Introduction: The standard-of-care for intracranial meningiomas is surgical resection ± radiation therapy (RT). However, surgery may not be possible when meningiomas are present in locations where resection may result in significant morbidity or when a patient is medically inoperable. The long-term clinical outcomes of patients with magnetic resonance imaging (MRI)-defined meningiomas treated with RT alone are reported.
Methods: The charts of 211 patients with meningiomas diagnosed by contrast-enhanced MRI treated with either stereotactic radiosurgery (SRS) or fractionated radiation therapy (FRT) between 1991 and 2012 at a single institution were reviewed. Actuarial rates for overall survival (OS), local control (LC), and development of treatment-related radiographic edema (TRE) were determined by the Kaplan Meier method.
Results: 211 patients received radiation therapy for 223 lesions. Median follow-up was 5.7 years. Eleven patients experienced a local failure, of whom 2 were ultimately found to have pathologically proven metastatic carcinoma. Five and 10-year OS and LC were 94.9% & 89.4% and 97.8% & 94.6%, respectively, with no significant difference based on modality of therapy. 3.3% of patients were found to have a diagnosis other than grade I meningioma. Actuarial rate for development of TRE at 1 & 2 years was 30.1% & 34.6% for the SRS group and 1.6% & 2.5% for the FRT group (p < 0.001).
Conclusions: RT alone using limited margin is an effective treatment option for MRI-defined meningiomas and should be considered even without biopsy if surgery will present significant morbidity. Although local control with SRS versus FRT was comparable, FRT was associated with a significantly decreased risk of TRE.
Patient Care: In this study, we show that radiation (RT) alone using limited margin is an effective treatment option for MRI-defined meningiomas and should be considered even without biopsy if surgery will present significant morbidity. This adds to the limited literature showing the safety and efficacy of treating presumed meningiomas with radiation alone.
Learning Objectives: By the conclusion of this session, participants should be able to discuss the feasibility and safety of treating image-defined meningiomas with radiation alone (SRS vs. FRT)