Pediatric brain tumor classification using deep learning on MR-images from the children’s brain tumor network

ABSTRACT Background and purpose Brain tumors are among the leading causes of cancer deaths in children. Initial diagnosis based on MR images can be a challenging task for radiologists, depending on the tumor type and location. Deep learning methods could support the diagnosis by predicting the tumor type. Materials and methods A subset (181 subjects) of the data from “Children’s Brain Tumor Network” (CBTN) was used, including infratentorial and supratentorial tumors, with the main tumor types being low-grade astrocytomas, ependymomas, and medulloblastomas. T1w-Gd, T2-w, and ADC MR sequences were used separately. Classification was performed on 2D MR images using four different off-the-shelf deep learning models and a custom-designed shallow network all pre-trained on adult MR images. Joint fusion was implemented to combine image and age data, and tumor type prediction was computed volume-wise. Matthew’s correlation coefficient (MCC), accuracy, and F1 scores were used to assess the models’ performance. Model explainability, using gradient-weighted class activation mapping (Grad-CAM), was implemented and the network’s attention on the tumor region was quantified. Results The shallow custom network resulted in the highest classification performance when trained on T2-w or ADC MR images fused with age information, when considering infratentorial tumors only (MCC: 0.71 for ADC and 0.64 for T2-w), and both infra- and supratentorial tumors (MCC: 0.70 for ADC and 0.57 for T2-w). Conclusion Classification of pediatric brain tumors on MR images could be accomplished using deep learning, and the fusion of age information improved model performance.