ATA 2025 Risk Calculator

Educational and clinical decision-support use only.

Initial risk stratification inputs
Histology
Primary tumor extent (T)
T1: Tumor ≤2 cm, limited to the thyroid T2: Tumor >2 cm but ≤4 cm, limited to the thyroid
Nodal status
Resection / margin status
Microscopic ETE
No
Aggressive histology
tall / hobnail / columnar etc.
No
Multifocality (PTC)
Vascular invasion (PTC)
Poor differentiation / high grade
No
Distant metastasis (M)
Initial risk stratification result
Risk category
Low
Recommended RAI
RAI generally not given; if considered: ~30–50 mCi (1.1–1.85 GBq).
Rationale
  • No triggers met → Low
Dynamic risk stratification
RAI received
Yes
Tg stimulated?
Non-stimulated
Tg band (ng/mL)
TgAb trend
Imaging
Response
Excellent
Estimated ROR after treatment
<2%
  • Imaging negative
  • Non-stimulated Tg <0.2
  • Stable/declining TgAb