Evaluation of Ex Vivo Shear Wave Elastography of Axillary Sentinel Lymph Nodes in Patients with Early Breast Cancer.

The pretherapeutic assessment of axillary lymph node status is crucial in staging early breast cancer patients, significantly influencing their further treatment and prognosis. According to current guidelines, patients with clinically unsuspicious axillary status regularly undergo a biopsy of sentinel lymph nodes (SLNs), whereby metastasis is detected in up to 20% of cases. In recent years, the use of shear wave elastography (SWE) has been studied as an additional ultrasound tool for the non-invasive assessment of tumors in the breast parenchyma and axillary lymph nodes. Previous studies (examining the axilla in patients) have shown that metastases have significantly higher SWE values than benign nodes. This study aims to evaluate whether SWE can differentiate between tumor-free and metastatic-affected SLN ex vivo, i.e., by examining the pathological specimen. SWE was performed ex vivo on SLN specimens and compared with final histopathological results. A total of 168 SLNs from 105 patients were measured using ex vivo SWE and subjected to standard histopathological processing. In this group, 17 metastases in 17 patients (16.19%) were detected. Tumor-free SLNs had a mean velocity of 1.33 ± 0.23 m/s, while metastatic nodes showed a mean velocity of 1.35 ± 0.29 m/s ( = 0.724). There was no significant difference in ex vivo SWE between benign and malignant SLNs in this population. Contrary to previous studies, this study did not find SWE effective in differentiating lymph node metastases. Further research is needed to clarify SWE's potential role in axillary staging.