Nan Liu, Yi Zheng, Xiaojun Xu
Minimal residual disease (MRD) is the most robust independent prognostic biomarker for pediatric acute lymphoblastic leukemia (ALL). Conventional MRD detection assays suffer from insufficient sensitivity and inherent technical limitations, failing to identify ultra-low-level leukemic blasts and thereby contributing to disease relapse. Next-generation sequencing (NGS)-based MRD detection (NGS-MRD) overcomes these drawbacks by targeting immunoglobulin (Ig)/T-cell receptor (TCR) gene rearrangements and enabling the precise quantification of residual leukemic clones. In recent years, NGS-MRD has undergone extensive technological optimization in target panel design, result interpretation and sample type expansion, and has been validated for its clinical utility in therapeutic threshold definition, prognostic stratification, post-therapy monitoring and treatment adjustments in pediatric ALL. This review synthesizes the latest technological refinements and clinical applications of NGS-MRD in pediatric ALL, critically discusses the current challenges that limit its routine clinical use, and proposes future research directions to address these issues.