Outcomes following Upfront Radiation versus Monitoring in Atypical Meningiomas: 16-year Experience at a Tertiary Medical Center
Abstract Background The role of post-operative upfront radiotherapy (RT) in the management of gross totally resected atypical meningiomas remains unclear. This single-center retrospective review of newly-diagnosed histologically-confirmed cases of World Health Organization (WHO) Grade II atypical meningioma at Weill Cornell Medicine from 2004-2020 aims to compare overall survival (OS) and progression free survival (PFS) of post-operative upfront radiotherapy versus observation, stratified by resection status (gross total resection [GTR)] versus subtotal resection [STR]). Methods 90 cases of atypical meningioma were reviewed (56% women; median age 61 years; median follow-up 41 months). Results In patients with GTR, hazard ratio (HR) of PFS was 0.09 for post-operative upfront RT versus observation alone (95% confidence interval [CI] 0.01-0.68; p = 0.02), though HR for OS was not significant (HR 0.46; 95% CI 0.05-4.45; p = 0.5). With RT, PFS was 100% at 12 and 36 months (compared to 84% and 63% respectively with observation); OS at 36 months was 100% (compared to 94% with observation). In patients with STR, though PFS at 36 months was higher for RT arm versus observation (84% versus 74%), OS at 36 months was 100% in both arms. HR was not significant (HR 0.76; 95% CI 0.16-3.5; p = 0.73). Conclusion This retrospective study suggests post-operative upfront radiotherapy following GTR of atypical meningioma is associated with improved PFS compared to observation. Further studies are required to draw conclusions about OS.