The overuse of radioactive iodine in low-risk papillary thyroid cancer patients.

Background: The aim of this study was to use current American Thyroid Association (ATA) management guidelines to identify groups who might be at risk of overtreatment with radioactive iodine (RAI) ablation after surgery for low-risk papillary thyroid cancer (PTC).

Methods: PTC patients were identified using the Surveillance, Epidemiology and End Results database. Characteristics of low-risk patients (defined as T1 without metastasis) were compared to those not low-risk. Predictors of receiving RAI for low-risk disease were determined using logistic regression.

Results: Of 32,229 cases, 17,286 (53.6%) were low-risk. Low-risk patients, compared to others, were older (mean age 51.3 versus 48.5 years), and more often female (81.6% versus 71.7%), white (69.7% versus 62.0%), and insured (87.6% versus 85.6%)(all p-values < 0.001). Nearly 25% of low-risk patients received RAI. Predictors of overtreatment with RAI included age <45 years (OR: 1.393; 95% CI: 1.250-1.552), age 45-64 years (OR: 1.275; 95% CI: 1.152-1.412), male sex (OR: 1.191; 95% CI: 1.086-1.305), Hispanic (OR: 1.236; 95% CI: 1.110-1.376) and Asian (OR: 1.306; 95% CI: 1.159-1.473) race, and extensive lymphadenectomy (OR: 1.243; 95% CI: 1.119-1.381).

Conclusion: Low-risk PTC patients were more likely to receive post-surgical RAI when not indicated under ATA guidelines if they were younger, male, Hispanic or Asian, or underwent extensive lymph node surgery. Identification of groups at risk for overtreatment can help impact practice patterns and improve the effective utilization of healthcare resources.