The Impact of Radioactive Iodine on Outcomes Among Pediatric and Adolescent Thyroid Cancer Patients: A SEER Database Analysis

Background/objectives: Pediatric populations with well-differentiated thyroid cancer typically have favorable prognoses. However, the role of radioactive iodine (RAI) ablation in these patients remains uncertain. This investigation evaluates the national trends, therapeutic practices, and the impact of RAI on clinical outcomes.

Methods: Patients aged 21 years or younger with differentiated thyroid cancer, identified from the SEER database between 2000 and 2019, were analyzed. We compared the treatment approaches and survival outcomes of patients who underwent RAI ablation with those who did not.

Results: This retrospective cohort study encompassed 5318 pediatric patients, with 55.9% (n = 2973) who underwent RAI ablation. RAI utilization declined from 65% to 38.4% in 2019. Compared with those who did not undergo RAI, RAI patients presented with a larger tumor size (mean size: 27.7 vs. 20.4 mm), a higher T3/T4 stage (35.8% vs. 15.3%), nodal metastases (60.7% vs. 28.8%), and distant metastases (2.7% vs. 0.9%) (all p < 0.001). Despite this, RAI was not an independent predictor of recurrence, second malignancy, or mortality. The analysis showed no significant differences in long-term survival between the RAI and non-RAI groups (p > 0.05), with African American patients having an increased risk of mortality (HR = 3.81; p = 0.038). Cancer-directed surgery emerged as a protective factor (HR = 0.08; p = 0.018), while RAI treatment did not significantly affect mortality risk (p = 0.09).

Conclusions: Excellent pediatric thyroid cancer outcomes were achieved regardless of RAI use. Further research should clarify appropriate RAI indications while addressing racial outcome inequities.