Gamma knife radiosurgery for intraventricular meningiomas

Abstract

Intraventricular meningiomas are relatively rare tumors that may benefit from stereotactic radiosurgery as a minimally invasive treatment strategy. We report our experience using gamma knife radiosurgery (GKR) for intraventricular meningiomas. Over a 16-year period, we identified 9 patients with intraventricular meningiomas who were eligible for GKR out of a total management experience of 1,045 patients. The mean patient age was 51 years (range, 14 to 81). Three had radiosurgery for recurrent tumors after prior resection, and GKR was used as an adjunctive after subtotal resection in 1 patient. In the other 5 patients, GKR was used as primary management. Two had a diagnosis of meningioma confirmed by biopsy. The median tumor volume at GKR was 3.9 cc (range, 0.8-11.8). A median margin dose of 16.0 Gy (range, 14.0-22.5) was delivered to the tumor margin. The average follow-up was 64 months. None of the patients developed hydrocephalus or treatment-related morbidity. The progression-free periods after radiosurgery varied from 7 to 160 months (mean, 60). Four tumors regressed and 2 remained unchanged. Three patients showed delayed tumor progression. Meningioma growth control was obtained in 7 out of 9 patients, but 1 patient required two radiosurgical procedures. Gamma knife radiosurgery may be an additional minimally invasive management option for small intraventricular meningiomas in patients who either fail or are unsuitable for resection.