Outcomes of I-131 therapy in pediatric and adolescent differentiated thyroid cancer: a long-term follow-up of a single-center Indian cohort.

Abstract

Background: Pediatric differentiated thyroid cancer (DTC), particularly papillary thyroid carcinoma, is the most common endocrine malignancy in children and adolescents. Despite its aggressive presentation, including lymph nodes and distant metastases, pediatric DTC generally has an excellent prognosis. The 2015 American Thyroid Association (ATA) guidelines emphasize a risk-stratified approach, but dynamic risk stratification (DRS) has been less studied in this population. This study aimed to evaluate DRS in predicting persistent and recurrent disease in pediatric DTC over a mean follow-up of nearly 10 years.

Materials and methods: A retrospective analysis was conducted on 88 pediatric patients with DTC who underwent surgery and radioactive iodine therapy (RAIT) between March 2009 and September 2017. Inclusion criteria were patients aged less than or equal to 18 years with postsurgical RAIT and at least 5 years of follow-up. DRS was applied based on clinical, biochemical, and imaging findings.

Results: The cohort had a mean age of 15 years, predominantly female (72.7%). At diagnosis, 70.5% had lymph node metastases, and 15.9% had distant metastases. DRS categorized patients into excellent response, biochemical incomplete response, and structural incomplete response. At the final follow-up, 86.4% of patients had complete or stable disease. High-risk patients required additional treatments, including repeat RAIT.

Conclusion: DRS is a valuable tool for predicting persistent and recurrent disease in pediatric DTC, refining risk categories beyond ATA stratification. It provides a more personalized approach, potentially improving outcomes by identifying high-risk individuals for tailored treatment and follow-up. Further prospective studies are needed to standardize DRS in pediatric DTC.