Outcomes from treatment of asymptomatic skull base meningioma with stereotactic radiosurgery

Background Optimal management of asymptomatic skull base meningiomas is controversial. We evaluated the safety and efficiency of Gamma Knife radiosurgery (GKRS) for the management of asymptomatic skull base meningiomas. Methods This retrospective study involved patients managed with GKRS for asymptomatic, skull base meningiomas from 1997 to 2019. Patient clinico-radiologic data, tumor characteristics, and procedural details were analyzed. Favorable outcome was defined as lack of procedure-related mortality or permanent neurologic morbidity and radiologic evidence of tumor control. Tumor progression and regression were defined as an increase or decrease of > 20% in volume from baseline to the last neuroimaging study respectively. Tumor volumes within +/- 20% of baseline volume were considered stable. Results Thirty-seven patients (30 women), median age 68 years old (range 42-83 months) were managed with a single-session GKRS for 40 asymptomatic, skull base meningiomas. At a median clinical follow-up of 58.5 months (range 14-150 months), no mortality associated with the procedure or the treated tumor was noted. Permanent neurologic morbidity was 2.75%. There was a statistically significant decrease in mean tumor volume (p < 0.001) from 4.04 cc (SD 3.09 cc) prior to radiosurgery to 2.73 cc (SD 2.24 cc) at last follow-up. Higher margin dose was associated with tumor regression at last follow-up (HR = 1.351; 95%CI [1.094-1.669]; p = 0.05). Conclusion As compared to natural history studies, GKRS affords long-standing tumor control and neurologic preservation in the vast majority of patients treated for asymptomatic, skull base meningiomas. Further study is necessary to identify the optimal management of asymptomatic skull base meningiomas.