Stereotactic radiosurgery in the management of intracranial hemangiopericytomas: a meta-analytic review.

Introduction: Intracranial hemangiopericytomas (HPCs) are rare and aggressive mesenchymal tumors with high rates of local recurrence and metastasis. This meta-analysis evaluates the effectiveness of stereotactic radiosurgery (SRS) in managing these tumors.

Methods: A systematic search was conducted up to January 2025 for studies reporting outcomes of SRS in intracranial HPCs. Inclusion criteria comprised original studies with extractable data on at least one predefined outcome. Data were synthesized using random-effects meta-analysis, with heterogeneity assessed by I² statistics. Sensitivity analyses and influence diagnostics were performed. Risk of bias was evaluated using ROBINS-I, and publication bias was assessed with funnel plots and Egger's test when applicable.

Results: Sixteen studies (329 patients, 483 tumors) were included. Tumor size reduction occurred in 47.9% (95% CI: 36.1-59.7%; I² = 81%) and complete response in 29.9% (95% CI: 16.5-43.3%; I² = 74%). Tumor progression was reported in 22.7% (95% CI: 9.1-36.4%; I² = 90%) and tumor stability in 12.1% (95% CI: 6.2-17.9%; I² = 63%). Extracranial metastases occurred in 21.3% of patients (95% CI: 16.1-26.5%; I² = 0%). Neurological improvement was observed in 16.0% (95% CI: 9.2-22.8%; I² = 28%), and mortality reached 31.3% (95% CI: 20.7-41.8%; I² = 71%). Treatment-related complications occurred in 10.8% (95% CI: 2.5-19.2%; I² = 0%). No major publication bias was identified.

Conclusion: SRS provides meaningful tumor control and favorable safety in intracranial HPCs, with notable rates of size reduction and complete response, though progression, metastasis, and mortality remain substantial.