Radiosurgery for malignant meningioma: results in 22 patients

Abstract

Object. The initial treatment of malignant meningiomas in the past has included surgical removal followed by fractionated external-beam radiotherapy. Radiosurgery has been added to the options for treatment of primary or recurrent tumors over the last 10 years. The authors report their results of using gamma knife radiosurgery (GKS) to treat 22 patients over an 8-year period. Methods. Twenty-two patients who underwent GKS for malignant meningioma between December 1991 and May 1999 were evaluated. Three patients were treated with GKS as a boost to radiotherapy and 19 for recurrence following radiotherapy. Outcome factors including patient survival, freedom from progression, and complications were analyzed. In addition, in the recurrent group, variables such as patient age, sex, tumor location, target volume, margin dose, and maximum dose were also analyzed. Univariate and multivariate analyses were performed. Overall 5-year survival and progression-free survival estimates were 40% and 26%, respectively. Age (p ≤ 0.003) and tumor volume (p ≤ 0.05) were significant predictors of time to progression and survival in both univariate and multivariate analyses. Five patients (23%) developed radiation necrosis. Significant relationships between complications and treatment variables or patient characteristics could not be established. Conclusions. Tumor control following GKS is greater in patients with smaller-sized tumors (< 8 cm3) and in younger patients. Gamma knife radiosurgery can be performed to treat malignant meningioma with acceptable toxicity. The efficacy of GKS relative to other therapies for recurrent malignant meningioma as well as the value of GKS as a boost to radiotherapy will require further evaluation.

Long-Term Experience With World Health Organization Grade III (Malignant) Meningiomas at a Single Institution

“…designation, regardless of the other tumor characteristics. As a result, studies published using this definition considered brain-invasive meningiomas as malignant, or Grade III (6,7).…”

“…Atypical and malignant meningiomas, however, are rarer and these patients have a worse prognosis. Malignant meningiomas account for 1.0-2.8% of meningiomas (1) and are particularly aggressive tumors, with reported 5-year patient survival rates of 32-64% (3)(4)(5)(6)(7)(8)(9).…”

Combined Proton and Photon Conformal Radiotherapy for Intracranial Atypical and Malignant Meningioma

“…According to limited literature, stereotactic irradiation for treatment of atypical and malignant meningioma results in a low rate of morbidity (6,14,15). However, the local control of these tumors and the overall survival remain poor.…”

Clinicopathologic Features of Aggressive Meningioma Emphasizing the Role of Radiotherapy in Treatment

“…The use of adjuvant radiotherapy in the treatment of aggressive meningiomas is still controversial. Several irradiation techniques were proposed including fractionated stereotactic radiotherapy (FSRT), radiosurgery, and brachytherapy [9,11,18,26,31,35,37].…”