Gamma Knife Radiosurgery for Patients with Multiple Intracranial Meningiomas

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of Gamma Knife radiosurgery (GKRS) in patients with multiple intracranial meningiomas (MIMs). METHODS: The authors performed a retrospective analysis of 42 consecutive patients (7 men and 35 women) with MIMs who underwent GKRS. The median age of the patients at the time of GKRS was 57.5 years (range, 27-77 years). A total of 115 tumors among 42 patients were identified through imaging or postoperative histopathologic examination, of which 90 were treated with GKRS. RESULTS: Follow-up imaging studies were available for 75 tumors in 36 patients (83.3%), with a mean follow-up period of 45.0 months (range, 6.6-90.4 months); 41 patients (97.6`)/0) received clinical follow-up for 16.7 to 106.7 months (average, 57.1 months). Local tumor control was achieved in 68 tumors (90.7%) at the last follow-up. On univariate analysis, surgical resection before GKRS more than once (P = 0.048) and high World Health Organization (WHO) classification (grades II and III) (P = 0.001) were associated with tumor progression. Patients with worsening clinical manifestation showed correlation with peritumor edema (P < 0.001) and had >2 lesions treated by GKRS (P < 0.001) on univariate analysis. CONCLUSIONS: GKRS is a safe and effective treatment for MIMs. Variables including surgical resection before GKRS more than once, high grade WHO classification, peritumor edema, and >2 tumors treated by GKRS are predictors of unfavorable outcome after GKRS.