CLINICAL PRACTICE. Thyroid Nodules

Investigating thyroid nodules

Thyroid nodules are common clinically and even more common as an incidental finding during ultrasonography. Routine screening of thyroid nodules in patients with hyperthyroidism or hypothyroidism without risk factors for thyroid cancer is not recommended.

Most thyroid nodules are benign. Sonographic risk-stratification systems should be used to estimate the risk of malignancy and the need for fine-needle aspiration biopsy.

Malignant thyroid nodules require surgical management. Most thyroid cancers are well-differentiated papillary or follicular thyroid neoplasms, which have an excellent prognosis with a low mortality rate.

Adjusted association between type 2 immunity and low risk thyroid nodules: a retrospective cohort study

BACKGROUND

Immune responses, especially type 2 immunity, might be related to the prevalence of thyroid nodules, while the key regulators and potential pathways are remaining largely unknown. In addition, the immune status of individuals could be affected by mixed metabolic background. Herein our aim was to investigate the adjusted association between ultrasound-diagnosed low risk thyroid nodules and immune responses, excluding the interference of metabolic effects on immunity.

METHODS

We retrospectively enrolled 1764 subjects who underwent a thorough thyroid ultrasound examination. To eliminate the interference of confounders, we used propensity score matching (PSM) to match age, gender, cigarette smoking and alcohol drinking, parameters that are related with metabolic syndrome (MetS). Then the potential effectors of immune responses involved in the laboratorial assays were evaluated. Binary logistic regression analysis was used to assess the independent predictors of thyroid nodules in a multivariate manner.

RESULTS

The 1172 subjects were remained after PSM, and differences of demographic background between subjects with and without thyroid nodules were eliminated. Metabolic parameters comprising blood pressure, fasting blood glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein and serum uric acid were shown no significant difference between post-PSM subjects with and without thyroid nodules. Among the biochemistry and hematological parameters, white blood cell count and the positive rate of eosinophil percentage were increased in subjects with thyroid nodules than in those without thyroid nodules. In contrast, the positive rate of basophil percentage was lower in subjects with thyroid nodules than in those without thyroid nodules. In addition, the thyroid function test results showed that subjects with thyroid nodules had higher positive rates of antithyroglobulin antibody (TgAb) and antithyroid peroxidase antibody (TPOAb) than subjects without thyroid nodules. The logistic regression analysis indicated that the positive value of TgAb as well as high level of white blood cell count and BMI could serve as independent risk factors of thyroid nodules.

CONCLUSIONS

The type 2 immune responses mediated by increased level of eosinophils, along with positive value of TgAb and TPOAb were associated with the presence of thyroid nodules. In addition, the potential role of basophils in protecting against thyroid nodules and the pathogenesis of immune-metabolic status remains to be elucidated.

Reliability of a computer-aided system in the evaluation of indeterminate ultrasound images of thyroid nodules

INTRODUCTION

Computer-aided diagnostic (CAD) programs for malignancy risk stratification from ultrasound (US) imaging of thyroid nodules are being validated both experimentally and in real-world practice. However, they have not been tested for reliability in analyzing difficult or unclear images.

METHODS

US images with indeterminate characteristics were evaluated by five observers with different experience in US examination and by a commercial CAD program. The nodules, on which the observers widely agreed, were considered concordant and, if there was little agreement, not concordant or difficult to assess. The diagnostic performance of the readers and the CAD program was calculated and compared in both groups of nodule images.

RESULTS

In the group of concordant thyroid nodules (n = 37), the clinicians and the CAD system obtained similar levels of accuracy (77.0% vs 74.2%, respectively; P = 0.7) and no differences were found in sensitivity (SEN) (95.0% vs 87.5%, P = 0.2), specificity (SPE) (45.5 vs 49.4, respectively; P = 0.7), positive predictive value (PPV) (75.2% vs 77.7%, respectively; P = 0.8), nor negative predictive value (NPV) (85.6 vs 77.7, respectively; P = 0.3). When analyzing the non-concordant nodules (n = 43), the CAD system presented a decrease in accuracy of 4.2%, which was significantly lower than that observed by the experts (19.9%, P = 0.02).

CONCLUSIONS

Clinical observers are similar to the CAD system in the US assessment of the risk of thyroid nodules. However, the AI system for thyroid nodules AmCAD-UT® showed more reliability in the analysis of unclear or misleading images.

A Bibliometric Analysis of 8271 Publications on Thyroid Nodules From 2000 to 2021

INTRODUCTION

Thyroid nodules (TNs) are a common clinical condition. The probability of thyroid nodules being malignant is 7-15%. However, in recent decades, a number of publications on TNs have not been well summarized and discussed. The aim of this study was to summarize and sort out medical publications on TNs over the past 2 decades using a bibliometric method.

MATERIALS AND METHODS

Medical publications from January 1^st, 2000, to November 1^st, 2021, were searched in the Web of Science Core Collection database using the Medical Subject Heading (MeSH) term "thyroid nodule". Full associated data were downloaded, and detailed information was extracted using the bibliometric analysis platform VOSviewer.

RESULTS

A total of 8271 publications related to TNs from the last 2 decades were found and included in this study. An increasing trend was presented in the annual number of publications. The United States, China and Italy contributed the most publications. Carcinoma, management, ultrasound, and fine-needle aspiration were the most popular subjects in the field of TNs. The topics of the studies could be stratified into four clusters. The first cluster was using ultrasound to evaluate the nodules, including the thyroid imaging reporting and data system (TI-RADS), elastography and benign features. The second cluster was the fine-needle aspiration method, including the Bethesda system, cytology and BRAF mutations. The third cluster was the management of nodules, including radiofrequency and thermal ablation, surgery, and consensus statements. The last cluster was carcinoma, which is correlated with all three clusters described above. The preoperative diagnosis of cytologically indeterminate nodules was particularly highlighted in the top 10 most cited publications in recent years.

CONCLUSION

How to diagnose thyroid nodules as malignant or benign, especially in cytologically indeterminate nodules, is still the most concerning topic in TN research. Although the fine-needle aspiration method and gene-expression classifiers show promising results, there is still a crucial need for translations from fundamental studies to clinical applications.

Diagnostic performance of C-TIRADS in malignancy risk stratification of thyroid nodules: A systematic review and meta-analysis

BACKGROUND

Chinese thyroid imaging reports and data systems (C-TIRADS) is a novel malignancy risk stratification used for thyroid nodule diagnosis and guiding thyroid fine needle aspiration (FNA). In this review, we aim to assess the performance of C-TIRADS in malignancy risk stratification of thyroid nodules.

METHODS

PubMed, Medline, Web of Science, Embase, CNKI, and Wanfang databases were searched until 1 April 2022. Original articles reporting data about C-TIRADS and setting FNA or histology as reference standards were included. C-TIRADS 4A, 4B, and 4C were set as thresholds, respectively, to obtain pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), diagnostic odds ratio (DOR), and the area under the curve (AUC). Integrated nested Laplace approximation was used for Bayesian bivariate meta-analysis of diagnostic tests.

RESULTS

Sixteen studies were included, evaluating 11,506 thyroid nodules. The rate of malignancy in each risk classification is comparable with that in C-TIRADS. C-TIRADS 4B appeared to have better diagnostic performance than C-TIRADS 4A and 4C. The pooled sensitivity, specificity, LR+, LR-, and DOR of C-TI-RADS 4B were 0.94 (95% CI: 0.89-0.97), 0.70 (95% CI: 0.60-0.79), 3.20 (95% CI: 2.28-4.39), 0.09 (95% CI: 0.05-0.15), and 33.71 (95% CI: 25.51-42.40), respectively. The area under the summary ROC curve was 0.94 (95% CI: 0.90-0.96).

CONCLUSION

C-TIRADS performed well in malignancy risk stratification of thyroid nodules. C-TIRADS 4B showed strong evidence of detecting malignancy.

Peripheral Blood Inflammatory Markers Can Predict Benign and Malignant Thyroid Nodules

OBJECTIVE

Inflammation is related to the occurrence and development of various cancers. This study was designed to explore the role of peripheral blood platelet count, neutrophil-lymphocyte ratio (NLR), platelet count-lymphocyte count ratio (PLR), systemic inflammation index (SII), and other inflammatory markers in predicting benign and malignant Thyroid Imaging Reporting and Data System (TI-RADS) grade 3 thyroid nodules.

METHODS

In this retrospective study, 514 patients with TI-RADS grade 3 thyroid nodules were enrolled. According to the pathological results, the patients were divided into the benign and malignant nodule groups. We compared the clinical characteristics between the two groups and analysed the influencing factors for malignant thyroid nodules by univariate and stepwise multivariate logistic regression analyses and then analysed the cutoff value of each influencing factor according to the receiver operating characteristic curve.

RESULTS

The leukocyte count, neutrophil count, platelet count, NLR, PLR, and SII of the malignant nodule group were significantly higher than those of the benign nodule group (P < 0.05), the age and the diameter of nodule of the malignant nodule group were significantly smaller than those of the benign nodule group (P < 0.05). After excluding the influence of confounding factors, SII (odds ratio (OR) = 1.006; 95% confidence interval (CI) = 1.003-1.008; P < 0.001), PLR (odds ratio (OR) = 0.981; 95% confidence interval (CI) = 0.981-0.992; P < 0.05), leukocyte count (odds ratio (OR) = 0.654; 95% confidence interval (CI) = 0.466-0.892; P < 0.05), and age (OR = 0.969; 95% CI = 0.954-0.985; P < 0.001) were independent risk factors for malignant thyroid nodules, and the cutoff value of SII and PLR in predicting benign and malignant thyroid nodules were 545.63 × 10⁹/L and 138.63.

CONCLUSION

This study showed that peripheral blood SII, PLR, leukocyte count and age were independent risk factors for malignant thyroid nodules, and the combination of these can better predict benign and malignant thyroid nodules, which can further guide the diagnosis and treatment of TI-RADS grade 3 thyroid nodules.

Successful Applications of Food-Assisted and -Simulated Training Model of Thyroid Radiofrequency Ablation

BACKGROUND

Radiofrequency ablation (RFA) for benign thyroid nodules is one kind of scarless treatment for symptomatic or cosmetic benign thyroid nodules. However, how to train RFA-naive physicians to become qualified operators for thyroid RFA is an important issue. Our study aimed to introduce a successful training model of thyroid RFA.

MATERIALS AND METHODS

We used a food-assisted and -simulated training model of thyroid RFA. Chicken hearts were simulated into thyroid nodules, three-layer pork meats were simulated into peri-thyroid structure, and gel bottles were simulated into trachea, respectively. Successful training ablations were defined as chicken hearts that were fully cooked. After repeating training ablations of chicken hearts at least 100 times with the nearly 100% success rates for three young trainees, they served as the first assistant for the real procedures of thyroid RFA and then were qualified to perform thyroid RFA on real patients under the supervision of one experienced interventional radiologist.

RESULTS

23 real patients who received RFA and follow-up at least 6 months after treatment were included in Linkou Chang Gung Memorial Hospital from January 1, 2020 to October 1, 2021. Three young endocrinologists performed thyroid RFA independently. The outcomes were volume reduction rate (VRR), major complications and minor complications. The median VRR at 12 months was 82.00%, two major complications were transient hoarseness, and three minor complications were wound pain. All complications were completely recovered within three days.

CONCLUSIONS

For young and RFA-native physicians without any basic skills of echo-guided intervention, this food-assisted and -simulated training model of thyroid RFA was useful for medical training and education.

Serum TSH as a predictor of malignancy in indeterminate thyroid nodules

INTRODUCTION

Thyroid nodules are lesions that are radiologically distinct from the thyroid parenchyma. Cervical ultrasound diagnoses 19-67% of nodules and is crucial in identifying those that lack cytological characterisation. Approximately 25% of biopsies reveal an indeterminate cytological result (Bethesda III), in which the risk of malignancy is variable (5-15%). The clinical importance of the diagnostic strategy used for thyroid nodules results from the need to exclude malignancy. The aim of this study was to evaluate the usefulness of serum thyroid-stimulating hormone (TSH) levels as a predictor of malignancy in cytologically indeterminate thyroid nodules.

METHODS

Our retrospective study included 40 patients with cytologically indeterminate thyroid nodules seen in our hospital between January 2013 and December 2017. Clinical parameters were reviewed, including age, gender, serum TSH levels, family history of thyroid carcinoma, radiation exposure and some sonographic features of the nodules. Statistical analysis was performed using SPSS. Statistical significance was defined as p<0.05.

RESULTS

Female gender was predominant (85%) and the mean (SD) age was 53.3 (15) years. Thyroid carcinoma was confirmed in 28% of patients. Median TSH levels were higher in patients with malignant (2.73µIU/ml) compared with benign (1.56µIU/ml) nodules (p<0.05). We demonstrated an increased risk of malignancy in patients with TSH levels of 2.68µIU/ml or above (p<0.05).

CONCLUSION

Higher serum TSH levels are associated with an increased risk of thyroid carcinoma in cytologically indeterminate nodules. TSH can become a fundamental diagnostic tool in stratifying the risk of malignancy and assist in diagnostic and therapeutic approaches to these nodules.

Does insulin resistance trigger thyroid nodule?

The relationship between insulin resistance and thyroid nodules is not clearly understood. The purpose of this study is to investigate the relationship between insülin resistance and thyroid nodules in non-diabetic patients. 410 patients who applied to the Internal Medicine outpatient clinic from June 2018 to July 2019 were reviewed retrospectively. A total of 216 non-diabetic patients were divided into two groups. The relationship of 105 patients with thyroid nodules and 110 patients without thyroid nodules with insulin resistance was investigated. Homeostasis model assessment of insulin resistance value, serum triglycerides and total cholesterol level, and the ratio of women were higher in the group with thyroid nodules (p < 0.05). There was a positive and significant relationship between homeostasis model assessment of insulin resistance value and thyroid nodules (r + 0.29, p < 0.05). In non-diabetic thyroid nodule patients, a significant relationship was detected between nodule formation and insulin resistance. However, these data must be confirmed by other studies in the future.

Do Ultrasound Patterns and Clinical Parameters Inform the Probability of Thyroid Cancer Predicted by Molecular Testing in Nodules with Indeterminate Cytology?

Background: Molecular testing (MT) is commonly used to refine cancer probability in thyroid nodules with indeterminate cytology. Whether or not ultrasound (US) patterns and clinical parameters can further inform the risk of thyroid cancer in nodules predicted to be positive or negative by MT remains unknown. The aim of this study was to test if clinical parameters, including patient age, sex, nodule size (by US), Bethesda category (III, IV, V), US pattern (American Thyroid Association [ATA] vs. American College of Radiology Thyroid Image Reporting and Data System [TI-RADS] systems), radiation exposure, or family history of thyroid cancer can modify the probability of thyroid cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) predicted by MT. Methods: We studied 257 thyroid nodules in 232 patients from 10 study centers with indeterminate fine needle aspiration cytology and informative MT results using the ThyroSeq v3 genomic classifier (TSv3). Univariate and multivariate logistic regression was used for data analysis. Results: The presence of cancer/NIFTP was associated with positive TSv3 results (odds ratio 61.39, p < 0.0001). On univariate regression, patient sex, age, and Bethesda category were associated with cancer/NIFTP probability (p < 0.05 for each). Although ATA (p = 0.1211) and TI-RADS (p = 0.1359) US categories demonstrated positive trends, neither was significantly associated with cancer/NIFTP probability. A multivariate regression model incorporating the four most informative non-MT covariates (sex, age, Bethesda category, and ATA US pattern; Model No. 1) yielded a C index of 0.653; R² = 0.108. When TSv3 was added to Model number 1, the C index increased to 0.888; R² = 0.572. However, age (p = 0.341), Bethesda category (p = 0.272), and ATA US pattern (p = 0.264) were nonsignificant, and other than TSv3 (p < 0.0001), male sex was the only non-MT parameter that potentially contributed to cancer/NIFTP risk (p = 0.095). The simplest and most efficient clinical model (No. 3) incorporated TSv3 and sex (C index = 0.889; R² = 0.588). Conclusions: In this multicenter study of thyroid nodules with indeterminate cytology and MT, neither the ATA nor TI-RADS US scoring systems further informed the risk of cancer/NIFTP beyond that predicted by TSv3. Although age and Bethesda category were associated with cancer/NIFTP probability on univariate analysis, in sequential nomograms they provided limited incremental value above the high predictive ability of TSv3. Patient sex may contribute to cancer/NIFTP risk in thyroid nodules with indeterminate cytology.

Effect of an anti-adhesion agent on vision-based assessment of cervical adhesions after thyroid surgery: randomized, placebo-controlled trial

Many patients experience cervical adhesions after thyroid surgery. To date, however, no studies have objectively measured the effects of anti-adhesion agents on cervical adhesion symptoms. This study evaluated the effects of an anti-adhesion agent on cervical adhesions after thyroid surgery, as determined using a system that measures the extent of marker movement objectively. One hundred patients were randomized in a 1:1 ratio to undergo thyroid surgery with or without the anti-adhesion agent Collabarrier. Using specially manufactured recording equipment, the position of the marker on neck skin was measured before surgery, and 2 weeks, 3 months, and 9 months after surgery. Relative change in marker distance, calculated by subtracting the marker position before surgery from the marker positions 2 weeks, 3 months, and 9 months after surgery, differed significantly in the groups of patients who underwent thyroid surgery with and without the anti-adhesion agent (P < 0.05). A novel measuring system can objectively evaluate the effectiveness of a thyroid anti-adhesion agent. The anti-adhesion agent used significantly reduced adhesions compared with the control group. The trial is registered at www.cris.nih.go.kr (KCT0005745; date of registration, 08/01/2021).

PRKAR1A and Thyroid Tumors

Simple Summary

In 2021 it is estimated that there will be 44,280 new cases of thyroid cancer in the United States and the incidence rate is higher in women than in men by almost 3 times. Well-differentiated thyroid cancer is the most common subtype of thyroid cancer and includes follicular (FTC) and papillary (PTC) carcinomas. Over the last decade, researchers have been able to better understand the molecular mechanisms involved in thyroid carcinogenesis, identifying genes including but not limited to RAS, BRAF, PAX8/PPARγ chromosomal rearrangements and others, as well as several tumor genes involved in major signaling pathways regulating cell cycle, differentiation, growth, or proliferation. Patients with Carney complex (CNC) have increased incidence of thyroid tumors, including cancer, yet little is known about this association. CNC is a familial multiple neoplasia and lentiginosis syndrome cause by inactivating mutations in the PRKAR1A gene which encodes the regulatory subunit type 1α of protein kinase A. This work summarizes what we know today about PRKAR1A defects in humans and mice and their role in thyroid tumor development, as the first such review on this issue.

Abstract

Thyroid cancer is the most common type of endocrine malignancy and the incidence is rapidly increasing. Follicular (FTC) and papillary thyroid (PTC) carcinomas comprise the well-differentiated subtype and they are the two most common thyroid carcinomas. Multiple molecular genetic and epigenetic alterations have been identified in various types of thyroid tumors over the years. Point mutations in BRAF, RAS as well as RET/PTC and PAX8/PPARγ chromosomal rearrangements are common. Thyroid cancer, including both FTC and PTC, has been observed in patients with Carney Complex (CNC), a syndrome that is inherited in an autosomal dominant manner and predisposes to various tumors. CNC is caused by inactivating mutations in the tumor-suppressor gene encoding the cyclic AMP (cAMP)-dependent protein kinase A (PKA) type 1α regulatory subunit (PRKAR1A) mapped in chromosome 17 (17q22–24). Growth of the thyroid is driven by the TSH/cAMP/PKA signaling pathway and it has been shown in mouse models that PKA activation through genetic ablation of the regulatory subunit Prkar1a can cause FTC. In this review, we provide an overview of the molecular mechanisms contributing to thyroid tumorigenesis associated with inactivation of the RRKAR1A gene.

Diagnostic performance rates of the ACR-TIRADS and EU-TIRADS based on histopathological evidence

PURPOSE

In this study, we aimed to assess the effectiveness of malignancy stratification algorithms of the American College of Radiology (ACR) and European Thyroid Association (ETA) in the delineation of thyroid nodules using a database of nodules that were unequivocally diagnosed by means of histopathological examination and meticulously matched with the imaged nodules.

METHODS

A total of 165 patients having 251 thyroid nodules with histopathologically proven definitive diagnoses during a 5-year period were included in this study. All patients had preoperatively undergone ultrasonography (US) examination, and US characteristics of the thyroid nodules were retrospectively analyzed and assigned in compliance with the thyroid imaging reporting and data system categories recommended by the ACR (ACR-TIRADS) and ETA (EU-TIRADS). The diagnostic effectiveness in the delineation of thyroid nodules and unnecessary fine-needle aspiration (FNAB) rates were evaluated.

RESULTS

Overall, 189 nodules (75.30%) were diagnosed as benign, while 62 nodules (24.70%) were reported to be malignant based on histopathological assessment. Sensitivity and specificity rates were 71% and 75% for ACR-TIRADS and 73% and 80% for EU-TIRADS. The area under the curve values were 0.78 and 0.80 for ACR-TIRADS and EU-TIRADS, respectively. The unnecessary FNAB rates were 61% for ACR-TIRADS and 64% for EU-TIRADS as per the recommended criteria of each algorithm.

CONCLUSION

The diagnostic performance of both malignancy stratification systems was signified to be moderate and sufficient in a cohort of nodules with definite histopathological diagnosis. In light of our results, we demonstrated the strengths and weaknesses of the ACR- and EU-TIRADS for physicians who should be familiar with them for optimal management of thyroid nodules.

Is partial ablation appropriate for benign thyroid nodules? A retrospective study with long-term follow-up after microwave ablation

OBJECTIVE

This retrospective study aimed to investigate the efficacy and safety of partial ablation (PA) for benign thyroid nodules (BTNs) using microwave ablation (MWA) in a long-term follow-up.

MATERIALS AND METHODS

Between February 2015 and April 2019, 236 patients with 236 BTNs (maximum diameter ≥2 cm) treated with ultrasound-guided MWA were enrolled. Contrast-enhanced ultrasound (CEUS) was performed within 3 d after ablation to determine whether there was residual tissue according to which the patients were assigned PA or complete ablation (CA). The volume reduction ratio (VRR) and complications were evaluated during follow-up.

RESULTS

Eighty-two patients were enrolled in the PA group, and 154 were enrolled in the CA group. Both groups achieved continuous reductions in nodule volume and increases in VRR within 2 years after ablation. Although the VRR of the PA group at 4 years was lower than that of the CA group (65.54 vs. 95.08%; p<.05), PA still achieved 'technical efficacy' with a volume reduction of more than 50%. The complication and side effect rates between the two groups showed no significant difference (p>.05).

CONCLUSIONS

Both PA and CA were safe and effective in reducing the volumes of BTNs in the long-term follow-up. For nodules with a large initial volume and dangerous location, PA with a small amount of residual tissue may be acceptable.

Agreement between ACR TI-RADS and EU TI-RADS scoring systems in the diagnosis of 473 thyroid nodules from a single-center in Brazil

OBJECTIVES

This study compares two ultrasound-based risk-stratification systems in malignancy risk assessment of thyroid nodules and the clinical applicability of these guidelines in Brazil.

METHODS

We retrospectively reviewed the ultrasound findings of 314 patients (473 thyroid nodules) who underwent fine needle aspiration (FNA) biopsy and/or surgery between February 2018 and March 2019. All nodules were classified using two systems: The Thyroid Imaging, Reporting, and Data System of the American College of Radiology (ACR-TIRADS) and the TIRADS of the European Thyroid Association (EU-TIRADS). Both risk-stratification system was analyzed. We identify diagnostic predictive values that yielded optimal sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC).

RESULTS

Of the 473 nodules, all underwent FNA, and 332 nodules had histopathology performed. The agreement between the ACR-TIRADS and EU-TIRADS results and between cytology and histopathology findings was 92.6% (Kappa = 0.84) and 86.7% (Kappa = 0.73), respectively. The area under the curve (AUC) of the ACR-TIRADS and EU-TIRADS were 0.871 and 0.828, respectively (p < 0.001). The EU-TIRADS had the best SEN and NPV, whereas the ACR-TIRADS had the best SPE, PPV, and ACC. Only 33.4% of the nodules followed the FNA size criteria suggested by the ACR-TIRADS.

CONCLUSION

ACR-TIRADS and EU-TIRADS had good diagnostic performances. However, most aspirated nodules did not follow the TIRADS indication; thus, the overuse of FNA as a diagnostic tool was observed.

Ultrasound Image Classification of Thyroid Nodules Using Machine Learning Techniques

Background and Objectives: Thyroid nodules are lumps of solid or liquid-filled tumors that form inside the thyroid gland, which can be malignant or benign. Our aim was to test whether the described features of the Thyroid Imaging Reporting and Data System (TI-RADS) could improve radiologists' decision making when integrated into a computer system. In this study, we developed a computer-aided diagnosis system integrated into multiple-instance learning (MIL) that would focus on benign-malignant classification. Data were available from the Universidad Nacional de Colombia. Materials and Methods: There were 99 cases (33 Benign and 66 malignant). In this study, the median filter and image binarization were used for image pre-processing and segmentation. The grey level co-occurrence matrix (GLCM) was used to extract seven ultrasound image features. These data were divided into 87% training and 13% validation sets. We compared the support vector machine (SVM) and artificial neural network (ANN) classification algorithms based on their accuracy score, sensitivity, and specificity. The outcome measure was whether the thyroid nodule was benign or malignant. We also developed a graphic user interface (GUI) to display the image features that would help radiologists with decision making. Results: ANN and SVM achieved an accuracy of 75% and 96% respectively. SVM outperformed all the other models on all performance metrics, achieving higher accuracy, sensitivity, and specificity score. Conclusions: Our study suggests promising results from MIL in thyroid cancer detection. Further testing with external data is required before our classification model can be employed in practice.

Papillary Thyroid Carcinoma With Cystic Changes in a Patient With Prior History of Toxic Nodule

Thyroid nodules are palpable on up to 7% of asymptomatic patients. Cancer is present in 8% to 16% of those patients with previously identified thyroid nodules. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer, accounting for approximately 85% of thyroid cancers. Although most appear as solid nodules on ultrasound imaging, a subset of 2.5% to 6% has cystic components. The presence of cystic changes within thyroid nodules decreases the accuracy of fine needle aspiration (FNA) in the diagnosis of thyroid cancer, given the difficulty of obtaining appropriate cellular content. This becomes a diagnostic and therapeutic challenge. We present a case of a 31-year-old female with a 1-month history of palpitations, fatigue, and night sweats, who underwent evaluation, and was diagnosed with subclinical hyperthyroidism. She presented 4 years later with compressive symptoms leading to repeat FNA, showing Bethesda III-atypia of undetermined significance and negative molecular testing. Thyroid lobectomy revealed PTC with cystic changes. This case is a reminder that patients with hyperfunctioning thyroid nodule should have closer follow-up. It poses the diagnostic dilemma of how much is good enough in the evaluation and management of a thyroid nodule. Early detection and action should be the standard of care.

Deep Learning Based on ACR TI-RADS Can Improve the Differential Diagnosis of Thyroid Nodules

Objective

The purpose of this study was to improve the differentiation between malignant and benign thyroid nodules using deep learning (DL) in category 4 and 5 based on the Thyroid Imaging Reporting and Data System (TI-RADS, TR) from the American College of Radiology (ACR).

Design and Methods

From June 2, 2017 to April 23, 2019, 2082 thyroid ultrasound images from 1396 consecutive patients with confirmed pathology were retrospectively collected, of which 1289 nodules were category 4 (TR4) and 793 nodules were category 5 (TR5). Ninety percent of the B-mode ultrasound images were applied for training and validation, and the residual 10% and an independent external dataset for testing purpose by three different deep learning algorithms.

Results

In the independent test set, the DL algorithm of best performance got an AUC of 0.904, 0.845, 0.829 in TR4, TR5, and TR4&5, respectively. The sensitivity and specificity of the optimal model was 0.829, 0.831 on TR4, 0.846, 0.778 on TR5, 0.790, 0.779 on TR4&5, versus the radiologists of 0.686 (P=0.108), 0.766 (P=0.101), 0.677 (P=0.211), 0.750 (P=0.128), and 0.680 (P=0.023), 0.761 (P=0.530), respectively.

Conclusions

The study demonstrated that DL could improve the differentiation of malignant from benign thyroid nodules and had significant potential for clinical application on TR4 and TR5.

Appropriateness of ultrasound imaging for thyroid pathology, the standard of radiology reporting on thyroid nodules and the detection rates of thyroid malignancy: a tertiary centre retrospective audit

BACKGROUND

The incidence of thyroid cancer is increasing worldwide without a simultaneous rise in mortality. It is thought that the incidence of non-clinically significant thyroid cancers are on the rise as a result of more sensitive diagnostic imaging.

AIM

To determine the number of inappropriate requests for thyroid ultrasound (US), the quality of radiology reporting for thyroid nodules based on accepted guidelines and the resultant number of thyroid cancers identified because of these investigations.

METHODS

Electronic medical records of patients who underwent thyroid US imaging and thereafter referred to the Endocrine Department at Gold Coast University Hospital, Queensland, between July 2014 and July 2017 were reviewed. Data for 251 patients who had thyroid US were analysed and the final 201 patients who were found to have thyroid nodules were evaluated using descriptive statistics. Indications for thyroid US imaging among referring clinicians were assessed and we compared both clinical management and radiology reporting practices of thyroid nodules to the published 2009 and 2015 American Thyroid Association (ATA) guidelines.

RESULTS

There were 50.2% of patients with initial thyroid US imaging deemed outside of expert recommendations where 42% of these patients required further surveillance imaging and 25.4% required fine needle aspiration of their thyroid nodules. A definite recommendation whether to evaluate thyroid nodules further was provided in 44.8% of radiology reports. There were no radiology reports that described thyroid nodules findings based on patterns as recommended by the 2015 ATA guidelines. Two cases of thyroid cancer were detected including one patient with prior history of thyroid cancer and a second patient with hypothyroidism.

CONCLUSION

Routine use of US thyroid imaging outside expert recommendation is common. There is lack of standardised reporting when assessing thyroid nodules on US. Limiting the initial use of US in cases of palpable neck lumps and the use of systematic reporting according to the 2017 guidelines published by the American College of Radiology Thyroid Imaging Reporting and Data System may reduce unnecessary investigations for thyroid nodules in the future.

Long-term efficacy evaluation of a protocol for the management of symptomatic thyroid cysts with ultrasound-guided percutaneous ethanol injection

AIM

To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.

PATIENTS AND METHODS

100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.

RESULTS

Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.

CONCLUSIONS

PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.

Impact of Electronic Consultation on Timeliness and Guideline Concordance of Workups Leading to Thyroid Nodule Fine-Needle Aspiration Biopsy

OBJECTIVE

Electronic consultations (e-consults) are commonly used to obtain endocrinology input on clinical questions without a face-to-face visit, but sparse data exist on the resultant quality of care for specific conditions. We examined workups resulting in a thyroid nodule fine-needle aspiration (FNA) biopsy to investigate whether endocrinology e-consults were more timely and similarly guideline-concordant compared with endocrinology face-to-face visits and whether endocrinology e-consults were more guideline-concordant compared with workups without endocrinology input.

METHODS

We retrospectively reviewed charts of 302 thyroid FNA biopsies conducted in the Veterans Affairs health system between May 1, 2017, and February 4, 2020 (e-consult, n = 99; face-to-face visit, n = 100; no endocrinology input, n = 103). We used t tests to compare timeliness, χ² tests to compare the proportion of guideline-concordant workups, and multivariable linear and logistic models to control for demographic factors.

RESULTS

FNAs preceded by an endocrinology e-consult had more timely workups compared with those preceded by endocrinology face-to-face visits in terms of days elapsed between referral and FNA biopsy (geometric mean 44.7 days vs 61.7 days, P = .01). The difference in the summary measure of guideline concordance across groups was not statistically significant (P =.38).

CONCLUSION

E-consults were faster than face-to-face consults and similarly guideline-concordant compared with both face-to-face consults and no endocrinology input for workups resulting in FNA. Decisions about the appropriate use of e-consults for thyroid nodules should take into account these data while also considering the potential benefits of direct patient-endocrinologist interaction for complex situations.

Validation of American Thyroid Association Ultrasound Risk-Adapted Approach for Repeating Cytology in Benign Thyroid Nodules

Background: The 2015 American Thyroid Association (ATA) ultrasound (US) risk stratification system is used to identify thyroid nodules in which fine-needle aspiration cytology (FNAC) should be performed. In addition, this system is used to plan the long-term follow-up of patients with cytological benign thyroid nodules. The aim of our study was to evaluate the ATA US risk-adapted approach for repeating cytology in a large retrospective cohort of consecutive benign nodules with a second FNAC repeated after a median follow-up of 3.8 years (range 1.0-14.2 years). Methods: We retrospectively evaluated 1010 thyroid nodules, with an initial benign cytological diagnosis, that underwent at least one repeat FNAC during the follow-up. Results: The rate of missed cancer in the whole cohort of thyroid nodules was 1.0%, and it increased along by the US risk class (0.8% in very low/low-risk, 1.2% in intermediate-risk, and 3.1% in high-risk nodules). The 2015 ATA US risk stratification system showed a very high accuracy in selecting nodules that did not require a second FNAC (negative predictive value = 99.1%). In addition, the rate of missed cancer significantly increased along with the increase in the US risk class in nodules that showed an enlarged volume (0.4% in the low-risk class and 6.4% in the high-risk class, p = 0.005), while it was very low and not associated with the US features in the subgroup of thyroid nodules that did not grow during the follow-up (p = 0.96). Conclusions: Our results confirm the accuracy of the ATA recommendations in selecting benign nodules for FNAC repetition during the follow-up. An additional cytological evaluation maybe avoided in benign thyroid nodules with low-risk US features, regardless of the evidence of growth during the follow-up. While the utility of the routine repeat FNAC in all benign nodules with high-risk US features remains to be defined, based on our results, repetition of FNAC seems to be indicated in nodules with evidence of growth during the follow-up.

On the identification of thyroid nodules using semi-supervised deep learning

Detecting malign cases from thyroid nodule examinations is crucial in healthcare particularly to improve the early detection of such cases. However, malign thyroid nodules can be extremely rare and is hard to find using the traditional rule based or expert-based methods. For this reason, the solutions backed by Machine Learning (ML) algorithms are key to improve the detection rates of such rare cases. In this paper, we investigate the application of ML in the healthcare domain for the detection of rare thyroid nodules. The utilized dataset is collected from 636 distinct patients in 99 unique days in Turkey. In addition to the texture feature data of the Ultrasound (US), we have also included the scores of different assessment methods created by different health institutions (e.g., Korean, American and European thyroid societies) as additional features. For detection of extremely rare malign cases, we use auto-encoder based neural network model. Through numerical results, it is shown that the auto-encoder based model can result in an average Recall score of 0.98 and a Sensitivity score of 1.00 for detecting malign and non-malign cases from the healthcare dataset outperforming the traditional classification algorithms that are trained after Synthetic Minority Oversampling Technique (SMOTE) oversampling.

Effect of Chinese herbal medicine for patients with benign thyroid nodules in adults: A protocol for systematic review and meta-analysis

BACKGROUND

Thyroid nodules (TN) are discrete lesions within the thyroid gland and are a common clinical problem detected in 19% to 68% of people. TN are more common as age increases and occur more frequently in women. TN can cause pressure symptoms, cosmetic complaints, and thyroid dysfunction. Treatment for benign thyroid nodules includes thyroid hormone therapy, surgery, radioiodine treatment, percutaneous ethanol injection therapy, and laser or radiofrequency treatment to shrink nodules. In China and many other countries, doctors use Chinese herbal medicines (CHM) to treat TN. However, systematic review and meta-analysis has not been found to assess the effects and safety of CHM in curing TN at present. Hence, the systematic review is conducted to scientifically and methodically evaluate the value of its effectiveness and safety of CHM on TN.

METHODS

Literatures related to CHM for TN from the establishment of the database to November 2020 will be retrieved from the following databases: PubMed, Excerpta Medica Database (EMBASE), MEDLINE, Web of Science, Cochrane Library, SpringerLink, WHO International Clinical Trials Registry Platform (ICTRP), Wanfang Database, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), and Chinese Scientific Journal Database (VIP). There are no language restrictions for retrieving literatures. Case reports, animal studies, editorials, expert opinions, reviews without original data, and studies on pediatric population were excluded. Eligible randomized clinical trials (RCTs) evaluating the effectiveness and safety of CHM in TN patients will be put in the study including nodule volume reduction ≥50%, pressure symptoms, cosmetic complaints, quality of life, and adverse events. By scanning the titles, abstracts and full texts, 2 reviewers will independently select studies, extract data, and assess the quality of study. Meta-analysis of RCTs will be conducted using Review Manager 5.1 software. The results will be presented as risk ratio for dichotomous data, and standardized or weighted mean difference for continuous data.

RESULT

This study will provide high-quality available evidence for the treatment of TN with CHM based on nodule volume reduction ≥50%, pressure symptoms, cosmetic complaints, quality of life, and adverse events.

CONCLUSION

The systematic review will to evaluate the efficacy of CHM in treating benign thyroid nodules in adults and provide evidence for clinicians.

INPLASY REGISTRATION NUMBER

INPLASY2020120093.

Malignancy risk of hyperfunctioning thyroid nodules compared with non-toxic nodules: systematic review and a meta-analysis

Background

Hyperfunctioning or hot nodules are thought to be rarely malignant. As such, current guidelines recommend that hot nodules be excluded from further malignancy risk stratification. The objective of this systematic review and meta-analysis is to compare the malignancy risk in hot nodules and non-toxic nodules in observational studies.

Methods

Ovid MEDLINE Daily and Ovid MEDLINE, EMBASE, Scopus, and Web of Science databases were searched. Observational studies which met all of the following were included: (1) use thyroid scintigraphy for nodule assessment, (2) inclusion of both hyperfunctioning and non-functioning nodules based on scintigraphy, (3) available postoperative histopathologic nodule results, (4) published up to November 12, 2020 in either English or French. The following data was extracted: malignancy outcomes include malignancy rate, mapping of the carcinoma within the hot nodule, inclusion of microcarcinomas, and presence of gene mutations.

Results

Among the seven included studies, overall incidence of malignancy in all hot thyroid nodules ranged from 5 to 100% in comparison with non-toxic nodules, 3.8–46%. Odds of malignancy were also compared between hot and non-toxic thyroid nodules, separated into solitary nodules, multiple nodules and combination of the two. Pooled odds ratio (OR) of solitary thyroid nodules revealed a single hot nodule OR of 0.38 (95% confidence interval (CI) 0.25, 0.59), toxic multinodular goiter OR of 0.51 (95% CI 0.34, 0.75), and a combined hot nodule OR of 0.45 (95% CI 0.31, 0.65). The odds of malignancy are reduced by 55% in hot nodules; however, the incidence was not zero.

Conclusions

Odds of malignancy of hot nodules is reduced compared with non-toxic nodules; however, the incidence of malignancy reported in hot nodules was higher than expected. These findings highlight the need for further studies into the malignancy risk of hot nodules.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13044-021-00094-1.

Advances in the Relationship Between Regulator of Ribosome Synthesis 1 (RRS1) and Diseases

A regulator of ribosome synthesis 1 (RRS1) was discovered in yeast and is mainly localized in the nucleolus and endoplasmic reticulum. It regulates ribosomal protein, RNA biosynthesis, and protein secretion and is closely involved in cellular senescence, cell cycle regulation, transcription, translation, oncogenic transformation etc., Mutations in the RRS1 gene are associated with the occurrence and development of Huntington’s disease and cancer, and overexpression of RRS1 promotes tumor growth and metastasis. In this review, the structure, function, and mechanisms of RRS1 in various diseases are discussed.

Sonographic Features Differentiating Follicular Thyroid Cancer from Follicular Adenoma-A Meta-Analysis

Simple Summary

The risk of thyroid malignancy assessment may include certain ultrasound features. The analysis is lacking for the differentiation of follicular thyroid adenomas and cancers (FTAs and FTCs). Our meta-analysis aimed to identify sonographic features suggesting malignancy in the case of follicular lesions, potentially differentiating FTA and FTC. Based on twenty studies describing sonographic features of 10,215 nodules, we found that the most crucial feature associated with an increased risk of FTC were tumor protrusion (odds ratios—OR = 10.19), microcalcifications or mixed type of calcifications: 6.09, irregular margins: 5.11, marked hypoechogenicity: 4.59, and irregular shape: 3.6.

Abstract

Certain ultrasound features are associated with an increased risk of thyroid malignancy. However, they were studied mainly in papillary thyroid cancers (PTCs); these results cannot be simply extrapolated for the differentiation of follicular thyroid adenomas and cancers (FTAs and FTCs). The aim of our study was to perform a meta-analysis to identify sonographic features suggesting malignancy in the case of follicular lesions, potentially differentiating FTA and FTC. We searched thirteen databases from January 2006 to December 2020 to find all relevant, full-text journal articles written in English. Analyses assessed the accuracy of malignancy detection in case of follicular lesions, potentially differentiating FTA and FTC included the odds ratio (OR), sensitivity, specificity, positive and negative predictive values. A random-effects model was used to summarize collected data. Twenty studies describing sonographic features of 10,215 nodules met the inclusion criteria. The highest overall ORs to increase the risk of malignancy were calculated for tumor protrusion (OR = 10.19; 95% confidence interval: 2.62–39.71), microcalcifications or mixed type of calcifications (coexisting micro and macrocalcifications): 6.09 (3.22–11.50), irregular margins: 5.11 (2.90–8.99), marked hypoechogenicity: 4.59 (3.23–6.54), and irregular shape: 3.6 (1.19–10.92). The most crucial feature associated with an increased risk of FTC is capsule protrusion, followed by the presence of calcifications, irrespectively of their type.

The association between diabetes and thyroid cancer risk: a hospital-based case-control study in China

BACKGROUND

Previous studies have indicated inconsistent relationships of diabetes with thyroid cancer risk, yet little is known in China. In this study, we aimed to investigate the associations between diabetes, diabetes duration and the risk of thyroid cancer in Chinese population.

METHODS

A 1:1 matched case-control study was performed between 2015 and 2017 in Zhejiang Province including 2,937 thyroid cancer cases and 2,937 healthy controls. Odds ratios (ORs) with 95 % confidence intervals (CIs) for thyroid cancer were estimated in logistic regression models. Specific effects stratified by age, as well as sex, body mass index (BMI) and family history of diabetes were also examined.

RESULTS

Overall, neither diabetes (OR = 0.75, 95 % CI: 0.21-2.73) nor diabetes duration (OR = 0.14, 95 % CI: 0.02-1.22 for diabetes duration ≦ 5 years; OR = 2.10, 95 % CI: 0.32-13.94 for diabetes duration > 5 years) was significantly associated with thyroid cancer. In stratified analyses, significant lower risk of thyroid cancer was observed among subjects with diabetes and shorter diabetes duration ( ≦ 5 years), but limited to those who were aged more than 40 years, female, overweight/obese and had positive family history of diabetes.

CONCLUSIONS

Diabetes and shorter diabetes duration were significantly associated with decreased risk of thyroid cancer in individuals characterized by older age, female sex, higher BMI and positive family history of diabetes.

Should Contralateral Nodules Be an Indication of Total or Completion Thyroidectomy for Patients With Unilateral Papillary Thyroid Carcinoma?

OBJECTIVE

To determine whether papillary thyroid carcinoma (PTC) patients with benign or nonsuspicious nodules in the contralateral lobe have a higher rate of recurrence or worse survival after lobectomy compared to those without nodules in the contralateral lobe.

METHODS

Adult patients who underwent lobectomy and were diagnosed with unilateral PTC (2013-2015), were identified from an institutional database. Patients who previously had cytologically benign nodules or nonsuspicious nodules in the contralateral lobe comprised the contralateral nodule (CN) group. Patients who did not have nodules in the contralateral lobe comprised the unilateral nodule (UN) group.

RESULTS

370 patients were included: 242 in the UN group and 128 in the CN group. After a median follow-up of 62 months (range, 16-85 months), recurrence was confirmed in 4.1% patients in the UN group and 5.5% patients in the CN group (p = 0.559). Clinical contralateral lobe PTC was detected in 2.9% (7/242) of patients from the UN group and 3.9% (5/128) of patients from the CN group (p = 0.601). The 5-year contralateral lobe recurrence-free survival (RFS) rates were 96.8% in the UN group and 97.4% in the CN group (p = 0.396). The 5-year loco-regional RFS rates were 98.4% in the UN group and 97.8% in the CN group (p = 0.690). The 5-year disease-specific survival rates were both 100%.

CONCLUSION

PTC patients with benign or nonsuspicious CNs have similar recurrence and survival rates after lobectomy compared to those without CNs. CNs alone should not be an indication for total or completion thyroidectomy.

A Single-Center Retrospective Study of the Impact of Thyroid Cancer on the Malignant Risk of Contralateral TI-RADS 3 and 4 Nodules

BACKGROUND

The incidence of thyroid nodules increases in the general population. Similarly, we have also seen a dramatic increase in the number of thyroid surgeries. However, the mortality rate of thyroid cancer remained stable or even decreased. The purpose of our study was to investigate whether thyroid cancer affects the malignant risk of the contralateral TI-RADS 3 and 4 nodules.

METHODS

We conducted a retrospective cohort study in our institution for all thyroid procedures due to nodules from December 2018 to December 2019. All eligible patients were divided into the experimental group (bilateral nodules) and the control group (unilateral nodules) to assess whether the proportion of malignant nodules was different between the two groups. Multivariate logistic regression analysis was used to control potential confounding factors to investigate whether their differences were statistically significant.

RESULTS

A total of 330 patients underwent thyroid surgery, of whom 137 were eligible, including 84 in the experimental group and 53 in the control group. The proportion of malignant nodules was significantly different between the experimental group and the control group (29.8% versus 58.5%, unadjusted OR 0.30, 95% CI: 0.17-0.82, p=0.001). However, after controlling for potential confounding factors, including age (p=0.004), gender (p=0.775), and TI-RADS classification (p ≤ 0.001), we found that the difference was not significant (adjusted OR 1.08, 95% CI: 0.39-3.01, p=0.886).

CONCLUSION

There is no evidence that thyroid cancer affects the malignant risk of the contralateral TI-RADS 3 and 4 nodules. This study has been registered with the Chinese Clinical Trial Registry (clinical trial registration number: ChiCTR2000038611, registration time: September 26, 2020).

Correlation Between Thyroid Nodules and Metabolic Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

Thyroid nodules (TNs) are a common thyroid disorder that can be caused by many factors. Several studies have investigated the relationship between TNs and metabolic syndrome (MetS), but the role of sex and age remains controversial. The purpose of this paper was to analyze published data from all relevant studies to reliably estimate the relationship between TNs and MetS.

METHODS

Thirteen articles were included in this study; articles were identified by searching for publications until July 2021 in PubMed, EMBASE, the Cochrane Library and the Web of Science. The outcomes are presented as the summary odds ratio (OR) and 95% confidence interval (CI) and the pooled prevalence and 95% CI.

RESULTS

The TNs prevalence was significantly higher in MetS patients than in controls (OR 1.88, 95% CI 1.42-2.50, P < 0.0001) and was independent of sex (male: OR 1.53, 95% CI 1.20-1.94, P = 0.0006; female: OR 1.90, 95% CI 1.54-2.33, P < 0.00001; combined: OR 2.06, 95% CI 1.31-3.25, P = 0.002) and age (< 40 years old: OR 1.62, 95% CI 1.39-1.89, P < 0.0001; 40~50 years old: OR 2.14, 95% CI 1.49-3.08, P < 0.0001;50~60 years old: OR 1.50, 95% CI 1.08-2.07, P = 0. 01; 60 years old: OR 1.70, 95% CI 1.36-2.14, P < 0.00001); the pooled TNs prevalence in MetS patients was 45% (95% CI 36-54%). However, it has not yet been considered that MetS is related to TNs in people with iodine deficiency (OR 3.14, 95% CI 0.92-10.73, P = 0.07).

CONCLUSION

The meta-analysis results showed a strong correlation between TNs and MetS. Both male and female patients with MetS had an increased TNs prevalence. In addition, the prevalence was independent of age. However, MetS is not considered to be associated with TNs in iodine-deficient populations.

Association between Urinary Iodine Concentration and Thyroid Nodules in Adults: A Cross-Sectional Study in China

Background

Associations between iodine intake and thyroid nodules (TNs) were not consistent. We aimed to illustrate the relationship between urinary iodine concentration (UIC) and TNs.

Methods

A total of 12,698 participants were enrolled in analysis. All of the participants filled out questionnaires and underwent physical examinations, laboratory tests, and thyroid ultrasonography. UIC, serum thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb) were measured in the central laboratory.

Results

The prevalence of TNs was 16.00%, and the median UIC was 206.1 μg/L. TNs and UIC were negatively related when UIC was less than 527 μg/L (adjusted OR = 0.87; 95% CI, 0.80, 0.94), and the relationship between UIC and TNs was not statistically significant when UIC was greater than 527 μg/L (adjusted OR = 1.25; 95% CI, 0.98, 1.60). In women, UIC was negatively associated with risk for TNs (adjusted OR 0.95; 95% CI, 0.91, 0.99).

Conclusion

The relationship between TNs and UIC differed between men and women. The risk of TNs decreased with the elevation of UIC in men when UIC was lower than 527 μg/L, while UIC and the presence of TNs were negatively correlated in women. In the future, cohort studies or other studies that can explain causality must be conducted to explore the relationship between iodine status and TNs.

Prevalence of Thyroid Nodules in China: A Health Examination Cohort-Based Study

BACKGROUND

Thyroid nodules are a common clinical problem and some are potentially cancerous; however, little is known about the prevalence of thyroid nodules in China. The objective of this study was to investigate the prevalence of thyroid nodules in a healthy Chinese population.

METHODS

We reviewed electronic medical records of 13,178,313 participants from 30 provinces and regions who received health examinations and underwent thyroid ultrasound at Meinian Onehealth Healthcare in 2017. Among them, 6,192,357 were excluded based on predefined criteria. All thyroid nodules were diagnosed by ultrasonography, and standardized protocols were adopted for data collection, quality control, and data management.

RESULTS

A total of 6,985,956 participants (mean age: 42.1 ± 13.1 years) were included in this study. The overall prevalence of thyroid nodules was 36.9% (95% CI, 35.7%-38.1%; age- and sex-standardized prevalence 38.0% [95% CI, 37.0%-39.1%]). The prevalence of thyroid nodules in females (44.7% [95% CI, 43.4%-45.9%], age-standardized prevalence: 45.2% [95% CI, 44.1%-46.4%]) was significantly higher than that in males (29.9% [95% CI, 28.8%-31.0%], age-standardized prevalence 31.2% [95% CI, 30.1%-32.2%]; P < 0.001). The prevalence of thyroid nodules decreased from <18 to 25 years, while increased with age over 25 years old. The top three provinces with the highest prevalence of thyroid nodules were Jilin (47.6%), Liaoning (44.8%), and Shandong (43.9%), whereas Guizhou (23.9%), Chongqing (26.2%), and Shaanxi (26.4%) had the lowest prevalence. Females had more than 10% higher rates of thyroid nodules than males in all included provinces and regions, except for Tianjin (8.0%). Based on the geographical regions of China, the northeast had the highest prevalence (46.8% [95% CI, 44.1%-49.2%]), whereas northwest had the lowest prevalence (28.9% [95% CI, 26.9%-31.6%]. Based on multivariable logistic regression analysis, factors including age, gender, body mass index, systolic blood pressure, diastolic blood pressure, uric acid, fasting blood glucose, triglycerides, high-density lipoproteins, and low-density lipoproteins were significantly associated with the presence of thyroid nodules.

CONCLUSION

This study provides the first nationwide analysis of the prevalence of thyroid nodules in China. Our results showed that the prevalence of thyroid nodules was high in health screening Chinese people with regional-specific patterns.

Comprehensive guidance on the diagnosis and management of primary mesenchymal tumours of the thyroid gland

Most primary thyroid tumours are of epithelial origin. Primary thyroid mesenchymal tumours are rare but are being increasingly detected. A vast majority of thyroid mesenchymal tumours occur between the fourth and seventh decades of life, presenting as progressively enlarging thyroid nodules that often yield non-diagnostic results or spindle cells on fine needle aspiration biopsy. Surgery is the preferred mode of treatment, with adjuvant chemoradiotherapy used for malignant thyroid mesenchymal tumours. Benign thyroid mesenchymal tumours have excellent prognosis, whereas the outcome of malignant thyroid mesenchymal tumours is variable. Each thyroid mesenchymal tumour is characterised by its unique histopathology and immunohistochemistry. Because of the rarity and aggressive nature of malignant thyroid mesenchymal tumours, a multidisciplinary team-based approach should ideally be used in the management of these tumours. Comprehensive guidelines on the management of thyroid mesenchymal tumours are currently lacking. In this Review, we provide a detailed description of thyroid mesenchymal tumours, their clinical characteristics and tumour behaviour, and provide recommendations for the optimal management of these tumours.

On the possibility of using temperature to aid in thyroid nodule investigation

Thyroid nodules are common, and their investigation is very important to exclude the possibility of cancer. The increase in blood vessels of malignant tumours may be related to local temperature augmentation detectable on the skin surface. The objective of this paper is to evaluate the feasibility of Infrared Thermography for cancer identification. For this purpose, two studies were performed. One used numerical modelling to simulate regional metabolic temperature propagation to evaluate whether a nodule is perceptible on the skin surface. A second study considered thyroid nodule identification by using convolutional neural networks (CNNs). First, variations in nodular size and fat thickness were investigated, showing that the fat layer has an important role in regional heat transfer. In the second study, the training process achieved accuracy of 96% for in-sample and 95% for validation. In the testing phase, 92% accuracy, 100% precision and 80% recall were achieved. Thus, the presented studies suggest the feasibility of using Infrared Thermography with the CNN Artificial Intelligence technique as additional information in the investigation of thyroid nodules for patients without a very thick subcutaneous fat layer.

Development and validation of a Web-based malignancy risk-stratification system of thyroid nodules

OBJECTIVES

Previous publications on risk-stratification systems for malignant thyroid nodules were based on conventional ultrasound only. We aimed to develop a practical and simplified prediction model for categorizing the malignancy risk of thyroid nodules based on clinical data, biochemical data, conventional ultrasound and real-time elastography.

DESIGN

Retrospective cohort study.

PATIENTS

A total of 2818 patients (1890 female, mean age, 45.5 ± 13.2 years) with 2850 thyroid nodules were retrospectively evaluated between April 2011 and October 2016. 26.8% nodules were malignant.

MEASUREMENTS

We used a randomly divided sample of 80% of the nodules to perform a multivariate logistic regression analysis. Cut-points were determined to create a risk-stratification scoring system. Patients were classified as having low, moderate and high probability of malignancy according to their scores. We validated the models to the remaining 20% of the nodules. The area under the curve (AUC) was used to evaluate the discrimination ability of the systems.

RESULTS

Ten variables were selected as predictors of malignancy. The point-based scoring systems with and without elasticity score achieved similar AUCs of 0.916 (95% confidence interval [CI]: 0.885-0.948) and 0.906 (95% CI: 0.872-0.941) when validated. Malignancy risk was segmented from 0% to 100.0% and was positively associated with an increase in risk scores. We then developed a Web-based risk-stratification system of thyroid nodules (http: thynodscore.com).

CONCLUSION

A simple and reliable Web-based risk-stratification system could be practically used in stratifying the risk of malignancy in thyroid nodules.

Long-term efficacy evaluation of a protocol for the management of symptomatic thyroid cysts with ultrasound-guided percutaneous ethanol injection

AIM

To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.

PATIENTS AND METHODS

100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.

RESULTS

Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.

CONCLUSIONS

PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.

Thermal Ablation of Benign Thyroid Nodules and Papillary Thyroid Microcarcinoma

Due to the increasing rates of physical examination and application of advanced ultrasound machines, incidences of benign thyroid nodules (BTNs) and papillary thyroid microcarcinoma (PTMC) were dramatically up-regulated in recent years. Thermal ablation (TA) has been widely used and regarded as a safe and effective method to eliminate or reduce BTNs and recurrent low-risk PTMC. However, conclusions using TA to treat primary PTMC are controversial. Recently, several long-term and prospective studies on TA treatment of BTNs and primary PTMC have been reported. Here, we review current literatures and progress on TA treatment of BTNs and PTMC and underline the way to get the best treatment outcomes, providing a comprehensive insight into the research progresses in this field.

Development and Internal Validation of a Predictive Model for Individual Cancer Risk Assessment for Thyroid Nodules

OBJECTIVE

The objective of this study was to develop and validate a predictive model for the assessment of the individual risk of malignancy of thyroid nodules based on clinical, ultrasound, and analytic variables.

METHODS

A retrospective case-control study was carried out with 542 patients whose thyroid nodules were analyzed at our endocrinology department between 2013 and 2018 while undergoing treatment for thyroidectomy. Starting with a multivariate logistic regression analysis, which included clinical, analytic, and ultrasound variables, a predictive model for thyroid cancer (TC) risk was devised. This was then subjected to a cross-validation process, using resampling techniques.

RESULTS

In the final model, the independent predictors of the risk of malignancy were: being male, age of the extremes, family history of TC, thyroid-stimulating hormone level >4.7 μU/L, presence of autoimmune thyroiditis, solid consistency, hypoechogenicity, irregular or microlobed borders, nodules that are taller than they are wide, microcalcifications, and suspicious adenopathy. With a cut-off point of 50% probability of thyroid cancer, the predictive model had an area under the receiver operating characteristic curve of 0.925 (95% confidence interval 0.898 to 0.952). Finally, using the 10-fold cross-validation method, the accuracy of the model was found to be 88.46%, with a kappa correlation coefficient of 0.62.

CONCLUSION

A predictive model for the individual risk of malignancy of thyroid nodules was developed and validated using clinical, analytic, and ultrasound variables. An online calculator was developed from this model to be used by clinicians to improve decision-making in patients with thyroid nodules.

The effect of implementing pre-surgical ultrasound-guided fine-needle aspiration biopsy on thyroid surgery, a 6-year interrupted time series analysis in Qilu Hospital of Shandong University

Background

Thyroid fine-needle aspiration biopsy (FNAB) is not well developed in most of the large academic hospitals in China, including Qilu Hospital of Shandong University. Ultrasound-guided FNAB (UG-FNAB) was initiated as a pre-surgical diagnostic method in 2015 in Qilu Hospital, and the current study evaluates its impact on the number of thyroid surgeries and the ratio of malignancy (ROM) in surgically resected cases, comparing the post and pre-UG-FNAB periods.

Methods

Thyroid surgery and UG-FNAB data for the study period (Jan 2013 to Dec 2018) were collected from the hospital information system (HIS). A natural experimental approach using segmented linear regression was performed on the interrupted time-series (ITS) data to estimate the level-change of the number and the trend-change of ROM of surgically resected cases following the implementation of UG-FNAB diagnosis.

Results

The number of UG-FNAB cases in Qilu Hospital increased rapidly from 1,367 in 2015 to 3,402 in 2018, with an average annual increase of 678 cases. Comparing the pre-UG-FNAB and post-UG-FNAB periods, the overall ROM of thyroid resections increased from 58.7% to 73.2% (P<0.01). Due to the implementation of UG-FNAB, the regression line of surgical cases showed an inflection point in March 2015, and the slope of the regression line of post-intervention was lower than that of pre-intervention. For each additional month, the ROM in thyroid surgical cases increased by 0.389% (P<0.01). After excluding the influence of time, the ROM in surgically resected thyroid cases increased by 4.781% due to the application of the UG-FNAB examination (P<0.01).

Conclusions

This successful implementation of UG-FNAB further improved overall ROMs in surgically resected cases particularly as we acquired further experience with the procedure and reduced unnecessary diagnostic surgeries for patients with benign and borderline lesions.

Genetic alterations in cfDNA of benign and malignant thyroid nodules based on amplicon-based next-generation sequencing

Background

Circulating cell-free DNA (cfDNA) serves as a biomarker in multiple malignant diseases. However, controversy still surrounds the role of cfDNA detection in the diagnosis and monitoring of papillary thyroid carcinoma (PTC). This study set out to identify the role of cfDNA detection in distinguishing between benign and malignant thyroid nodules.

Methods

Tissue, blood cell, and plasma samples were collected from 10 patients with benign nodules and 10 patients with malignant nodules. The DNA isolated from these samples was subject to PCR-based amplification using primers designed for 50 proto-oncogenes and tumor suppressor genes. PCR products were sequenced using Illumina technology, and the mutations were detected with varScan among sequencing data for each sample and comparative analysis was carried out.

Results

Through amplicon sequencing, we found one non-synonymous somatic mutation in the benign nodules and three in the malignant nodules. Among these four mutations, BRAF^V600E mutation was detected in the tissue samples of 8 out of the 10 PTC patients, but it was not detected in the benign nodules. However, no BRAF^V600E mutation was detected in cfDNA. Further differential analysis of cfDNA indicated that some genes had more mutations in benign patients than in malignant patients, such as MET and IDH, and some genes had more mutations in malignant patients, such as PIK3CA and EZH2.

Conclusions

We found that BRAF^V600E mutation was a credible disease-related mutation in PTC; however, it could not be detected in cfDNA. Moreover, there was a large difference in mutation gene distribution between benign and malignant thyroid nodules.

A Clinical Assessment of an Ultrasound Computer-Aided Diagnosis System in Differentiating Thyroid Nodules With Radiologists of Different Diagnostic Experience

Introduction

This study aimed to assess the diagnostic performance and the added value to radiologists of different levels of a computer-aided diagnosis (CAD) system for the detection of thyroid cancers.

Methods

303 patients who underwent thyroidectomy from October 2018 to July 2019 were retrospectively reviewed. The diagnostic performance of the senior radiologist, the junior radiologist, and the CAD system were compared. The added value of the CAD system was assessed and subgroup analyses were performed according to the size of thyroid nodules.

Results

In total, 186 malignant thyroid nodules, and 179 benign thyroid nodules were included; 168 were papillary thyroid carcinoma (PTC), 7 were medullary thyroid carcinoma (MTC), 11 were follicular carcinoma (FTC), 127 were follicular adenoma (FA) and 52 were nodular goiters. The CAD system showed a comparable specificity as the senior radiologist (86.0% vs. 86.0%, p > 0.99), but a lower sensitivity and a lower area under the receiver operating characteristic (AUROC) curve (sensitivity: 71.5% vs. 95.2%, p < 0.001; AUROC: 0.788 vs. 0.906, p < 0.001). The CAD system improved the diagnostic sensitivities of both the senior and the junior radiologists (97.8% vs. 95.2%, p = 0.063; 88.2% vs. 75.3%, p < 0.001).

Conclusion

The use of the CAD system using artificial intelligence is a potential tool to distinguish malignant thyroid nodules and is preferable to serve as a second opinion for less experienced radiologists to improve their diagnosis performance.

DNA FISH Diagnostic Assay on Cytological Samples of Thyroid Follicular Neoplasms

Simple Summary

Cytopathology cannot distinguish benign from malignant follicular lesions in 20–30% of cases. These indeterminate cases includes the so-called follicular neoplasms (FNs) according to The Bethesda System for Reporting Thyroid Cytopathology. Frozen samples from 66 classic follicular adenomas (cFAs) and carcinomas (cFTCs) studied by array-comparative genomic hybridization identified three specific alterations of cFTCs (losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X) confirmed by fluorescent in situ hybridization (FISH) in a second independent series of 60 touch preparations from frozen samples of cFAs and cFTCs. In a third independent set of 27 cases of already stained pre-operative fine-needle aspiration cytology samples diagnosed as FNs and histologically verified, FISH analysis using these three markers identified half of cFTCs. Specificity of our assay for identifying cFTCs is higher than 98% which might be comparable with BRAF^600E testing in cases of suspicion of classic papillary thyroid carcinomas.

Abstract

Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

A Survey of Deep-Learning Applications in Ultrasound: Artificial Intelligence-Powered Ultrasound for Improving Clinical Workflow

Ultrasound is the most commonly used imaging modality in clinical practice because it is a nonionizing, low-cost, and portable point-of-care imaging tool that provides real-time images. Artificial intelligence (AI)-powered ultrasound is becoming more mature and getting closer to routine clinical applications in recent times because of an increased need for efficient and objective acquisition and evaluation of ultrasound images. Because ultrasound images involve operator-, patient-, and scanner-dependent variations, the adaptation of classical machine learning methods to clinical applications becomes challenging. With their self-learning ability, deep-learning (DL) methods are able to harness exponentially growing graphics processing unit computing power to identify abstract and complex imaging features. This has given rise to tremendous opportunities such as providing robust and generalizable AI models for improving image acquisition, real-time assessment of image quality, objective diagnosis and detection of diseases, and optimizing ultrasound clinical workflow. In this report, the authors review current DL approaches and research directions in rapidly advancing ultrasound technology and present their outlook on future directions and trends for DL techniques to further improve diagnosis, reduce health care cost, and optimize ultrasound clinical workflow.

Influence of Care Pathway on Thyroid Nodule Surgery Relevance: A Historical Cohort Study

Background: Guidelines recommend using fine-needle aspiration cytology (FNAC) to guide thyroid nodule surgical indication. However, the extent to which these guidelines are followed remains unclear. This study aimed to analyze the quality of the preoperative care pathway and to evaluate whether compliance with the recommended care pathway influenced the relevance of surgical indications. Methods: Nationwide historical cohort study based on data from a sample (1/97th) of French health insurance beneficiaries. Evaluation of the care pathway of adult patients operated on between 2012 and 2015 during the year preceding thyroid nodule surgery. The pathway containing only FNAC was called “FNAC”, the pathway including an endocrinology consultation (ENDO) with FNAC was called “FNAC+ENDO”, whereas the no FNAC pathway was called “NO FNAC”. The main outcome was the malignant nature of the nodule. Results: Among the 1080 patients included in the study, “FNAC+ENDO” was found in 197 (18.2%), “FNAC” in 207 (19.2%), and “NO FNAC” in 676 (62.6%) patients. Cancer diagnosis was recorded in 72 (36.5%) “FNAC+ENDO” patients and 66 (31.9%) “FNAC” patients, against 119 (17.6%) “NO FNAC” patients. As compared to “NO FNAC”, the “FNAC+ENDO” care pathway was associated with thyroid cancer diagnosis (OR 2.67, 1.88–3.81), as was “FNAC” (OR 2.09, 1.46–2.98). Surgeries performed in university hospitals were also associated with thyroid cancer diagnosis (OR 1.61, 1.19–2.17). Increasing the year for surgery was associated with optimal care pathway (2015 vs. 2012, OR 1.52, 1.06–2.18). Conclusions: The recommended care pathway was associated with more relevant surgical indications. While clinical guidelines were insufficiently followed, compliance improved over the years.