Fractionated Radiotherapy Is Associated with Lower Rates of Treatment-Related Edema than Stereotactic Radiosurgery in Magnetic Resonance Imaging-Defined Meningiomas.

Abstract

Both stereotactic radiosurgery (SRS) and fractionated radiation therapy (FRT) techniques are used for treatment of intracranial meningiomas with excellent local control (LC) rates. Although SRS techniques are convenient, toxicity including treatment-related edema can significantly impact patient quality of life. The long-term clinical outcomes of patients with magnetic resonance imaging (MRI)-defined meningiomas treated with radiation therapy (RT) alone are reported. The charts of 211 patients with meningiomas diagnosed by contrast-enhanced MRI treated with either SRS or FRT between 1991 and 2012 at a single institution were reviewed. Actuarial rates for LC and development of treatment-related radiographic edema (TRE) were determined by the Kaplan-Meier method. There were 211 patients who received radiation therapy for 223 lesions. Median follow-up was 5.7 years. Eleven patients experienced a local failure; of these, 2 were ultimately found to have pathologically proven metastatic carcinoma. Two- and 5-year LC was 97.8% and 94.6%, respectively, with no significant difference based on modality of therapy. Actuarial rate for development of TRE at 1 and 2 years was 30.1% and 34.6% for the SRS group and 1.6% and 2.5% for the FRT group, respectively (P < 0.001). RT alone using a 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 LC with SRS versus FRT was comparable, FRT was associated with a significantly decreased risk of TRE.