoma (n=58) median OS 26.4 months, breast (n=46) median OS not reached (67% still alive) but 18 months survival was 70%, renal (n=22) median OS 15.4 months and colorectal (n=19) median OS 6 months. “Other” tumour sites (n=22) included patients with ovarian, neuroendocrine, sarcoma, testis, oesophagus, unknown primary and gallbladder which were grouped together due to small patient numbers. 41% of patients treated were alive at the time of analysis. Conclusion Patients with brain metastases treated with SRST at UHFST have similar outcomes compared to other SRST centres. These patients have a median overall survival of 14.7 months. However, 29% of patients analysed did not survive more than 6 months. Further collection and analysis of the data might improve patient selection and their outcomes.