Efficacy and Safety of Stereotactic Radiosurgery for Foramen Magnum Meningiomas: A Systematic Review and Meta-analysis

Introduction: gement of foramen magnum meningiomas (FMMs) is challenging due to their anatomical complexity. Surgical resection to achieve gross total resection (GTR) is the main therapeutic option; however, due to adjacency to nerves and arteries, resection is challenging and associated with considerable morbidity and mortality, reported to be as high as 50% and 25%, respectively. Stereotactic radiosurgery (SRS) is a non-invasive radiotherapeutic modality that has been extensively utilized to treat intracranial meningiomas and is reported to be associated with high rates of favorable outcomes and low complications. In this study, we aimed to evaluate the efficacy and safety of SRS in FMMs.

Methods: The electronic databases of PubMed, Scopus, Embase, and Web of Science were searched from inception to October 24th, 2024. Studies that evaluated the radiological and clinical outcomes of SRS application in FMMs were included. The risk of bias was assessed using the Risk of Bias in Non-Randomized Studies of Interventions tool. The R program performed the meta-analyses, sensitivity analysis, and publication bias.

Results: Five studies with 174 patients were included in our study. Our meta-analysis revealed that SRS resulted in a pooled local control (LC) rate of 99% (95% CI: 96% - 100%), objective response (OR) rate of 49% (95% CI: 25% - 74%) stable disease (SD) rate of 48% (95% CI: 25% - 71%), and progressive disease (PD) rate of 1% (95% CI: 0% - 4%). Our results revealed a pooled clinical improvement rate of 43% (95% CI: 11% - 80%) and a clinical stability rate of 56% (95% CI: 21% - 87%). Our meta-analysis revealed that SRS resulted in a pooled adverse radiation effect (ARE) rate of 0% (95% CI: 0% - 1%) with low heterogeneity (I2 = 0%, P = 0.84).

Conclusion : SRS is associated with promising clinical and radiological outcomes concurrent with low complication rates. It can be considered in asymptomatic or minimally symptomatic individuals with small- to medium-sized lesions, symptomatic individuals with significant comorbidities without brainstem compression, and those reluctant to perform surgery.