Melanoma brain metastasis treated with stereotactic radiosurgery (SRS) and systemic agents (SACT): A single centre perspective from Northeast England.
Authors: Gautam Ashram , Mariappan Lavanya , Hashmi Ahmed , Mott Judith H. , Zarroug Maha , Burns Alexander 
Published: July 2024

e21500

Background: Melanoma incidence rates in the UK will increase and given its proclivity for brain metastasis, it will be a growing challenge. Real-world survival data reflecting the impact of modern SACTs and SRS is lacking. Here we report our single-centre experience. Methods: All melanoma brain metastasis patients treated with both SRS and SACT in Newcastle-upon-Tyne, UK between January 2017 and January 2022 were identified. Data was collected from patient records until data-lock in January 2023. Survival analysis was performed using R (version 4.2.2). The primary objective was to measure the overall survival. Results: 51 patients were included. The median age was 60 years. Most patients had ECOG PS of 0 (43%, n = 22) or 1 (53%, n = 27). 15 (29%) had de-novo brain metastasis. 21 (41%) were on SACT before diagnosis of brain metastasis. 28 (55%) patients had solitary brain metastasis. 8 (16%) had no radiologically reported extracranial disease. Superficial spreading melanoma was the most common histological subtype (45%, n = 23). 55% (n = 26) had a sensitizing BRAF mutation. 25 patients (49%) received SRS before SACT. 12 (26%) patients had undergone primary debulking surgery. The median time to start SRS was 54 days (IQR 35 - 90) from brain metastasis diagnosis. Median extracranial progression-free survival was 25 months (95% CI 10 – NA). Median intracranial progression-free survival was 29 months (95% CI 15 – NA). 17 (33%) patients had both intra and extracranial progression. 7 (13%) had in-field intracranial progression. The median target volume was similar between subgroups that had infield (1.78mL, IQR 0.56 - 13.81), out-of-field (1.78mL, IRQ 1.62 - 3.97) or no intracranial progression (2.38mL, IQR 1.29 - 6.73). The median total dose to target was 21 Grays for all subgroups. Median overall survival was 27 months (95% CI 16 - NA). With intracranial progression, the median overall survival was 21 months (95% CI 10 –36). The survival was 15 months (95% CI 9.5 - 27) with extracranial progression, which was significantly less than without extracranial progression (HR = 0.25, 95% CI 0.11 – 0.60, p = 0.002). In the absence of intracranial progression, median overall survival was not reached. Patients with infield progression had an overall survival of 8.6 months (95% CI 6.8 – NA), HR 2.83 (95% CI 1.20 - 6.7), p = 0.018. Those with melanoma-specific Graded Prognostic Assessment score (molGPA) > 2.5 had a median overall survival of 31 months (95% CI 14 – NA) with a HR of 0.73 (95% CI 0.32 - 1.64, p = 0.4). Conclusions: Survival in our cohort is notably better than reports from prior series. This is despite our catchment in the North East of England being adversely affected by health disparity. This could be explained by the selection bias of our cohort. However, in the wake of improved treatment modalities, the need for more up-to-date cancer data tracking cannot be overstated.