Radiotherapy for aggressive meningiomas and recurrent low grade tumors

High-grade meningiomas, classified as World Health Organization (WHO) Grade II or III lesions, represent rare central nervous system tumors, with significantly worse local control of disease and disease-free survival than their benign, WHO Grade I counterparts. Similarly, recurrent meningiomas, too, confer markedly worse clinical outcomes, even for low-grade disease. This chapter discusses standard of care management for WHO Grade II and III and recurrent meningiomas, including surgical resection, as well as external beam radiotherapy and stereotactic radiosurgery. The evidence regarding disease outcomes is reviewed in details, as are specifics of radiation indications, dosing, fractionation, treatment planning, radiation delivery, and adverse effects of treatment. Practice patterns for WHO Grade II and III and recurrent meningioma patients are discussed. Additionally, emerging radiographic techniques for diagnosis, delineation, and treatment of meningiomas are addressed.