Imaging score for differentiation of meningioma grade.

PURPOSE: We sought to establish a comprehensive imaging score indicating the likelihood of higher WHO grade meningiomas pre-operatively. METHODS: All surgical intracranial meningioma patients at our institution between 2014 and 2018 underwent retrospective chart review. Preoperative MRI sequences were reviewed, and imaging features were included in the score based on statistical and clinical significance. Point values for each significant feature were assigned based on the beta coefficients obtained from multivariate analysis. The imaging score was calculated by adding up the points, for a total score of 0 to 5. The predictive ability of the score to identify higher-grade meningiomas was evaluated. RESULTS: Ninety patients, 50% of whom had a postoperative diagnosis of WHO grade II meningioma, were included. The mean age for the population was 59.9 years and 70% were female. Tumor volume ≥ 36.0 cc was assigned 2 points, presence of irregular tumor borders was assigned 2 points, and presence of peritumoral edema was assigned 1 point. The probability of having a WHO grade II meningioma was 0% with a score of 0, 25.0% with a score of 1, 38.5% with a score of 2, 65.4% with a score of 3, and 83.3% with a score of 4 or greater. A threshold of ≥ 3 points achieved a recall of 0.80, precision of 0.73, F1-score of 0.77, accuracy of 0.76, and AUC of 0.82. CONCLUSION: The proposed imaging scoring system had good predictive capability for WHO grade II meningiomas with good discrimination and calibration. External validation is needed.