Abstract
BACKGROUND: Medulloblastoma (MB) is classified into different molecular subgroups: wingless (WNT), sonic hedgehog (SHH), group 3, and group 4. This study aims to investigate the potential of the molecular-structural mismatch signs for distinguishing the MB molecular subgroups in children non-invasively. METHODS: In this prospective study, 60 newly diagnosed pediatric MB patients underwent conventional structural MRI and molecular amide proton transfer (APT) MRI from February 2018 to April 2022. Molecular-structural mismatch images were generated based on the APTw, T2-weighted (T2w), and fluid-attenuated inversion recovery (FLAIR) images. The mean values were calculated from the region of interest defined on APTw and mismatch images. The classification performance of mean values was assessed using the receiver operating characteristic (ROC) analysis. The statistical significance of differences between the area under the curve (AUC) values was evaluated using the DeLong test. RESULTS: In total, 46 participants (mean age: 75.1±43.4 months; 33 males) were included in the final analysis: 5 WNT, 13 SHH, 9 group 3, and 19 group 4 patients. The AUC values of the mean values of APTw images for discriminating the WNT, SHH, group 3, and group 4 subgroups were 0.87, 0.66, 0.56, and 0.56, respectively. The AUC values for distinguishing the WNT, SHH, group 3, and group 4 subgroups with the mean values of molecular-structural mismatch images were improved to 0.90, 0.67, 0.68, and 0.77, respectively. CONCLUSIONS: Molecular-structural mismatch signs have the potential for distinguishing the molecular subgroups of MB in children non-invasively.