Long-term results of stereotactic gamma radiosurgery of meningiomas

BACKGROUND The early effects at a mean of 30 months and long-term results at 7 years after gamma radiosurgery for meningiomas were evaluated. METHODS Changes in tumor size were evaluated every 3 to 6 months after treatment using a five-point grading system, as well as changes in neurological signs and general status. RESULTS Early effects in 87 cases of benign meningioma showed a minimal size reduction of 16.1% and a response rate of 8.0%, but a higher control rate of 93%. The cavernous sinus meningioma showed a size reduction of 23.2%, a response rate of 11.1%, and control of 100%. A greater size reduction of 24.8% and response rate of 33.3%, but a lower control rate of 75% were obtained in 12 cases of malignant meningioma. Side effects were found in 12 cases (13.8%): radiation-induced edema in 9, hearing disturbance in 2, and visual deterioration in 1. Long-term results for 54 of 87 patients with benign tumors showed that response increased from 8% to 42.6% but control decreased slightly due to increased disease progression. CONCLUSION Gamma radiosurgery is effective and safe for meningiomas to control residual or recurrent tumors after surgery and initial tumors, with acceptable side effects and rate of tumor progression. (C) 2001 by Elsevier Science Inc.