title: Gamma knife stereotactic radiosurgery for atypical and malignant meningiomas.
abstract: BACKGROUND
  Non-benign meningioma has a known trend to recur repeatedly. The results of Gamma Knife stereotactic radiosurgery (GKS) for recurrent or residual atypical and malignant meningiomas are reported.
  
  
  METHODS
  Thirty patients (13 men, 17 women) with World Health Organization (WHO) grade II (24 cases) or grade III (6 cases) intracranial meningiomas underwent GKS. Their age varied from 30 to 86 years (mean 64 years). Before GKS, the tumor was surgically resected in all patients, and 11 of them also underwent conventional external beam radiation therapy, LINAC-based stereotactic radiotherapy (SRT), or intensity-modulated radiation therapy.
  
  
  RESULTS
  Of the 30 patients, 23 were followed after the initial GKS for a median period of 28 months (range 2-135 months). Local tumor control after treatment was 74 % at 1 year, 52 % at 2 years, and 34 % at 3 years. A total of 15 patients underwent repeat GKS (one to nine times) because of local or distant intracranial tumor progression, seven were subjected to surgical re-resection of the neoplasm, and four had additional SRT. At the time of the last follow-up, 21 patients were alive, and 2 had died. One of the latter expired because of brain tumor progression at 91 months after the initial GKS, and the other patient died from lung cancer.
  
  
  CONCLUSIONS
  Although atypical and malignant meningiomas have a trend to recur repeatedly, aggressive tumor management with repeat GKS at the time of progression can provide long survival in these patients.
authors: Department of Radiology and Radiation Oncology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho, Mizuho, Nagoya, Aichi, 467-8601, Japan. yoshim@med.nagoya-cu.ac.jp
authors: Yoshimasa
authors: Y
authors: Mori
authors: Takahiko
authors: T
authors: Tsugawa
authors: Chisa
authors: C
authors: Hashizume
authors: Tatsuya
authors: T
authors: Kobayashi
authors: Yuta
authors: Y
authors: Shibamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000601:surgery*; D008579:Meningioma / Q000145:classification / Q000401:mortality / Q000601:surgery*; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome