Stereotactic radiosurgery for brain metastases from malignant melanoma and the impact of hemorrhagic metastases

Introduction: Stereotactic radiosurgery (SRS) is a common treatment modality among patients with brain metastases, particularly from malignant melanoma. Our objective was to investigate the difference in local control, toxicity, and survival among patients with hemorrhagic and solid melanoma brain metastases. Methods: We collected demographic, treatment, local control, toxicity, and survival for 134 patients with a total of 936 intracranial melanoma metastases who underwent SRS between 1998 and 2015. Pre-radiosurgical diagnostic imaging was reviewed for evidence of hemorrhage (melanin-containing or clearly hemorrhagic). Results: The cohort consisted of 92 men and 42 women with a mea age of 61.7 years (range 21.2–84.9) at the time of radiosurgery. Overall survival of patients with brain metastases from malignant melanoma was 42, 31, 12% at 12, 24, and 72 months from date of first SRS. At 6 months, 43% of the patients with hemorrhagic metastases had local tumor control compared to 83% of solid melanoma metastases (p < 0.001). No significant difference in toxicity was noted between the two groups. Factors that were significantly associated with time to local tumor progression on multivariate analysis include prior WBRT (HR 1.62, p = 0.003), prior chemotherapy (HR 0.69, p = 0.011), margin dose (HR 0.88, p < 0.001) and radiographic features of melanin deposition (HR 3.73, p < 0.001), or clear hemorrhage (HR 2.20, p < 0.001). Conclusions: Our findings demonstrate that hemorrhagic intracranial melanoma metastases are associated with inferior local tumor control when treated with SRS, as compared to solid tumors. These results highlight the importance of early radiosurgery among patients with melanoma brain metastases before hemorrhage occurs.