Post-SRS haemorrhage and oncological outcome of patients with melanoma brain metastases undergoing stereotactic radiotherapy.

Purpose: Melanoma brain metastases (MBM) pose significant challenges in management due to their propensity for intralesional haemorrhage. This retrospective analysis aims to evaluate the oncological outcomes and incidence of haemorrhage following stereotactic radiosurgery (SRS) in patients with MBM.

Methods: Patients who received SRS for MBM between 10/2020 and 01/2023 were included. The primary objective was to analyse the incidence of post-SRS haemorrhage. Secondary objectives included oncological outcomes and radiation necrosis. Descriptive statistics and Kaplan-Meier curves were used. Uni- and multivariate statistics analysed factors influencing the incidence of haemorrhage and local failure.

Results: A total of 69 patients with 250 MBMs were included; 65 metastases (26.0%) showed signs of haemorrhage at the time of SRS. Post-SRS, new or increased haemorrhage occurred in 13.2% of treated metastases, primarily within the first year. The 1‑ and 2‑year local control rates were 76.6% each. The 1‑ and 2‑year distant brain failure rates were 40.6% and 34.1% and median overall survival was 14.3 months. For the haemorrhage endpoint, the presence of initial haemorrhage, biologically effective prescription dose, lesion diameter and the planning target volume margin were statistically significant in univariate analysis, and initial haemorrhage remained significant in multivariate analysis. For local control, significant factors in uni- and multivariate analysis were the status of extracranial disease, post-SRS haemorrhage and the use of anticoagulation.

Conclusion: Stereotactic radiosurgery is an effective treatment for MBM with good local control. The risk of haemorrhage after SRS is low and strongly associated with the presence of pre-SRS haemorrhage. Patients are at risk of developing haemorrhage in new, formerly untreated metastases.