Role of shear wave elastography in the evaluation of cervical lymph nodes during follow-up of differentiated thyroid carcinoma.

OBJECTIVE

To evaluate the role of shear wave elastography (SWE) in the characterization of cervical lymph nodes in patients undergoing follow-up for differentiated thyroid carcinoma.

METHODS

This cross-sectional study included 45 patients and 49 cervical lymph nodes (node-level analysis) evaluated by B-mode ultrasonography, color Doppler, and SWE. Cytology was the primary reference standard, with histopathology when available. SWE stiffness (kPa) and ultrasonographic features were analyzed. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis, and independent predictors were evaluated using Generalized Estimating Equations.

RESULTS

Mean lymph node stiffness was 34.24 ± 30.57 kPa. Malignant lymph nodes showed higher stiffness than benign ones (54.58 ± 34.14 vs. 20.21 ± 17.67 kPa; p < 0.0001). Nodes with positive FNA-Tg also demonstrated higher stiffness (48.64 ± 34.39 vs. 21.04 ± 18.05 kPa; p = 0.0015). ROC analysis for cytological malignancy yielded an AUC of 0.737 (95% CI: 0.59-0.88), with 94.7% sensitivity (95% CI: 85-100%) and 50.0% specificity (95% CI: 32-69%) at a sample-derived cutoff of 12.9 kPa, requiring external validation. A non-habitual Doppler pattern was the only independent predictor of malignancy in the multivariable model (p < 0.0001).

CONCLUSION

SWE showed moderate discriminatory performance, with high sensitivity but limited specificity. Doppler pattern remained the strongest predictor of malignancy. SWE may be useful as a complementary tool within a multiparametric assessment, but should not be used as a standalone diagnostic method.