Primary or Salvage Stereotactic Radiosurgery for Meningiomas Invading the Superior Sagittal Sinus

Meningiomas invading the superior sagittal sinus (SSS) present significant challenges for surgical management. Stereotactic radiosurgery (SRS) is increasingly used as a primary or salvage management in these difficult cases. The aims of this study were to evaluate the rate of long-term tumor control and the long-term neurological outcomes.

The authors retrospectively reviewed outcomes in 248 patients (152 females, 67.3%; median age, 61 years) with SSS invasive meningiomas who underwent primary or salvage SRS during a 22-year interval. The clinical presentation, radiographic characteristics, and neurological function of each patient were recorded. A total of 140 patients underwent resection before SRS for their SSS meningiomas. Overall, 56% of the patient had tumors involve the posterior one-third of the SSS; 51.6% of patients presented with peritumoral edema before SRS.

The 1-, 2-, 5-, and 10-year local tumor control (LTC) rates were 97.7%, 94.1%, 85.7%, and 78.3%, respectively. Upfront SRS for SSS-invading meningiomas provided LTC comparable with that observed with salvage SRS for histologically confirmed WHO Grade I meningiomas (hazard ratio 0.86, CI 95% 0.33-2.24, P = .76). Tumor volumes <5.2 cc predicted better LTC (hazard ratio 5.1, CI 95% 1.9-19.3, P = .03). The median overall survival after SRS was 14.6 years. Ten patients (4%) died related to documented local intracranial tumor progression. A total of 12 patients (4.8%) developed symptomatic adverse radiation effects at median duration post-SRS of 14 months (range 2-182 months). Motor function improved in 20% patients who presented with motor weakness, after SRS.

SRS is safe and effective in managing small to medium sized SSS invading meningiomas, especially when the tumors involve the posterior one-third of the SSS. For larger SSS meningioma with symptomatic mass effect, adjuvant SRS for residual or recurrent tumors provides long-term tumor control.