Response Assessment in Pediatric Neuro-Oncology: Current Standards and Future Directions

Imaging of pediatric brain tumors poses a significant clinical challenge, ranking among the primary causes of mortality and morbidity in children. Despite neuroimaging advancements, these tumors exhibit distinct features that demand specialized diagnostic and therapeutic approaches. The complexity of pediatric brain tumor reporting still poses challenges. The Response Assessment in Pediatric Neuro-Oncology (RAPNO) Working Group has attempted to create an evidence-based approach to evaluate these tumors, but no streamlined approach incorporating imaging reporting has been devised. The Brain Tumor Reporting and Data System (BT-RADS) is a system to standardize reporting of follow-up MRIs in patients with brain tumors. However, BT-RADS has limitations when attempting to apply the published diagnostic algorithm to the unique pathology and imaging characteristics of pediatric brain tumors. We propose the development of a pediatric-specific reporting system, pBT-RADS, informed by the RAPNO Working Group recommendations. Key proposed changes include the incorporation of metrics for CSF dissemination, tumor cyst changes, and T2 FLAIR and DWI changes. Distinct pathology and imaging features of pediatric tumors that necessitate an adjustment to the BT-RADS assessment, such as medulloblastoma, diffuse leptomeningeal glioneuronal tumor, craniopharyngioma, and low-grade glioma, are discussed. Further work is needed to hone, implement, and evaluate the pBT-RADS template.