Ultrasonographic Differentiation Between Nodular Hyperplasia and Neoplastic Follicular-Patterned Lesions of the Thyroid Gland

A bibliometric analysis of follicular thyroid carcinoma: Current situation, hot spots, and global trends

BACKGROUND

Follicular thyroid carcinoma (FTC), the second most prevalent thyroid cancer after papillary thyroid cancer (PTC), tends to metastasize distantly, leading to poorer outcomes. Despite substantial research, a holistic bibliometric analysis of FTC literature is lacking. This study aims to fill this gap by employing bibliometric methods to track FTC research evolution.

METHODS

English FTC publications were systematically gathered from the Web of Science. Bibliometric analysis, using R, VOSviewer, CiteSpace, and Excel, synthesized data and explored global research trends and topics.

RESULTS

From 2000 to 2023, 9086 authors from 1953 institutions across 75 countries contributed to 1776 papers in 491 academic journals on FTC. The last two decades have witnessed a steady increase in publications related to FTC, with the United States leading in terms of publication volume. The United States dominated both in publications and citations, with the National Cancer Institute and Sheue-Yann Cheng as leading contributors. The journal 'Thyroid' featured the most publications, while the 'Journal of Clinical Endocrinology and Metabolism' ranked highest in citation frequency. Research focused on gene expression analysis and preoperative diagnostics, with recent trends shifting toward prognosis management and machine learning due to advances in medical technology and increased health awareness.

CONCLUSION

This comprehensive bibliometric analysis has mapped the landscape of FTC research, highlighting key contributors, institutions, and thematic trends. Current discourse predominantly revolves around genetic analysis, prognostic determinants, and preoperative diagnostics in FTC. This foundational work guides future FTC research, providing insights into its evolution.

Ultrasound characteristics of follicular and parafollicular thyroid neoplasms: diagnostic performance of artificial neural network

BACKGROUND

Ultrasound is the first-line imaging modality for detection and classification of thyroid nodules. Certain features observable by ultrasound have recently been equated with potential malignancy. This retrospective cohort study was conducted to test the hypothesis that radiomics of the four categorical divisions (medullary [MTC], papillary [PTC], or follicular [FTC] carcinoma and follicular thyroid adenoma [FTA]) demonstrate distinctive sonographic characteristics. Using an artificial neural network model for proof of concept, these sonographic features served as input.

METHODS

A total of 148 patients were enrolled for study, all with confirmed thyroid pathology in one of the four named categories. Preoperative ultrasound profiles were obtained via standardized protocols. The neural network consisted of seven input neurons; three hidden layers with 50, 250, and 100 neurons, respectively; and one output layer.

RESULTS

Radiomics of contour, structure, and calcifications differed significantly according to nodule type (p = 0.025, p = 0.032, and p = 0.0002, respectively). Levels of accuracy shown by artificial neural network analysis in discriminating among categories ranged from 0.59 to 0.98 (95% confidence interval [CI]: 0.57-0.99), with positive and negative predictive ranges of 0.41-0.99 and 0.78-0.97, respectively.

CONCLUSIONS

Our data indicate that some MTCs, PTCs, FTCs, and FTAs have distinctive sonographic characteristics. However, a significant overlap of these characteristics may impede an explicit classification. Further prospective investigations involving larger patient and nodule numbers and multicenter access should be pursued to determine if neural networks of this sort are beneficial, helping to classify neoplasms of the thyroid gland.

A beneficial role of computer-aided diagnosis system for less experienced physicians in the diagnosis of thyroid nodule on ultrasound

Ultrasonography (US) is the primary diagnostic tool for thyroid nodules, while the accuracy is operator-dependent. It is widely used not only by radiologists but also by physicians with different levels of experience. The aim of this study was to investigate whether US with computer-aided diagnosis (CAD) has assisting roles to physicians in the diagnosis of thyroid nodules. 451 thyroid nodules evaluated by fine-needle aspiration cytology following surgery were included. 300 (66.5%) of them were diagnosed as malignancy. Physicians with US experience less than 1 year (inexperienced, n = 10), or more than 5 years (experienced, n = 3) reviewed the US images of thyroid nodules with or without CAD assistance. The diagnostic performance of CAD was comparable to that of the experienced group, and better than those of the inexperienced group. The AUC of the CAD for conventional PTC was higher than that for FTC and follicular variant PTC (0.925 vs. 0.499), independent of tumor size. CAD assistance significantly improved diagnostic performance in the inexperienced group, but not in the experienced groups. In conclusion, the CAD system showed good performance in the diagnosis of conventional PTC. CAD assistance improved the diagnostic performance of less experienced physicians in US, especially in diagnosis of conventional PTC.

EU-TIRADS-Based Omission of Fine-Needle Aspiration and Cytology from Thyroid Nodules Overlooks a Substantial Number of Follicular Thyroid Cancers

BACKGROUND

The classification of nodules by Thyroid Imaging Reporting and Data Systems (TIRADS) is important in guiding management. Whether sensitivity in identifying thyroid cancers varies with thyroid cancer phenotype remains unclarified.

METHODS

The ultrasound (US) characteristics of nodules of 26,908 nodular goiter patients were recorded. Fine-needle aspiration cytology (FNA) was performed in all nodules >1 cm irrespective of US findings (n = 25,025) and in nodules between 5 mm and 10 mm with suspicious US characteristics (n = 1,883). Of the 3281 operated cases, 221, 30, and 23 were papillary (PTC), follicular (FTC), and medullary (MTC) cancers, respectively. The US-based indication of FNA, as defined by EU-TIRADS scores, combined with lesion size, was calculated. This study design is unique in avoiding the common selection bias when TIRADS' sensitivity is tested in a cohort selected for FNA and surgery based on the same US characteristics on which TIRADS is based.

RESULTS

The EU-TIRADS score influences decision of FNA in the 10-20 mm range. In such nodules (n = 118), the number of suspicious features (marked hypoechogenicity, microcalcifications, irregular shape, and irregular border) per lesion was lower in FTC (0.7 ± 0.6) than in PTC (1.7 ± 1.0) or MTC (1.8 ± 0.7; p < 0.02), resulting in EU-TIRADS scores of 4.1 ± 0.6, 4.8 ± 0.3, and 4.9 ± 0.2, respectively (p < 0.01). The EU-TIRADS-based FNA indication rate was lower in FTC (55.5%) compared to PTC (85.0%) and MTC (88.9%) (p=0.02).

CONCLUSIONS

EU-TIRADS-defined suspicious US features are less common in FTC than in PTC and MTC. Therefore, a substantial number of FTCs in the 10-20 mm range escape surgery.

Ultrasound malignancy risk stratification of thyroid nodules based on the degree of hypoechogenicity and echotexture

OBJECTIVES

The ultrasound (US) lexicon of nodule echogenicity and echotexture is one of the major differences among various risk stratification systems of thyroid nodules. This study aimed to stratify the US malignancy risk of thyroid nodules based on their degree of hypoechogenicity and echotexture.

MATERIAL AND METHODS

This retrospective study included a total of 2255 consecutive thyroid nodules (≥ 1 cm) with final diagnoses (malignancy rate, 13%) from 2011 to 2016. Thyroid nodules were stratified according to the US degree of hypoechogenicity (mild, moderate, or marked hypoechogenicity) and echotexture (homogeneous vs. heterogeneous). The calculated malignancy risk was compared between each category.

RESULTS

There was no significant difference of malignancy risk between the homogeneous markedly hypoechoic and moderately hypoechoic nodules (p ≥ .18). However, the malignancy risks of markedly and moderately hypoechoic nodules were significantly higher than those of mildly hypoechoic nodules (p < .001). Heterogeneous predominantly hypoechoic thyroid nodules showed a significantly higher malignancy risk than predominantly iso- or hyperechoic thyroid nodules (p < .001). There were no significant differences of malignancy risk between heterogeneous predominantly hypoechoic and homogeneous hypoechoic nodules according to the degree of hypoechogenicity (p ≥ .12) and between heterogeneous predominantly iso- or hyperechoic nodules and homogeneous iso- or hyperechoic thyroid nodules (p = .36).

CONCLUSIONS

The malignancy risk of nodule hypoechogenicity is stratified as mild vs. moderate to marked hypoechogenicity, and the malignancy risk of nodules with heterogeneous echotexture is stratified by the predominant echogenicity of the nodules.

KEY POINTS

• Thyroid nodule echogenicity is categorized as marked, moderate, or mild hypoechogenicity and iso- or hyperechogenicity with the reference standard of adjacent thyroid tissue and anterior neck muscles. • The malignancy risk of thyroid nodule echogenicity is stratified as iso- or hyperechoic vs. mild vs. moderate or marked hypoechogenicity. • The malignancy risk of nodules with heterogeneous echotexture is stratified by the predominant echogenicity.

2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Prevention of total thyroidectomy in noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) based on combined interpretation of ultrasonographic and cytopathologic results

OBJECTIVE

To explore the potential preoperative ultrasonography (US) and cytopathological features to avoid total thyroidectomy in NIFTP.

CONTEXT

Recently, it has been proposed that that noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) be classified as tumours, rather than cancer.

PATIENTS

A total of 142 surgically proven follicular variant papillary thyroid carcinomas (FVPTCs; 45 NIFTP, 97 non-NIFTP; mean size: 20.4±11.0 mm, range: 10.0-65.0 mm) from 142 patients were included in this study.

MEASUREMENTS

Three preoperative features of thyroid nodules (each US finding, US and Bethesda category) were compared in NIFTP and non-NIFTP groups. The preoperative decision-making process to avoid total thyroidectomy in NIFTP was evaluated based on combination of those features.

RESULTS

In each US finding, there was only significantly less macrocalcification in the NIFTP group than in the non-NIFTP group (8.8% [4/45] vs 32.0% [31/97], P = .006). In US category, all of the NIFTP nodules were a low or intermediate suspicion (100% [45/45]). In Bethesda category, 26.7% [12/45] of the NIFTP was diagnosed as either suspicious malignancy or malignant, which increased the risk of a total thyroidectomy. In our study, a total thyroidectomy might be avoided in all of the NIFTP cases if lobectomy was selected for the nodules classified as a low or intermediate suspicion in US, despite being classified as a suspicious malignancy or malignant by cytopathology.

CONCLUSIONS

Combining the US and cytopathological results could sensitively reduce total thyroidectomy in cases of NIFTP.

Korean Thyroid Imaging Reporting and Data System features of follicular thyroid adenoma and carcinoma: a single-center study

PURPOSE

This study aimed to assess the diagnostic efficacy of Korean Thyroid Imaging Reporting and Data System (K-TIRADS) features for distinguishing follicular thyroid adenoma (FTA) from follicular thyroid carcinoma (FTC).

METHODS

From January 2013 to July 2016, 46 follicular neoplasms in 45 patients who underwent preoperative thyroid ultrasonography (US) and thyroid surgery were included. The US features of each thyroid nodule were retrospectively evaluated by a single radiologist using a picture archiving and communication system. The diagnostic indices of K-TIRADS for follicular neoplasms were calculated according to whether K-TIRADS category 4 lesions were excluded or classified as benign or malignant.

RESULTS

Of the 46 follicular neoplasms (mean size, 3.1±1.6 cm), 37 were FTAs (mean size, 3.1±1.7 cm) and nine were FTCs (mean size, 3.0±1.5 cm). A statistically significant difference was found between FTAs and FTCs regarding the margin (P=0.035), while no significant differences were observed in the composition, echogenicity, shape, orientation, calcification, or vascularity of the lesions (P<0.05). The FTAs belonged to K-TIRADS categories 3 (n=22) and 4 (n=15), while the FTCs belonged to K-TIRADS categories 3 (n=4), 4 (n=4), and 5 (n=1). However, there was no statistically significant difference in the distribution of K-TIRADS categories between FTAs and FTCs (P=0.184).

CONCLUSION

K-TIRADS features were not helpful for distinguishing FTA from FTC, although follicular neoplasms showed a high prevalence of K-TIRADS categories 3 and 4.