Efficacy of Shear-Wave Elastography for Detecting Postoperative Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma

Abstract

Aims. To evaluate shear-wave elastography (SWE) as a tool to detect postoperative cervical lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC). Methods. Forty-three LNs of 43 patients with PTC undergoing ultrasound (US) and SWE before ultrasound-guided fine-needle aspiration (FNA) for the evaluation of postoperative cervical LN recurrences were analyzed. The mean (E-Mean) minimum (E-min), maximum (E-Max), and standard deviation (E-SD) of SWE elasticity indices were measured. . Results. Among 43 indeterminate or suspicious LNs, 12 were malignant and 31 were benign. The E-Mean, E-Min, E-Max, and E-SD values were significantly higher in malignant LNs than in benign LNs (E-Mean: 37.1 kPa in malignant versus 11.8 kPa in benign LNs, P < 0.001; E-Min: 11.3 kPa versus 5.1 kPa, P = 0.046; E-Max: 50.5 kPa versus 23.7 kPa, P < 0.001; and E-SD : 7.8 kPa versus 4.1 kPa, P = 0.006). E-Max had the highest accuracy (93.0%) when applied with a cut-off value of 37.5 kPa. It had a positive likelihood ratio of 25.83 and a diagnostic odds ratio of 150.0. Conclusions. The shear elasticity index of E-Max with higher likelihood ratios for malignant LNs, may help identify postoperative cervical LN metastasis in PTC patients with indeterminate or suspicious LNs.