Radiosurgery for Intracranial Meningiomas: A Review of Anatomical Challenges and an Update on the Evidence

Abstract

Radiation has been used to treat meningiomas since the mid-1970s. Traditionally, radiation was reserved for patients unfit for major surgery or those with surgically inaccessible tumors. With an increased quantity and quality of imaging, and an aging population, there has been a rise in incidentally diagnosed meningiomas with smaller tumors at diagnosis time. Deciding if, how, and when to intervene must be determined on a case-by-case basis. Anatomical location and adjacent vital structures are crucial for decision-making. Prior review articles have detailed outcomes of radiosurgery in broad anatomical regions such as the skull base, but a recent deluge of research on increasingly specific anatomical subregions deserves attention. This narrative review synthesizes information regarding specific anatomical subregions, including anatomical challenges, radiosurgical outcomes, and unique considerations. Via MEDLINE and ascendancy search, we utilized evidence available for each anatomical region and herein discuss details of published research and explore future directions. Meningioma management remains individualized based on patient comorbidities, tumor location/characteristics, symptomatic burden, and patient age. In addition to stereotactic radiosurgery's established role for surgically inaccessible, recurrent, and high-grade meningiomas, its use as upfront management for small asymptomatic meningiomas is increasingly investigated. For all subregions reported, radiosurgical intervention resulted in high tumor control rates and acceptably low adverse radiation events.

Keywords: anatomy; brain tumor; meningioma; neurosurgery; radiation; radiation oncology.

Figure 1

This figure depicts anatomical regions of interest covered within this review. Convexity meningiomas being of the more superficial and surgically accessible compared with cavernous sinus and intraventricular meningiomas.