A) At one-year after RAI treatment.

	Sensitivity	Specificity	PPV	NPV	Diagnostic accuracy
ATA	76,6	47,4	27,1	88,8	53,3
ETA	70,3	62,2	32,1	89,1	63,8
ATA after SPECT/CT	65,6	73,3	38,5	89,3	71,7
SPECT/CT	60,9*	88,0**	56,5	89,8	82,5***

Positive predictive value (PPV), negative predictive value (NPV), Risk stratification of American Thyroid Association (ATA), Risk stratification of European Thyroid Association (ETA), Risk stratification of American Thyroid Association after SPECT/CT (ATA after SPECT/CT) and SPECT/CT alone (SPECT/CT).

*Sensitivity of SPECT/CT compared to the ATA classification was significantly lower (p = 0.021).

**Specificity of SPECT/CT was significantly higher than any other classification (p < 0.001).

***Diagnostic accuracy of SPECT/CT was significantly better than any other classification (p < 0.001).