Outcomes of Patients With Five or More Brain Metastases Treated With Stereotactic Radiosurgery From 2014 to 2019: A UK Series

Treatment with stereotactic radiosurgery/radiotherapy (SRS/SRT) is standard practice in selected patients with small numbers of brain metastases (BMs). It is less accepted in those with ≥5 BMs, due to the lack of a prospective evidence base. While randomised trials are ongoing, we present the experience of a single UK cancer centre in using SRS/SRT for patients with 5 or more BMs without whole brain radiotherapy (WBRT). Patients undergoing treatment at a single centre between 2014 and 2019 were prospectively identified. All follow-up imaging was reviewed to identify any evidence of local failure or distant brain progression, which was analysed using a death-censored approach. A total of N = 88 patients were included, with a median of seven BMs (range: 5–37). Post-SRS/SRT toxicity events occurred in 42%, most commonly reliance on steroids for ≥4 weeks (36% of the cohort). Median survival was 10 months, with median freedom from local failure and distant brain progression of 12 and 8 months, respectively; none of these outcomes differed significantly by the number of BMs. Brain-directed salvage treatment was required after a median of 21 months, and was not significantly associated with the number of BMs. SRS/SRT alone may have a role in the management of selected patients with multiple BMs. Since the number of BMs were not significantly associated with overall survival or disease control, the National Health Service (NHS) commissioning criteria should continue to be based on tumour volume. •Select patients with ≥5 BM can be treated with SRS.•Largest series of UK patients treated with SRS for multiple brain metases.•With appropriate imaging surveillance and salvage therapy, WBRT can be avoided.