Differentiating cervical metastatic lymphadenopathy and lymphoma by shear wave elastography

Abstract

Shear wave elastography (SWE) is a recent technological advance of ultrasonography (US) to assess tissue stiffness. The purpose of this study is to assess tissue stiffness of malignant cervical lymph nodes (LN) with SWE, to reveal diagnostic performance of SWE in differentiating metastatic LN from lymphoma, and to assess inter-observer agreement of SWE. We assessed 62 malignant LN (24 lymphomas and 38 metastatic LN) and their median speed was 6.34 m/s and median elasticity was 69.7 kPa. Add of SWE with conventional US improved diagnostic accuracy of differentiating metastasis from lymphoma (16.13, 8.07 and 11.3% for three radiologists). Kendall’s Coefficient of Concordance of three readers for analyzing SWE patterns was 0.86. SWE can be a useful tool to discriminate metastatic cervical LN from lymphoma with improvement of diagnostic accuracy when using with conventional US.

Quantitative and Qualitative Approach for Shear Wave Elastography in Superficial Lymph Nodes

“…Despite including various pathologies, we found, as already published by several groups, that malignant LNs were significantly stiffer than benign ones and, additionally, we found that lymphomas showed stiffness values intermediate between benign LNs and carcinomas. Our results are similar to those obtained by Zhang et al (Zhang et al, 2017) using a point SWE system and Chae using Toshiba SWE (Chae et al, 2019).…”

“…Our "nodular pattern" that was found to be related to malignancy could be similar to the "markedly heterogeneous with some unfilled regions" pattern described by Bhatia et al (Bhatia et al, 2016), the "heterogeneous pattern" described by Luo for metastatic disease in breast cancer (Luo et al, 2019), or the "large red area" and "almost red" patterns described by Chae (Chae et al, 2019). The "rim pattern" that was also suggestive of malignancy has been reported in primary breast cancer.…”

“…Combination of quantitative SWE with conventional US increased the sensitivity to the detriment of specificity. However, contrarily to previous reports, the accuracy for diagnosing malignancy did not improve (Chae et al, 2019;Chang et al, 2018;Desmots et al, 2016;Seo and Sohn, 2018).…”

“…In previous preliminary results, we reported for the first time how qualitative SWE might be related to histology in lymph nodes (Chami et al, 2015). More recently, some published studies proposed SWE color map patterns as biomarkers to differentiate LNs (Chae et al, 2019;Luo et al, 2019). In our study, all the strategies that combined quantitative and/or qualitative SWE to conventional ultrasound exhibited close performances: they improved the sensitivity with a loss of specificity and thus accuracy performance close to that of conventional US alone.…”

“…However an overlap of stiffness values between the two groups exists, leading to various accuracies of SWE used alone. The color elasticity map has been very little exploited for LN diagnosis and only few recent studies showed that some SWE color patterns might be useful to discriminate LNs according to histology (Chae et al, 2019;Luo et al, 2019).…”