Traditional Machine Learning Methods versus Deep Learning for Meningioma Classification, Grading, Outcome Prediction, and Segmentation: A Systematic Review and Meta-Analysis

Meningiomas are common intracranial tumors. Machine learning (ML) algorithms are emerging to improve accuracy in 4 primary domains: classification, grading, outcome prediction, and segmentation. Such algorithms include both traditional approaches that rely on hand-crafted features and deep learning (DL) techniques that utilize automatic feature extraction. The aim of this study was to evaluate the performance of published traditional ML versus DL algorithms in classification, grading, outcome prediction, and segmentation of meningiomas. A systematic review and meta-analysis were conducted. Major databases were searched through September 2021 for publications evaluating traditional ML versus DL models on meningioma management. Performance measures including pooled sensitivity, specificity, F1-score, area under the receiver-operating characteristic curve, positive and negative likelihood ratios (LR+, LR−) along with their respective 95% confidence intervals (95% CIs) were derived using random-effects models. Five hundred thirty-four records were screened, and 43 articles were included, regarding classification (3 articles), grading (29), outcome prediction (7), and segmentation (6) of meningiomas. Of the 29 studies that reported on grading, 10 could be meta-analyzed with 2 DL models (sensitivity 0.89, 95% CI: 0.74–0.96; specificity 0.91, 95% CI: 0.45–0.99; LR+ 10.1, 95% CI: 1.33–137; LR− 0.12, 95% CI: 0.04–0.59) and 8 traditional ML (sensitivity 0.74, 95% CI: 0.62–0.83; specificity 0.93, 95% CI: 0.79–0.98; LR+ 10.5, 95% CI: 2.91–39.5; and LR− 0.28, 95% CI: 0.17–0.49). The insufficient performance metrics reported precluded further statistical analysis of other performance metrics. ML on meningiomas is mostly carried out with traditional methods. For meningioma grading, traditional ML methods generally had a higher LR+, while DL models a lower LR−.