Usefulness of real‐time elastography for diagnosing lymph node metastasis of skin cancer: does elastography potentially eliminate the need for sentinel lymph node biopsy in squamous cell carcinoma?

Abstract

Background The metastatic involvement of regional lymph nodes is the most important prognostic factor for overall survival of skin cancer patients. The sonographic technique of freehand real‐time tissue elastography (RTE), which displays tissue rigidity as a colour overlay of the tissue image, was developed. Objective Our purpose was to evaluate the benefit of RTE for detecting lymph node metastases of skin cancer non‐invasively before operation. Methods We first selected lymph nodes of skin cancer patients which had already been diagnosed by biopsy as being reactive or metastatic, and then retrospectively collected images of RTE and B‐mode and colour Doppler ultrasound on those lymph nodes performed preoperatively. Twenty‐one lymph nodes from 12 patients with squamous cell carcinoma (SCC), 23 lymph nodes from 14 patients with malignant melanoma (MM) and 14 lymph nodes from six patients with extramammary Paget disease (Paget) were investigated. Elastographic images were assessed on a scale of one to four according to the percentage of high elasticity (hard) area (HEA) in the lymph node. Results In all three skin cancers, lymph nodes evaluated as grade 3 or 4 by RTE were metastatic. All lymph nodes evaluated as grade 1 or 2 by RTE were reactive in SCC, whereas some lymph nodes evaluated as grade 1 or 2 were metastatic in MM and Paget. Conclusion Real‐time tissue elastography may aid in distinguishing reactive lymph nodes from metastatic ones especially in SCC.

Diagnostic Value of Real-Time Elastography in Diagnosing Lymph Node Metastasis of Skin Cancer

“…Hinz et al showed that the sensitivity was 90% and the specificity was 76% in their study performed with 42 lymph nodes [24]. Tanaka et al reported the sensitivity of RTE as 43%, specificity as 100%, and accuracy as 82% for 23 MM metastases [22]. Our results for MM metastasis are higher than those observed in the literature.…”

“…on SCC, the sensitivity, specificity, and accuracy of RTE were found to be 100% in the detection of metastatic lymph nodes [22]. These different results in the literature may be attributed to the different parameters selected in the examinations in different studies.…”

Limitation of Using Ultrasonography After Positive Sentinel Lymph Node Biopsy in a Patient with Melanoma in the Detection of Lymph Node Metastasis

“…Recently developed techniques including elastography may be useful for improving the sensitivity. 7,8 We consider that immediate CLND is still one of the therapeutic options in patients with SLNpositive melanoma due to its excellent local control. 1 Local control is one of important factors for patients of melanoma without BRAF mutation, which is common in Asian and colored skin people, because therapeutic options are limited.…”

Sentinel lymph node mapping in endometrial cancer after 2020 ESGO-ESTRO-ESP consensus update: what will happen in the next few years?

“…Generally, routine preoperative ultrasound assessment of regional lymph nodes in cancer patients does not provide reliable nodal staging, because SLN tumor volume is too small to be reliably detected [32]. More reliable results are obtained by use of real-time tissue elastography [33] or contrast-enhanced ultrasound imaging [34]. Nam et al proved in swine melanoma model that such molecular lymphosonography with the use of targeted microbubbles labelled with P-selectin and α V β 3 -integrin antibodies can increase the specificity of metastatic SLN detection and provide a measure to quantify the extent of metastatic involvement [34].…”