Ultrasonographic features associated with malignancy in cytologically indeterminate thyroid nodules. Eur J Surg Oncol. 2014;40:182-186. [PMID: 24373298 DOI: 10.1016/j.ejso.2013.11.015]

Correlation between EpCAM expression and cervical lymph node metastasis in papillary thyroid carcinoma: a study integrating ultrasonographic features

OBJECTIVES

The epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein that is overexpressed in various epithelial tumors and has been associated with tumor aggressiveness and unfavorable prognosis. This study aimed to explore the association between ultrasonic characteristics and EpCAM expression in papillary thyroid carcinoma (PTC), as well as the value in predicting the risk of cervical lymph node metastasis (CLNM).

METHODS

Participants with suspected thyroid cancer underwent conventional and contrast-enhanced ultrasonography (CEUS) before surgery. Age, sex, and nodule features in ultrasound were recorded. Participants were classified based on the presence of CLNM. EpCAM expression was detected using immunohistochemistry. The risk predictors of CLNM were evaluated by using univariate and multivariate Cox model.

RESULTS

The final dataset included 53 participants, of whom 27(50.94%) had CLNM, while 26(49.06%) did not. The EpCAM-positive area (p < 0.001), score (p < 0.001), and nuclear expression (p = 0.027) were significantly different between the CLNM and non-CLNM groups. Receiver operating characteristic curve analysis showed that EpCAM score with 4.5 had sensitivity and specificity of 85.2% and 76.9%, respectively, for diagnosing CLNM. Multivariate logistic regression results showed that overexpression EpCAM (score ≧ 4.5) [OR:46.54, p = 0.007], tumor size ≧ 1.05 cm [OR:14.21,p = 0.01] and extrathyroidal extension (ETE) on CEUS [OR:113.33, p = 0.01] were independent risk factors of CLNM. Overexpression of EpCAM (62.07%, 18/29) correlated with ETE of PTC confirmed by postoperative pathology (p = 0.01, 0.027). No significant difference in PTC histological variants was detected based on EpCAM expression (p = 0.05).

CONCLUSIONS

EpCAM overexpression demonstrated a significant association with ETE and CLNM in PTC. The integration of ultrasonography with EpCAM expression profiling offers A promising multiparameter diagnostic model to enhance predictive accuracy. Further studies evaluating EpCAM expression in fine-needle aspiration biopsy (FNAB) samples are required to determine its possible preoperative predictive value.

Optimizing thyroid AUS nodules malignancy prediction: a comprehensive study of logistic regression and machine learning models

Background

The accurate diagnosis of thyroid nodules with indeterminate cytology, particularly in the atypia of undetermined significance (AUS) category, remains challenging. This study aims to predict the risk of malignancy in AUS nodules by comparing two machine learning (ML) and three conventional logistic regression (LR) models.

Methods

A retrospective study on 356 AUS nodules in 342 individuals from 6728 patients who underwent thyroid surgery in 2021. All the clinical, ultrasonographic, and molecular data were collected and randomly separated into training and validation cohorts at a ratio of 7: 3. ML (random forest and XGBoost) and LR (lasso regression, best subset selection, and backward stepwise regression) models were constructed and evaluated using area under the curve (AUC), calibration, and clinical utility metrics.

Results

Approximately 90% (321/356) of the AUS nodules were malignant, predominantly papillary thyroid carcinoma with 68.6% BRAF V600E mutations. The final LR prediction model based on backward stepwise regression exhibited superior discrimination with AUC values of 0.83 (95% CI: 0.73-0.92) and 0.80 (95% CI: 0.67-0.94) in training and validation, respectively. Well calibration, and clinical utility were also confirmed. The ML models showed moderate performance. A nomogram was developed on the final LR model.

Conclusions

The LR model developed using the backward stepwise regression, outperformed ML models in predicting malignancy in AUS thyroid nodules. The corresponding nomogram based on this model provides a valuable and practical tool for personalized risk assessment, potentially reducing unnecessary surgeries and enhancing clinical decision-making.

Applying machine-learning models to differentiate benign and malignant thyroid nodules classified as C-TIRADS 4 based on 2D-ultrasound combined with five contrast-enhanced ultrasound key frames

Objectives

To apply machine learning to extract radiomics features from thyroid two-dimensional ultrasound (2D-US) combined with contrast-enhanced ultrasound (CEUS) images to classify and predict benign and malignant thyroid nodules, classified according to the Chinese version of the thyroid imaging reporting and data system (C-TIRADS) as category 4.

Materials and methods

This retrospective study included 313 pathologically diagnosed thyroid nodules (203 malignant and 110 benign). Two 2D-US images and five CEUS key frames ("2nd second after the arrival time" frame, "time to peak" frame, "2nd second after peak" frame, "first-flash" frame, and "second-flash" frame) were selected to manually label the region of interest using the "Labelme" tool. A total of 7 images of each nodule and their annotates were imported into the Darwin Research Platform for radiomics analysis. The datasets were randomly split into training and test cohorts in a 9:1 ratio. Six classifiers, namely, support vector machine, logistic regression, decision tree, random forest (RF), gradient boosting decision tree and extreme gradient boosting, were used to construct and test the models. Performance was evaluated using a receiver operating characteristic curve analysis. The area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy (ACC), and F1-score were calculated. One junior radiologist and one senior radiologist reviewed the 2D-US image and CEUS videos of each nodule and made a diagnosis. We then compared their AUC and ACC with those of our best model.

Results

The AUC of the diagnosis of US, CEUS and US combined CEUS by junior radiologist and senior radiologist were 0.755, 0.750, 0.784, 0.800, 0.873, 0.890, respectively. The RF classifier performed better than the other five, with an AUC of 1 for the training cohort and 0.94 (95% confidence interval 0.88-1) for the test cohort. The sensitivity, specificity, accuracy, PPV, NPV, and F1-score of the RF model in the test cohort were 0.82, 0.93, 0.90, 0.85, 0.92, and 0.84, respectively. The RF model with 2D-US combined with CEUS key frames achieved equivalent performance as the senior radiologist (AUC: 0.94 vs. 0.92, P = 0.798; ACC: 0.90 vs. 0.92) and outperformed the junior radiologist (AUC: 0.94 vs. 0.80, P = 0.039, ACC: 0.90 vs. 0.81) in the test cohort.

Conclusions

Our model, based on 2D-US and CEUS key frames radiomics features, had good diagnostic efficacy for thyroid nodules, which are classified as C-TIRADS 4. It shows promising potential in assisting less experienced junior radiologists.

Ultrasonographic predictors of thyroid cancer in Bethesda III and IV thyroid nodules

Background

Bethesda III and IV thyroid nodules continue to be difficult to manage. Although molecular testing may assist in decision-making, it is expensive, not widely available, and not without pitfalls. The objective of this study is to assess whether certain thyroid ultrasonographic features may predict the risk of thyroid cancer in patients with Bethesda III and IV thyroid nodules and be used as additional decision-making tools to complement cytopathological results in deciding on diagnostic thyroidectomy.

Methods

We retrospectively evaluated the ultrasonographic features of Bethesda categories III and IV thyroid nodules in patients who underwent subsequent thyroidectomy. We used the final histopathological examination of the surgical specimens as the gold-standard test and analyzed individual preoperative ultrasonographic features as predictors of malignancy.

Results

Of the 278 patients who were diagnosed with Bethesda III and IV thyroid nodules on fine needle aspiration cytology (FNAC), 111 (39.9%) had thyroid cancer, and 167 (59.9%) exhibited benign nodules. The malignancy rate was higher in patients with Bethesda IV nodules (28/50, 56%) than those with Bethesda III nodules (83/228, 36.4%; p=0.016). In univariate analysis, hypoechogenicity (55.6% in malignant vs. 35.3% in benign, p=0.006) and calcifications (54.5 in malignant vs. 35.4% in benign, p=0.008) were significantly different between the benign and malignant pathology groups, whereas the size of the dominant nodule, number of nodules, irregular borders, taller-than-wide shape, and the presence of lymph nodes were comparable between the two groups. These two ultrasonographic features (hypoechogenicity and calcifications) remained significantly associated with the risk of malignancy in multivariate logistic regression analysis (for hypoechogenicity, p=0.014, odds ratio: 2.1, 95% CI:1.0-3.7 and for calcifications, p=0.019, odds ratio: 1.98, 95% CI:1.12-3.50). The sensitivity, specificity, positive and negative predictive values, and accuracy were 31.5%, 83%, 55.6%,64.7%, and 62.6%, for hypoechogenicity, respectively and 32.4%, 82%, 54.5%, 67.8%, and 62%, for calcification, respectively.

Conclusions

Hypoechogenicity and calcifications in Bethesda III and IV thyroid nodules are strong predictors of thyroid cancer and associated with a two-fold increased risk of malignancy.

Comparison of six machine learning methods for differentiating benign and malignant thyroid nodules using ultrasonographic characteristics

BACKGROUND

Several machine learning (ML) classifiers for thyroid nodule diagnosis have been compared in terms of their accuracy, sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and area under the receiver operating curve (AUC). A total of 525 patients with thyroid nodules (malignant, n = 228; benign, n = 297) underwent conventional ultrasonography, strain elastography, and contrast-enhanced ultrasound. Six algorithms were compared: support vector machine (SVM), linear discriminant analysis (LDA), random forest (RF), logistic regression (LG), GlmNet, and K-nearest neighbors (K-NN). The diagnostic performances of the 13 suspicious sonographic features for discriminating benign and malignant thyroid nodules were assessed using different ML algorithms. To compare these algorithms, a 10-fold cross-validation paired t-test was applied to the algorithm performance differences.

RESULTS

The logistic regression algorithm had better diagnostic performance than the other ML algorithms. However, it was only slightly higher than those of GlmNet, LDA, and RF. The accuracy, sensitivity, specificity, NPV, PPV, and AUC obtained by running logistic regression were 86.48%, 83.33%, 88.89%, 87.42%, 85.20%, and 92.84%, respectively.

CONCLUSIONS

The experimental results indicate that GlmNet, SVM, LDA, LG, K-NN, and RF exhibit slight differences in classification performance.

Clinical Value of Artificial Intelligence-Based Computer-Aided Diagnosis System Versus Contrast-Enhanced Ultrasound for Differentiation of Benign From Malignant Thyroid Nodules in Different Backgrounds

OBJECTIVES

The aim of this study was to compare the value of AI-SONIC ultrasound-assisted diagnosis system versus contrast-enhanced ultrasound (CEUS) for differential diagnosis of thyroid nodules in diffuse and non-diffuse backgrounds.

METHODS

A total of 555 thyroid nodules with pathologically confirmed diagnosis were included in this retrospective study. The diagnostic efficacies of AI-SONIC and CEUS for differentiating benign from malignant nodules in diffuse and non-diffuse backgrounds were evaluated, with pathological diagnosis as the gold standard.

RESULTS

The agreement between AI-SONIC diagnosis and pathological diagnosis was moderate in diffuse backgrounds (κ = 0.417) and almost perfect in non-diffuse backgrounds (κ = 0.81). The agreement between CEUS diagnosis and pathological diagnosis was substantial in diffuse backgrounds (κ = 0.684) and moderate in non-diffuse backgrounds (κ = 0.407). In diffuse backgrounds, AI-SONIC had slightly higher sensitivity (95.7 vs 89.4%, P = .375), but CEUS had significantly higher specificity (80.0 vs 40.0%, P = .008). In non-diffuse background, AI-SONIC had significantly higher sensitivity (96.2 vs 73.4%, P < .001), specificity (82.9 vs 71.2%, P = .007), and negative predictive value (90.3 vs 53.3%, P < .001).

CONCLUSION

In non-diffuse backgrounds, AI-SONIC is superior to CEUS for differentiating malignant from benign thyroid nodules. In diffuse backgrounds, AI-SONIC could be useful for screening of cases to detect suspicious nodules requiring further examination by CEUS.

Ultrasonographic differentiation and Ultrasound-based management of partially cystic thyroid nodules

Objective

To determine sonographic features of malignancy in partially cystic thyroid nodules and assess the diagnostic efficacy of these features for differentiating between benign and malignant lesions in the nodules with indeterminate cytology.

Methods

From January 2016 to December 2017, a total of 91 patients with 94 partially cystic thyroid nodules who had undergone ultrasound-guided fine-needle aspiration biopsy and thyroid surgery in our hospital were included in this study. The sonographic features of the thyroid nodules were analyzed to identify the predictive features of malignancy and assess the diagnostic efficacy of these features.

Results

The features of hypoechogenicity, microcalcification, composition, and an eccentric solid component with an acute angle had statistically significant associations with malignant nodule (p<005) by univariable analysis. Binary logistic regression analysis showed that microcalcification and hypoechogenicity were significantly associated with malignancy. Using the combination of microcalcification, hypoechogenicity, and a solid component comprising of greater than or equal to 50% of the total volume, the diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 97.6%, 32.7%, 53.9%, and 94.4%, respectively. In these nodules with indeterminate cytology, this combination also exhibited a high sensitivity of 92.3% and an NPV of 83.3%.

Conclusion

This study demonstrated that microcalcification and hypoechogenicity were independently associated with malignancy in partially cystic thyroid nodules. The combination of microcalcification, hypoechogenicity, and a solid portion that is greater than or equal to 50% of the total volume will help guide clinical decisions in mixed cystic solid nodules.

The diagnostic value of ultrasonography in detection of different types of thyroid nodules

Background

This article discusses the importance of high frequency ultrasonography in detection of different types of thyroid nodules considering only the histopathological examination of the surgical specimens as the final diagnosis. We studied 50 patients referred to ENT clinic with a thyroid nodule. Ultrasonography and ultrasound-guided fine-needle aspiration biopsy were done to all the patients. Thyroid surgery was done according to FNAB results.

Result

From 50 thyroid specimens, the US could predict the malignancy in 18 specimens. By histopathology, only 16 specimens were malignant, and 34 were benign thyroid disease. The sensitivity, specificity, and accuracy of US were 100%, 94.12%, and 96% respectively. The most suspicious ultrasongraphic feature was microcalcification followed by taller than wider (T ˃ W).

Conclusion

High frequency ultrasound is a very important tool to predict the malignant possibility during thyroid nodule evaluation.

The combination of ATA classification and FNA results can improve the diagnostic efficiency of malignant thyroid nodules

PURPOSE

To determine the diagnostic efficiency of the ATA classification and ultrasound-guided fine-needle aspiration (FNA) results in identifying the risk factors of malignancy, we analyzed the thyroid nodules of patients who underwent thyroidectomy and compared preoperative ATA classifications with FNA results.

METHODS

We retrospectively analyzed 274 nodules of 196 patients who underwent ultrasonography, FNA and thyroidectomy. Histopathological findings of thyroid nodules were considered as the Au standard in the analysis of the diagnostic efficiency of the ATA classification and FNA results. Univariate analysis and binary multivariate logistic regression analysis were applied to identify the ultrasound features associated with malignancy.

RESULTS

The overall malignancy rate of 274 nodules was 41.6%. The areas under the ROC curves (AUCs) for the ATA classification and FNA results were 0.88 and 0.878, respectively (P < 0.001). The sensitivity and specificity of the ATA classification were 86 and 86.9%, whereas those of FNA results were 68.5 and 91.4%, respectively. The specificity (98.7%) and sensitivity (94.3%) increased after the combined use of the ATA classification and FNA results. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy. Microcalcifications had the highest OR (7.58), and taller-than-wide shape had the highest specificity in BSRTC I, II, III and IV cytology.

CONCLUSION

The diagnostic efficiency of the ATA classification and FNA results in identifying malignant nodules was high, and the use of both criteria improved the diagnostic accuracy. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy.

USING THE ATA AND ACR TI-RADS SONOGRAPHIC CLASSIFICATIONS AS ADJUNCTIVE PREDICTORS OF MALIGNANCY FOR INDETERMINATE THYROID NODULES

Objective: Thyroid nodules with indeterminate cytology pose management challenges in clinical practice. The aim of this study was to determine the efficacy of ultrasound features in navigating clinical decision making in thyroid nodules with indeterminate cytology. Methods: We retrospectively reviewed ultrasound imaging from 186 adult patients with thyroid nodules and indeterminate cytology who underwent thyroidectomy at a quaternary hospital from 2010-2017. All nodules were classified based on the American Thyroid Association (ATA) and 2017 American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS). Nodules were included if good quality pre-operative ultrasound imaging and surgical pathology were available. Results: A total of 202 thyroid nodules were included. The median age was 57 years; 82.8% were female. Risk of malignancy (ROM) in resected nodules with Bethesda 3 and 4 cytology was 19.4% and 30.3%, respectively. ATA high-suspicious and TI-RADS 5 nodules had high ROM, 100% in both systems for Bethesda 3 nodules; 66.7% and 50.0%, respectively, for Bethesda 4 nodules. For ATA very-low suspicious/TI-RADS 1 and 2, ROM was 0%. ROM in ATA low-suspicious/TI-RADS 3 nodules with Bethesda 3 cytology was lower (15.2% and 16.0%, respectively) than Bethesda 4 cytology (33.8% and 34.3%, respectively). ATA intermediate-suspicious/TI-RADS 4 nodules with Bethesda 4 cytology had a lower ROM (11.1% and 18.2%, respectively) than Bethesda 3 cytology (28.6 % and 31.6%, respectively). Conclusion: Using either the ATA or the TI-RADS system to risk-stratify nodules with indeterminate cytology may help clinicians plan better for additional diagnostic testing and treatment. Abbreviations: ACR = American College of Radiology; ATA = American Thyroid Association; AUS = atypia of undetermined significance; FLUS = follicular lesion of undetermined significance; FN = follicular neoplasm; PPV = positive predictive value; ROM = risk of malignancy; SFN = suspicious for follicular neoplasm; TI-RADS = Thyroid Imaging Reporting and Data System.

Prediction of follicular thyroid carcinoma associated with distant metastasis in the preoperative and postoperative model

BACKGROUND

Only clinicopathological findings are reported for predicting follicular thyroid carcinoma (FTC) associated with distant metastasis, and preoperative ultrasound (US) findings are unknown.

METHODS

Associations between distant metastases of FTC and predicting factors were evaluated by using logistic regression analysis in the preoperative and postoperative models.

RESULTS

Distant metastasis was present in 37 (11.5%) of the 321 patients with FTC. In the preoperative model, independent predictors of distant metastasis were age, marked hypoechogenicity, nodule-in-nodule appearance, and rim calcification on US. Postoperative predictors were marked hypoechogenicity, rim calcification, and widely invasive histology. Sensitivities, specificities, and the area under the curves for predicting distant metastasis were 86.5%, 80.3%, and 0.889 on preoperative status and 86.5%, 78.5%, and 0.908 on postoperative status. Although not statistically significant, all four patients with gross extrathyroidal extension had metastasis.

CONCLUSION

Age, ultrasound features, and widely invasive histology allow preoperative and postoperative prediction of FTC associated with distant metastasis.

Value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in papillary thyroid carcinoma

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.

A Proposal to Stratify the Intermediate-Risk Thyroid Nodules According to the AACE/ACE/AME Guidelines with Ultrasound Features

To propose a risk stratification system for intermediate-risk thyroid nodules (TNs) according to American Association of Clinical Endocrinologists, American College of Endocrinology and Associazione Medici Endocrinologi Medical (AACE/ACE/AME) Guideline with ultrasound (US) features. 1000 patients with 1000 nodules (902 benign nodules and 98 malignant nodules) were included. All the nodules were confirmed with either fine needle aspiration (FNA) cytology and follow-up or histology results after surgery. Univariate analysis and binary multivariate logic regression analysis were applied to analyze the possible risk US features associated with malignancy. Receiver operating characteristic curves (ROC) were drew and compared. Univariate analysis and binary multivariate logistic regression analysis showed that indeterminate hyper-echoic spot (OR = 4.544), slightly ill-defined margin (OR = 2.559), slight hyper-echogenicity (OR = 1.992) and no macro-calcification (OR = 1.921) were risk factors for the intermediate-risk thyroid nodules (TNs). A predicting model was established based on the 4 risk factors. The risk rates of malignancy were 5.7% (26/455) in Stage I, 11.0% (49/445) in Stage II, 23.1% (21/91) in Stage III, 33.3% (3/9) in Stage IV. In conclusion, for the intermediate-risk TNs, special attention should be paid to the TNs with indeterminate hyper-echoic spot, slightly ill-defined margin, slight hyper-echogenicity, or no macro-calcification. The probability of malignancy increased with the number of risk factors increasing.

Logistic regression analysis of conventional ultrasonography, strain elastosonography, and contrast-enhanced ultrasound characteristics for the differentiation of benign and malignant thyroid nodules

The aim of the study is to screen the significant sonographic features by logistic regression analysis and fit a model to diagnose thyroid nodules. A total of 525 pathological thyroid nodules were retrospectively analyzed. All the nodules underwent conventional ultrasonography (US), strain elastosonography (SE), and contrast -enhanced ultrasound (CEUS). Those nodules' 12 suspicious sonographic features were used to assess thyroid nodules. The significant features of diagnosing thyroid nodules were picked out by logistic regression analysis. All variables that were statistically related to diagnosis of thyroid nodules, at a level of p < 0.05 were embodied in a logistic regression analysis model. The significant features in the logistic regression model of diagnosing thyroid nodules were calcification, suspected cervical lymph node metastasis, hypoenhancement pattern, margin, shape, vascularity, posterior acoustic, echogenicity, and elastography score. According to the results of logistic regression analysis, the formula that could predict whether or not thyroid nodules are malignant was established. The area under the receiver operating curve (ROC) was 0.930 and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 83.77%, 89.56%, 87.05%, 86.04%, and 87.79% respectively.

Practical Application of Elastography in the Diagnosis of Thyroid Nodules in Children and Adolescents

BACKGROUND

Ultrasound elastography is a noninvasive method of imaging based on the estimation of the mechanical properties of tissue. Data in adults indicate that decreased flexibility in comparison to the surrounding healthy tissue is characteristic of malignancy (in most thyroid carcinomas, except for follicular thyroid carcinoma). The purpose of our study was to assess the deformation of thyroid nodules and to evaluate the usefulness of elastography in predicting malignant thyroid nodules in adolescent patients.

METHODS

We examined 47 children with 62 thyroid nodules. All patients underwent elastography and fine needle aspiration cytology (FNAC).

RESULTS

Thirty-seven girls (79%) and 10 boys (21%) were included in the study. A strain ratio <2 was observed in 17 nodules (27% of the study group), a strain ratio between 2 and 4.9 in 34 nodules (55%) and a strain ratio >5 in 11 nodules (18%). According to cytological examination, 3 nodules (4.8% of the study group) were malignant. Two of them were hard (strain ratio ≥5), and 1 nodule had a strain ratio of 2.

CONCLUSIONS

Our results suggest that elastography can be complementary to conventional ultrasonography and useful while making a decision about FNAC. At the same time, it should not replace the cytological assessment of thyroid nodules in children and adolescents.

Accuracy of international ultrasound risk stratification systems in thyroid lesions cytologically classified as indeterminate

BACKGROUND

Eminent international societies have published their thyroid ultrasound risk stratification system (US-RSS) to give a friendly tool for thyroidologists. In particular, American Thyroid Association (ATA), American Association Clinical Endocrinologists/American College of Endocrinologists and Associazione Medici Endocrinologi (AACE/ACE/AME), British Thyroid Association (BTA), and Thyroid Imaging Reporting and Data System (TIRADS) are often adopted for clinical practice. The reliability of these US-RSS has not been evaluated in discriminating cancers from benignancy in nodules with indeterminate FNA.

METHODS

Indeterminate thyroid lesions were searched in our database and only those with histology were finally included. The matching of US and histologic data of nodule's location and size were verified. All US images and clips were re-evaluated and nodules classified according to the above US-RSS.

RESULTS

A series of 101 indeterminate lesions, diagnosed by FNA were included (mean size 2.4 cm) and a 21% of cancers was found at histology. When all lesions were classified by US-RSS, poor accuracy (up to 54%) and specificity (up to 19%) were recorded. Highest sensitivity (91%) and NPV (94%) was obtained by BTA. Of relevance, the rate of nodules with indeterminate US risk recorded by BTA was significantly lower than the other (P < 0.001). At nodule's size analysis, cancers had significantly higher estimated volume (P < 0.05). When we considered the size thresholds proposed by guidelines, ATA system reached the highest sensitivity in detecting cancers (95%).

CONCLUSIONS

Even if international US-RSS have suboptimal accuracy in indeterminate thyroid nodules, high sensitivity can be obtained using ATA system with specific dimensional cut-offs. Diagn. Cytopathol. 2017;45:113-117. © 2016 Wiley Periodicals, Inc.

Diagnostic Accuracy of Contrast-Enhanced Ultrasound Enhancement Patterns for Thyroid Nodules

Background

The aim of this study was to investigate the accuracy of contrast-enhanced ultrasound (CEUS) enhancement patterns in the assessment of thyroid nodules.

Material/Methods

A total of 158 patients with suspected thyroid cancer underwent conventional ultrasound (US) and CEUS examinations. The contrast enhancement patterns of the lesions, including the peripheries of the lesions, were assessed by CEUS scans. The relationship between the size of the lesions and the degree of enhancement was also studied. US- and/or CEUS-guided biopsy was used to obtain specimens for histopathological diagnosis.

Results

The final data included 148 patients with 157 lesions. Seventy-five patients had 82 malignant lesions and 73 patients had 75 benign lesions. Peripheral ring enhancement was seen in 40 lesions. The differences of enhancement patterns and peripheral rings between benign and malignant nodules were significant (p=0.000, 0.000). The diagnostic sensitivity, specificity, and accuracy for malignant were 88%, 65.33%, and 88.32%, respectively, for CEUS, whereas they were 98.33%, 42.67%, and 71.97%, respectively, for TC by conventional US. The misdiagnosis rate by conventional US was 57.33% and 34.67% by CEUS (p=0.005). With regard to the size of lesions, a significant difference was found between low-enhancement, iso-enhancement, high-enhancement, iso-enhancement with no-enhancement area and no-enhancement (p=0.000).

Conclusions

In patients with suspicious US characteristics, CEUS had high specificity and contributed to establishing the diagnosis. Therefore, CEUS could avoid unnecessary biopsy.

Predictive value of intratumoral heterogeneity of F-18 FDG uptake for characterization of thyroid nodules according to Bethesda categories of fine needle aspiration biopsy results

The current study was aimed to investigate the clinical value of intratumoral heterogeneity of F-18 FDG uptake for characterization of thyroid nodule (TN) with inconclusive fine-needle aspiration biopsy (FNAB) results. The current study enrolled 200 patients who showed F-18 FDG incidentaloma and were performed FNAB. The intratumoral heterogeneity of F-18 FDG uptake was represented as the heterogeneity factor (HF), defined as the derivative (dV/dT) of a volume-threshold function for a primary tumor. The diagnostic and predictive values of HF and F-18 FDG PET/CT parameters were evaluated for characterization of inconclusive FNAB results. Among F-18 FDG PET/CT parameters, SUVmax, MTV, and TLG of malignant group were statistically higher than those of Bethesda category of suspicious malignant group. However, HF values were not statistically different between the groups of Bethesda categories (Kruskal-Wallis statistics, 9.924; p = 0.0774). In ROC analysis, when HF > 2.751 was used as cut-off value, the sensitivity and specificity for prediction of malignant TN were 100 % (95 % CI 69.2-100 %) and 60 % (95 % CI 42.1-76.1 %), respectively. The AUC was 0.826 (95 % CI 0.684-0.922) and standard error was 0.0648 (p < 0.0001). In conclusion, the intratumoral heterogeneity of F-18 FDG uptake represented by HF could be a predictor for characterization of TN with inconclusive FNAB results. Additional large population-based prospective studies are needed to validate the diagnostic utility of HF of F-18 FDG PET/CT.

Relevance of BRAF(V600E) mutation testing versus RAS point mutations and RET/PTC rearrangements evaluation in the diagnosis of thyroid cancer

BACKGROUND

A molecular profile including BRAF and RAS mutations as well as RET/PTC rearrangement evaluation has been proposed to provide an accurate presurgical assessment of thyroid nodules and to reduce the number of unnecessary diagnostic surgeries, sparing patients' health and saving healthcare resources. However, the application of such molecular analyses may provide different results among different centers and populations in real-life settings. Our aims were to evaluate the diagnostic utility of assessing the presence of BRAF and RAS mutations and RET/PTC1 and RET/PTC3 rearrangements in all cytological categories in an Italian group of thyroid nodule patients assessed prospectively, and to understand whether and which mutation testing might be helpful in cytologically indeterminate nodules.

METHODS

A total of 911 patients were submitted to ultrasound and fine-needle aspiration biopsy examination. Cytological evaluation was performed in parallel with molecular testing and compared to pathological results in 940 thyroid nodules, including 140 indeterminate lesions.

RESULTS

BRAF mutation testing provided the best contribution to cancer diagnosis, allowing the disease to be detected at an early stage, and identifying indeterminate nodules in which diagnostic lobectomy could be spared. On the contrary, RAS and RET/PTC analysis did not further increase diagnostic sensitivity for thyroid cancer. In addition, we found RET/PTC rearrangements in benign lesions, indicating that this molecular marker might not be useful for the detection of thyroid cancer.

CONCLUSION

BRAF(V600E) mutation analysis is superior to RAS point mutations and evaluation of RET/PTC rearrangements in the diagnosis of thyroid cancer, even in indeterminate lesions.

The use of semi-quantitative ultrasound elastosonography in combination with conventional ultrasonography and contrast-enhanced ultrasonography in the assessment of malignancy risk of thyroid nodules with indeterminate cytology

Background

The pre-surgical selection of thyroid nodules with indeterminate cytology (Thy 3 according to British Thyroid Association) after fine-needle aspiration biopsy (FNAB) is currently required in order to reduce unnecessary total thyroidectomy. The objective of our study was to use a surgical series of Thy 3 nodules to evaluate the predictive role of ultrasound elastosonography (USE) and contrast-enhanced ultrasonography (CEUS) in pre-surgical diagnoses of malignancy.

Subjects and methods

We enrolled 63 patients with Thy 3 nodules in which cytological–histological correlation was available. The ELX 2/1 strain index was obtained by means of semi-quantitative USE, which was performed before surgery in addition to conventional ultrasonography (US) and contrast-enhanced US (CEUS) on the Thy 3 nodules. The ELX 2/1 strain index, a five-item US score and both peak (P) index and time to peak (TTP) index from CEUS were correlated with the histological results. After surgical diagnosis, the data were analysed by using a receiver-operating characteristic (ROC) curve.

Results

Histology was benign in 50 and malignant in 13 Thy 3 nodules. No difference in maximal diameter was noted between benign (22.8 ± 1.6 mm) and malignant (18.9 ± 2.9 mm) nodules. Significant correlations were found between histology and cumulative US findings (p=0.005), ELX 2/1 index (p=0.002), P index (p=0.01) and TTP index (p=0.02). On analysing data from US, USE and CEUS, significant ROC areas under the curve were observed (p<0.0001). A cut-off value was set for US (>2), ELX 2/1 (>0.95), P index (<0.99) and TTP index (>0.98) scores. The diagnostic power of the cumulative pre-surgical analysis of Thy 3 nodules with US, USE and CEUS, considering the experimental cut-off points obtained from the ROC curves was: sensitivity 64%, specificity 92%, PPV 75% and accuracy 84%.

Conclusion

The ELX 2/1 index in conjunction with the US score can be useful in orienting surgical strategies in Thy 3 nodules. The information added by CEUS is less sensitive than that provided by US and USE. The use of a cut-off based on histology can reduce thyroidectomy. Observation should be the first choice when not all instrumental results are suspect.