ABSTRACT
PURPOSE: We evaluated the survival rate, prognostic factors and patterns of failure in malignant and atypical meningiomas, and investigated the role of radiation therapy in the treatment of these tumors. MATERIALS AND METHODS: We retrospectively reviewed nineteen patients treated at Asan Medical Center between Mar. 1994 and Jun. 2000 with histologically confirmed malignant or atypical meningiomas. The median patient age was 52 years. The extent of surgery prior to radiation was gross total resection in 13 and subtotal resection in 6. Eleven patients were referred for radiation immediately after diagnosis and the remainder after at least one recurrence. All patients received megavoltage radiation to a median dose of 55.8 Gy. The median follow-up period was 41 months. RESULTS: Eleven patients (57.9%) showed no evidence of disease, five patients died of meningioma and three were alive with disease. The 5-year overall and relapse-free survivals were 75.9 and 50.6%, respectively. There were no statistically significant prognostic factors found to be associated with relapse-free survival by univariate or multivariate analysis. During the follow-up period, no significant treatment-related complications were detected. CONCLUSION: The major patterns of failure were in-field recurrence. In order to reduce local failure, a higher radiation dose may be needed and a high precision therapy should be considered.