NIMG-49. IMAGING PREDICTIVE FACTORS OF BRAIN ADHESION IN SUPRATENTORIAL MENINGIOMA

Abstract OBJECTIVES 80 % of meningioma are benign and are classified as WHO grade 1. However, meningioma frequently adheres to surrounding brain and make tumor detach difficult during surgery. This study retrospectively analyzed the adhesion of meningioma to the brain based on preoperative MR images and operative findings. METHODS We retrospectively reviewed 238 tumor planes of 60 supratentorial meningioma cases with WHO grade 1 (parasagittal: 15, convexity: 20, falcine: 7, sphenoidal ridge 13 and frontal base 5) underwent surgical treatment. The tumor adhesion to the surrounding brain was defined during surgery as the rupture of arachnoid membrane or leaving tumor capsule due to tight adhesion. The location of MRI image was identified during surgery and verified reference to operation video postoperatively. We assessed following items, tumor diameter, T2 hyper rim, T1 hypo rim, FLAIR hypo rim and brain edema of surrounding tumor. We performed univariate analysis for each item with and without adhesion, and extracted predictors for tumor adhesion by logistic regression analysis. RESULTS We confirmed 127 tumor planes without adhesion and 111 tumor planes adhered to surrounding brain. The cutoff value obtained from the ROC curve for tumor adhesion and tumor diameter was 2.3 cm. In univariate analysis, tumor diameter ≧ 2.3 cm, T2 hyper rim, T1 hypo rim, FLAIR hypo rim and brain edema of surrounding tumor were significantly associated with adhesion. In logistic regression analysis, tumor diameter ≧ 2.3 cm (odds ratio (OR) 2.7, P = 0.02), T2 hyper rim (OR 0.04, P < 0.001), and brain edema of surrounding tumor (OR 25, P < 0.001) were significantly independent predictive factors for tumor adhesion. CONCLUSION Meningioma adhesion to surrounding brain might be predicted by tumor diameter ≧2.3 cm, T2 hyper rim, and brain edema of surrounding tumor.