An optimal treatment for pediatric Graves' disease is radioiodine

[Guideline for Radioiodine Therapy for Benign Thyroid Diseases (6/2022 - AWMF No. 031-003)]

This version of the guideline for radioiodine therapy of benign thyroid disorders is an update of the version, which was published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) in co-ordination with the German Society of Endocrinology (Deutsche Gesellschaft für Endokrinologie, DGE, Sektion Schilddrüse) and the German Society of General- and Visceral-Surgery (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie, DGAV) in 2015. This guideline was harmonized with the recommendations of the European Association of Nuclear Medicine (EANM). According to the German "Directive on Radiation Protection in Medicine" the physician specialised in nuclear medicine ("Fachkunde in der Therapie mit offenen radioaktiven Stoffen") is responsible for the justification to treat with radioiodine. Therefore, relevant medical indications for radioiodine therapy and alternative therapeutic options are discussed within the guideline. This procedure guideline is developed in the consensus of an expert group. This fulfils the level S1 (first step) within the German classification of Clinical Practice Guidelines.

The EANM guideline on radioiodine therapy of benign thyroid disease

This document provides the new EANM guideline on radioiodine therapy of benign thyroid disease. Its aim is to guide nuclear medicine physicians, endocrinologists, and practitioners in the selection of patients for radioiodine therapy. Its recommendations on patients' preparation, empiric and dosimetric therapeutic approaches, applied radioiodine activity, radiation protection requirements, and patients follow-up after administration of radioiodine therapy are extensively discussed.

Radioactive Iodine: A Living History

Background: Before the development of antithyroid drugs in the 1940s, treatment of Graves' hyperthyroidism was primarily surgical. Surgical mortality was quite variable, but a significant minority of patients died during or after surgery. Summary: In 1936, Karl Compton, President of the Massachusetts Institute of Technology, in a lecture attended by Massachusetts General Hospital physicians, suggested that artificially radioactive isotopes might be useful for studying metabolism. By 1942, Hertz and Roberts reported on the successful use of radioactive iodine (RAI) to treat Graves' hyperthyroidism. RAI uptake was subsequently demonstrated in well-differentiated thyroid cancer metastases. In 1948, Seidlin demonstrated stimulation of uptake in thyroid cancer metastases by thyrotropin (TSH). By 1990, 69% of endocrinologists in North America recommended RAI for Graves' hyperthyroidism. Currently RAI is less frequently used for Graves' hyperthyroidism, related to concerns about exacerbation of thyroid eye disease, about radiation exposure, and about potential adverse consequences of permanent hypothyroidism. Similarly, RAI was administered to the majority of patients with thyroid cancer for decades, but its use is now more selective. Conclusions: RAI is a remarkable example of interinstitutional cooperation between physicians and scientists to transition from bench to bedside in only three years. It is the model for a theranostic approach to disease (the simultaneous use of a radioactive drug for diagnosis and therapy). The future of RAI is less certain; inhibition of TSH receptor stimulating antibodies in Graves' disease and more precise targeting of genes that drive thyroid oncogenesis may diminish the use of RAI. Alternatively, redifferentiation techniques may improve the efficacy of RAI in RAI-refractory thyroid cancer.

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

UPDATED AGE-SPECIFIC EXTERNAL DOSE AND EXPOSURE RATE COEFFICIENTS FOR 131I PATIENT RELEASE

Updated effective dose rate and exposure rate coefficients for age-specific receptors representing members of the public were computed for external exposures from age-specific patients administered 131I to treat thyroid dysfunction for patient release evaluation. Coefficients were compared to the simplified point source method described by United States Nuclear Regulatory Commission Regulatory Guide (RG) 8.39, which does not consider age-specific parameters, morphometry or time-dependent 131I biodistribution. Monte Carlo age-specific phantom simulations were correlated with modified continuous voiding patient biokinetic models approximating age-specific dose and exposure rates as a function of time postadministration. Dose rates resulted in an overapproximation by a factor of ~3 from differentiated thyroid cancer patients (5% uptake) and by ~2 from hyperthyroid patients (80%) at 8 h postadministration compared to RG8.39. This study provides a paradigm where age-specific morphometry and biokinetic integration must be jointly considered when developing patient release guidelines for 131I and future radionuclide therapies.

[Definitive treatment of Graves' disease in children]

BACKGROUND

Hyperthyreoidism due to Graves' disease is a rare disorder in pediatric practice. There is 2 treatment options in Graves' disease: medical treatment and definitive treatment, including surgery and radioactive iodine. Each method has its advantages and disadvantages. If medical therapy is ineffective the choice between radical treatment method is raised: radioactive iodine or total thyroidectomy. In this research we analyze treatment outcomes in pediatric Graves' disease patients after different radical treatment methods.

AIM

Comparative analysis of radical treatment outcomes in pediatric patients with Graves' disease.

MATERIALS AND METHODS

Retrospective and prospective one-center research of 122 patients with Graves' disease after radical treatment (between 2016 and 2021)RESULTS: The mean age was 13.5±3,5 year at the moment of examination. Patients were divided into 2 groups due to the radical treatments method: 1 group (n=60) were children after surgical treatment, 2 group (n=62) - after radioactive iodine. The mean dose of medical treatment in these groups did not reliably differ (p=0,06), duration of the medical treatment was reliably longer in patients after radioactive iodine (p=0,024). Graves' orbitopathy was diagnosed in 58 patients (47,5%) and met equally often in both groups, but active stage of Graves' orbitopathy was diagnosed only in patients from the 1st group. Thyroid size was reliable bigger in patients from the 1st group (p=0,004), and thyroid gland nodes were diagnosed only in patients from 1st group (p=0,0007).

CONCLUSION

RI can be considered an effective and safe treatment for GD. The effectiveness of RI depends on the volume of the thyroid gland; according to the results of the constructed ROC curve, the risk of repeated RI is higher with a volume of more than 55 cm3. Also radioactive iodine is undesirable if there is signs of ophatalmopathy due to its possible deterioration. According to the results of the study hypoparathyroidism after surgical treatment was diagnosed in 20%, recurrent laryngeal nerve injury was diagnosed after surgical treatment in 5% of patients. In patients with identified nodular goiter according to the results of ultrasound, surgical treatment is preferable due to the impossibility of excluding thyroid cancer.

Hyperthyroidism in adolescents

The term 'hyperthyroidism' refers to a form of thyrotoxicosis due to inappropriate high synthesis and secretion of thyroid hormone(s) by the thyroid. The leading cause of hyperthyroidism in adolescents is Graves' disease (GD); however, one should also consider other potential causes, such as toxic nodular goitre (single or multinodular), and other rare disorders leading to excessive production and release of thyroid hormones. The term 'thyrotoxicosis' refers to a clinical state resulting from inappropriate high thyroid hormone action in tissues, generally due to inappropriate high tissue thyroid hormone levels. Thyrotoxicosis is a condition with multiple aetiologies, manifestations, and potential modes of therapy. By definition, the extrathyroidal sources of excessive amounts of thyroid hormones, such as iatrogenic thyrotoxicosis, factitious ingestion of thyroid hormone, or struma ovarii, do not include hyperthyroidism. The aetiology of hyperthyroidism/and thyrotoxicosis should be determined. Although the diagnosis is apparent based on the clinical presentation and initial biochemical evaluation, additional diagnostic testing is indicated. This testing should include: (1) measurement of thyroid-stimulating hormone receptor (TSHR) antibodies (TRAb); (2) analysis of thyroidal echogenicity and blood flow on ultrasonography; or (3) determination of radioactive iodine uptake (RAIU). A 123I or 99mTc pertechnetate scan is recommended when the clinical presentation suggests toxic nodular goitre. A question arises regarding whether diagnostic workup and treatment (antithyroid drugs, radioiodine, surgery, and others) should be the same in children and adolescents as in adults, as well as whether there are the same goals of treatment in adolescents as in adults, in female patients vs in male patients, and in reproductive or in postreproductive age. In this aspect, different treatment modalities might be preferred to achieve euthyroidism and to avoid potential risks from the treatment. The vast majority of patients with thyroid disorders require life-long treatment; therefore, the collaboration of different specialists is warranted to achieve these goals and improve patients' quality of life.

The Efficacy and Short- and Long-Term Side Effects of Radioactive Iodine Treatment in Pediatric Graves' Disease: A Systematic Review

BACKGROUND

Graves's disease (GD) is the most common cause of hyperthyroidism. Maximal 30% of pediatric GD patients achieve remission with antithyroid drugs. The majority of patients therefore require definitive treatment. Both thyroidectomy and radioactive iodine (RAI) are often used as definitive treatment for GD. However, data on efficacy and short- and long-term side effects of RAI treatment for pediatric GD are relatively scarce.

METHODS

A systematic review of the literature (PubMed and Embase) was performed to identify studies reporting the efficacy or short- and long-term side effects of RAI treatment in pediatric GD.

RESULTS

Twenty-three studies evaluating 1,283 children and adolescents treated with RAI for GD were included. The treatment goal of RAI treatment changed over time, from trying to achieve euthyroidism in the past to aiming at complete thyroid destruction and subsequent hypothyroidism in the last 3 decades. The reported efficacy of a first RAI treatment when aiming at hypothyroidism ranged from 42.8 to 97.5%, depending on the activity administered. The efficacy seems to increase with higher RAI activities. When aiming at hypothyroidism, both short- and long-term side effects of treatment are very rare. Long-term side effects were mainly seen in patients in whom treatment aimed at achieving euthyroidism.

CONCLUSION

RAI is a safe definitive treatment option for pediatric GD when aiming at complete thyroid destruction. When aiming at hypothyroidism, the efficacy of treatment seems to increase with a higher RAI activity. Prospective studies are needed to determine the optimal RAI dosing regimen in pediatric GD.

Success rate of radioactive iodine treatment for children and adolescent with hyperthyroidism

PURPOSE

To assess the success rate of first dose radioiodine for treatment of hyperthyroidism in children and adolescent.

METHODS

This is a retrospective data analysis of children and adolescent with hyperthyroidism who received radioiodine (RAI) therapy from January 2013 to December 2017. Age, gender, family history of hyperthyroidism, duration of anti-thyriod drugs (ATDs) treatment, rapid turnover status, 2 h and 24 h I-131 radioiodine uptake (RAIU), thyroid volume, and treatment dose were also analyzed. The goal of RAI therapy was to achieve hypothyroidism within 3-6 months after treatment. Treatment result was evaluated at 6 months after treatment and divided into 2 groups: treatment success (hypothyroid and euthyroid) and treatment failure (hyperthyroid). The same parameters were compared between both groups.

RESULTS

32 hyperthyroid patients, 26 female with mean age at treatment of 13.84 ± 1.83 years. All patients had prior treatment with ATDs, with a median treatment duration of 32.5 months (range 2-108). The median estimated thyroid gland size was 24.62 g, range 9.29-72.8. RAI doses ranged from 4.1 to 29.9 mCi (median dose = 7.54 mCi). Significant difference in 24-h I-131 uptake and RI status was demonstrated. Successful treatment rate after single dose of therapeutic I-131 was 65.63%.

CONCLUSION

With the I-131 dose of 220 μCi/g of thyroid tissue, successful treatment rate after single dose of therapeutic I-131 was 65.63%. RAI therapy with I-131 dose of 250-400 μCi/g of thyroid tissue might be suitable in patients with medical failure from ATDs. Possible role of RI as the predictor for RAI therapy failure are needed to investigate in both adult and children clinical settings.

Long-Term Outcomes of Radioiodine Therapy for Juvenile Graves Disease with Emphasis on Subsequently Detected Thyroid Nodules: A Single Institution Experience from Japan

OBJECTIVE

To investigate the long-term outcomes of radioiodine therapy (RIT) for juvenile Graves disease (GD) and the ultrasonographic changes of the thyroid gland.

METHODS

All of 117 juvenile patients (25 males and 92 females, aged 10 to 18 [median 16] years) who had undergone RIT for GD at our clinic between 1999 and 2018 were retrospectively reviewed. Each RIT session was delivered on an outpatient basis. The maximum 131I dose per treatment was 13.0 mCi, and the total 131I dose per patient was 3.6 to 29.8 mCi (median, 13.0 mCi). 131I administration was performed once in 89 patients, twice in 26, and three times in 2 patients. Ultrasonography of the thyroid gland was regularly performed after RIT. The duration of follow-up after the initial RIT ranged from 4 to 226 (median 95) months.

RESULTS

At the latest follow-up more than 12 months after RIT (n = 111), the patients' thyroid functions were overt hypothyroidism (91%), subclinical hypothyroidism (2%), normal (5%), or subclinical hyperthyroidism (2%). New thyroid nodules were detected in 9 patients, 4 to 17 years after initial RIT. Patients with newly detected thyroid nodules underwent RIT with lower doses of 131I and had larger residual thyroid volumes than those without nodules. None of the patients were diagnosed with thyroid cancer or other malignancies during the follow-up period.

CONCLUSION

Over a median follow-up period of 95 months (range, 4 to 226 months), RIT was found to be effective and safe in juvenile GD. However, cumulative evidence from further studies is required to confirm the long-term safety of RIT for juvenile GD.

ABBREVIATIONS

ATD = antithyroid drug; GD = Graves disease; KI = potassium iodide; LT4 = levothyroxine; MMI = methimazole; PTU = propylthiouracil; RAIU = radio-active iodine uptake; RIT = radioiodine therapy; 99mTc = technetium-99m; TSH = thyrotropin.

Surgical treatment of children Graves' disease with huge goiter-a case report and literature review

Graves' disease is the most common cause of hyperthyroidism in children. The surgery treatment for children Graves' disease with huge goiter is high risk and controversial. A 14-year-old girl suffered Graves' disease with huge goiter and failed to the antithyroid drug therapy for nearly 4 years was surgically treated with total thyroidectomy. The excised thyroid weighed 449.1 g and heavier than any excised children goiter reported so far. After operation, the patient's symptoms of Graves' disease were significantly improved without any complication, including normal basal metabolic rate, relieved exophthalmia and euthyroidism. So, a children Graves' disease with huge goiter was cured by total thyroidectomy, suggesting that a total/near-total thyroidectomy is a good option for children Graves' disease with huge goiter.

Correlation of radioiodine doses for 6-hr and 24-hour iodine-131 thyroid uptake values for Graves' hyperthyroidism

The destruction of thyroid follicular cells by iodine-131 treatment for Graves' hyperthyroidism to a large extent depends on the amount of intrathyroidal activity absorbed (IAA). A thyroid weighing 50 g should receive an iodine-131 therapeutic dosage of between 110 MBq and 350 MBq for the effective treatment of Graves' hyperthyroidism. An IAA received of more than 350 MBq to the thyroid will bestow an unnecessary high iodine-131 therapeutic dosage. The objective of the study was to determine if the IAA would remain between 110 MBq and 350 MBq if the calculated administered activity (CAA) has been used with the highest radioactive iodine uptake (RAIU) value. A retrospective analysis was made of the 6- and 24-hr iodine-131 RAIU results of Graves' hyperthyroid patients (n = 124). Male (n = 18) and female (n = 106) patients from different racial groups and ranging from 15 to 75 years of age were included in the study. Overall, the CAA using the 6-hr RAIU value was higher. The CAA by the 6-hr RAIU values was used with the 24-hr RAIU values to calculate the IAA. 53.3% (n = 66) of the study group would have received IAA higher than 350 MBq when the CAA by the 6-hr RAIU values was used with the 24-hr RAIU values to calculate the IAA. These results suggested that the 24-hr RAIU value was most valuable for the calculation of an administered activity so that IAA of between 110 and 350 MBq can be achieved.

Safety of long-term antithyroid drug treatment? A systematic review

Continued low-dose MMI treatment for longer than 12-18 months may be considered in patients not in remission. However, ATDs are not free from adverse effects. We undertook a systematic review to clarify safety of long-term ATD treatment. Medline and the Cochrane Library for trials published between 1950 and Nov 2018 were systematically searched. We included original studies containing data for long-term (> 18 months) ATD treatment. Two reviewers independently extracted data from included trials and any disagreement was adjudicated by consensus. Of 615 related articles found, 12 fulfilled the criteria. Six articles had data for adults, five for non-adults and one article had data for both groups. The sample sizes ranged between 20 and 249 individuals, and the mean duration of ATD treatment ranged between 2.1 and 14.2 years. Considering all data from 1660 patients treated with ATD for a mean duration of 5.8 years (around 10,000 patient-years), major complications occurred only in 14 patients: 7 severe agranulocytosis, 5 severe liver damage, one ANCA-associated glomerulonephritis and one vasculitis with small cutaneous ulcerations. Minor complications rates were between 2 and 36%, while more complications were in higher doses and in the children. The most reported AE was cutaneous reaction; the other adverse events were elevated liver enzymes, leukocytopenia, arthritis, arthralgia, myalgia, thrombocytopenia, fever, nausea and oral aphthous. Long-term ATD treatment is safe, especially in low dose and in adults, indicating that it should be considered as an earnest alternative treatment for GD.

Long-term outcome of hyperthyroidism diagnosed in childhood and adolescence: a single-centre experience

Background The objective of the study was to evaluate the long-term outcome of paediatric-onset hyperthyroidism with follow-up into adulthood and to identify any early predictors of a need for definitive therapy (DT). Methods In a retrospective analysis of patients diagnosed with hyperthyroidism under the age of 18 years and at follow-up, a comparison was made by categorising them into those who underwent definitive therapy (DT group), i.e. thyroidectomy/radioactive iodine (RAI), those who remained on antithyroid drugs (ATD) (CBZ group) and those who had complete remission (RE group). Results Sixty-one (49 females, 12 males) patients with a median age of 15.1 years (range: 3.6-18) at diagnosis were studied. The duration of the first course of ATD varied from <1 year (7%), 1-2 years (26%), >2 years (46%) and ATD never discontinued (21%). Disease relapsed in 69% of patients with <1 year of ATD vs. 79% with >2 years of ATD. At follow-up, the median duration since diagnosis was 8.75 years (range 2.0-20.7 years) and the median age at follow-up was 23.2 years (8-36 years). Thirty-three percent (20/61) had undergone DT (DT group) - with 16.5% (n=10) on RAI and 16.5% (n=10) on surgery, 36% (22/61) were on ATD (CBZ group), whilst 32% (19/61) had undergone full remission (RE group). The comparison did not identify any statistically significant difference for predictor factors at diagnosis including age, T4 and free T4 levels, thyroid peroxidise antibody levels (TPO) and the duration of the first course of carbimazole (CBZ) treatment. Conclusion Long-term complete remission of paediatric-onset hyperthyroidism in our study was 31%. There were no predictors identified that could help predict the long-term outcome, especially into adulthood.

Controversies in the pharmacological treatment of Graves' disease in children

INTRODUCTION

Graves' disease (GD) is a disorder, in which auto-immunity against the thyroid- stimulating hormone (TSH) receptor is the pivotal pathogenetic element. This disease may have different clinical manifestations, the most common being thyrotoxicosis. Treatment of this condition differs according to its etiology, but there is currently no evidence-based therapeutic strategy which is universally adopted in all countries. Areas covered: a systematic review of the updates on the management of pediatric GD was performed using the Pubmed data base until March 2018. Systematic reviews with or without meta-analysis were analyzed using the following terms: Antithyroid drugs, Childhood, Hyperthyroidism, Radioactive iodine, Thyroidectomy. Expert commentary: As the best way to manage children with GD remains a matter of debate among pediatric endocrinologists, and there is currently no evidence-based therapeutic strategy which is universally adopted, we confirm that the original and prolonged treatment with anti-thyroid drugs (ATDs) remains the mainstay of treatment for juvenile hyperthyroidism. Alternative treatments include radioiodine (RAI) therapy or surgery (total thyroidectomy). We recommend individualizing the therapeutic approach, without prejudices toward radical therapies that become necessary in case of relapse, adverse effects or poor compliance to ATDs. The optimal approach depends on patient or family preference, and specific patient clinical features.

Long-Term Antithyroid Drug Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies have reported inconsistent findings on the advantages and disadvantages of long-term treatment with antithyroid drugs (ATD). A systematic review and meta-analysis was undertaken to clarify the numerous aspects of long-term treatment with ATD.

METHODS

Medline and the Cochrane Library for trials published between 1950 and May 2016 were systematically searched. Studies containing data for long-term (>24 months) ATD treatment were included. Summary estimates of pooled prevalence, odds ratio, and weighted mean difference were calculated with a random effects model.

RESULTS

Of 587 related articles found, six fulfilled the inclusion criteria. Long-term ATD treatment induced a remission rate of 57% [confidence interval (CI) 45-68%], a rate that was higher in adults than in non-adults (61% vs. 53%). The rate of complications was 19.1% [CI 9.6-30.9%], of which only 1.5% were major complications. The annual remission rate for each year of treatment was 16% [CI 10-27%], which was higher in adults than non-adults (19% vs. 14%). However, it should be noted that this is not a true linear correlation, but a positive relationship can be suggested between time and remission rate. Meta-regression revealed that smoking had a significant lowering effect on remission rate.

CONCLUSIONS

Long-term ATD treatment is effective and safe, especially in adults, indicating that it should be considered as an alternative treatment for Graves' disease.

Guidelines for the treatment of childhood-onset Graves' disease in Japan, 2016

Purpose behind developing these guidelines: Over one decade ago, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (Japan Thyroid Association (JTA)) were published as the standard drug therapy protocol for Graves’ disease. The “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” were published to provide guidance on the treatment of pediatric patients. Based on new evidence, a revised version of the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (JTA) was published in 2011, combined with the “Handbook of Radioiodine Therapy for Graves’ Disease 2007” (JTA). Subsequently, newer findings on pediatric Graves’ disease have been reported. Propylthiouracil (PTU)-induced serious hepatopathy is an important problem in pediatric patients. The American Thyroid Association’s guidelines suggest that, in principle, physicians must not administer PTU to children. On the other hand, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2011” (JTA) state that radioiodine therapy is no longer considered a “fundamental contraindication” in children. Therefore, the “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” required revision.

Graves' disease in a 3 year-old patient with agranulocytosis due to anti-thyroid drugs: Radioiodine ablation therapy as an effective alternative

The case is presented of a 3 year-old girl with mitochondrial disease (subacute necrotizing encephalomyelopathy of Leigh syndrome), v-stage chronic kidney disease of a diffuse mesangial sclerosis, as well as developmental disorders, and diagnosed with hyperthyroidism Graves-Basedow disease. Six weeks after starting the treatment with neo-carbimazole, the patient reported a serious case of agranulocytosis. This led to stopping the anti-thyroid drugs, and was treated successfully with ¹³¹I ablation therapy. The relevance of the article is that Graves' disease is uncommon in the paediatric age range (especially in children younger than 6 years old), and developing complications due to a possible late diagnosis. Agranulocytosis as a potentially serious adverse effect following the use of anti-thyroid drugs, and the few reported cases of ablation therapy with ¹³¹I at this age, makes this case unique.

DYNAMIC CHANGES OF TRAb AND TPOAb AFTER RADIOIODINE THERAPY IN GRAVES' DISEASE

Context

To analyze the dynamic changes of serum thyrotrophin receptor antibody (TRAb) and thyroid peroxidase antibody (TPOAb) in Graves' disease (GD) patients before and after radioactive iodine (RAI) treatment and to investigate if TRAb and TPOAb play a role in the occurrence of early hypothyroidism after ¹³¹I therapy for Graves' hyperthyroidism.

Subjects and Methods

A total of 240 patients newly diagnosed with GD were selected to study. A clinical and laboratory assessment was performed before and at 3, 6, and 12 months after ¹³¹I therapy. Chemiluminescent immunoassays were used to detect serum free triiodothyronine (FT3), free thyroxine (FT4), sensitive thyroid-stimulating hormone (TSH) and TPOAb concentration. Radio-receptor assay was used to measure serum TRAb concentration. According to the early onset of hypothyroidism in a year after RAI therapy, patients were divided into early hypothyroidism group (group A) and non-early hypothyroidism group (group B).

Results

In both groups, serum TRAb and TPOAb increased at 3 months, reached the highest level at 6 months and returned to the baseline at 12 months after RAI therapy. TRAb showed a significant difference between the two groups at 6 months (P<0.01). Serum TPOAb in group A was higher than that in group B before and at 3, 6, 12 months after RAI therapy (P<0.05).

Conclusions

Serum TRAb and TPOAb are closely related to the occurrence of the early hypothyroidism, and play an important role in judging prognosis after ¹³¹I treatment in Graves' disease.

Radioiodine therapy of thyrotoxicosis in children and adolescents. Indications, efficacy and safety. Literature review

Болезнь Грейвса (БГ) – основная причина тиреотоксикоза у детей. В современной клинической практике применяется три метода лечения БГ: тиреостатики, радиоактивный йод и операция. Все эти методы лечения применяются давно, и в мире накоплен огромный опыт применения каждого из методов лечения. Лечение начинают практически всегда с тиреостатиков, непереносимость или неэффективность которых становится показанием к выбору альтернативных методов лечения. Для осознанного выбора метода лечения необходимо понимать его потенциальные параметры эффективности и безопасности, а также влияющие на них факторы. Цель обзора – критический анализ эффективности и безопасности радиойодтерапии в лечении тиреотоксикоза у детей и подростков в сравнении с аналогичными показателями других методов лечения, а также показания и противопоказания к данному виду лечения в современной клинической практике эндокринологов, радиологов и эндокринных хирургов. Выбор тактики лечения БГ у ребенка на каждом этапе осуществляется согласованно с ним и его родителями/опекунами путем информирования лечащим врачом об объективных преимуществах и недостатках методов лечения на основе имеющейся доказательной базы. Также приведены основные рекомендации эффективной и безопасной терапии радиоактивным йодом БГ у детей и подростков.

[Radioiodine therapy for benign thyroid diseases (version 5). German Guideline]

The version 5 of the guideline for radioiodine therapy of benign thyroid disorders is an update of the version 4, which was published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) in co-ordination with the German Society of Endocrinology (Deutsche Gesellschaft für Endokrinologie, DGE, Sektion Schilddrüse) and the German Society of General- and Visceral-Surgery (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie, DGAV) in 2007. This guideline was harmonized with the recommendations of the European Association of Nuclear Medicine (EANM). According to the German "Directive on Radiation Protection in Medicine" the physician specialised in nuclear medicine ("Fachkunde in der Therapie mit offenen radioaktiven Stoffen") is responsible for the justfication to treat with radioiodine. Therefore, relevant medical indications for radioiodine therapy and alternative therapeutic options are discussed within the guideline. This procedure guideline is developed in the consensus of a representative expert group. This fulfils the level S1 (first step) within the German classification of Clinical Practice Guidelines.

Complications in head and neck surgery

Head and neck anatomy is topographically complex and the region is densely populated by vital nerves and vascular and lymphatic structures. Injury to many of these structures is associated with significant morbidity and may even be fatal. A thorough knowledge of regional anatomy is imperative and complications need to be managed in a thoughtful directed manner. The pediatric surgeon may be called upon to address both congenital and acquired conditions and should be prepared to encounter reoperative fields after failed initial surgery. This review summarizes the current literature on four frequently encountered surgical conditions of the head and neck: branchial cleft anomalies, thyroglossal duct cyst, thyroid disease, and lymphatic malformations, with a focus on the prevention and treatment of complications.

Delayed methimazole-induced agranulocytosis in a 6-year old patient with Graves’ disease

Background

Agranulocytosis is regarded as a rare side effect of methimazole (MMI) therapy that occurs in a dose dependent manner and that usually develops within the first 3–6 months of treatment. Although delayed development beyond this timeline has been documented in adults, very few children have been reported with this presentation.

Case presentation

We present a 6-year old patient who developed agranulocytosis 18 months after the start of MMI therapy.

Conclusions

This is an unusual case of a 6-year old patient who developed this serious side effect on stable MMI therapy well beyond the typical timeline. Our review of the literature revealed that there really is inconclusive data on the incidence, time, and dose-dependency of MMI-induced agranulocytosis in the pediatric Graves’ disease population.

Comparative analysis of radioactive iodine versus thyroidectomy for definitive treatment of Graves disease

BACKGROUND

Management of Graves disease includes antithyroid drugs, ¹³¹I therapy, or thyroidectomy. Our aim was to review our institutional experience with definitive treatments for Graves disease.

METHODS

This was a retrospective review of patients undergoing ¹³¹I therapy (n = 295) or thyroidectomy (n = 103) for Graves disease (2003-2015). Demographic, clinical, pathology, and outcome data were collected from institutional databases.

RESULTS

¹³¹I therapy patients were older (39.1 years vs 33.4 years, P = .001). There was no difference in the presence of ophthalmopathy between groups. A larger proportion of children received thyroidectomy than ¹³¹I therapy (17.1% vs 9.2%, P = .026). The success rate of the first ¹³¹I therapy dose was 81.4%. Overall success rate, including additional doses, was 90.1%. Rapid turnover of iodine correlated with ¹³¹I therapy failure (58.3% rapid turnover failure vs 14.9% non-rapid turnover failure, P < .05). All surgical patients underwent total or near-total thyroidectomy. ¹³¹I therapy complications included worsening thyrotoxicosis (1%) and deteriorating orbitopathy (0.7%). Operative complications were higher than ¹³¹I therapy complications (P < .05) but were transient. There was no worsening orbitopathy or recurrent Graves disease among surgical patients.

CONCLUSION

A higher proportion of pediatric Graves disease patients underwent thyroidectomy than ¹³¹I therapy. Rapid turnover suggested more effective initial management with operation than ¹³¹I therapy. Although transient operative complications were high, ¹³¹I therapy complications included worsening of Graves orbitopathy among those with pre-existing orbitopathy.

Thyroidectomy for Graves' disease in children: Indications and complications

BACKGROUND

The utilization of thyroidectomy for Graves' disease remains controversial; we aim to evaluate the indications for and complications of thyroidectomy for Graves' in children.

METHODS

A retrospective analysis was performed on all Graves' patients who underwent thyroidectomy from 2009 to 2013 at a high volume academic center. Pediatric patients were <18years old, and a comparative analysis of indications for surgery and complications was performed.

RESULTS

167 patients underwent thyroidectomy: 31 pediatric patients and 136 adults. Failure of antithyroid medications was the indication for surgery in 55% of the children vs 36% of adults (p=0.05). Mean duration of medications prior to surgery was similar. No children had failed RAI therapy prior to surgery, but 12.5% of the adult population had (p=0.04). Surgical outcomes were similar.

CONCLUSION

Clinicians may be more likely to refer children who fail medical treatment to surgery over RAI. Thyroidectomy at a high volume hospital should be discussed as a treatment option for children with Graves'.

Graves' disease in children: long-term outcomes of medical therapy

BACKGROUND AND OBJECTIVES

Management options are limited for the treatment of Graves' disease, and there is controversy regarding optimal treatment. We describe the demographic and biochemical characteristics of children with Graves' disease and the outcomes of its management.

METHODS

This is a retrospective study reviewing medical records from 2001 to 2011 at a tertiary-care paediatric hospital. Diagnostic criteria included elevated free T4 and total T3, suppressed TSH, and either positive thyroid-stimulating immunoglobulin or thyroid receptor antibodies or clinical signs suggestive of Graves' disease, for example exophthalmos. Patients were treated with antithyroid drugs (ATD), radioactive iodine, or thyroidectomy. The main outcome measures were remission after medical therapy for at least 6 months and subsequent relapse.

RESULTS

A total of 291 children met diagnostic criteria. A total of 62 were male (21%); 117 (40%) were Hispanic, 90 (31%) Caucasian, and 59 (20%) African American. Mean age (±standard deviation) at diagnosis was 12·3 ± 3·8 (range 3-18·5) years. At diagnosis, 268 patients were started on an antithyroid drug and 23 underwent thyroid ablation or thyroidectomy. Fifty-seven (21%) children achieved remission and 16 (28%) of these patients relapsed, almost all within 16 months. Gender and ethnicity did not affect rates of remission or relapse. Of 251 patients treated with methimazole, 53 (21%) had an adverse reaction, including rash, arthralgias, elevated transaminases, or neutropenia.

CONCLUSIONS

Most children with Graves' disease treated with ATD do not experience remission, but most remissions do not end in relapse. Adverse reactions to methimazole are common but generally mild.

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.

Management of hyperthyroidism in children

Treatment of hyperthyroidism in children differs according to its etiology; in particular, the optimal therapy of Graves' disease (GD) remains a matter of debate and there is currently no evidence-based therapeutic strategy that is universally adopted in all the countries. Areas covered: The most recent treatment strategies in the different pediatric conditions which may be associated with hyperthyroidism. We searched PubMed and Cochrane (1990 to 2016) in order to identify articles to include in this review using the following terms: Hyperthyroidism, Childhood, Antithyroid drug therapy, Thyroidectomy, Radioactive iodine. Expert commentary: Although pharmacological therapy represents the first-line approach for GD children, we recommend to individualize, as much as possible, the overall therapeutic approach, with no prejudices towards radical therapies, particularly in the cases with frequent relapses. Clinical and laboratory preferential criteria for an individualized therapeutic approach to GD children are given. Treatment procedures for hyperthyroid children without GD are also discussed.

Predictive factors for early response to methimazole in children and adolescents with Graves disease: a single-institute study between 1993 and 2013

PURPOSE

We aimed to investigate the predictive factors for early response to methimazole (MMI) in pediatric patients with Graves disease (GD).

METHODS

Our study included 44 pediatric patients who were diagnosed with GD between January 1, 1993, and December 31, 2013, and were available for follow-up, achieving a normalization of thyroid functions (TFs) at the Chonbuk National University Hospital Pediatric Department. We retrospectively analyzed TFs such as tri-iodothyronine (T3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), and thyroid antibody levels at diagnosis. We also examined their family history of thyroid disease, symptoms at presentation, and normalization time for TF after treatment. We divided our clinical series of patients into the following 4 age groups: <7 years old, 7-12 years old, 13-15 years old, and 16-18 years old.

RESULTS

At diagnosis, the time of normalization of T3 was significantly shorter in the higher antimicrosomal antibody (AMA) group compared with the lower AMA group (2.53 months vs. 6.18 months) (P<0.05). However, the time of normalization of T3/fT4/TSH had no significant correlations with other variables such as age, sex, a family history of thyroid diseases, thyroglobulin, thyroid-stimulating immunoglobulin, or antithyroglobulin antibody (ATA).

CONCLUSION

Higher serological titers of AMA at diagnosis may have prognostic value in the response to initial MMI treatment in pediatric hyperthyroid GD patients.

Nuclear Medicine in Thyroid Diseases in Pediatric and Adolescent Patients

Both benign and malignant diseases of the thyroid are rare in the pediatric and adolescent population, except congenital hypothyroidism. Nuclear medicine plays a major role, both in the diagnosis and therapy of thyroid pathologies. Use of radioactivity in pediatric population is strictly controlled due to possible side effects such as secondary cancers; therefore, management of pediatric patients requires detailed literature knowledge. This article aims to overview current algorithms in the management of thyroid diseases and use of radionuclide therapy in pediatric and adolescent population.

Influence of prior carbimazole on the outcome of radioiodine therapy in pediatric and adolescent Graves' disease

OBJECTIVE OF THE STUDY

Therapeutic options for pediatric Graves' disease (PGD) include antithyroid drug therapy (ATD) as the first line and radioiodine (I-131) therapy as the second line of treatment. To date, controversies persist regarding the true effect of prior ATD in the outcome of I-131 therapy in PGD. This study evaluated the effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD.

METHODS

This is a retrospective study covering the years 1995-2012, with a median follow-up of 75 months. Records of 114 children (84 girls and 30 boys, age range: 5-20 years, mean 24-h radioiodine uptake, 58%) who had clinically and biochemically proven Graves' disease irrespective of prior ATD therapy were included. All patients were treated with fixed doses of 5 mCi (185 MBq) I-131 for Graves' disease; 74 had undergone prior carbimazole treatment (group 1) and 40 were drug naive (group 2). The endpoint of follow-up was stable euthyroid or hypothyroid in patients. The effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD patients was evaluated. The success of radioiodine therapy was defined as the cure of hyperthyroidism. Variables were analyzed to identify the potential predictive factors for euthyroidism/hypothyroidism after treatment.

RESULTS

The cure rate was 70% in group 1 and 83% in group 2 with a single dose of radioiodine (P=0.299). The success rate achieved at the end of 1-year follow-up in group 1 and group 2 was 81 and 87%, respectively (P=0.401). No independent predictor was associated with success or failure of treatment. At the median follow-up of 75 months (range: 12-216 months), 76% of patients were hypothyroid on replacement doses of levothyroxine and 24% still continued to be euthyroid.

CONCLUSION

Prior carbimazole treatment does not alter the outcome of radioiodine therapy in PGD.

The treatment of Graves' disease in children and adolescents

Graves' disease (GD) accounts for 10%-15% of thyroid disorders in children and adolescents. The use of antithyroid drugs as the initial treatment option in GD is well accepted. An average two years remission is achieved in about 30% of children treated with antithyroid drugs. However, the optimal treatment duration and the predictive marker of remission after antithyroid drug therapy are still controversial. Additionally, (131)I therapy and surgery are considered the option for treatment in children and adolescents with GD. We review the treatment options for pediatric GD and the possible determinants of remission and relapse on antithyroid drug treatment in children and adolescents.

The Brazilian consensus for the diagnosis and treatment of hyperthyroidism: recommendations by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

INTRODUCTION

Hyperthyroidism is characterized by increased synthesis and release of thyroid hormones by the thyroid gland. Thyrotoxicosis refers to the clinical syndrome resulting from excessive circulating thyroid hormones, secondary to hyperthyroidism or due to other causes. This article describes evidence-based guidelines for the clinical management of thyrotoxicosis.

OBJECTIVE

This consensus, developed by Brazilian experts and sponsored by the Department of Thyroid Brazilian Society of Endocrinology and Metabolism, aims to address the management, diagnosis and treatment of patients with thyrotoxicosis, according to the most recent evidence from the literature and appropriate for the clinical reality of Brazil.

MATERIALS AND METHODS

After structuring clinical questions, search for evidence was made available in the literature, initially in the database MedLine, PubMed and Embase databases and subsequently in SciELO - Lilacs. The strength of evidence was evaluated by Oxford classification system was established from the study design used, considering the best available evidence for each question.

RESULTS

We have defined 13 questions about the initial clinical approach for the diagnosis and treatment that resulted in 53 recommendations, including the etiology, treatment with antithyroid drugs, radioactive iodine and surgery. We also addressed hyperthyroidism in children, teenagers or pregnant patients, and management of hyperthyroidism in patients with Graves' ophthalmopathy and various other causes of thyrotoxicosis.

CONCLUSIONS

The clinical diagnosis of hyperthyroidism usually offers no difficulty and should be made with measurements of serum TSH and thyroid hormones. The treatment can be performed with antithyroid drugs, surgery or administration of radioactive iodine according to the etiology of thyrotoxicosis, local availability of methods and preferences of the attending physician and patient.

Graves' disease in children

Graves' disease is an autoimmune disorder resulting from thyrotropin receptor stimulation by autoantibodies. It may occur at any age during childhood, but its frequency increases with age, peaking during adolescence. Symptoms and signs are often recognizable and proportional to the increase in serum free thyroid hormone levels. Antithyroid drug treatment with methimazole (or carbimazole) is recommended for initial treatment, but relapse rates are high, with remission achieved in only 30% of children after a first course of treatment for about two years. More prolonged medical treatment may increase the remission rate to up to 50%. Alternative treatments, such as radioactive iodine or thyroidectomy, are considered in cases of relapse, lack of compliance or antithyroid drug toxicity. Relapse risk decreases with increasing duration of the first course of antithyroid drug treatment. The identification of other predictive factors, such as severe biochemical hyperthyroidism at diagnosis, young age and the absence of other autoimmune conditions, has made it possible to stratify patients according to the risk of relapse, leading to improvements in patient management, by facilitating the identification of patients requiring long-term antithyroid drug treatment or early alternative therapy.

A teenage boy with hypocalcemia after radioablation for Graves' disease

Excessive thyroid hormone production, as seen in Graves' disease, stimulates osteoblast-mediated bone turnover in favor of bone resorption. Acute reversal of bone resorption can lead to hungry bone syndrome (HBS), a state of rapid calcium deposition into newly synthesized osteoid resulting in hypocalcemia. Hypocalcemia due to subsequent functional or relative hypoparathyroidism is a recognized complication of therapy for Graves' disease. HBS is most recognized as an outcome of rapid correction of vitamin D deficiency or of acute hypoparathyroidism in cases of parathyroid gland function disruption after surgical removal of the thyroid. We report the case of an adolescent boy with Graves' disease who presented with hypocalcemia after radioactive iodine (131I) therapy due to HBS. Our report highlights the risk of HBS and severe hypocalcemia following treatment for Graves' disease in pediatric patients and also underscores the importance of pretreatment assessment and intervention for coexistent vitamin D deficiency.

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.

Thyroid disease in children: part 2 : State-of-the-art imaging in pediatric hyperthyroidism

Hyperthyroidism occurs secondary to overproduction of thyroid hormone by the thyroid gland. This condition can have rather serious effects on children, and thus timely diagnosis and treatment are of utmost importance. Imaging is quite useful in the management of children with hyperthyroidism. In addition to determining the underlying pathology, radiologic exams are crucial for therapy. This article describes the underlying etiologies of pediatric hyperthyroidism and provides general information on treatment.

Radioactive iodine for thyrotoxicosis in childhood and adolescence: treatment and outcomes

OBJECTIVE

The aim of the present study was to evaluate the outcome of radioiodine treatment in thyrotoxicosis in childhood and adolescence.

METHODS

This was a retrospective study of 27 patients (ages 7.2- 19.8 years) with a diagnosis of thyrotoxicosis who received iodine-131 (I-131) treatment from January 2007 to December 2011 in the Nuclear Medicine Division, Department of Radiology, Faculty of Medicine, Chiang Mai University. Gender, duration of antithyroid drug (ATD) treatment, 24-hour I-131 uptake, thyroid weight, total dose and number of treatments with I-131, and thyroid status at 6 months after treatment were recorded.

RESULTS

The outcomes of 27 patients (85.2% female, 14.8% male) treated with radioactive iodine were analyzed to assess the effectiveness of therapy as related to dose and gland size. All children and adolescents received 150 µCi of I-131/g of thyroid tissue (n=27). Six 6 months after treatment, 44.5% of the patients were hyperthyroid, 14.8% were euthyroid, and 40.7% were hypothyroid. Of the 12 cases with hyperthyroidism, 2 cases needed a second dose of I-131 treatment, and they finally reached a hypothyroid state. The patients were classified into 2 groups according to treatment success (euthyroid and hypothyroid) and treatment failure (hyperthyroid). There were no significant differences in age, gender, duration of ATD treatment, 2- and 24-hour I-131 uptake, thyroid weight, and total I-131 dose between these two groups.

CONCLUSIONS

Radioiodine treatment is safe and effective for thyrotoxicosis in childhood and adolescence. It is suitable as a good second-line therapy for patients with severe complications, those who show poor compliance, and those who fail to respond to ATD treatment.

Clinical experience with radioactive iodine in the treatment of childhood and adolescent Graves' disease

BACKGROUND/AIMS

Treatments for Graves' disease (GD) in children and adolescents include oral antithyroid drugs (ATDs), near total thyroidectomy, and radioactive iodine (RAI). ATDs remain the preferred choice in this age group, but because persistent remission occurs in 30% of cases, RAI is becoming a common option for definitive therapy.

METHODS

We performed a review of 65 medical records of GD patients under age 19 years who were followed between 1985 and 2005.

RESULTS

The prevalence of GD was higher in females (3:1) and during puberty (for both genders). If no remission was detected during ATD treatment, RAI was indicated when the following criteria were present: non-compliance, relapse, or side effects that were related to ATDs, large goiter, and long-term use of ATDs. The majority of patients developed hypothyroidism within 6 months after RAI. A progressive higher dose regimen was implemented in the last 10 years of the study period. A second RAI dose was necessary in eight cases. During the follow-up period, three pregnancies occurred. One patient with a thyroid nodule and benign cytology was detected.

CONCLUSIONS

RAI therapy is effective and safe in the treatment of GD in children and adolescents.

Anaplastic thyroid carcinoma following radioactive iodine therapy for graves' disease

Radioactive iodine (RAI) therapy has been used as a treatment option for Graves' disease, and it has been widely accepted to be safe. On the other hand, some evidence suggests that RAI therapy is possibly associated with a small increased risk of thyroid cancer. Herein, we report a rare case of anaplastic thyroid carcinoma (ATC) associated with Graves' disease, following RAI treatment. A 42-year-old woman had been diagnosed with Graves' disease and although she was treated with an antithyroid drug, she remained in a hyperthyroid state, which led to two RAI treatments. More than 10 years later, the patient revisited our clinic due to hoarseness, dysphagia, and dyspnea, which had lasted for 2 months. Neck computed tomography suggested thyroid carcinoma and a lymph node biopsy showed metastatic papillary carcinoma. The patient underwent total thyroidectomy and was finally diagnosed as having an ATC. It is not clear if the occurrence of ATC reported here was influenced by the RAI therapy or alternatively, it may only represent the delayed recognition of a rare change in the natural history of Graves' disease. Nevertheless, this report is worthwhile since it presents a very rare case of ATC that occurred eleven years after the RAI therapy for Graves' disease.

Hyperthyroidism in childhood: causes, when and how to treat

Graves' disease (GD) is the most common cause of hyperthyroidism in children. This review gives an overview and update of management of GD. Antithyroid drugs (ATD) are recommended as the initial treatment, but the major problem is the high relapse rate (30%) as remission is achieved after a first course of ATD. More prolonged medical treatment may increase the remission rate up to 50%. Alternative treatments, such as radioactive iodine or thyroidectomy, are considered in cases of relapse, lack of compliance, or ATD toxicity. Therefore, clinicians have sought prognostic indicators of remission. Relapse risk decreases with longer duration of the first course of ATD treatment, highlighting the positive impact of a long period of primary ATD treatment on outcome. The identification of other predictive factors such as severe biochemical hyperthyroidism at diagnosis, young age, and absence of other autoimmune conditions has made it possible to stratify patients according to the risk of relapse after ATD treatment, leading to improvement in patient management by facilitating the identification of patients requiring long-term ATD or early alternative therapy. Neonatal autoimmune hyperthyroidism is generally transient, occurring in only about 2% of the offspring of mothers with GD. Cardiac insufficiency, intrauterine growth retardation, craniostenosis, microcephaly and psychomotor disabilities are the major risks in these infants and highlight the importance of thyroid hormone receptor antibody determination throughout pregnancy in women with GD, as well as highlighting the need for early diagnosis and treatment of hyperthyroidism.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Increasing use of radioiodine in young people with thyrotoxicosis in Great Britain

OBJECTIVE

Radioiodine (RI) is an important therapeutic option in young patients with thyrotoxicosis. We wanted to determine whether RI is being used more frequently in this age group.

DESIGN

National survey of Great Britain (England, Wales and Scotland).

METHODS

Sixty-one medical physics departments were asked to provide the age and number of patients with thyrotoxicosis <21 years treated with RI (1990-2008). Information on the total number of RI treatments for thyrotoxicosis was also collected.

RESULTS

Forty-three departments (70%), with representation from 21 of the 25 most populous areas of Great Britain, provided data on 69,258 treatments. The number of treatments recorded on patients <21 years during this period was 560 (0.9%). The frequency of treatments in young people as a percentage of the total increased from 0.2% in 1990 to 1.5% in 2008 (P<0.001). When the 18 centres submitting at least 17 years of data were analysed, a similar pattern was observed. The maximum number of young people treated was greatest in 2008 (62) with a fall in the youngest age at which RI was administered from 18 years (1990) to 11 years (2008).

CONCLUSIONS

A rising proportion of patients with thyrotoxicosis receiving RI are in those <21 years. This is largely due to an increase in the number of young people treated with a reduction in the minimum age at RI administration. We suspect that European clinicians are becoming more comfortable with RI treatment in young people with thyrotoxicosis, although a changing incidence is a potential contributing factor.

In contrast to matrix metalloproteinases, serum adiponectin concentrations increase after radioiodine treatment of thyrotoxicosis

BACKGROUND

Matrix metalloproteinases (MMPs), together with their tissue inhibitors (TIMPs), remodel extracellular matrix under physiological and pathological conditions and are implicated in pathogenesis of cardiovascular diseases, cancer and in chronic inflammation. We have endeavoured to assess whether concentrations of MMPs, TIMPs, and anti-inflammatory adiponectin are altered by pharmacological treatment of acute thyrotoxicosis or by radioiodine therapy (RIT).

MATERIAL AND METHODS

We measured serum concentrations of MMP-2, MMP-9, TIMP-1, TIMP-2, and adiponectin, TSH, free T4 (FT4) and free T3 (FT3) in 15 patients (4 males), age (years) 51.8±15.3 (mean±SD) with hyperthyroidism treated with thiamazole (Group 1) and in 20 subjects (2 males), treated for thyrotoxicosis with radioiodine, age 52.3±12.4 (Group 2), where blood samples were taken before RIT, visit 1 (V1), seven days post RIT, visit 2 (V2), and two to three months post RIT, visit 3 (V3).

RESULTS

In Group 1 there was no significant change in concentrations of MMP-2, MMP-9, TIMP-1, TIMP-2 or adiponectin, despite a fall in FT4 and FT3 (8.74±4.79 pg/ml vs 3.54±2.40 pg/ml, for FT3, and 4.48 ±2.21 ng/ml vs 1.02±1.07 ng/ml, for FT4, p<0.001). In Group 2 RIT did not cause any acute change in serum MMP-2, MMP-9, TIMP-1 and TIMP-2 or adiponectin (V1 vs V2). However, there was a significant increase in serum adiponectin [from 15201±8860 ng/ml (V1) to 19373±8657 ng/ml (at V3), p<0.05], and TIMP-2 at V3 [from 129±45 ng/ml (V1) to 149±38 ng/ml (V3), p<0.01]. There was no significant change MMP-2, MMP-9 and TIMP-1 between V1 and V3. There was a decrease in FT4 and FT3 from 24.4±15.4 pmol/l (V1) to 14.7±10.6 pmol/l (V3), and from 10.0±5.65 (V1) to 6.1±4.8 pmol/l (V2), p<0.01, for FT4 and FT3, respectively.

CONCLUSIONS

Radioiodine therapy of thyrotoxicosis does not alter serum MMP-2, MMP-9 or TIMP-1 concentrations either acutely or after about three months of observation. An increase in serum adiponectin might reflect favourable effects of radioiodine administration on cardiovascular risk factors, while an increase in TIMP-2 (principal MMP-2 inhibitor) might lead to a decrease in free MMP-2 concentrations.

Pediatric pulmonary arterial hypertension and hyperthyroidism: a potentially fatal combination

CONTEXT

Patients with pulmonary arterial hypertension (PAH) who develop hyperthyroidism are at risk for acute cardiopulmonary decompensation and death.

CASES AND SETTING

We present a series of eight idiopathic PAH/heritable PAH pediatric patients who developed hyperthyroidism between 1999 and 2011. Institutional Review Board approval was obtained; informed consent was waived due to the retrospective nature of the series. All eight patients were receiving iv epoprostenol; five of the eight patients presented with acute cardiopulmonary decompensation in the setting of hyperthyroidism. In the remaining three patients, hyperthyroidism was detected during routine screening of thyroid function tests. The one patient who underwent emergency thyroidectomy was the only survivor of those who presented in cardiopulmonary decline.

EVIDENCE SYNTHESIS

Aggressive treatment of the hyperthyroid state, including emergency total thyroidectomy and escalation of targeted PAH therapy and β-blockade when warranted, may prove lifesaving in these patients. Prompt thyroidectomy or radioactive iodine ablation should be considered for clinically stable PAH patients with early and/or mild hyperthyroidism to avoid potentially life-threatening cardiopulmonary decompensation.

CONCLUSIONS

Although the association between hyperthyroidism and PAH remains poorly understood, the potential impact of hyperthyroidism on the cardiopulmonary status of PAH patients must not be ignored. Hyperthyroidism must be identified early in this patient population to optimize intervention before acute decompensation. Thyroid function tests should be checked routinely in patients with PAH, particularly those on iv epoprostenol, and urgently in patients with acute decompensation or symptoms of hyperthyroidism.

Radioiodine treatment in McCune-Albright syndrome with hyperthyroidism

McCune-Albright syndrome (MAS) is a sporadic disease characterized by polyostotic fibrous dysplasia, "café-au-lait" spots and hyperfunctional endocrinopathies. Pathophysiological basis is activating mutation of the gene that encodes the alpha subunit of Gs membrane protein that stimulates the intracellular production of cAMP, conferring autonomous secretion of the gland in particular. One of the uncommon endocrine manifestations is hyperthyroidism. We present a patient who had café-au-lait spots, polyostotic fibrous dysplasia and hyperthyroidism. She was treated with radioactive iodine for the symptoms of hyperthyroidism and subsequently relieved from hyperthyroid features.