The role of imaging in Graves’ disease: A cost-effectiveness analysis

Association of autoimmune thyroid disease with type 1 diabetes mellitus and its ultrasonic diagnosis and management

As a common hyperglycemic disease, type 1 diabetes mellitus (T1DM) is a complicated disorder that requires a lifelong insulin supply due to the immune-mediated destruction of pancreatic β cells. Although it is an organ-specific autoimmune disorder, T1DM is often associated with multiple other autoimmune disorders. The most prevalent concomitant autoimmune disorder occurring in T1DM is autoimmune thyroid disease (AITD), which mainly exhibits two extremes of phenotypes: hyperthyroidism [Graves' disease (GD)] and hypo-thyroidism [Hashimoto's thyroiditis, (HT)]. However, the presence of comorbid AITD may negatively affect metabolic management in T1DM patients and thereby may increase the risk for potential diabetes-related complications. Thus, routine screening of thyroid function has been recommended when T1DM is diagnosed. Here, first, we summarize current knowledge regarding the etiology and pathogenesis mechanisms of both diseases. Subsequently, an updated review of the association between T1DM and AITD is offered. Finally, we provide a relatively detailed review focusing on the application of thyroid ultrasonography in diagnosing and managing HT and GD, suggesting its critical role in the timely and accurate diagnosis of AITD in T1DM.

Diabetes Mellitus Secondary to Endocrine Diseases: An Update of Diagnostic and Treatment Particularities

Secondary diabetes mellitus is frequently ignored in specialized literature. In this narrative review, the main endocrinopathies accompanied by increased glycemic values are identified, as well as the mechanisms by which the excess or deficiency of certain hormones impact beta cell function or insulin resistance. The main endocrinopathies (acromegaly, Cushing's syndrome, Basedow-Graves' disease, pheochromocytoma, somatostatinoma and glucagonoma) and their characteristics are described along with the impact of hormone changes on blood sugar, body mass index and other parameters associated with diabetes. The overall information regarding the complex molecular mechanisms that cause the risk of secondary diabetes and metabolic syndrome is of crucial importance in order to prevent the development of the disease and its complications and particularly to reduce the cardiovascular risk of these patients. The purpose of this study is to highlight the particular features of endocrine pathologies accompanied by an increased risk of developing diabetes, in the context of personalized therapeutic decision making. The epidemiological, physiopathological, clinical and therapeutic approaches are presented along with the importance of screening for diabetes in endocrine diseases.

Is beta-carotene consumption associated with thyroid hormone levels?

The thyroid hormones play a pivotal role in various physiological processes, including growth, metabolism regulation, and reproduction. While non-modifiable factors are known to impact thyroid function, such as genetics and age, nutritional factors are also important. Diets rich in selenium and iodine are conventionally acknowledged to be beneficial for the production and release of thyroid hormones. Recent studies have suggested a potential link between beta-carotene, a precursor to vitamin A (retinol), and thyroid function. Beta-carotene is known for its antioxidant properties and has been shown to play a role in the prevention of various clinical conditions such as cancer and cardiovascular and neurological diseases. However, its impact on thyroid function is still unclear. Some studies have suggested a positive association between beta-carotene levels and thyroid function, while others have found no significant effect. Conversely, the hormone produced by the thyroid gland, thyroxine, enhances the conversion of beta-carotene to retinol. Furthermore, vitamin A derivatives are being explored as potential therapeutic options for thyroid malignancies. In this review, we highlight the mechanisms through which beta-carotene/retinol and thyroid hormones interact and review the findings of clinical studies examining the association between beta-carotene consumption and thyroid hormone levels. Our review underscores the need for further research to clarify the relationship between beta-carotene and thyroid function.

Imaging of the Thyroid: Practical Approach

Imaging evaluation of the thyroid gland spans a plethora of modalities, including ultrasound imaging, cross-sectional studies, and nuclear medicine techniques. The overlapping of clinical and imaging findings of benign and malignant thyroid disease can make interpretation a complex undertaking. We aim to review and simplify the vast current literature and provide a practical approach to the imaging of thyroid disease for application in daily practice. Our approach highlights the keys to differentiating and diagnosing common benign and malignant disease affecting the thyroid gland.

Change in newly diagnosed Graves' disease phenotype between the twentieth and the twenty-first centuries: meta-analysis and meta-regression

PURPOSE

According to a few recent studies, the clinical phenotype of Graves' disease (GD) at onset is becoming milder in recent years, in terms of prevalence and severity of hyperthyroidism, goiter and overt eye disease. The aim of this study was to assess the change in GD phenotype across the late twentieth and the early twenty-first centuries.

MATERIALS AND METHODS

We carried out a systematic search of studies published between 1/1/1980 and 12/31/2017 describing naïve GD patients at diagnosis. We collected epidemiological, clinical, biochemical and serological data reported in the selected studies, and (1) conducted a single-arm meta-analysis to compare clinical and biochemical characteristics of naïve GD patients before and after year 2000 and (2) performed a meta-regression to identify the trend of the observed clinical presentations.

RESULTS

Eighty selected articles were related to the period before the year 2000, 30 to the years 2000-2017. According to demographics, the two defined populations were homogeneous at meta-analysis: overall estimated female prevalence was 81% [95% CI 79-82], mean estimated age of the entire population was 39.8 years [95% CI 38.4-41.1], with no significant differences between pre- and post-2000 groups (p > 0.05). The overall estimated prevalence of smokers was 40% [95% CI 33-46], with no significant difference between the two groups (p > 0.05). Mean estimated free thyroxine (FT4) and free triiodothyronine (FT3) levels at diagnosis were higher in the pre-2000 group: 4.7 ng/dl [95% CI 4.5-4.9] for FT4 and 14.2 pg/ml [95% CI 13.3-15.1] for FT3, as compared to the post-2000 group: 3.9 ng/dl [95% CI 3.6-4.2] for FT4 and 12.1 pg/ml [95% CI 11.0-13.3] for FT3 (all p < 0.01). Goiter estimated prevalence was higher in the pre-2000 group, 87% [95% CI 84-90], than in the post-2000 group, 56% [95% CI 45-67]. Estimated prevalence for Graves' Orbitopathy (GO) was 34% [95% CI 27-41] in the pre-2000 group and 25% [95% CI 19-30] in the post-2000 group (p = 0.03). Accordingly, meta-regression adjusted for covariates showed an average annual reduction of FT4 (- 0.040 ± 0.008 ng/dl, p < 0.0001), FT3 (- 0.316 ± 0.019 pg/ml, p < 0.0001), goiter prevalence (- 0.023 ± 0.008%, p = 0.006), and goiter size (- 0.560 ± 0.031 ml, p < 0.0001).

CONCLUSIONS

Our meta-analysis and meta-regression confirmed that GD phenotype at diagnosis is nowadays milder than in the past; we hypothesize that conceivable factors involved in this change are iodoprophylaxis, worldwide decrease in smoking habits, larger use of contraceptive pill and micronutrient supplementation, as well as earlier diagnosis and management.

Evaluation of choroidal circulation and stromal features in Graves' disease

PURPOSE

This study aimed to evaluate choroidal thickness (CT) and choroidal vascularity index (CVI) in patients with Graves' disease (GD) without ocular involvement.

METHODS

Fifty patients diagnosed with GD and 50 age and gender matched healthy control subjects were retrospectively evaluated. Measurements were taken from five different points on CT images. Choroid images were classified as lumen regions (LA) and stromal regions (SA) using the image binarization method. CVI was calculated by dividing LA by the total choroidal area (TCA). The effects of Thyrotropin Receptor Antibody (TRAb), age, GD duration, blood pressure, axial length measurements, and intraocular pressure were analyzed on CT and CVI measurements.

RESULTS

Mean age was 40.1 ± 13.5 years in the patient group and 39.3 ± 13.6 years in the control group (p = 0.89). There was no significant difference between the GD group and control group in terms of CT measurements. There was a significant difference between the mean CVI measurements of the GD group and control group (68.03 ± 3.41 and 66.62 ± 3.11, respectively) (p < 0.001). Univariate linear regression analysis revealed a positive correlation between TRAb and CVI (p = 0.013).

CONCLUSION

While there was no significant difference between the CT measurements of the GD group and the control group, the GD group had significantly higher CVI measurements.

Ultrasound of benign thyroid nodules: A 120 months follow-up study

OBJECTIVE

Some evidence suggests that most benign nodules exhibit no significant size increase during 5 years of follow-up, although conflicting results have emerged. The aim of the present study is to evaluate the frequency and the magnitude of growth in benign nodules during 120 months of follow-up.

DESIGN

We reviewed the medical and imaging records of patients who were submitted to ultrasound-guided FNA of thyroid nodules at our hospital from January 2007 to March 2009. We selected only patients with benign nodules who underwent annual ultrasound evaluation in our Department.

RESULTS

Among 966 selected patients, 289 were lost during follow-up, meaning that the total number of patients analysed was 677 (474 women and 203 men), with a mean age of 45.6 (16-71) years. In 559/677 patients (82.7%), the size of the nodule remained stable during follow-up; 42 (6.2%) patients experienced spontaneous nodule shrinkage, and 75 (11.1%) patients showed nodule growth. Patients with or without nodule growth during follow-up were superimposable at baseline for age, gender, TSH values, number of patients on levothyroxine treatment and nodule characteristics. All baseline variables in predicting nodular growth were entered to an adjusted multivariate logistic regression model. None of the parameters taken into account was associated with nodular growth.

CONCLUSIONS

In conclusion, the majority of benign nodules remained stable over the period of monitoring. On the basis of our experience, we recommend ultrasound examination at a distance of 2 and 5 years following cytological evaluation, then every 4-5 years from then on.

Evaluation of the role of thyroid scintigraphy in the differential diagnosis of thyrotoxicosis

OBJECTIVE

A differential diagnosis of thyrotoxicosis is crucial as the treatment of the main causes of this condition can vary significantly. Recently published diagnostic guidelines on thyrotoxicosis embrace the presence of thyrotropin receptor (TSH-R) antibodies (TRAb) as the primary and most important diagnostic step. The application of diagnostic algorithms to aid in the treatment of hyperthyroidism supports using thyroid radionuclide scintigraphy (TRSt) in baffling clinical scenarios, when TRAb are absent or when third-generation TRAb are not available. First-generation TRAb measurement may have limitations. Consequently, patients with thyrotoxicosis and first-generation TRAb results may be misdiagnosed and consequently improperly treated. Our purpose was to compare first-generation TRAb values to TRSt in the differential diagnosis of hyperthyroidism.

METHODS

We conducted a retrospective study of 201 untreated outpatients with overt or subclinical hyperthyroidism on whom first-generation TRAb and TRSt had been performed at the time of diagnosis. Histological specimens were analysed in patients who had previously undergone thyroid surgery at our centre. SPSS 20.0 was used in statistical analysis.

RESULTS

Seventy-three out of 201 (36.3%) patients had positive TRAb. A diffuse uptake was present in 83.5% (61/73), whereas 13.7% (10/73) had a heterogeneous uptake and 2.7% (2/73) had an absent uptake. Thirty out of 91 (33%) patients with diffuse uptake were negative for positive TRAb and were diagnosed with Graves' disease. Analysis of 37 histological specimens indicated that TRSt had greater accuracy (81% vs 75.7%) and specificity (79.2% vs 57.1%) when compared to TRAb in the differential diagnosis of thyrotoxicosis. However, TRSt sensitivity was inferior to TRAb (84.6% vs 92.3%).

CONCLUSIONS

Our study endorses that initial differential diagnosis of thyrotoxicosis should not be based solely on first-generation TRAb as this approach may leave nearly 20% of the patients misdiagnosed and, consequently, improperly treated. Our results underscore that thyroid scintigraphy should also be performed when only first-generation TRAb assays are available during the initial differential diagnosis of thyrotoxicosis.

Scintigraphy evaluation of hyperthyroidism and its correlation with clinical and biochemical profiles

Objective

Hyperthyroidism is the excessive synthesis of thyroid hormones. Thyroid uptake scans and ultrasonography provide an accurate diagnosis of hyperthyroidism, especially when thyroid receptor antibody (TRAb) measurement is not readily available. This study explored the prevalence of various hyperthyroidism causes using retrospective scintigraphy results and evaluated their relationship with clinical, biochemical, and sonographic imaging parameters from patients who underwent ^99mTc-pertechnetate thyroid scans between 2016 and 2019 in Taif, Saudi Arabia, where literature is insufficient. Furthermore, the inappropriate use of thyroid scanning in different thyroid diseases was evaluated.

Results

The study enrolled 207 patients (mean age: 42.5 ± 14.7 years). The mean free T4, T3, antithyroid peroxidase antibody, antithyroglobulin antibody, C-reactive protein, and erythrocyte sedimentation rate levels were high. Graves’ disease was the most common diagnosis. Compared to toxic solitary/multinodular goiter, patients with Graves’ disease were usually younger, used carbimazole during both the uptake and the scan, had an enlarged thyroid gland, and had higher FT4 and FT3 levels. Inappropriate thyroid uptake and scan use was reported in approximately 10% of patients, and 25% of the patients used carbimazole during the uptake and scan. Thus, better patient education is needed to avoid misinterpreting the scan results.

Quantitative Color Doppler Ultrasonography Measurement of Thyroid Blood Flow in Patients with Graves' Disease

BACKGROUND

Graves' Disease is an autoimmune disorder characterized by increased levels of thyroid hormones correlated with increased thyroid blood flow. Thyroid scintigraphy is an important and conventional method. However, it has limited accessibility, has ionizing radiation, and is expensive.

OBJECTIVES

To investigate the thyroid blood flow in patients with Graves' Disease by color Doppler Ultrasonography and a newly developed software Color Quantification.

METHODS

Forty-one consecutive subjects with GD and 41 healthy controls were enrolled. Color Doppler ultrasonography parameters of the thyroid arteries and Color Quantification values of the gland were measured by a radiologist. The correlations between thyroid blood flow parameters, levels of 99mTechnetium pertechnetate uptake, thyrotropin, and free thyroxine were evaluated. The diagnostic performances of these parameters were investigated.

RESULTS

The peak systolic-end diastolic velocities of thyroid arteries and Color Quantification values were increased in the study group (p < 0.05 for all). We observed negative correlations between thyrotropin levels and peak-systolic and end-diastolic velocities of superior thyroid arteries and Color Quantification values. There were positive correlations between 99mTechnetium uptake levels and thyroid blood flow parameters (p < 0.05 for all). In the diagnostic performance of thyroid blood flow parameters, we observed utilities significantly in peak-systolic and end-diastolic velocities of thyroid arteries and Color Quantification values (p < 0.05 for all).

CONCLUSION

The increased peak-systolic and end-diastolic velocities of thyroid arteries, and increased Color Quantification values might be helpful in the diagnosis of Graves' Disease.

Thyroid vascularization is an important ultrasonographic parameter in untreated Graves' disease patients

Graves’ disease is characterized by two sonographic features, hypoechogenicity and increased blood flow. The aim of this study was to review retrospectively ultrasound features and biochemical data of a cohort of untreated Graves’ disease patients. We reviewed charts of 42 such patients, who were referred to our Endocrinology Unit from January 2013 to May 2018. One operator performed all the thyroid sonographic scans. Serum TSH, FT3, FT4 and TSH-receptor antibodies (TRAb) levels at the time of ultrasound examination were evaluated. Over a mean follow-up of 30.9 months, about one in three patients (38%) experienced at least one recurrence of hyperthyroidism (1.4 ± 0.6 recurrence per patient), either on or off antithyroid drugs. We found that thyroid vascularization correlated directly with thyroid volume and that larger thyroids tended to be more vascularized. We also found that greater vascularization was associated with marked hypoechogenicity, and greater FT4 and TRAb levels. Patients who experienced recurrence(s) had 1.7-fold higher levels of TRAb at onset. In conclusion, thyroid hypervascularization at onset of Graves’ disease is an important sonographic feature.

A survey of current approaches to thyroid nodules and thyroid operations

INTRODUCTION

Thyroid nodules are commonly seen. Our aim is to learn the behaviors and operational attitudes of surgeons approaching the thyroid nodules. In a literature search, our study is the first and only study performed merely on surgeons.

MATERIALS- METODS

This cross-sectional study was done between June 2014-January 2015. The questionnaire consists of 25 questions. Initially, general questions consisting of demographic findings were asked. In step 2, questions consisting of the index case and case variants were asked. Results were compared with American Thyroid Association, European Thyroid Association guidelines, and Australia survey results. In the last step, questions about thyroid operations were asked.

RESULTS

A total of 301 surgeons responded to the survey. The response rate was approximately 20%. Thirty nine were female and 262 were male. For the question that asks the diameter of the thyroid nodule that will require a thyroid fine needle aspiration biopsy (TFNAB), 47.5% of the surgeons will require a TFNAB for 1-2 cm solid nodules. 40.15% of the surgeons required a TFNAB regardless of size. 46.1% of the surgeons who required a TFNAB between 1 and 2 cm solid nodules also required scintigraphy at diagnosis of suppressed TSH case variant.

CONCLUSION

In this survey, we identified differences from up-to-date guidelines about approaching thyroid nodules and perioperative thyroid surgery. From our perspective, surgeons need updated training requirements. This can be done with updated seminars across the country. Thereby approaches may become standard and consequently patients may have qualified services.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Hyperthyroidism

Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source. The most common cause of hyperthyroidism is Graves' disease, followed by toxic nodular goitre. Other important causes of thyrotoxicosis include thyroiditis, iodine-induced and drug-induced thyroid dysfunction, and factitious ingestion of excess thyroid hormones. Treatment options for Graves' disease include antithyroid drugs, radioactive iodine therapy, and surgery, whereas antithyroid drugs are not generally used long term in toxic nodular goitre, because of the high relapse rate of thyrotoxicosis after discontinuation. β blockers are used in symptomatic thyrotoxicosis, and might be the only treatment needed for thyrotoxicosis not caused by excessive production and release of the thyroid hormones. Thyroid storm and hyperthyroidism in pregnancy and during the post-partum period are special circumstances that need careful assessment and treatment.

A 2013 European survey of clinical practice patterns in the management of Graves' disease

OBJECTIVE

Management of Graves' disease (GD) in Europe was published in 1987. Aim of this survey was to provide an update on clinical practice in Europe, and to compare it with a 2011 American survey.

DESIGN

Members of the European Thyroid Association (ETA) were asked to participate in a survey on management of GD, using the same questionnaire of a recent American survey.

RESULTS

A total of 147 ETA members participated. In addition to serum TSH and free T4 assays, most respondents would request TSH-receptor autoantibody (TRAb) measurement (85·6%) and thyroid ultrasound (70·6%) to confirm aetiology, while isotopic studies were selected by 37·7%. Antithyroid drug (ATD) therapy was the preferred first-line treatment (83·8%). Compared to the previous European survey, Europeans currently more frequently use TRAb measurement and thyroid ultrasound for diagnosis and evaluation, but first-line treatment remains ATDs in a similar percentage of respondents. Current clinical practice patterns differ from those in North America, where isotopic studies are more frequently used, and radioiodine (RAI) still is first-line treatment. When RAI treatment is selected in the presence of mild Graves' orbitopathy and/or associated risk factors for its occurrence/exacerbation, steroid prophylaxis is frequently used. The preferred ATD in pregnancy is propylthiouracil in the first trimester and methimazole in the second and third trimesters, similar to North America.

CONCLUSIONS

Significant changes in clinical practice patterns in Europe were noted compared to the previous European survey, as well as persisting differences in diagnosis and therapy between Europe and North America.

Elastography Evaluation of Benign Thyroid Nodules in Patients Affected by Hashimoto's Thyroiditis

The aim of the present prospective study was to evaluate the predictive value of elastography in benign thyroid nodules of patients affected by Hashimoto's thyroiditis (HT). From January 2011 to January 2012, 242 nodules in patients affected by HT were submitted to fine needle aspiration cytology (FNAC). All of the patients underwent sonography and elastography performed before FNAC. 230 (95%) nodules were benign, 8 papillary cancers, and 4 follicular lesions. Score 1 was found in 79.1% of benign lesions (sensitivity 79.1%; specificity 66.7%; PPV 97.8%; NPV 14.3%; accuracy 78.5%; p < 0.05). In order to evaluate the outcome of thyroid ultrasound echogenicity in relation to elastography features of nodule(s), all the patients with benign nodules were stratified according to their hypoechoic pattern of thyroid (mild-moderate and severe). Following stratification score 1 was found in 84.2% of benign nodules (sensitivity 75.0%; specificity 88.9%; PPV 27.3%; NPV 98.4%; accuracy 88.2%; p < 0.0001) of patients with a mild-moderate ultrasound thyroid hypoechogenicity, whereas it was found in 60% of benign nodules (p = 0.715) of patients with a marked thyroid hypoechogenicity. Elastography appears to have limited value in detecting thyroid cancer in patients affected by Hashimoto's thyroiditis with severe hypoechoic thyroid tissue.

Ultrasound findings of subacute thyroiditis: a single institution retrospective review

BACKGROUND

High resolution ultrasonography features have also been described as having a useful supporting role in the diagnosis of subacute granulomatous thyroiditis (ST), and images are generally characterized by heterogeneous hypoechoic areas of the affected tissue with lack of flow on color Doppler US.

PURPOSE

To determine the sonographic features of subacute granulomatous thyroiditis.

MATERIAL AND METHODS

We reviewed the medical records of patients referred at the Endocrine and Metabolic Unit of our Institution between January 2010 and December 2011.

RESULTS

A total of 7520 patients were evaluated in our department between January 2010 and December 2011. Among them, 22 (0.3%) patients had a diagnosis of ST (19 women and 3 men, 45.4 ± 9.7 year; range, 33-62 years). Ultrasound examination showed bilateral ST in 64% of patients. Thyroid volume was 13.2 ± 7.7 mL, without difference if ST was unilateral (13.2 ± 7.1 mL) or bilateral (13.9 ± 8.3 mL). On grayscale US, heterogeneous diffusely or focally marked hypoechoic areas, like "lava flow", were found in all the lesions.

CONCLUSION

Our data confirm the high sensitivity of US in the diagnosis of ST: diffuse hypoechoic and confluent areas with the characteristic features like "lava flow".

Diagnosis and management of Graves disease: a global overview

Graves disease is an autoimmune disorder characterized by goitre, hyperthyroidism and, in 25% of patients, Graves ophthalmopathy. The hyperthyroidism is caused by thyroid hypertrophy and stimulation of function, resulting from interaction of anti-TSH-receptor antibodies (TRAb) with the TSH receptor on thyroid follicular cells. Measurements of serum levels of TRAb and thyroid ultrasonography represent the most important diagnostic tests for Graves disease. Management of the condition currently relies on antithyroid drugs, which mainly inhibit thyroid hormone synthesis, or ablative treatments ((131)I-radiotherapy or thyroidectomy) that remove or decrease thyroid tissue. None of these treatments targets the disease process, and patients with treated Graves disease consequently experience either a high rate of recurrence, if receiving antithyroid drugs, or lifelong hypothyroidism, after ablative therapy. Geographical differences in the use of these therapies exist, partially owing to the availability of skilled thyroid surgeons and suitable nuclear medicine units. Novel agents that might act on the disease process are currently under evaluation in preclinical or clinical studies, but evidence of their efficacy and safety is lacking.

The role of thyrotrophin receptor antibody assays in graves' disease

Thyrotrophin receptor antibodies (TRAb) exist as stimulating or blocking antibodies in the serum (neutral TRAb have been identified recently). The clinical features of GD occur when stimulating TRAb predominate. But the relationship of TRAb to clinical phenotype and outcome is not clear when current assay methods are used. Therefore no consensus exists about its utility in diagnosing and predicting outcome in GD. The most commonly used TRAb assays, measure thyroid binding inhibiting immunoglobulins (TBII or “receptor assays”) and don't differentiate between stimulating and blocking antibodies. However, the more expensive, technically demanding and less freely available “biological assays” differentiate between them by their ability to stimulate cyclic AMP or failure to do so. Failure to differentiate between TRAb types and its heterogeneous molecular and functional properties has limited TBII use to GD diagnosis and differentiating from other forms of thyrotoxicosis. The current 2nd-3rd generation receptor assays are highly sensitive and specific when used for this purpose. TRAb assays should also be done in appropriate pregnant women. Current data do not support its use in outcome prediction as there is a significant variability of assay methodology, population characteristics and study design in published data, resulting in a lack of consensus.

Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists

OBJECTIVE

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This article describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspeciality physicians and others providing care for patients with this condition.

METHODS

The development of these guidelines was commissioned by the American Thyroid Association in association with the American Association of Clinical Endocrinologists. The American Thyroid Association and American Association of Clinical Endocrinologists assembled a task force of expert clinicians who authored this report. The task force examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to develop the text and a series of specific recommendations. The strength of the recommendations and the quality of evidence supporting each was rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' ophthalmopathy; and management of other miscellaneous causes of thyrotoxicosis.

CONCLUSIONS

One hundred evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

The role of TSH receptor antibodies in the management of Graves' disease

The central role of thyrotropin receptor antibodies (TRAbs) in the pathogenesis of Graves' disease has been recognised for several decades. However, the practical application of testing for TRAbs in clinical decision making remains the subject of controversy. The diagnosis of Graves' disease can be made in most cases simply based on a patient's clinical presentation. The TRAb test is therefore of most value in ambiguous clinical scenarios such as in the differential diagnosis of unilateral exophthalmos, euthyroid Graves' ophthalmopathy, subclinical hyperthyroidism, thyrotoxicosis associated with hyperemesis gravidarum, amiodarone-induced thyrotoxicosis and painless thyroiditis. It may also have a role in predicting the risk of a recurrence of Graves' disease following a course of antithyroid drug treatment. One further clinical utility of the TRAb test is in pregnancy where antibody titre measured during the third trimester is used to predict the risk of neonatal thyroid dysfunction. The TRAb titre not only aids in clinching a difficult diagnosis but can also help guide treatment in some patients. Although the TRAb assay has become more affordable in recent years, cost remains an important factor when considering its use routinely. Nonetheless, this is an underutilised blood test that could augment standard endocrine investigations in the differential diagnosis of hyperthyroidism.

Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This article describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspeciality physicians and others providing care for patients with this condition.

METHODS

The development of these guidelines was commissioned by the American Thyroid Association in association with the American Association of Clinical Endocrinologists. The American Thyroid Association and American Association of Clinical Endocrinologists assembled a task force of expert clinicians who authored this report. The task force examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to develop the text and a series of specific recommendations. The strength of the recommendations and the quality of evidence supporting each was rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' ophthalmopathy; and management of other miscellaneous causes of thyrotoxicosis.

CONCLUSIONS

One hundred evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Decreased number of circulating endothelial progenitor cells in patients with Graves' hyperthyroidism

OBJECTIVE

A relevant biological role of circulating endothelial progenitor cells (EPC) was recently demonstrated. EPC are generated in the bone marrow, and interact with damaged endothelium, restoring the integrity of the monolayer. Therefore, aim of the present study was to evaluate EPC in the blood of patients with untreated Graves' hyperthyroidism (GD), in whom an increased oxidative stress was observed.

DESIGN AND METHODS

Twenty-three patients with untreated active GD and 18 matched normal controls (NC) were included in the study. Circulating EPC were isolated from peripheral blood. Mononuclear cells were cultured with endothelial basal medium supplemented with EGM SingleQuots, and were identified by positive double staining after 7 days in culture. Circulating levels of C reactive protein, total antioxidant power, interleukin (IL)-6, IL- 18, monocyte chemoattractant protein-1, tumor necrosis facotr- α, soluble vascular cell adhesion molecule (VCAM) and intracellular adhesion molecule were evaluated by enzymelinked immunosorbent assay kit. EPC number was also evaluated in a subgroup of GD patients after restoration of euthyroidism.

RESULTS

Systolic blood pressure resulted increased in GD patients compared with control subjects whereas diastolic blood pressure was not significantly different. Patients with GD showed an increase in circulating levels of IL-18 and VCAM-1 and a reduction of total antioxidant power (p<0.05) compared to NC. Moreover, a reduced number of EPC was observed in patients with GD compared to NC (p<0.05) which turned to NC values after restoring euthyroidism.

CONCLUSION

Patients with GD showed a reduction in the physiological protective mechanisms against endothelial damage, probably induced by increased inflammation and oxidative stress.

Role of ultrasound in thyroid disorders

Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders, both malignant and benign. Although its use has traditionally been the domain of radiologists, surgeons and endocrinologists are increasingly integrating this technology into their daily clinical and operative practice. This article provides an overview of the relevant uses and indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in these diseases, and reviews the relevant literature and guidelines concerning its uses.

Prevalence of incidental thyroid cancer and its ultrasonographic features in subcentimeter thyroid nodules of patients with hyperthyroidism

In patients, who undergo surgery for hyperthyroidism, many cases of incidental thyroid cancer (ITC) have been detected. In the literature, there is no study about ITC in subcentimeter nodules in these patients. We performed this study to determine the frequency of ITC in subcentimeter nodules and ultrasonographic features that can predict malignancy in the patients with hyperthyroidism. We retrospectively reviewed our database about 3114 patients, who underwent thyroidectomy in our hospital. Among 869 patients (27.9%), who were operated because of hyperthyroidism, we enrolled 337 patients, who underwent total thyroidectomy and had subcentimeter nodule [59 Graves’ disease (GD) 98 subcentimeter nodule; 278 toxic multinodular goitre (TMNG), 359 subcentimeter nodule], in this study. Twenty-five nodules with ITC and 432 benign nodules have been detected and compared for ultrasonographic (US) features. Incidental thyroid cancer detection ratio was 5.4% [10.2% (10/98) in subcentimeter thyroid nodules in individuals with GD, and 4.1% (15/359) in individuals with TMNG, P = 0.018)]. Significant differences have been observed between the groups in terms of microcalcification in US examination of malign and benign subcentimeter thyroid nodules and the ratio of anterioposterior diameter to transverse diameter (A/T) ≥1 [(OR = 5.172; 95% CI: 1.495–17.886, P = 0.015), and (OR = 5.930; 95% CI: 1.531–22.971, P = 0.007), respectively]. We detected a higher incidence of ITC in subcentimeter thyroid nodules in GD compared to TMNG. US examination of subcentimeter nodules in hyperthyroid individuals has indicated that microcalcification and ratio of A/T ≥1 are the parameters that predict malignancy.

Accuracy and Cost Comparison of Ultrasound Versus Alternative Imaging Modalities, Including CT, MR, PET, and Angiography

Ultrasound (US) has become widely used in clinical medicine for the diagnosis of a variety of disease processes. The unique ability of US to provide accurate information through an efficacious, painless, portable, and nonionizing method has expanded its role and application in diverse medical settings. Given the current economic environment and the related interest in creating the greatest value for health care expenditures, US has been evaluated to compare its clinical accuracy/efficacy and cost-effectiveness versus other imaging modalities. The following literature review reports the results of research studies aimed at comparing the accuracy/efficacy and cost of US versus alternative imaging modalities, including magnetic resonance imaging, computed tomography, contrast angiography, and single-photon emission computed tomography.

Prevalence of parathyroid cysts by neck ultrasound scan in unselected patients

BACKGROUND

Parathyroid cysts (PC) are a rare entity, representing only 0.5-1% of all parathyroid lesions and <1% of neck masses. Since its first description, in the second half of the 19th century, fewer than 300 cases have been reported. By reviewing the literature, it appears that the data available arose from surgical series, and the precise incidence of PC as detected by ultrasound (US) has not been described. The aim of this study was to review 5 yr of routine neck US, mainly performed for thyroid diseases, in order to estimate the prevalence of PC in a large series of patients.

METHODS

We reviewed our database of neck US investigations performed from 2003 to 2007: all data regarding patient's clinical history, US images, and fine needle aspiration cytology were retrospectively collected.

RESULTS

Among 6621 patients submitted to neck US investigation, a PC (mean diameter 36.4+/-14.2 mm; range 25-61 mm) was diagnosed in 5 cases. Serum PTH levels were high in all the patients (221+/-140.7 pg/ml; range 111-456 pg/ml), whereas serum calcium levels only in 3 subjects (10.8+/-1.4 mg/dl; range 9.2-12.9 mg/ml).

CONCLUSION

This is the first study evaluating the prevalence of PC in a large series of unselected patients by US. Our results demonstrate a much lower incidence (0.075%) of incidentally detected PC than previously reported.

Evidence-based assessment of the role of ultrasonography in the management of benign thyroid nodules

BACKGROUND

Although ultrasonographic (US) evaluation is currently recommended for the workup of all palpable thyroid nodules, little guidance exists regarding the manner in which US data are to be used. Herein, we examine the available evidence and recommend how US can be used most effectively to predict malignancy. We discuss the role of US-guided fine needle aspiration (FNA) and other special topics regarding US evaluation and management of benign nodules.

METHODS

We also present a systematic review of the literature using evidence-based criteria.

RESULTS

US features alone cannot predict malignancy or benignity, but techniques that combine US features and FNA cytology are most effective and most accurate for predicting malignancy (Level III and IV evidence). US features suggesting malignancy include a blurred or ill-defined margin, irregular shape, solid echo structure, hypoechogenicity, absent halo, fine calcifications, and intranodular vascular pattern. Most patients with malignancies have more than two US features characteristic of malignancy. US-guided FNA has nonsignificantly higher sensitivity, specificity, and accuracy than the palpation-guided technique (Level III and IV evidence). US guidance is particularly beneficial in patients with nonpalpable, multiple, or heterogeneous nodules for preferentially aspirating a specific segment of the nodule (large or partially cystic nodule) or when nodule palpation is difficult (patients with diffuse glandular disease or obesity).

CONCLUSIONS

US is an essential component of thyroid nodule evaluation and management. Techniques that combine US features and FNA cytology for thyroid nodule workup are more accurate than either technique alone. US-guided FNA can decrease the rate of nondiagnostic aspirates.