RESUMO
The main goal of radioactive iodine (RAI) administrated for patients with indeterminate-risk differentiated thyroid cancer (DTC) is removing occult microscopic residual disease after a total thyroidectomy, aiming to reduce recurrence and metastasis, then to improve disease-free survival. This treatment is called as adjuvant therapy, which also ablates the remnant thyroid tissue together. According to the current thyroid cancer management guidelines (2015 American Thyroid Association management guidelines), intermediate-risk patients can be selectively administered RAI. By reviewing articles about DTC patients with indeterminate-risk who underwent RAI or not after thyroidectomy, this article shows that there are inconsistent opinions on 131I decreasing recurrence and improving survival. In addition, apart from unexplained hyperthyroglobulinemia as an indication for 131I therapy, no other uniform clinicalpathological characteristics are recommended.