Table 3. Risk Stratification based on response to therapy 6-24 months after initial treatment (total thyroidectomy + RAI).
| Response to Therapy | Definitions | |
|---|---|---|
| Excellent Response | No clinical, biochemical or structural evidence of disease | Nonstimulated Tg <0.2 ng/mL and/or Stimulated Tg <1 ng/mL + Undetectable TgAb + Negative imaging |
| Indeterminate Response | Non-specific biochemical or structural findings which cannot be confidently classified as either benign or malignant | Nonstimulated 0.2-1 ng/mL and/or Stimulated Tg 1-10 ng/mL and/or TgAb levels stable or declining and/or Nonspecific findings on imaging studies |
| Biochemical Incomplete Response | Abnormally elevated serum Tg and/or increasing Tg values over time with similar TSH levels and/or rising TgAb levels in the absence of localizable structural disease | Nonstimulated >1 ng/mL and/or Stimulated Tg >10 ng/mL and/or Increasing TgAb + Negative imaging |
| Structural Incomplete Response | Persistent or newly identified loco-regional or distant metastases with or without abnormal Tg or TgAb | Structural evidence of disease in anatomic (US, CT), functional (WBS) or hybrid (18FDG-PT/CT) imaging regardless of Tg or TgAb values |