Radiosurgery for parasagittal and parafalcine meningiomas: Clinical article

Object. Parasagittal and parafalcine (PSPF) meningiomas represent the second most common location for intracranial meningiomas. Involvement of the superior sagittal sinus or deep draining veins may prevent gross-total resection of these tumors without significant morbidity. The authors review their results for treatment of PSPF meningiomas with radiosurgery. Methods. The authors retrospectively reviewed the institutional review board-approved University of Virginia Gamma Knife database and identified 65 patients with 90 WHO Grade I parasagittal (59%) and parafalcine (41%) meningiomas who had a mean MRI follow-up of 56.6 months. The patients' mean age was 57 years, the median preradiosurgery Karnofsky Performance Status score was 80, and the median initial tumor and treatment volumes were 3 and 3.7 cm³, respectively. The median prescription dose was 15 Gy, isodose line was 40%, and the number of isocenters was 5. Kaplan-Meier analysis was used to determine progression-free survival (PFS). Univariate and multivariate Cox regression analyses were used to identify factors associated with PFS. Results. The median overall PFS was 75.6 months. The actuarial tumor control rate was 85% at 3 years and 70% at 5 years. Parasagittal location, no prior resection, and younger age were found to be independent predictors of tumor PFS. For the 49 patients with clinical follow-up (mean 70.8 months), the median postradiosurgery Karnofsky Performance Status score was 90. Symptomatic postradiosurgery peritumoral edema was observed in 4 patients (8.2%); this group comprised 3 patients (6.1%) with temporary and 1 patient (2%) with permanent clinical sequelae. Two patients (4.1%) died of tumor progression. Conclusions. Radiosurgery offers a minimally invasive treatment option for PSPF meningiomas, with a good tumor control rate and an acceptable complication rate comparable to most surgical series.