Predicting lymph node metastasis in patients with papillary thyroid carcinoma by vascular index on power Doppler ultrasound

Predictive Values of Clinical Features and Multimodal Ultrasound for Central Lymph Node Metastases in Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC), the predominant pathological type among thyroid malignancies, is responsible for the sharp increase in thyroid cancer. Although PTC is an indolent tumor with good prognosis, 60-70% of patients still have early cervical lymph node metastasis, typically in the central compartment. Whether there is central lymph node metastasis (CLNM) or not directly affects the formulation of preoperative surgical procedures, given that such metastases have been tied to compromised overall survival and local recurrence. However, detecting CLNM before operation can be challenging due to the limited sensitivity of preoperative approaches. Prophylactic central lymph node dissection (PCLND) in the absence of clinical evidence of CLNM poses additional surgical risks. This study aims to provide a comprehensive review of the risk factors related to CLNM in PTC patients. A key focus is on utilizing multimodal ultrasound (US) for accurate prognosis of preoperative CLNM and to highlight the distinctive role of US-based characteristics for predicting CLNM.

Correlation of lymph node metastasis with contrast-enhanced ultrasound features, microvessel density and microvessel area in patients with papillary thyroid carcinoma

OBJECTIVE

This study aims to investigate the relationship of cervical lymph node metastasis (LNM) with contrast-enhanced ultrasound (CEUS) features, microvessel density (MVD) and microvessel area (MVA) in patients with papillary thyroid carcinoma (PTC), and to evaluate the diagnostic value of CEUS for PTC.

METHODS

A total of 108 patients diagnosed with PTC at the First Affiliated Hospital of Jinzhou Medical University from January 2016 to December 2018 were selected and underwent preoperative CEUS of the thyroid, surgical resection and postoperative histopathological examination of their resected lesion. They were divided into a lymphatic metastasis-positive group (LNM+, n = 61) and a lymphatic metastasis-negative group (LNM-, n = 47) based on their lymph node status. The CEUS quantitative parameters, MVD and MVA, were compared between the two groups, and risk factors for LNM were analyzed by univariate and multivariate logistic regression.

RESULTS

Compared with patients with in the LNM-group, the tumor diameter and the proportion of capsule contact of patients in the LNM+group were significantly greater and the patients in this group were younger. The rise time (RT), peak intensity (PI), area under the curve (AUC), MVD, and MVA were also significantly higher in the LNM+group than in the LMN-group, while there was no significant difference in time to peak (TP), mean transit time (mTT), velocity of intensity increase (IIV), and velocity of intensity decrease (IDV) between the two groups. Univariate and multivariate correlation analysis indicated that tumor size, RT, PI, AUC, MVD, and MVA were risk factors for LNM, and ROC curves further suggested that RT had the best overall predictive performance.

CONCLUSION

Tumor size, RT, PI, AUC, MVD and MVA are risk factors for LNM in PTC. In other words, CEUS is an important non-invasive and preoperative tool for evaluating PTC, with MVD and MVA identified as vital postoperative diagnostic indicators.

Microvessel density in differentiated thyroid carcinoma: A systematic review and meta-analysis

BACKGROUND

Microvessel density (MVD) has been proposed as a direct quantification method of tumor neovascularization. However, the current literature regarding the role of MVD in differentiated thyroid carcinoma (DTC) remains inconclusive.

AIM

To appraise the effect of tumoral MVD on the survival of patients with DTC.

METHODS

This meta-analysis was based on the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The electronic databases Medline, Web of Science, and Scopus were systematically screened. A fixed-effects or random-effects model was used, according to the Cochran Q test. The data were then extracted and assessed on the basis of the Reference Citation Analysis (https://www.referencecitationanalysis.com/).

RESULTS

A total of nine studies were included in the present study. Superiority of low MVD tumors in terms of 10-year disease free survival (OR: 0.21, 95%CI: 0.08-0.53) was recorded. Lowly vascularized thyroid cancers had a lower recurrence rate (OR: 13.66, 95%CI: 3.03-61.48). Moreover, relapsing tumors [weighed mean difference (WMD): 11.92, 95%CI: 6.32-17.52] or malignancies with regional lymph node involvement (WMD: 8.53, 95%CI: 0.04-17.02) presented with higher tumoral MVD values.

CONCLUSION

MVD significantly correlates with the survival outcomes of thyroid cancer patients. However, considering several study limitations, further prospective studies of higher methodological and quality level are required.

Efficacy of logistic regression model based on multiparametric ultrasound in assessment of cervical lymphadenopathy - a retrospective study

OBJECTIVES

To investigate whether a multiparametric ultrasound (MPUS) diagnostic model improves differential diagnosis of benign and malignant cervical lymph nodes.

METHODS

MPUS evaluation was performed on 87 lesions in 86 patients, and related characteristics and parameters of the patients and lesions were studied and logistic regression models based on the MPUS characteristics of cervical lymph nodes were built. A receiver operating characteristic curve and area under the curve (AUC) were built for the evaluation of diagnostic performances.

RESULTS

Of the 87 lesions in 86 patients, there were 31 benign and 56 malignant lesions. Regression models for Duplex ultrasound and MPUS were established. The Duplex ultrasound regression model showed a sensitivity, specificity, positive predictive value and negative predictive value of 94.4, 61.3, 86.3 and 80.9%, respectively. The predictive accuracy was 82.4%, and the AUC was 0.861. The MPUS regression model showed a sensitivity, specificity, positive predictive value and negative predictive value of 98.1, 61.3, 81.5 and 95.0%, respectively. The predictive accuracy was 84.7%, and the AUC was 0.894. The differences in AUCs between the Duplex ultrasound model and MPUS model, ultrasound model and ultrasonic elastography (UE), and Duplex ultrasound and UE were not significant (all p > 0.05); the differences in AUCs between the MPUS model and Duplex ultrasound, Duplex ultrasound model and Duplex ultrasound, and MPUS model and UE were significant (all p < 0.05).

CONCLUSIONS

The Duplex ultrasound and MPUS models achieve significantly higher diagnostic performance for differentiating between benign and malignant cervical lymph nodes.

Advanced Ultrasound Techniques for Differentiation of Benign Versus Malignant Thyroid Nodules: A Review

ABSTRACT

Grayscale ultrasound (US) is decisive in stratifying which thyroid nodules benefit from fine-needle aspiration to evaluate for malignancy. Unfortunately, a significant percentage of nodules remain indeterminate.Herein, we review the clinical considerations and diagnostic accuracy of advanced US, Doppler US, contrast-enhanced US, and US elastography techniques in the evaluation of indeterminate nodules.We conclude that these techniques may be used in combination with grayscale US to improve the assessment of lesion vascularity and tissue property.

Nomogram to assess risk of central cervical lymph node metastasis in patients with cN0 papillary thyroid carcinoma

OBJECTIVE

This study developed and validated an individualized prediction risk model for the need for central cervical lymph node dissection in patients with cN0 papillary thyroid carcinoma (PTC) diagnosed by ultrasound.

METHODS

Upon retrospective review, derivation and internal validation cohorts comprised 1585 consecutive patients with PTC treated from January 2017 to December 2019 at Hospital A. The external validation cohort consisted of 406 consecutive patients treated at Hospital B from January 2016 to June 2020. Independent risk factors for central cervical lymph node metastasis (CLNM) were determined through univariable and multivariable logistic regression analysis. An individualized risk prediction model was constructed and illustrated as a nomogram, which was internally and externally validated.

RESULTS

The following risk factors of CLNM were established: the solitary primary thyroid nodule's diameter, shape, calcification, and capsular abutment-to-lesion perimeter ratio. The areas under the receiver operating characteristic curves of the risk prediction model for the internal and external validation cohorts were 0.921 and 0.923, respectively. The calibration curve showed good agreement between the nomogram-estimated probability of CLNM and the actual CLNM rate in the three cohorts. The decision curve analysis confirmed the clinical usefulness of the nomogram.

CONCLUSION

This study developed and validated a model for predicting risk of CLNM in the individual patient with cN0 PTC, which should be an efficient tool for guiding clinical treatment.

The advantages of carbon nanoparticles in level VII lymph node dissection in patients with papillary thyroid cancer

Background

The characteristics of level VII lymph nodes were explored and the advantages of using carbon nanoparticles (CNs) in papillary thyroid cancer (PTC) surgeries were examined. This was a retrospective study investigating the clinical data of patients with PTC who underwent surgical treatment.

Methods

From September 2019 to December 2020, a total of 191 consecutive patients with PTC were retrospectively analyzed. The patients were randomly divided into the CNs group and the control group. CNs were used in the CNs group during the operation. There were 103 cases in the CNs group, including 25 males and 78 females, and 88 cases in the control group, including 21 males and 67 females. Parameters, including the characteristics of dissected lymph nodes in level VII, metastatic rate, postoperative complications, and other inpatient-related indicators, were compared between the two groups.

Results

The number of lymph nodes dissected in level VII in the CNs group was significantly greater than that in the control group, and the metastatic rate of black-stained lymph nodes was significantly higher than that of non-black-stained lymph nodes (P<0.05). The postoperative hypoparathyroidism rate in the CNs group was significantly lower than that in the control group (P<0.05). There were no differences in the operation duration, intraoperative blood loss, postoperative drainage duration, or hospitalization days between the two groups (P>0.05).

Conclusions

The application of CNs for patients with PTC significantly increased the number of lymph nodes dissected in level VII and helped to protect the parathyroid glands (PGs). Moreover, the use of CNs did not increase the rate of postoperative complications. Thus, CNs may be a simple and safe approach when performing surgery in PTC patients.

Diagnostic value of endobronchial ultrasound image features: A specialized review

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) technology is important in the diagnosis of intrathoracic benign and malignant lymph nodes (LNs). With the development of EBUS imaging technology, its role in noninvasive diagnosis, as a supplement to pathology diagnosis, has been given increasing attention in recent years. Many studies have explored qualitative and quantitative methods for the three EBUS modes, as well as a variety of multimodal analysis methods, to find the optimal method for the noninvasive diagnosis using EBUS for LNs. Here, we review and comment on the research methods and predictive diagnostic value, discuss the existing problems, and look ahead to the future application of EBUS imaging.

A Clinical Decision Support System Using Ultrasound Textures and Radiologic Features to Distinguish Metastasis From Tumor-Free Cervical Lymph Nodes in Patients With Papillary Thyroid Carcinoma

OBJECTIVES

This study investigated the potential of a clinical decision support approach for the classification of metastatic and tumor-free cervical lymph nodes (LNs) in papillary thyroid carcinoma on the basis of radiologic and textural analysis through ultrasound (US) imaging.

METHODS

In this research, 170 metastatic and 170 tumor-free LNs were examined by the proposed clinical decision support method. To discover the difference between the groups, US imaging was used for the extraction of radiologic and textural features. The radiologic features in the B-mode scans included the echogenicity, margin, shape, and presence of microcalcification. To extract the textural features, a wavelet transform was applied. A support vector machine classifier was used to classify the LNs.

RESULTS

In the training set data, a combination of radiologic and textural features represented the best performance with sensitivity, specificity, accuracy, and area under the curve (AUC) values of 97.14%, 98.57%, 97.86%, and 0.994, respectively, whereas the classification based on radiologic and textural features alone yielded lower performance, with AUCs of 0.964 and 0.922. On testing the data set, the proposed model could classify the tumor-free and metastatic LNs with an AUC of 0.952, which corresponded to sensitivity, specificity, and accuracy of 93.33%, 96.66%, and 95.00%.

CONCLUSIONS

The clinical decision support method based on textural and radiologic features has the potential to characterize LNs via 2-dimensional US. Therefore, it can be used as a supplementary technique in daily clinical practice to improve radiologists' understanding of conventional US imaging for characterizing LNs.

Differentiation between metastatic and tumour-free cervical lymph nodes in patients with papillary thyroid carcinoma by grey-scale sonographic texture analysis

PURPOSE

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer, and cervical lymph nodes (LNs) are the most common extrathyroid metastatic involvement. Early detection and reliable diagnosis of LNs can lead to improved cure rates and management costs. This study explored the potential of texture analysis for texture-based classification of tumour-free and metastatic cervical LNs of PTC in ultrasound imaging.

MATERIAL AND METHODS

A total of 274 LNs (137 tumour-free and 137 metastatic) were explored using the texture analysis (TA) method. Up to 300 features were extracted for texture analysis in three normalisations (default, 3sigma, and 1-99%). Linear discriminant analysis was employed to transform raw data to lower-dimensional spaces and increase discriminative power. The features were classified by the first nearest neighbour classifier.

RESULTS

Normalisation reflected improvement on the performance of the classifier; hence, the features under 3sigma normalisation schemes through FFPA (fusion Fisher plus the probability of classification error [POE] + average correlation coefficients [ACC]) features indicated high performance in classifying tumour-free and metastatic LNs with a sensitivity of 99.27%, specificity of 98.54%, accuracy of 98.90%, positive predictive value of 98.55%, and negative predictive value of 99.26%. The area under the receiver operating characteristic curve was 0.996.

CONCLUSIONS

TA was determined to be a reliable method with the potential for characterisation. This method can be applied by physicians to differentiate between tumour-free and metastatic LNs in patients with PTC in conventional ultrasound imaging.