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Pushing the Limits of Radiotherapy for Atypical and Malignant Meningioma

Purpose:The purpose of this study was to report the outcome of an extremely aggressive radiotherapy program in patients with atypical and malignant meningioma (60 Gy at 1.5 Gy per fraction twice daily ± radiosurgery boost). Methods and Materials:Thirty-six patients received radiotherapy with curative intent between 1984 and 1999 for atypical (27 patients) or malignant (9 patients) meningioma. All patients had a minimum of 2 years follow up. Results:The overall 5-year local control, cause-specific survival, and absolute survival rates were 45%, 39%, and 36%, respectively. Accelerated hyperfractionated radiotherapy resulted in a local control rate of 45% compared with 50% for patients treated with less aggressive schedules (P = 0.99). A radiosurgery boost did not improve tumor control. The complication rate for those treated with accelerated hyperfractionated radiotherapy was dramatically higher (grade 3–5: 55% vs. 0%, grade 4–5: 27% vs. 0%. both P <0.05). Conclusion:Our data suggests that 50 to 60 Gy delivered with conventional, once-daily fractionation is probably the optimal schedule for atypical and malignant meningioma. More aggressive radiotherapy fractionation schedules and radiosurgery are unlikely to improve outcome.