Stereotactic radiosurgery as adjuvant or salvage treatment for sporadic hemangioblastomas: A multi-center international study

Introduction: Hemangioblastomas are rare benign CNS tumors, occurring sporadically or with von Hippel-Lindau disease. While surgical resection is the primary treatment, GKRS serves as an adjuvant or salvage option when resection is not feasible. This study evaluates long-term outcomes of GKRS in patients with sporadic hemangioblastomas. Methods: We retrospectively analyzed 82 patients with sporadic hemangioblastomas treated with GKRS across 17 International Radiosurgery Research Foundation centers (1993–2022). Univariate and multivariate analysis was conducted to identify variables influencing local control and tumor regression. Results: Among 82 patients (52.4 % male, median age 51.5 years [IQR: 40.3–63.0]), most tumors were cerebellar (70.7 %), solid (63.4 %), with a median volume of 1.8 cc [IQR: 0.8–6.1]. The median margin dose was 16.0 Gy [IQR: 14.0–18.0]. With a median follow-up of 51.5 months [IQR: 21.0–92.0], local control was achieved in 69.5 % of cases (40.2 % regression, 29.3 % stability). Local control rates were 95 % (90 %, 100 %) at 6 months but declined to 75 % (65 %, 87 %) at 60 months. Radiation necrosis occurred in 6.1 % of patients (5/82), and no tumor-related deaths were reported among the 11.1 % overall mortality. Brainstem location was significantly linked to lower odds of tumor regression in the multivariate analysis (OR: 0.29, 95 % CI: 0.09–0.98, p = 0.045). Conclusion: GKRS demonstrated efficacy and safety in treating sporadic hemangioblastomas, achieving reasonable long-term local control rates with minimal complications. Our findings support its role as a viable treatment option, particularly for surgically challenging cases.