Table 2.

Performance of models

Model	Cutoff	Training cohort					Testing cohort
		AUC	95% CI	Accuracy	Specificity	Sensitivity	AUC	95% CI	Accuracy	Specificity	Sensitivity
SAD	1.000	0.697	0.622–0.773	0. 659	0.719	0.461	0.729	0.619–0.839	0.513	0.750	0.500
SUVmax	2.500	0.797	0.734–0.860	0.719	0.573	0.876	0.828	0.739–0.917	0.718	0.575	0.868
Rad-Score	− 0.044	0.849	0.796–0.903	0.768	0.802	0.730	0.828	0.782–0.919	0.769	0.725	0.816
Int-Score	0.331	0.881	0.834–0.928	0.789	0.688	0.899	0.872	0.797–0.946	0.756	0.625	0.895

The values in italics indicate the cut-off values used in the diagnosis process

AUC, the area under receiver operating characteristic (ROC) curves; CI, confidence interval

*SUVmax ≥ 2.5 or SAD ≥ 1.0 cm to be malignant LNs, which are usually used as reference standards in our diagnosis process