Shear wave elastography combined with gray-scale ultrasound for predicting central lymph node metastasis of papillary thyroid carcinoma.

OBJECTIVE

To investigate the relationship between shear wave elastography (SWE) elasticity indices of papillary thyroid carcinoma (PTC) and central lymph node metastasis (CLNM) and to evaluate the value of SWE combined with gray-scale ultrasound (US) for predicting preoperative CLNM.

METHOD: This study included 172 patients with a pathology diagnosis of PTC who underwent preoperative gray-scale US and SWE evaluation. Patients were divided into CLNM-positive and CLNM-negative groups. We analyzed the association between SWE elasticity indices (Emax, Emean and Emin) and CLNM, compared the diagnostic efficacy of gray-scale US alone versus SWE combined with gray-scale US for predicting CLNM, and analyzed the influence of Hashimoto's thyroiditis (HT) on the diagnostic efficacy of CLNM.

RESULTS

SWE elasticity values Emax, Emean and Emin were significantly higher in CLNM-positive patients (P=0.000, 0.000 and 0.003, respectively). The AUC of Emax was higher than that of other SWE indices for predicting CLNM (AUC = 0.749; 95% CI = 0.676-0.822). In multivariate analysis, microcalcification (OR = 5.254; 95% CI = 2.496-11.061), extrathyroidal extension (OR = 4.210; 95% CI = 1.423-12.456), multifocality (OR = 3.084; 95% CI = 1.190-7.991) and Emax >59.0 kpa (OR = 4.934; 95% CI = 2.318-10.500) were independent risk factors for predicting CLNM. The AUC of SWE combined with gray-scale US for predicting CLNM (AUC = 0.825; 95% CI = 0.760-0.879) was significantly higher (P = 0.011) than that for gray-scale US alone (AUC = 0.774; 95% CI = 0.704-0.834). There was no significant difference in AUC between the HT and non-HT subgroups in predicting CLNM (0.798 vs. 0.833, P = 0.640).

CONCLUSIONS

SWE can be used to predict CLNM in PTC patients. SWE combined with gray-scale US can improve the prediction of CLNM.