2000 Comparison of Active Surveillance to Stereotactic Radiosurgery for the Management of Elderly Patients With an Incidental Meningioma – A Sub-Analysis of the IMPASSE Study

INTRODUCTION: The optimal management for elderly patients (>65yo) with incidental meningiomas remains unclear. The aim of this study is to characterize the functional and tumor outcomes of expectant and stereotactic radiosurgery (SRS) management of asymptomatic meningioma patients. METHODS: Data from 14 centers was retrospectively reviewed with propensity score matching. RESULTS: In the unmatched cohort, 193 patients with incidental meningiomas were treated with SRS and were followed for a mean of 50.9 months. In the conservatively managed cohort, 166 patients were managed for 32.9 months. Tumor control was 97.92% in patients that received SRS and in 66.32% of patients who were observed (p<0.01; OR 14.03 [95% CI 4.89-40.26]). New neurological deficit developed in cohort compared to none of the patients in the observation cohort, none of these patients had tumor progression. After matching, tumor control was achieved at 97.37% and 71.93% rates in the SRS and observation cohorts respectively (p<0.01; OR 14.44 [95% CI 4.27-48.78]). New neurological deficits developed in 1.39% of the SRS cohort but in none of the patients managed conservatively. 3.5% of patients underwent resection in the active surveillance matched cohort compared to 0.9% of patients in the SRS cohort (p=0.063; OR 0.135 [95% CI 0.163-1.117]). CONCLUSIONS: SRS achieves superior radiologic tumor control compared to active surveillance without significantly increasing the risk of new neurological deficits in elderly patients with asymptomatic meningiomas. SRS alters the natural history of meningiomas including halting tumor progression, reduces the need for of an open neurosurgical procedure to resect the tumor in this older patient population, and lessens the risk of overall mortality compared to active surveillance alone.