Non-Invasive Evaluation of Axillary Lymph Node Status in Breast Cancer Patients Using Shear Wave Elastography

Abstract

Less invasive procedures are currently required to examine the axillary lymph node status. Shear wave elastography with acoustic radiation force impulse provides objective and reproducible quantification of the intrinsic property of the soft tissue. In this study, we measured shear wave velocity of the axillary lymph nodes of patients with breast cancer using Virtual Touch Tissue Quantification (VTTQ). The degree of lymph node metastasis was evaluated by measuring the expression level of cytokeratin 19 (CK19) mRNA, a specific marker for breast cancer cells. The one-step nucleic acid amplification (OSNA) was used to determine the copy number of CK19 mRNA in 149 lymph node specimens of 149 primary breast cancer patients. Axillary lymph node status according to OSNA (copy number/μl) were categorized as 0-249 copies (−), 250-5,000 copies (+), and copy number > 5,000 (++). A category (−) represents no metastasis in the axillary lymph node. There were 121 patients with OSNA−, 9 with OSNA+ and 19 with OSNA++. The average velocities according to OSNA categories were 1.64 ± 0.42 m/second for OSNA−, 2.25 ± 0.78 m/second for OSNA+, and 2.79 ± 0.98 m/second for OSNA++. There were significant differences in the shear wave velocity between OSNA− and OSNA+ (P = 0.040) or OSNA++ (P < 0.001). The most optimal cutoff velocity to distinguish benign from metastasis is 1.44 m/second, as determined using the receiver operating characteristic method. The shear wave velocity measured with VTTQ could provide clinically useful information about axillary lymph node metastasis in patients with primary breast cancer.

Predictive value of comb-push ultrasound shear elastography for the differentiation of reactive and metastatic axillary lymph nodes: A preliminary investigation

“…The results from our study show that the Young's modulus (i.e., measure of elasticity) from the lymph node cortex is significantly different when compared between reactive and malignant ALNs, distinguishing the two mechanisms with an accuracy of up to 92.3%. Our results concur with those of previous investigations on lymph nodes performed with other SWE techniques, such as Supersonic Imagine [13,14,16,26] and Virtual Touch Tissue Quantification [15,27] in that malignant lymph nodes presented higher elasticity than benign lymph nodes. Most of these studies focused on the preoperative value of US SWE and primarily evaluated axillary SLNs as a result.…”

“…[5,6]. These features can provide valuable information for the characterization of abnormal ALNs [7][8][9], and help identify lymph nodes suitable for needle biopsy [10][11][12][13][14][15][16][17].…”

“…In this study, B-mode US features and elasticity parameters were assessed to evaluate the predictive performance of CUSE for the differentiation of reactive and metastatic axillary lymph nodes. Although, other SWE techniques such as Supersonic Imagine [13,14,16,26] and Virtual tissue quantification [15,27] have been used to predict ALN metastasis; to the best of our knowledge, this is the first report showing the performance of CUSE for the differentiation of reactive and metastatic ALNs.…”

Comparisons between elastographic stiffness scores for benign versus malignant lymph nodes in dogs and cats

“…Other clinical and ultrasonographic findings such as lymph node palpation, clinical suspicion, lymph node size, shape, and echogenicity are still valuable and necessary for an overall assessment. Most studies using elastography to determine malignancy of lymph nodes in people also conclude that it should be used as a complementary method to conventional ultrasound …”

The EFSUMB Guidelines and Recommendations for the Clinical Practice of Elastography in Non-Hepatic Applications: Update 2018

“…Both SWE and SE have been used in the evaluation of axillary lymph nodes, with one study reporting a sensitivity and specificity of 82.8 % and 69.6 %, respectively, using SWE to distinguish between benign and malignant lymph nodes using a cut-off of 1.44 m/s [37]. Using SE, the sensitivity was 60 % and the specificity was 79.6 % for the diagnosis of malignancy [38].…”