Droplet Biosciences and academic collaborators published validation data showing postoperative lymph fluid can detect circulating tumor DNA (ctDNA) with higher sensitivity than matched early plasma for identifying molecular residual disease (MRD) after head and neck cancer surgery. The study, in Clinical Cancer Research, reported lymph fluid sensitivities of 65–76% across discovery and replication cohorts versus ~35% for time‑matched plasma. The team analyzed postsurgical drain fluid collected within 24 hours and demonstrated improved detection of locoregional relapse compared with plasma; lymph fluid was particularly predictive for intermediate‑risk patients where adjuvant‑therapy decisions are uncertain. Droplet’s CSO noted lymph fluid outperformed plasma in catching locoregional MRD that typically drives post‑surgical recurrence. If validated prospectively, the approach could change early post‑op surveillance and adjuvant‑therapy selection in head and neck oncology, but adoption will depend on assay standardization, timing logistics and integration with existing pathology workflows.