Table 4.

ATA risk of recurrence classification after initial surgery [2].

Low risk
(i) No local or distant mets
(ii) All macroscopic tumor has been resected
(iii) There is no tumor invasion of locoregional tissues or structures
(iv) Tumor does not have aggressive histology (e.g., tall cell, insular, columnar cell carcinoma) or vascular invasion
(v) If I-131 is given, there is no I-131 uptake outside the thyroid bed on the first posttreatment whole-body RAI scan
Intermediate risk
(i) Microscopic invasion of tumor into the perithyroidal soft tissue at initial surgery
(ii) Cervical LN mets or I-131 uptake outside the thyroid bed on the post-treatment whole-body RAI scan done after thyroid
remnant ablation
(iii) Tumor with aggressive history or vascular invasion
High risk
(i) Macroscopic tumor invasion
(ii) Incomplete tumor resection
(iii) Distant mets
(iv) Possibly thyroglobulinemia out of proportion to what is seen on the post-treatment scan