Published online Jan 6, 2019. doi: 10.12998/wjcc.v7.i1.49
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
Cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC) is closely related to the prognosis of patients. Therefore, the accurate diagnosis of preoperative cervical metastatic lymph nodes has an important impact on the choice of surgical plan and the prognosis of PTC patients. Ultrasound is a common imaging method for detecting cervical lymph nodes in PTC patients. Some ultrasound signs of lymph nodes can indicate the possibility of lymph node metastasis, but these ultrasound signs are not accurate in determining lymph node metastasis.
Currently, contrast-enhanced ultrasound and elastography are new techniques for ultrasound diagnosis. Studies have revealed that contrast-enhanced ultrasound and elastography can be used to diagnose metastatic lymph nodes, but the accuracy is controversial. Our study aimed to combine traditional ultrasound results and contrast-enhanced ultrasound and elastography to improve the accuracy of lymph node metastasis diagnosis.
In this study, we analyzed the conventional ultrasound, contrast-enhanced ultrasound and elastography data of lymph nodes in PTC patients. The purpose of this study was to explore the accuracy of combined use of contrast-enhanced ultrasound and elastography based on conventional ultrasound in the diagnosis of PTC cervical lymph node metastasis.
A total of 94 patients with PTC were recruited, and the patients were divided into a metastasis group and a reactive group. There were 50 nodules in the metastatic group and 63 nodules in the reactive group. Conventional ultrasound, contrast-enhanced ultrasound and elastography were performed and data were recorded. Logistic regression was used to generate predictive probability distributions for the diagnosis of lymph node metastasis with different indicators, and ROC curves were used to test the accuracy of different indicator combinations.
The long diameter/short diameter (L/S) ratio and missing lymphatic portal as revealed by traditional ultrasound, the peak intensity (PI) measured by contrast-enhanced ultrasound and the elastic score measured by elastography had an effect on the occurrence of PTC cervical lymph node metastasis (P < 0.05). The accuracy of combined PI, elastic score, missing lymphatic portal and LS ratio in diagnosing lymph node metastasis was higher than the accuracy of individual diagnosis. The fitting equation for combined diagnosis was logit(P) = -12.341 + 1.482 × L/S ratio + 3.529 × missing lymphatic portal + 0.392 × PI + 3.288 × elasticity score.
Compared with traditional ultrasound diagnosis, the combination of contrast-enhanced ultrasound and elastography based on gray-scale ultrasound is expected to accurately assess PTC lymph node metastasis.
Both contrast-enhanced ultrasound and elastography are non-invasive ultrasound diagnostic techniques. The combined diagnosis can improve the diagnostic accuracy for PTC lymph node metastasis and provide important reference for the selection of clinical surgical plans.