Prospective Evaluation of Standalone Endovascular Embolization for Growing Meningiomas: A Multicenter Study Protocol

Endovascular embolization for meningiomas has traditionally been performed as a preoperative adjunct; however, embolization alone can induce tumor necrosis and volume reduction. This study aims to prospectively evaluate the efficacy and safety of standalone embolization in patients with growing meningiomas. This multicenter, prospective, single-arm study will include patients diagnosed with meningioma using imaging findings that showed interval growth. The primary end point is tumor growth control at 180 days after treatment, defined as a stable or reduced tumor volume based on quantitative volumetric assessment of the contrast-enhancing portion on magnetic resonance imaging. The secondary end points include the tumor volume change rate, embolized vessels, embolic materials, embolization results and characteristics, procedure-related complications, perioperative complications, functional outcomes (Karnofsky Performance Status and modified Rankin Scale), changes in clinical symptoms, and the need for additional treatment. Exploratory analyses will also assess the association between intratumoral penetration of embolic material and treatment outcomes. Patient recruitment is ongoing, and the results will be reported upon completion of the study. This study represents a prospective attempt to evaluate the efficacy and safety of standalone embolization for meningiomas. If safe tumor growth control can be achieved, this study may provide preliminary evidence supporting standalone embolization as a potential less-invasive treatment strategy.