Real-Time Tissue Elastography as Promising Diagnostic Tool for Diagnosis of Lymph Node Metastases in Patients with Malignant Melanoma: A Prospective Single-Center Experience

Abstract

Background: Real-time tissue elastography is a new, noninvasive method inultrasonography, differentiating tissues according to their stiffness. Earlier studies have highlighted this technique as a useful diagnostic tool for the detection of noncutaneous malignancies like breast, prostate and thyroid cancer based on the principle that tumor cells present a higher stiffness compared to the adjacent normal tissue. Objective: The purpose of our study was to investigate the value of real-time tissue elastography for the differentiation of benign and metastatic peripheral lymph nodes (LN) in patients with cutaneous melanoma by comparing this technique with conventional B-mode sonography combined with power Doppler sonography (PDS). Methods: In this prospective study, 36 melanoma patients (23 females and 13 males, mean age 62.7 ± 11.1 years) undergoing LN excision at the Department of Dermatology and Allergy, University of Bonn, were included between July 2011 and July 2012. Real-time tissue elastography was planned prior to surgery and histopathological examination. Elasticity images had been qualitatively scored for the proportion of stiff areas from pattern 1-5 (soft to stiff) on the basis of a newly defined system for LNs. Results: A total of 42 LNs have been removed in 36 patients. Of these 42 LNs, 21 carried melanoma cells and 21 were benign LNs. Significant differences in elastographic patterns were found between metastatic and nonmetastatic LNs. In real-time tissue elastography, 19 (90.5%) of 21 metastatic LNs showed a pattern of 3, 4 or 5. Of all benign LNs, 76.2% had a pattern of 1 or 2 in their elastogram. Sensitivity and specificity of B-mode sonography combined with PDS were 80.9 and 76.2%, respectively, 90.5 and 76.2% for elastography and 95.2 and 76.2% for the combined evaluation. Conclusion: An elastography pattern ≥3 was identified as an independent significant factor, predicting a metastatic LN involvement. The combination of elastography with conventional B-mode sonography has the potential to further improve the differentiation between benign and metastatic peripheral LNs in melanoma patients.

Doppler ultrasound and strain elastography in the assessment of cutaneous melanoma: preliminary results

“…Few research studies conducted in the early period of clinical elastography have demonstrated that this technique has potential in the diagnosis of skin tumors. In reported cases the tumors were diagnosed as malignant based on the color distribution on elastographic images [25][26][27]. In this present study, tumor elasticity represented a statistically significant factor: almost half of the tumors were stiff at SE and another important percentage had medium elasticity.…”

“…The use of elastography in the evaluation of skin lesions has been the subject of several studies, in an attempt to differentiate between benign and malignant lesions [25][26][27]. Few research studies conducted in the early period of clinical elastography have demonstrated that this technique has potential in the diagnosis of skin tumors.…”

Ultrasonography-guided percutaneous radiofrequency ablation for cervical lymph node metastasis from thyroid carcinoma

“…[8] Elasticity image of each ablated lymph node had been qualitatively scored for the proportion of stiff areas from score 1 to 5 (soft to stiff) on the basis of a newly defined system for lymph nodes. [12][13][14] Devices for radiofrequency ablation The RFA procedure was performed under real-time ultrasonographic guidance (model: LOGIQ E9, GE Health Care) with 10-MHz linear probe. A18-gauge 7-cm shaft length 0.5 cm straight fixed active-tip electrode with internally cooled (Star RF Electrode-Fixed, STARmed Co., Ltd., Korea) was connected to a radiofrequency generator (VRS01, STARmed Co., Ltd., Korea).…”

Effects of compression force on elasticity index and elasticity ratio in ultrasound elastography

“…The technique has been used to assess the hardness of various normal and abnormal tissues, [1][2][3][4][5][6] and to differentiate malignant from benign lesions in the breast, prostate, thyroid, lymph nodes and salivary glands. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Ultrasound elastography uses either strain or shear wave velocity. 25,26 In strain elastography, tissue strain induced by compression with the probe is used as an indicator of hardness.…”

“…The hardness of tissues or lesions is visually and qualitatively assessed on the basis of the strain distribution and pattern of elastographic images. 1,[6][7][8][9][10]12,[15][16][17][19][20][21][22][23][24] Semi-quantitative analysis, in which strain is represented in numerical values, has recently been used as a more objective method. [1][2][3][4][5][9][10][11]13,17 However, whether these values can be effectively used for clinical assessment remains unclear because the image quality of strain elastography, which is performed manually, depends strongly on the imaging procedure.…”