The diagnostic value of two-dimensional shear-wave elastography in identifying malignant lesions in lymph nodes: a prospective study

Abstract

This study evaluates the diagnostic performance of two-dimensional shear wave elastography (2D-SWE) in differentiating between benign, metastatic lymph nodes (LNs) and lymphomas. From May 2022 to February 2023, a total of 137 patients who presented with unexplained LN enlargement were examined at the Ultrasound Medical Department of Union Hospital of Huazhong University of Science and Technology. The conventional ultrasound recorded the location, longitudinal diameter, transverse diameter, L/T ratio, blood supply mode, lymphatic hilum and 2D-SWE calculated the average elasticity (E) of LN. Histopathology was the diagnostic gold standard. A total of 124 patients with 159 superficial LNs were included (32 benign, 70 metastatic, 57 lymphoma). Malignant LNs had significantly higher E values than benign ones (49.38 ± 29.96 kPa vs. 25.00 ± 14.42 kPa, P < 0.001). When E > 25.46 kPa, the AUC, sensitivity, specificity, PPV, NPV and accuracy were 0.807, 0.787, 0.750, 0.926, 0.471 and 0.780, respectively, in identifying malignant LNs. For distinguishing benign LNs from lymphoma, the E cutoff was 25.03 kPa, with the AUC, sensitivity, specificity, PPV, NPV and accuracy of 0.727, 0.754, 0.719, 0.827, 0.622 and 0.742, respectively. To differentiate benign from metastatic LNs, an E cutoff of 36.97 kPa yielded an AUC, sensitivity, specificity, PPV, NPV and accuracy of 0.872, 0.757, 0.875, 0.930, 0.622 and 0.794, respectively. Comparing lymphoma and metastatic LNs, the E cutoff was 42.57 kPa. And the AUC, sensitivity, specificity, PPV, NPV and accuracy were 0.787, 0.700, 0.860, 0.860, 0.700 and 0.772, respectively. 2D-SWE parameter (the average elasticity) can effectively evaluate benign, metastatic LNs and lymphoma, which provides valuable information for preoperative evaluation of superficial LNs.

Keywords: Differential diagnosis; Shear-wave elastography; Superficial lymph nodes; Ultrasound.

Fig. 1

Flowchart of the study. LNs, lymph nodes; 2D-SWE, two-dimensional shear wave elastography.

Fig. 2

The 2D-SWE images of LNs, with pathological results proven reactive LN (A), lymphoma (B) and metastatic LN of breast cancer (C), respectively.

Fig. 3

ROC curves of E value for differentiating between benign and malignant LNs.

Fig. 4

ROC curves of E value for differentiating between benign and lymphoma (A), benign and metastatic LNs (B), lymphoma and metastatic LNs (C).

Fig. 5

Relationship between the E value and the longitudinal axis (A) or the transverse axis (B).