Observational Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jan 6, 2019; 7(1): 49-57
Published online Jan 6, 2019. doi: 10.12998/wjcc.v7.i1.49
Value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in papillary thyroid carcinoma
Wei Jiang, Hong-Yan Wei, Hai-Yan Zhang, Qiu-Luan Zhuo
Wei Jiang, Hong-Yan Wei, Hai-Yan Zhang, Qiu-Luan Zhuo, Department of Ultrasound, Shenzhen Nanshan District People’s Hospital, Shenzhen 518052, Guangdong Province, China
Author contributions: Jiang W and Wei HY designed the research; Jiang W and Zhang HY performed the research; Zhuo QL contributed new analytic tools; Jiang W analyzed the data; and Jiang W, Wei HY and Zhuo QL wrote the paper.
Supported by Shenzhen Science and Technology Plan Funding Project, No. 201102125.
Institutional review board statement: The study was reviewed and approved by the ethics committee of Shenzhen Nanshan District People’s Hospital.
Informed consent statement: All patients gave informed consent.
Conflict-of-interest statement: The authors declare that they have no competing interests.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Wei Jiang, MD, Doctor, Department of Ultrasound, Shenzhen Nanshan District People’s Hospital, No. 89, Taoyuan Road, Nanshan District, Shenzhen 518052, Guangdong Province, China. jwszdr@126.com
Telephone: +96-130-26628099
Received: November 9, 2018
Peer-review started: November 12, 2018
First decision: November 28, 2018
Revised: December 1, 2018
Accepted: December 12, 2018
Article in press: December 12, 2018
Published online: January 6, 2019
Abstract
BACKGROUND

Cervical lymph node metastasis in papillary thyroid carcinoma (PTC) affects the treatment and prognosis of patients. Ultrasound is a common imaging method for detecting cervical lymph nodes in PTC patients; however, it is not accurate in determining lymph node metastasis.

AIM

To evaluate the value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in PTC.

METHODS

A total of 94 patients with PTC were recruited. According to pathological results, lymph nodes were divided into two groups: metastatic group (n = 50) and reactive group (n = 63). The routine ultrasound findings, contrast-enhanced ultrasound and elastography data were recorded and compared. Logistic regression was used to generate predictive probability distributions for the diagnosis of lymph node metastasis with different indicators. Receiver operating characteristic curve analysis was used to test the efficacy of contrast-enhanced ultrasound combined with elastography based on routine ultrasound in evaluating PTC cervical lymph node metastasis.

RESULTS

The ratio of long diameter/short diameter (L/S) ≤ 2, irregular marginal morphology, missing lymphatic portal, peripheral or mixed blood flow distribution, peak intensity (PI), non-uniform contrast distribution and elasticity score in the metastatic group were significantly higher than those in the reactive group (P < 0.05). L/S ratio, missing lymphatic portal, PI and elasticity score had a significant influence on the occurrence of PTC cervical lymph node metastasis (P < 0.05). Furthermore, the area under the curve (AUC) for lymph node metastasis diagnosed using the combination of PI ratio, elasticity score, missing lymphatic portal and LS was 0.936, which was significantly higher than the AUC for PI ratio alone. The difference was statistically significant (P < 0.05). The fitting equation for the combined diagnosis was logit(P) = -12.341 + 1.482 × L/S ratio + 3.529 × missing lymphatic portal + 0.392 × PI + 3.288 × elasticity score.

CONCLUSION

Based on the gray-scale ultrasound, the combination of contrast-enhanced ultrasound and elastography can accurately assess PTC cervical lymph node metastasis.

Keywords: Contrast-enhanced ultrasound, Elastography, Papillary thyroid cancer, Cervical lymph node metastasis

Core tip: Cervical lymph node metastasis of papillary thyroid carcinoma affects the prognosis and treatment of patients. Currently, contrast-enhanced ultrasound and ultrasound elastography have been gradually applied to the diagnosis of cervical lymph node metastasis. However, it is not clear whether contrast-enhanced ultrasound and elastography combined with conventional ultrasound improve the accuracy of lymph node metastasis diagnosis. In this study, we analyzed the differences among conventional ultrasound, contrast-enhanced ultrasound and elastography in metastatic and reactive lymph nodes, and used a logistic regression model to fit the probability equation of lymph node metastasis to improve the diagnostic accuracy of metastatic lymph nodes.