Table 1.
Patient characteristics.
Fig 1.
Result of postablation I-131 whole-body scintigraphy and postablation SPECT/CT in the low-or intermediate-risk group.
SPECT/CT: single-photon emission computed tomography; RAI: radioactive iodine; mLN: metastatic lymph node; RxWBS: postablation I-131 whole-body planar scintigraphy.
Fig 2.
Postablation I-131 whole body planar scan and SPECT/CT of a patient with papillary thyroid cancer.
Preablation TSH-stimulated serum thyroglobulin level was 4.7 ng/ml. A focal iodine uptake was seen in the right neck on postablation I-131 planar scintigraphy (a). The SPECT/CT image also revealed RAI uptake on a small LN in the right upper neck (b).
Fig 3.
Receiver-operating-characteristics (ROC) curve analysis for preablation TSH-stimulated serum thyroglobulin level of RAI avid metastatic lymph node on SPECT/CT in low- or intermediate-risk group.
The optimal cut-off value of TSH-stimulated serum Tg was 0.5 ng/ml for predicting residual RAI avid mLN (sensitivity, 68.6%; specificity, 61.1%; area under the curve, 0.615; p = 0.022).
Table 2.
Comparison of clinicopathological parameters between patients with and without RAI-avid mLN.
Table 3.
Prevalence of RAI-avid mLN according to risk group and preablation TSH-stimulated serum Tg level.
Fig 4.
Receiver-operating-characteristics (ROC) curve analysis for preablation TSH-stimulated serum thyroglobulin level of RAI avid metastatic lymph node on SPECT/CT in low-risk group.
The optimal cut-off of TSH-stimulated serum Tg level for predicting RAI-avid mLN in the low-risk group was 1.0 ng/ml (sensitivity, 100.0%; specificity, 71.9%; area under the curve, 0.798; p = 0.039).
Table 4.
Comparison of clinicopathological parameters between patients with and without RAI-avid mLN in the low-risk group.
Table 5.
Comparison of clinicopathological parameters between patients with and without RAI-avid mLN in the intermediate-risk group.