Radiologic Classification of Convexity Meningioma to Predict the Aggressive Meningioma Behavior
Background: The aim of present study is to propose a radiologic classification to predict aggressive meningioma behavior.
Methods: A retrospective review was conducted for convexity meningioma patients who underwent surgery as primary treatment at our institution. WHO-classification was used for histopathological diagnosis. The radiologic parameters including signal intensity on diffusion weighted MRI (DWI), heterogeneity on T1-weighted gadolinium enhanced MRI, arachnoid layer and peritumoral edema (PTE) on T2-weighted MRI and tumor shape were employed. Each parameter was scored 0 or 1 based on their appearance and all patients were then classified into three groups. The overall survival time and progression free survival (PFS) for each group was analyzed.
Results: The hyperintensity on DWI, disruption of arachnoid layer and PTE on T2-weighted MRI, heterogenicitiy on T1-weighted gadolinium enhanced MRI and irregular shape of the tumor were all independent predictors of non-grade I meningioma. The mean follow-up period was 94.6 months (range 12–117 months). Mean overall survival and PFS in groups-I, II and III was 114.1 ± 1.2 and 115.7 ± 0.8, 88 ± 3.3 and 58.5 ± 3.9, 43.2 ± 5.1 and 18.2 ± 1.7 months respectively. Group-II (p < 0.0001, OR– 15.7, CI –4.9–50.1) and group-III (p < 0.0001, OR – 151.2, CI – 37.8–604.2) predicted unfavorable survival outcome.
Conclusions: The proposed scoring system predicted survival for convexity meningioma. Group-I meningioma demonstrated benign radiologic, histopathologic and clinical behavior; group-III meningioma demonstrated aggressive behavior. Group-II meningioma might be considered intermediate and need for more aggressive follow-up and/or treatment should be further investigated.