Selective use of radioactive iodine in intermediate-risk papillary thyroid cancer

Objective: To describe the outcomes with the selective use of radioactive iodine (RAI) in patients who are at intermediate risk of death from papillary thyroid cancer, focusing on 2 subgroups: patients older than 45 years with low-risk tumors and patients younger than 45 years with high-risk tumors. Design : Retrospective case review. Setting: Tertiary referral US cancer center. Patients: The study incluced 532 consecutive patients who were surgically treated between 1986 and 2005. Interventions: All patients underwent total thyroidectomy; 307 also received RAI. Main Outcome Measures: Disease-specific survival (DSS) and recurrence-free survival (RFS). Results: Of 344 patients older than 45 years with lowrisk tumors, 148 (43%) received RAI and 196 (57%) were selected not to receive RAI. The patients who were treated without RAI were more likely to be female and have pT1N0 disease. The 5-year DSS and RFS were 100% and 98%, respectively. The presence of nodal metastases predicted poorer 5-year RFS within this group (99% vs 91%; P =.004). Of 188 patients younger than 45 years with high-risk tumors, 159 (85%) received RAI, and only 29 (15%) were selected not to receive RAI. The 5-year DSS and RFS for these patients were 100% and 95%, respectively. The presence of nodal metastases predicted poorer 5-year RFS within this group (100% vs 86%; P =.02). Conclusion: Our study shows that the subgroup of patients who are older than 45 years with tumors that are smaller than 4 cm in greatest dimension and confined to the thyroid gland and who do not have nodal metastases can safely be treated without RAI.