Comparison of shear wave elastography and histopathologic findings in benign-malignant differentiation of cervical lymph nodes

Aim: The aim of this prospective study was to quantitatively evaluate the SWV's obtained by examining lymph nodes with SWE in patients with persistant lymphadenopathy in the cervical region and to quantify the diagnostic performance of SWE in differentiating benign-malign lymph nodes by taking histopathological findings as a reference standard. Materials and Methods: Our study included 100 lymph nodes from 72 patients. After conventional US examination SWE was performed using virtual touch tissue imaging quantification (VTIQ) before histopathological sampling of all patients. Conventional examination assessed lymph node level, short axis, axial ratio, presence or absence of fatty hilum in lymph node, presence or absence of calcification, presence or absence of cystic change, and lymph node vascularity pattern. In the SWE study, SWVmax, SWVmean values indicating tissue stiffness were measured. Diagnostic performance was assessed by ROC analysis. Cut-off values were determined by Youden index. Histopathological diagnosis of benign and malignant lymph nodes was established as a reference standard. Findings: Histopathologically, 52 lymph nodes were benign and 48 lymph nodes were malignant. Mean values of SWVmax and SWVmean in benign lymph nodes were 3.21 ± 1.23 m/s, 2.96 ± 1.15 m/s and 4.51 ± 1.16 m/s, 4.18 ± 1.10 m/s respectively in malignant lymph nodes. SWVmax and SWVmean values were found statistically higher in malignant lymph nodes compared to benign lymph nodes (p <0.001). The best cutoff value for SWVmax and SWVmean was determined to be 3.03 m/s using ROC curve. Sensitivity, specificity, positive and negative predictive value and accuracy percentages were 93%, 59%, 68%, 91%, 75% for SWVmax respectively and 91%, 63%, 69%, 89%, 77% for SWVmean respectively. Conclusion: SWE is a promising repeatable non-invasive diagnostic imaging technique in distinguishing between malignant and benign lymph nodes. SWVmax and SWVmean values are highly valuable independent quantitative indicators in lymph node characterization. We think that the routine use of SWE may provide information about the lymph node characterization, reduce fine needle aspiration biopsies and surgical excision cases, and contribute significantly to the identification of the high-risk lymph node to be sampled.