Comparable efficacies in differentiating WHO grade II from III oligodendrogliomas with machine-learning and radiologist’s reading
Abstract Abstract (236 words) Background: The medical imaging differentiation of World Health Organization (WHO) grade II (ODG2) from III (ODG3) oligodendrogliomas remains a challenge. We investigate whether combination of machine leaning with radiomics from conventional T1 contrast-enhanced (T1CE) magnetic resonance imaging (MRI) can offer improved efficacy. Methods: Thirty-six patients with histologically confirmed ODGs who underwent the T1CE MR examination before any intervention between January 2015 and July 2017 were recruited in the current study. The volume of interest (VOI) covering the whole tumor enhancement were manually drawn on the T1CE slice by slice using ITK-SNAP and a total of 1044 features were extracted from the VOI using Analysis-Kinetics software. Random forest (RF) algorithm and 5-fold cross validation were applied to differentiate ODG2 from ODG3. The diagnostic efficacies of radiomics-based machine learning and radiologist’s assessment were also compared. Results: Nineteen ODG2 and 17 ODG3 were included in the current study and ODG3 tended to present with prominent necrosis and nodular/ring-like enhancement (P < 0.05). The RF strategy with radiomics features produced the stable diagnostic efficiency, with an AUC, ACC, sensitivity, and specificity of 0.765, 0.763, 82.8% and 70.0%, respectively. The AUCs of radiologists 1, 2 and 3 were 0.700, 0.687, and 0.714, respectively. The efficacy of machine learning based on radiomics is comparable to that of radiologist. Conclusions: Machine-learning based on radiomics of T1CE offered comparable efficacy to that of radiologist on differentiating ODG2 from ODG3.