实体瘤约占所有儿童癌症的30%。通常，诊断是基于对原发肿瘤活检标本进行组织学和分子学分析。液体活检相对传统的组织活检具有几个优势。然而，液体活检在儿童实体肿瘤的基因组分析和治疗反应监测方面仍处于实验阶段，主要是以回顾性方式进行，对患者管理直接影响有限。在这个病例系列中，我们讨论了六个儿童实体瘤的临床病例，进行了液体活检检测，并展示了液体活检用于未来临床决策的潜力。我们在荷兰Princess Máxima儿童肿瘤中心治疗的2017年至2023年间，对六名接受固体肿瘤治疗的儿童患者的液体活检样本进行了定量实时聚合酶链式反应（RT-qPCR）、微滴数字PCR（ddPCR）或还原表示亚硫酸单酯测序（cfRRBS）。结果用于辅助临床决策，通过对建立诊断、预后和治疗反应监测的贡献进行。对于三名患者，通过cfRRBS有助于确诊肌肉肉瘤、尤文肉瘤和神经母细胞瘤（案例1-3）。在两名患者中，通过液体活检用于预后，通过MYCN ddPCR来预测神经母细胞瘤患者的预后，通过RT-qPCR在骨髓中检测肌肉肉瘤特异性mRNA来预测患有肌肉肉瘤的患者的预后（案例4和5）。在案例6中，mRNA检测显示疾病进展，并协助临床决策。这个病例系列展示了液体活检的价值。我们进一步展示并推荐在确定转移状态、预后和治疗反应监测方面，将液体活检与传统方法结合使用于儿童实体肿瘤患者中。版权所有 © 2023 Gelineau, van Barneveld, Samim, Van Zogchel, Lak, Tas, Matser, Mavinkurve-Groothuis, van Grotel, Zsiros, van Eijkelenburg, Knops, van Ewijk, Langenberg, Krijger, Hiemcke-Jiwa, Van Paemel, Cornelli, De Preter, De Wilde, Van Der Schoot and Tytgat.

Solid tumors account for about 30% of all pediatric cancers. The diagnosis is typically based on histological and molecular analysis of a primary tumor biopsy. Liquid biopsies carry several advantages over conventional tissue biopsy. However, their use for genomic analysis and response monitoring of pediatric solid tumors is still in experimental stages and mostly performed retrospectively without direct impact on patient management. In this case series we discuss six clinical cases of children with a solid tumor for whom a liquid biopsy assay was performed and demonstrate the potential of liquid biopsy for future clinical decision making.We performed quantitative real-time PCR (RT-qPCR), droplet digital PCR (ddPCR) or reduced representation bisulphite sequencing of cell-free DNA (cfRRBS) on liquid biopsies collected from six pediatric patients with a solid tumor treated between 2017 and 2023 at the Princess Máxima Center for Pediatric Oncology in the Netherlands. Results were used to aid in clinical decision making by contribution to establish a diagnosis, by prognostication and response to therapy monitoring.In three patients cfRRBS helped to establish the diagnosis of a rhabdomyosarcoma, an Ewing sarcoma and a neuroblastoma (case 1-3). In two patients, liquid biopsies were used for prognostication, by MYCN ddPCR in a patient with neuroblastoma and by RT-qPCR testing rhabdomyosarcoma-specific mRNA in bone marrow of a patient with a rhabdomyosarcoma (case 4 and 5). In case 6, mRNA testing demonstrated disease progression and assisted clinical decision making.This case series illustrates the value of liquid biopsy. We further demonstrate and recommend the use of liquid biopsies to be used in conjunction with conventional methods for the determination of metastatic status, prognostication and monitoring of treatment response in patients with pediatric solid tumors.Copyright © 2023 Gelineau, van Barneveld, Samim, Van Zogchel, Lak, Tas, Matser, Mavinkurve-Groothuis, van Grotel, Zsiros, van Eijkelenburg, Knops, van Ewijk, Langenberg, Krijger, Hiemcke-Jiwa, Van Paemel, Cornelli, De Preter, De Wilde, Van Der Schoot and Tytgat.