Thyroid function and ultrasound surveillance in childhood cancer survivors (CCS): a position paper of the Italian Society of Pediatric Endocrinology and Diabetology (ISPED)

Purpose: Thyroid sequelae are the most frequent endocrine late effects of cancer treatment in childhood cancer survivors (CCS), making periodic life-long surveillance essential for the prompt diagnosis and management of hypothyroidism, hyperthyroidism, and thyroid nodules. Methods: Considering the large CCS population and the high relevance of thyroid sequelae in pediatric age (< 18 years), eight clinical questions (CQ) were addressed to provide a practical, tailored framework. Results: Although conclusive evidence is lacking, the significant morbidity associated with hypothyroidism in children and adolescents—including adverse effects on metabolism, growth, neurocognitive development, and quality of life—supports regular thyroid function monitoring in all CCS, regardless of treatment type. Assessment is recommended at baseline and subsequently according to the treatment protocol for all patients receiving chemotherapy, radiation to the head, neck, or mediastinum, sellar/suprasellar surgery, or iodinated contrast agents. In children treated with tyrosine kinase inhibitors or immune checkpoint inhibitors, thyroid function and antibody titers should be assessed at baseline, monthly during treatment, every six months during the first year after discontinuation, and annually thereafter. Ultrasound surveillance protocol may start at baseline, in order to evaluate also thyroid volume changes, and then every 2-3years after the radiation exposure or 131−IMIBG treatment or annually if nodules are present. Conclusion: Given the high prevalence of thyroid sequelae requiring life-long follow-up, pediatric endocrinologists play a pivotal role in the multidisciplinary management of CCS.