Radiosurgery for Intracranial Meningiomas

The purpose of this study was to review the results of stereotactic radiosurgery for intracranial meningiomas. A prospective computer database was queried for patient characteristics, radiosurgical parameters, tumor control, and complications of 310 patients having radiosurgery for 335 meningiomas at our center between January 1990 and October 2002. One hundred thirty-one patients (42%) had recurrent/residual tumors after prior surgical resection; 179 patients (58%) had radiosurgery as primary treatment. The majority of patients (69%) had skull-based tumors. The median tumor volume was 7.5 cc (range: 0.5–50.5 cc). The median tumor margin dose was 16 Gy (range: 12–20 Gy). Two hundred ninety-seven tumors (278 patients) had clinical and imaging follow-up at a mean of 43 months (range: 2–138 months) after radiosurgery. Two hundred seventy-nine tumors (94%) remained stable or decreased in size; 18 tumors progressed. Factors associated with progression were tumor histology and prior surgery. Treatment-related complications occurred in 26 patients (9%) and included cranial neuropathies, symptomatic edema, cyst formation, and stenosis of the internal carotid artery. Radiosurgery is safe and effective for many meningioma patients and has become the primary treatment of patients with small tumors in critical locations such as the cavernous sinus. Patients with atypical or malignant tumors have a high recurrence rate despite the use of radiosurgery. Further study is needed to determine the tumor control and complication rates 10 or more years after meningioma radiosurgery.