This podcast explores the principles and clinical applications of circulating ctDNA-based MRD testing in diffuse large B-cell lymphoma, including how personalized sequencing assays can detect microscopic residual disease with greater sensitivity than imaging. Dr. David Russler-Germain discusses the growing evidence supporting ctDNA MRD testing for prognostication and treatment monitoring, while also addressing current limitations, such as variability across lymphoma subtypes and factors that can affect assay performance and interpretation.