British Thyroid Association 2014 classification ultrasound scoring of thyroid nodules in predicting malignancy: Diagnostic performance and inter-observer agreement

Evaluation of the departmental inter-rater reliability when scoring thyroid nodules according to the British Thyroid Association Ultrasound-classification model: Is there significant disagreement?

Introduction

The British Thyroid Association Ultrasound-classification is a risk stratification model which grades thyroid nodules in U2-5 based on their sonographic appearance. Existence of variability between the ultrasound operators when U-scoring is reported in the literature with some evidence found in the author's department. The aim of this study was to investigate whether there is significant disagreement in the department and identify potential reasons for variability.

Methods

Eight operators, radiologists and sonographers, were recruited to grade 33 TNs and answer a tick box questionnaire using the British Thyroid Association lexicon. The inter-operator variability for the U-categories, indication for fine-needle aspiration biopsy and ultrasound features was assessed using Fleiss' kappa and Gwet-AC1. The operators' accuracy was measured against the most experienced operator in the department using Cohen's kappa and percentage agreement.

Results

Fair agreement (Fleiss' K = 0.21) was obtained between the participants when U-scoring (U2-5). Fair-to-moderate agreement was noted between sonographers (K = 0.40). Significant variability was demonstrated between radiologists (p > 0.05). Indication for fine-needle aspiration biopsy reached fair to almost substantial agreement (radiologists' AC1 = 0.34, sonographers' AC1 = 0.58, overall AC1 = 0.41). No significant variability measured for echogenicity (K = 0.29), composition (K = 0.33), shape (K = 0.58), margin (K = 0.45), halo (K = 0.34) and vascularity (K = 0.44). Accuracy reached fair agreement (mean Cohen's K = 0.29) and moderate agreement (mean AC1 = 0.53) for the U-categories and fine-needle aspiration biopsy, respectively. Radiologists demonstrated lower accuracy.

Conclusion

No significant inter-rater variability in U-scoring or recommending fine-needle aspiration biopsy was demonstrated between all the operators in the department. Radiologists showed significant variability in U-scoring and lower accuracy. Reliability and accuracy could be improved by addressing those problematic categories and features identified with this study.

Diagnostic Accuracy of Ultrasound and Fine-Needle Aspiration Cytology in Thyroid Malignancy

Introduction: Thyroid nodule incidence is increasing due to the widespread application of ultrasonography. Fine-needle aspiration cytology is widely applied for the detection of malignancies. The aim of this study was to evaluate the predictive value of ultrasonography in thyroid cancer. Methods: This retrospective study included patients that underwent total thyroidectomy for benign thyroid disease or well-differentiated thyroid carcinoma from January 2017 to December 2022. The study population was divided into groups: the well-differentiated thyroid cancer group and the control group with benign histopathological reports. Results: In total, 192 patients were enrolled in our study; 159 patients were included in the well-differentiated thyroid cancer group and 33 patients in the control group. Statistical analysis demonstrated that ultrasonographic findings such as microcalcifications (90.4%), hypoechogenicity (89.3%), irregular margins (92.2%) and taller-than-wide shape (90.5%) were correlated to malignancy (p < 0.001). Uni- and multivariate analysis revealed that both US score (OR: 2.177; p < 0.001) and Bethesda System (OR: 1.875; p = 0.002) could predict malignancies. In terms of diagnostic accuracy, the US score displayed higher sensitivity (64.2% vs. 33.3%) and better negative predictive value (34.5% vs. 24.4%) than the Bethesda score, while both scoring systems displayed comparable specificities (90.9% vs. 100%) and positive predictive values (97.1% vs. 100%). Discussion: The malignant potential of thyroid nodules is a crucial subject, leading the decision for surgery. Ultrasonography and fine-needle aspiration cytology are pivotal examinations in the diagnostic process, with ultrasonography demonstrating better negative predictive value.

Can we better advise our patients with nodular thyroid disease?

BACKGROUND

The 2014 British Thyroid Association guidelines acknowledged the value of risk-stratifying thyroid nodules by utilising an ultrasound reporting system ('U' classification). This study assessed whether using pre-existing parameters in combination can better stratify patients' malignancy and completion thyroidectomy risks.

METHOD

A multicentre, retrospective, observational review identified 936 NHS Greater Glasgow and Clyde patients from pathology records who underwent hemithyroidectomy between 1 January 2014 and 31 December 2019.

RESULTS

A total of 308 patients had thyroid malignancy, 180 (58.4 per cent) progressed to completion thyroidectomy. A nodule classified as 'U3' (indeterminate) was associated with a 35.4 per cent chance of malignancy and a 21.6 per cent risk of requiring completion surgery. Amalgamation of 'U' score with Thy score enhanced risk prediction. The malignancy rate in U3, Thy-3f nodules was 38 per cent, and 21 per cent required completion surgery. The malignancy and completion thyroidectomy rates were comparatively lower for U3, Thy-3a nodules (22 per cent and 14.3 per cent, respectively).

CONCLUSION

Combining ultrasound 'U' score and Thy score improves pre-operative thyroid nodule risk stratification, leading to better informed patients regarding the risks of malignancy and completion surgery. A move towards an integrated assessment approach should be considered.

Risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma: A clinical study

Currently, there is a lack of evidence-based risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma (PTC). Thus, the risk factors and recurrence rate of lateral cervical lymph node metastasis were investigated in the present study for patients with PTC who underwent initial radical surgery. The data of 274 patients with PTC who underwent initial radical surgery over a 10-year period from January, 2009 to December, 2018 were retrospectively analyzed. By applying univariate analysis, lymphovascular invasion, venous invasion, extrathyroidal infiltration, paratracheal lymph node metastasis and tumor size were designated as significant risk factors for lateral cervical lymph node metastasis. As regards multivariate analysis, paratracheal lymph node metastasis and tumor size were identified as independent risk factors. The recurrence rate was higher in patients presenting with lateral cervical lymph node metastasis, and the disease-free survival rate was significantly lower in the patient group presenting with lateral cervical lymph node metastasis. On the whole, the present study demonstrated that paratracheal lymph node metastasis and tumor size were independent risk factors for lateral cervical lymph node metastasis.

Inter-Rater Reliability of Thyroid Ultrasound Risk Criteria: A Systematic Review and Meta-Analysis

OBJECTIVE

The most commonly employed diagnostic criteria for identifying thyroid nodules include Thyroid Imaging and Reporting Data System (TI-RADS) and American Thyroid Association (ATA) guidelines. The purpose of this systematic review and meta-analysis is to determine the inter-rater reliability of thyroid ultrasound criteria.

METHODS

We performed a library search of MEDLINE (Ovid), EMBASE (Ovid), and Web of Science for full-text articles published from January 2005 to June 2022. We included full-text primary research articles that used TI-RADS and/or ATA guidelines to evaluate thyroid nodules in adults. These included studies must have calculated inter-rater reliability using any validated metric. The Quality Appraisal for Reliability Studies (QAREL) was used to assess study quality. We planned for a random-effects meta-analysis, in addition to covariate and publication bias analyses. This study was performed in accordance with Preferred Reporting Items for a Systematic Review and Meta-analysis guidelines and registered prior to conduction (International prospective register of systematic reviews-PROSPERO: CRD42021275072).

RESULTS

Of the 951 articles identified via the database search, 35 met eligibility criteria. All studies were observational. The most commonly utilized criteria were ACR Thyroid Imaging and Reporting Data System (TI-RADS) and/or ATA criteria, while the majority of studies employed Κ statistics. For ACR TI-RADS, the pooled Κ was 0.51 (95% confidence interval [CI]: 0.42, 0.57; n = 7) while for ATA, the pooled Κ was 0.52 (95% CI: 0.37, 0.67; n = 3). Due to the small number of studies, covariate or publication bias analyses were not performed.

CONCLUSION

Ultrasound criteria demonstrate moderate inter-rater reliability, but these findings are impacted by poor study quality and a lack of standardization. Laryngoscope, 133:485-493, 2023.

Risk of malignancy in thyroid nodules with indeterminate (THY3f) cytology

BACKGROUND

Fine-needle aspiration cytology (FNAC) is an integral part of thyroid nodule assessment. Nodules with an indeterminate cytology (THY3a-f) require formal histological assessment to confirm benign or malignant pathology. This study aimed to provide data for an evidence-based approach for management of patients with THY3f nodules.

METHODS

Retrospective review of patients who had a thyroid FNAC reported as suspicious of follicular neoplasm (THY3f) or showing atypia (THY3a) were identified, and clinical, operative and outcomes data were analysed.

RESULTS

Between 2018 and 2020, 200 patients (167F:33M, median age 51 years (range:18-86 years)) had a THY3f cytology. Most presented with a palpable nodule (n=104; 68.4%). Overall, 152 (76.0%;130F:23M) underwent surgery and 31 (20.4%) were found to have a thyroid carcinoma (22 follicular carcinomas, 7 papillary carcinomas, 1 medullary thyroid carcinoma and 1 metastatic renal carcinoma). An additional incidental carcinoma (size: 0.7-13mm) was found in seven (4.6%). Among those with cancer, a completion thyroidectomy and radioactive iodine treatment was indicated in nine (<6% of the entire cohort). Previously suggested risk factors for malignancy, eg male gender, large tumour size (>4cm) or age, were not found to be associated with increased risk. During the same period, THY3a cytology was reported in 53 patients, of whom 29 underwent diagnostic surgery and 4 patients were found to have a thyroid cancer (follicular, n=3 and medullary, n=1).

CONCLUSION

One in five patients with features suspicious of a follicular neoplasm (THY3f) has a thyroid carcinoma. This risk is much lower for THY3a. This study reinforces the current recommendation for thyroid surgery in all patients with a reliable THY3f cytology, as no further stratifying risk factors could be identified.

Head and Neck Ultrasound - EFSUMB Training Recommendations for the Practice of Medical Ultrasound in Europe

Different surgical and medical specialists increasingly use head and neck ultrasound and ultrasound-guided interventions as part of their clinical practice. We need to ensure high quality and standardized practice across specialties, and this position paper of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) describes the training requirements for head and neck ultrasound. Traditionally, a minimum number of ultrasound examinations indicates competence, but this is unreliable, and a general shift towards competence-based training is ongoing. For each EFSUMB level, we will outline the theoretical knowledge and skills needed for clinical practice. The recommendations follow the three EFSUMB competency levels for medical ultrasound practice. Level 1 describes the skills required to perform essential head and neck ultrasound examinations independently, level 2 includes ultrasound-guided interventions, while level 3 involves the practice of high-level neck ultrasound and use of advanced technologies. Our goal is to ensure high quality and standardized head and neck ultrasound practice performed by different clinical specialists with these recommendations.

Ultrasound for the assessment of thyroid nodules: an overview for non-radiologists

Upon discovery of a thyroid nodule (or nodules), a patient is usually referred for evaluation by ultrasound, which is typically performed by a trained radiologist or sonographer. More recently, this technology has been used intraoperatively by endocrine surgeons and also by endocrinologists, often in the context of ‘one-stop shops’ or point of care ultrasound in the outpatient setting. Although thyroid nodules are common and most will be benign, the subsequent work up of these can cause anxiety for patients and place a burden on radiologists. In the UK, sonographic features of benign, suspicious or malignant nodules are classified by the British Thyroid Association U1–U5 criteria, which decide whether to biopsy the nodule (typically U3 and above). This article provides an overview of ultrasound in assessing the thyroid nodule in the context of this classification. This can be used as a guide to interpretation of thyroid ultrasonography for non-radiologists.

Suspected Malignant Thyroid Nodules in Children and Adolescents According to Ultrasound Elastography and Ultrasound-Based Risk Stratification Systems-Experience from One Center

The risk of malignancy in thyroid nodules correlates with the presence of ultrasonographic features. In adults, ultrasound risk-classification systems have been proposed to indicate the need for further invasive diagnosis. Furthermore, elastography has been shown to support differential diagnosis of thyroid nodules. The purpose of our study was to assess the application of the American Thyroid Association (ATA), British Thyroid Association (BTA) ultrasound risk-classification systems and strain elastography in the management of thyroid nodules in children and adolescents from one center. Seventeen nodules with Bethesda III, IV, V and VI were selected from 165 focal lesions in children. All patients underwent ultrasonography and elastography followed by fine needle aspiration biopsy. Ultrasonographic features according to the ATA and BTA stratification systems were assessed retrospectively. The strain ratio in the group of thyroid nodules diagnosed as malignant was significantly higher than in benign nodules (6.07 vs. 3.09, p = 0.036). According to the ATA guidelines, 100% of malignant nodules were classified as high suspicion and 73% of benign nodules were assessed as low suspicion. Using the BTA U-score classification, 80% of malignant nodules were classified as cancerous (U5) and 20% as suspicious for malignancy (U4). Among benign nodules, 82% were classified as indeterminate or equivocal (U3) and 9% as benign (U2). Our results suggest that application of the ATA or BTA stratification system and elastography may be a suitable method for assessing the level of suspected malignancy in thyroid nodules in children and help make a clinical decision about the need for further invasive diagnosis of thyroid nodules in children.

Comparison of thyroid nodule FNA rates recommended by ACR TI-RADS, Kwak TI-RADS and ATA guidelines

OBJECTIVES

To compare the differences among the thyroid imaging reporting and data system (TI-RADS) proposed by American College of Radiology (ACR TI-RADS), TI-RADS proposed by Kwak (Kwak TI-RADS), and American Thyroid Association (ATA) guidelines in the specificity, sensitivity and the unnecessary FNA rate (the UFR, the false positive rate) of recommended fine needle aspiration (FNA), and to observe the changes of the UFR in the KwakTI-RADS and ATA guidelines with the recommended FNA nodule size threshold.

METHODS

The specificities, sensitivities and UFRs of recommended FNA in the ACR TI-RADS, ATA guidelines and Kwak TI-RADS were calculated and compared. The nodule sizes for recommended FNA of ATA guidelines and Kwak TI-RADS were systematically varied to establish new FNA thresholds. The specificities, sensitivities and UFRs of recommended FNA under the new models were calculated and compared to those in the ACR TI-RADS.

RESULTS

For all thyroid nodules, the UFRs in the ACR TI-RADS, ATA guidelines and Kwak TI-RADS were 26.3%, 47.4% and 40.0%, respectively. The UFR in the ACR TI-RADS was lower than that in the others, and the specificity of recommended FNA in the ACR TI-RADS(73.7%) was higher than that in the others (all P < 0.001), but the sensitivity of recommended FNA in the ACR TI-RADS(89.3%) was lower than that in the others (all P < 0.001). When nodule sizes threshold of the recommended FNA for ATA guidelines Intermediate Suspicion, Low Suspicion, and Very Low Suspicion, and Kwak TI-RADS grade 4b and 4a were gradually increased, the UFRs gradually decreased.

CONCLUSIONS

The UFRs of FNA recommended by the Kwak TI-RADS and ATA guidelines were higher than that of the ACR TI-RADS, and were affected by the recommended FNA nodule size threshold.

Prediction of central compartment nodal metastases in papillary thyroid cancer using TI-RADS score, blood flow, and multifocality

BACKGROUND

The relationship between the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the risk of lymph node metastases in papillary thyroid cancer (PTC) could improve the detection rate of lymph node metastases in thyroid cancer and provide a scientific basis for clinical diagnosis.

PURPOSE

To evaluate the risk of lymph node metastases of PTC associated with the score from ACR TI-RADS adjusted for other correlative factors.

MATERIAL AND METHODS

A total of 560 patients with pathologically confirmed PTC were included in the study and classified into a metastases group and a non-metastases group. Clinical and pathological manifestations of the patients were collected.

RESULTS

The median TI-RADS score was 13 (p₂₅-p₇₅ = 11-14) among the patients with lymph node metastases, higher than those without metastases 9 (8-10) (P < 0.001). Multiple logistic regression indicated that TI-RADS score (odds ratio [OR] = 2.204), male sex (OR = 2.376), multifocality (OR = 4.170), and rich blood flow (OR = 3.656) were risk factors for lymph node metastases in patients with thyroid carcinoma. Some related factors such as TI-RADS score, age(<45years old), male, multifocality and rich blood flow were related to lymph node metastases in the central area of the neck which could provide therapeutic strategy for further treatment.

CONCLUSION

it is not just the TI-RADS score but also multifocality, blood flow, and sex that influence the prediction of the risk of PTC central lymph node metastases.

Thyroid Cancer Risk Factors in Children with Thyroid Nodules: A One-Center Study

Thyroid nodules are common in the adult population (13%), but in childhood, they are relatively rarely diagnosed (0.2–5%). The risk factors and diagnostic and therapeutic algorithms are well-known and effectively used in adults, but no clear procedures supported by scientific research are available in the pediatric population. Our aim in this study was to identify predictive factors for thyroid cancer in a pediatric population. We retrospectively analyzed 112 children (80 girls and 32 boys, aged 0.6–18 years, with an average group age of 13.4 ± 4.5 years) with thyroid nodules who presented or were referred between 2010 and 2021. A total of 37 children qualified for partial or total thyroidectomy. After histopathological nodule examination, the most common cases were benign lesions in 23 patients (57.5%) and malignant lesions in 14 children (32.5%). Solitary benign thyroid nodules were found in 16 children (40%). Malignancy risk was higher in children with increased nodule diameter (greater than 7 mm; p = 0.018) or hypoechogenic lesions in ultrasound (p = 0.010), with no correlation between increased blood flow in the vessels and tumor diagnosis. The relative risk of developing thyroid cancer for class III was found to be higher in comparison to adults and 11.1 times higher than for classes I and II combined.

The New Era of TIRADSs to Stratify the Risk of Malignancy of Thyroid Nodules: Strengths, Weaknesses and Pitfalls

Simple Summary

The aim of this review is to provide the reader with a comprehensive overview of thyroid imaging and reporting data systems used for thyroid nodules, so as to understand how nodules are scored with all existing systems. Both ultrasound based risk stratification systems and indications for fine-needle aspirations are described. Systems are compared by analyzing their strengths and weaknesses. Studies show satisfactory sensitivities and specificities for the diagnosis of malignancy for all systems, and none of them have shown a real significant advantage over the others in terms of raw diagnostic value. Interobserver agreement is also very similar for all systems, fairly adequate to robust. Dimensional cut-offs for fine-needle aspiration are quite similar and all RSSs seem to reduce effectively the number of unnecessary FNAs. Merging all existing systems in a common international one is desirable.

Abstract

Since 2009, thyroid imaging reporting and data systems (TI-RADS) have been playing an increasing role in the field of thyroid nodules (TN) imaging. Their common aims are to provide sonologists of varied medical specialties and clinicians with an ultrasound (US) based malignancy risk stratification score and to guide decision making of fine-needle aspiration (FNA). Schematically, all TI-RADSs scores can be classified as either pattern-based or point-based approaches. The main strengths of these systems are their ability (i) to homogenize US TN descriptions among operators, (ii) to facilitate and shorten communication on the malignancy risk of TN between sonologists and clinicians, (iii) to provide quantitative ranges of malignancy risk assessment with high sensitivity and negative predictive values, and (iv) to reduce the number of unnecessary FNAs. Their weaknesses are (i) the remaining inter-observer discrepancies and (ii) their insufficient sensitivity for the diagnosis of follicular cancers and follicular variant of papillary cancers. Most common pitfalls are degenerating shrinking nodules and confusion between individual and coalescent nodules. The benefits of all TI-RADSs far outweigh their shortcomings, explaining their rising use, but the necessity to improve and merge the different existing systems remains.

Comparing ultrasound assessment of thyroid nodules using BTA U classification and ACR TIRADS measured against histopathological diagnosis

INTRODUCTION

The British Thyroid Association (BTA) recommends ultrasound assessment of thyroid nodules using the U classification. The American College of Radiologists (ACR) recommend assessment with the Thyroid Imaging Reporting and Data System (TIRADS). We conduct the first UK study to compare these two systems.

METHODS

Ultrasound (US) reports of patients who underwent surgical excision of thyroid nodules over a 10-year period in one UK centre were reviewed. US findings were collected, and the classifications were retrospectively applied. The systems were compared to histopathological diagnosis.

RESULTS

308 nodules in 296 patients are included. 135 nodules (43.8%) were malignant. U classification showed sensitivity of 88.1% in recommending FNA, significantly higher than TIRADS at 73.3% (p = .0002). The U classification showed specificity of 41.6%, significantly lower than TIRADS at 64.2% (p=<0.0001). PPV between classifications at equivalent levels showed no significant difference at U3/TR-3 (p=.81), U4/TR-4 (p=.30) or U5/TR-5 (p=.90).

DISCUSSION

Classification systems enable risk stratification of potentially malignant thyroid nodules. This study shows BTA U classification has a higher sensitivity but lower specificity than TIRADS.

Overview of the Ultrasound Classification Systems in the Field of Thyroid Cytology

The increasing application of ultrasound (US) in recent years has led to a greater number of thyroid nodule diagnoses. Consequently, the number of fine needle aspirations performed to evaluate these lesions has increased. Although the majority of thyroid nodules are benign, identifying methods to define specific lesions and tailor risk of malignancy has become vital. Some of the tools employed to stratify thyroid nodule risk include clinical factors, thyroid US findings, and reporting systems for thyroid cytopathology. Establishing high concordance between US features and cytologic diagnoses might help reduce healthcare costs by diminishing unnecessary thyroid procedures and treatment. This review aims to review radiology US classification systems that influence the practice of thyroid cytology.