title: Treatment Results of Postoperative Radiation Therapy for Malignant and Atypical Meningioma.
abstract: OBJECTIVE
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Yoon
authors.forename: Seung Do
authors.initials: SD
authors.lastname: Ahn
authors.forename: Hyesook
authors.initials: H
authors.lastname: Chang
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Choi
authors.forename: Jong Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sang Wook
authors.initials: SW
authors.lastname: Lee
authors.forename: Chang Jin
authors.initials: CJ
authors.lastname: Kim
authors.forename: Jung Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Byung Deuk
authors.initials: BD
authors.lastname: Kwon
keywords: Meningioma; Postoperative radiotherapy