From:  Precision oncology in the treatment of patients with bone sarcomas: an up-to-date narrative review

 Liquid biopsy biomarkers and clinical applications in bone sarcomas.

ctDNA (fusion-based)Ewing sarcomaMRD detection, relapse predictionEmerging–strongLimited large validation
ctDNA (genomic instability)OsteosarcomaResponse monitoringEmergingVariable sensitivity
ctRNAEwing sarcomaFunctional activity trackingEarlyRNA instability
CTCsMetastatic diseaseBiological characterizationEarlyLow detection rate
Exosomal markersInvestigationalMicroenvironment insightEarlyStandardization lacking

ctDNA: circulating tumor DNA; ctRNA: circulating tumor RNA; CTCs: circulating tumor cells; MRD: minimal residual disease.