Who leads, who treats, what dose? European paediatric differentiated thyroid carcinoma practice—an European Cooperative Study Group for Paediatric Rare Tumours survey

Objective: To map real-world management of paediatric differentiated thyroid carcinoma (DTC) across Europe and identify targets for harmonization. Design: Cross-sectional, web-based survey of centres providing paediatric DTC care. Setting & Participants: One consolidated response per centre was requested from a clinician overseeing paediatric DTC. The instrument covered centre profile/multidisciplinary tumour (MDT) board organization; staging and guideline use; risk stratification and dynamic response; diagnostics; surgery/lymph node management; radioactive iodine therapy (RAIT) policy and activity selection; and thyroid-stimulating hormone targets, follow-up, shared-care/transition. Analyses were descriptive at centre level. Results: Forty-two centres from 18 countries participated in the survey. Response denominators varied by item. Among responding centres, ≈75% were university or academic hospitals, ≈70% used a paediatric age cut-off of ≤18 years, and ≈60% reported having a dedicated MDT board. Staging and guideline use were heterogeneous: centres most often reported mixed or centre-specific guidance, followed by the American Thyroid Association (ATA) 2015 guideline, national guidelines, and the European Thyroid Association (ETA) 2022 guideline. Dynamic response-to-therapy categories were commonly used. For unilateral presumed low-risk disease, hemithyroidectomy was the usual initial surgery in approximately two-thirds to three-quarters of centres, whereas total thyroidectomy was less common. For low-risk patients, RAIT policy were split between de-escalation and risk-adapted use. When administered, RAIT activity was determined using weight-based, dosimetric, or fixed empirical approaches. Country-level patterns suggested clustering around ETA-leaning, ATA-leaning, and national guideline frameworks. Conclusions: Across Europe, centres broadly endorse risk-adapted care but diverge at key decision nodes—extent of surgery, formal risk framework, and RAIT in low-risk disease—reflecting guidance plurality and organizational context. Leveraging existing infrastructures offers pragmatic avenues to reduce unwarranted variation while generating paediatric-specific evidence to refine recommendations.