Comparison between peak systolic velocity of the inferior thyroid artery and technetium-99m pertechnetate thyroid uptake in differentiating Graves' disease from thyroiditis

Artificial intelligence-based CT-free quantitative thyroid SPECT for thyrotoxicosis: study protocol of a multicentre, prospective, non-inferiority study

INTRODUCTION

Technetium thyroid uptake (TcTU) measured by single-photon emission CT/CT (SPECT/CT) is an important diagnostic tool for the differential diagnosis of Graves' disease and destructive thyroiditis. Artificial intelligence (AI) may reduce CT-induced radiation exposure by substituting the role of CT in attenuation correction (AC) and thyroid segmentation, thus realising CT-free SPECT. This study aims to compare the diagnostic accuracy for the differential diagnosis of thyrotoxicosis between CT-free SPECT and SPECT/CT.

METHODS AND ANALYSIS

The AI-based CT-free SPECT is a single-blind, multicentre, prospective, non-inferiority, clinical trial with a paired design conducted in the Republic of Korea. Eligible participants are adult (≥19 years old) thyrotoxicosis patients without a previous history of hyperthyroidism or hypothyroidism. Approximately 160 subjects will be screened for quantitative thyroid SPECT/CT using Tc-99m pertechnetate. CT-free thyroid SPECT will be realised using only SPECT data by the trained convolutional neural networks. TcTU will be calculated by SPECT/CT and CT-free SPECT in each subject. The primary endpoint is the accuracy of diagnosing Graves' disease using TcTU. The trial will continue until 152 completed datasets have been enrolled to assess whether the 95% (two-sided) lower confidence limit of the accuracy difference (CT-free SPECT accuracy-SPECT/CT accuracy) for Graves' disease is greater than -0.1. The secondary endpoints include the accuracy of diagnosing destructive thyroiditis and predicting the need for antithyroid drug prescription within 1 month of the SPECT/CT.

ETHICS AND DISSEMINATION

The study protocol has been approved by the institutional review board of Seoul National University Bundang Hospital (IRB No. B-2304-824-301), Konkuk University Medical Center (IRB No. 2023-05-022-006) and Chonnam National University Hospital (IRB No. CNUH-2023-108). Findings will be disseminated as reports, presentations and peer-reviewed journal articles.

TRIAL REGISTRATION NUMBER

KCT0008387, Clinical Research Information Service of the Republic of Korea (CRIS).

A meta-analysis: elucidating diagnostic thresholds of peak systolic flow velocities in thyroid arteries for the discrimination of Graves' disease and destructive thyrotoxicosis

Objective

This meta-analysis examines peak systolic velocities (PSVs) in thyroid arteries as potential biomarkers for thyroid disorders, which includes treated and untreated Graves' disease(GD) and destructive thyrotoxicosis(DT).

Methods

A search across databases including PubMed, Google Scholar, Embase, and Web of Science identified studies assessing peak systolic flow velocity in the inferior thyroid artery (ITA-PSV) and superior thyroid artery (STA-PSV) diagnostic efficacy in GD and DT.And the search was restricted to publications in the English language.The analysis compared STA-PSV and ITA-PSV across patient groups, evaluating intra-group variances and synthesizing sensitivity and specificity data.

Results

The analysis covered 18 studies with 1276 GD, 564 DT patients, and 544 controls. The difference of STA-PSV between GD group, DT group and normal group and the difference of ITA-PSV were analyzed in subgroups, and there was no statistical significance between subgroups when comparing any two groups. Normal subjects displayed intra-group ITA-PSV and STA-PSV differences with established cut-off values of 20.33 cm/s (95% CI, 17.48-23.18) for ITA-PSV and 25.61 cm/s (95% CI, 20.37-30.85) for STA-PSV. However, no significant intra-group differences were observed in the STA-PSV and ITA-PSV cut-off values among groups with GD or DT. The combined cut-off values for these patient groups and normal subjects were 68.63 cm/s (95% CI, 59.12-78.13), 32.08 cm/s (95% CI, 25.90-38.27), and 23.18 cm/s (95% CI, 20.09-26.28), respectively. The diagnostic odds ratio(DOR) for these values was 35.86 (95% CI, 18.21-70.60), and the area under the summary receiver operating characteristic (SROC) curve was 0.91, with a sensitivity estimate of 0.842 (95% CI, 0.772-0.866).

Conclusion

PSVs in thyroid arteries are useful diagnostic tools in distinguishing DT from GD. A PSV above 68.63 cm/s significantly improves GD diagnosis with up to 91% efficacy. No notable differences were found between superior and inferior thyroid arteries in these conditions.

Atypical Clinical Courses of Graves' Disease Confound Differential Diagnosis of Hyperthyroidism

BACKGROUND

This study examined the appropriateness of the current paradigm for differential diagnosis of painless thyroiditis and Graves' disease (GD) in patients with thyrotoxicosis.

METHODS

We retrospectively evaluated the clinical course of 343 consecutive patients with hyperthyroidism diagnosed by Tc-99m pertechnetate thyroid uptake (TcTU) testing at our hospital from January 2011 to December 2017.

RESULTS

Of the 263 patients with normal or high TcTU levels (≥1.0%), 255 (97%) had unequivocal GD and 5 had spontaneous remission GD or atypical GD. Of the 10 patients with low TcTU levels (<1.0% and ≥0.5%), 7 had GD, while others had subclinical GD, spontaneous remission GD with later relapse, and painless thyroiditis. Of those with very low TcTU levels (<0.5%), most had thyroiditis (painless thyroiditis, 33/67 [49%]; subacute thyroiditis, 29/67 [43%]), and some were positive for anti-TSH receptor antibodies.

CONCLUSION

Given that atypical GD may confound the diagnosis of thyrotoxicosis, it is essential to follow the patient as a tentative diagnosis, whatever the diagnosis. This is the first report clearly demonstrating that so far there is no gold standard for the diagnosis of GD. It is therefore urgent to establish a consensus on the definition of GD so that the specificity and sensitivity of future diagnostic tests can be determined.

Duplex Hemodynamic Parameters of Both Superior and Inferior Thyroid Arteries in Evaluation of Thyroid Hyperfunction Disorders

Background

Thyrotoxicosis may be caused by Graves’ disease or destructive thyroiditis. Differentiation between causes of thyrotoxicosis is crucial as management will differ. ^99mTechnetium (Tc)-pertechnetate thyroid scintigraphy is currently the gold standard for this purpose, however, is expensive and uses ionizing radiation.

Objective

To evaluate the role of color flow Doppler Ultrasound (CDU) of the superior thyroid (STA) and inferior thyroid arteries (ITA) as an inexpensive, non-invasive tool that can aid in differentiating between Graves’ disease and thyroiditis and compare it with thyroid scintigraphy.

Methods

Sixty-nine patients with newly-diagnosed thyrotoxicosis and 30 controls were enrolled. Thyroid functions, thyroid scintigraphy, and CDU of STA and ITA with measurements of peak systolic velocity (PSV) and end diastolic velocity (EDV), were performed. According to thyroid scintigraphy results, patients were divided into two groups: 42 patients with Graves’ disease and 27 patients with thyroiditis.

Results

PSV and EDV of both STA and ITA were significantly higher in patients with Graves’ disease than thyroiditis (p-values <0.001). The STA-PSV had an equal sensitivity and specificity of 66.7%; cut-off value 76.57 cm/s, while those of STA-EDV were 73.8%, and 77.8% respectively; cut-off value 28.22 cm/s. ITA-PSV had a sensitivity and specificity of 76.2% and 77.8%, respectively; cut-off value 62.12 cm/s), while those of ITA-EDV were 78.6% and 77.8%, respectively; cut-off value 5.22 cm/s.

Conclusion

CDU parameters of the STA and ITA could be used as an alternative to thyroid scintigraphy for discriminating between Graves’ disease and thyroiditis.

Hyperthyroidism in children and adolescents: Experience in a university hospital in Colombia

Introduction: Hyperthyroidism is a heterogeneous condition characterized by the excessive production of thyroid hormones. It represents a diagnostic and therapeutic challenge. Objective: To describe the clinical and paraclinical characteristics and the evolution and differences between the main etiologies in patients with hyperthyroidism treated by the Pediatric Endocrinology Service at the Hospital Universitario San Vicente Fundación in Medellín, Colombia, between July 1st., 2015, and June 30th., 2020. Materials and methods: We conducted a cross-sectional observational study with retrospective data collection. Results: We included 54 patients with a mean age of 11.9 years, 72.2% of whom were female; 85.2% had no history of comorbidities related to autoimmunity; 11.1% had a family history of Graves’ disease, and 29.6% of other thyroid diseases. Goiter was the most frequent clinical manifestation (83.3%) and 92.6% of the patients received treatment with methimazole, 79.6% required beta-blockers, and 11.2% additional drug therapy. Adverse drug reactions occurred in 16.7% of the patients and in 20.4% there was a resolution of hyperthyroidism (spontaneous: 9.3%; after radio-iodine ablation: 9.3%, and after surgery: 1.9%). Conclusion: Hyperthyroidism is a disease with diverse clinical manifestations. Its most frequent cause is Graves’ disease followed by hashitoxicosis, which in this study had a higher frequency than that reported in the literature. The duration and side effects of pharmacological treatment were similar to those previously reported, but the higher frequency of agranulocytosis is noteworthy.

Rapid Differential Diagnosis of Thyrotoxicosis Using T3/T4 Ratio, FT3/FT4 Ratio and Color Doppler of Thyroid Gland

CONTEXT

Establishing the etiology of thyrotoxicosis is of utmost importance to plan the appropriate line of therapy. However, certain scenarios such as absence of pathognomonic clinical features of Graves' disease in some patients, or non-availability of radionuclide scanning and newer generation TRAb assays especially in resource-poor settings, necessitates utilization of other, simple and effective measures to differentiate between the two common causes of thyrotoxicosis, Graves' disease (GD) and Destructive thyroiditis (DT).

AIMS

The aim of this work was to study the role of FT3/FT4 ratio, T3/T4 ratio and color flow Doppler ultrasound in treatment-naïve patients with thyrotoxicosis, in comparison to Tc-99m pertechnetate thyroid scanning in the differentiation of thyrotoxicosis due to GD and DT.

MATERIALS AND METHODS

Clinical data was collected from all study subjects. Thyroid function tests including FT3, FT4, T3, T4 and TSH, TSH Receptor Antibody (TRAb), Technetium Tc 99m pertechnetate scan and the mean peak systolic velocity in inferior thyroid artery (mean PSV-ITA) by color Doppler ultrasonography of thyroid gland was done in all patients.

RESULTS

A total of 83 treatment-naïve patients with thyrotoxicosis (61 with GD and 22 with DT) were studied. Mean PSV-ITA, T3/T4 ratio and FT3/FT4 ratio showed a sensitivity of 85.2%, 73.8%, and 77.04%, and a specificity of 90.9%, 72.7%, and 59.09%, respectively. The three parameters in combination yielded a positive predictive value of 100% in the diagnosis of Graves' disease.

CONCLUSION

Results of this study show that inferior thyroid artery blood flow, T3/T4 ratio and FT3/FT4 ratio are useful parameters in the differentiation between GD and DT.