Thyrotoxicosis and thyroiditis

Thyrotoxicosis is a common presentation of thyroid disease. The commonest cause is Graves’ disease. The clinical features including goitre, eye disease, causes and diagnosis of thyrotoxicosis are discussed. Treatment strategies of Graves’ disease include anti-thyroid drugs, radioiodine and thyroidectomy. It is important to adequately prepare patients prior to surgery to reduce the possibility of thyroid storm. The preferred surgical procedure today is a total thyroidectomy, although historically subtotal thyroidectomy was performed. Less common but relevant surgical causes of thyrotoxicosis are also discussed.Thyroiditis (thyroid inflammation) has a variety of causes. Hashimoto's thyroiditis may present with a transient thyrotoxicosis or long term hypothyroidism. Surgery is rarely required. Subacute thyroiditis thought to be secondary to a viral infection can cause a short-term yet marked thyrotoxicosis due to thyroid damage. Other causes such as amiodarone-induced thyrotoxicosis can be more difficult to manage due to the underlying heart disease and may require thyroidectomy.     

All-trans-retinoic Acid Promotes Iodine Uptake Via Upregulating the Sodium Iodide Symporter in Medullary Thyroid Cancer Stem Cells

Recently, the main therapy of medullary thyroid cancer (MTC) is surgical, but by which way there is a poorprognosis with a mean survival of only 5 years. In some cases, some researchers found that it is the medullarythyroid cancer stem cells (MTCSCs) that cause metastasis and recurrence. This study aimed to eradicate MTCSCsthrough administration of all-trans-retinoic acid (ATRA). Here we demonstrate that MTCSCs possess stemlikeproperties in serum-free medium. The ABCG2, OCT4 and sodium iodide symporter (NIS) were changedby ATRA. Additionally, we found that ATRA can increase the expression of NIS in vivo. All the data suggestedthat ATRA could increase the iodine uptake of MTCSCs through NIS.     

Importance of Postoperative Stimulated Thyroglobulin Level at the Time of 131I Ablation Therapy for Differentiated Thyroid Cancer

Background: Serum thyroglobulin detection plays an essential role during the follow-up of thyroid cancerpatients treated with total/near total thyroidectomy and radioiodine ablation. The aim of this retrospective studywas to evaluate the relationship between stimulated serum thyroglobulin (Tg) level at the time of high dose 131Iablation and risk of recurrence, using a three-level classification in patients with differentiated thyroid cancer(DTC) according to the ATA guidelines. Also we investigated the relationship between postoperative stimulatedTg at the time of ablation and DxWBS results at 8-10 months thereafter. Materials and Methods: Patientswith radioiodine accumulation were regarded as scan positive (scan+). If there was no relevant pathologicalradioiodine accumulation or minimal local accumulation in the thyroid bed region, this were regarded as scannegative (scan-) at the time of DxWBS. We classified patients in 3 groups as low, intermediate and high riskgroup for assessment of risk of recurrence according to the revised ATA guidelines. Also, we divided patients into3 groups based on the stimulated serum Tg levels at the time of 131I ablation therapy. Groups 1-3 consisted ofpatients who had Tg levels of ≤2 ng/ml, 2-10 ng/ml, and ≥10 ng/ml, respectively. Results: A total of 221 consecutivepatients were included. In the high risk group according to the ATA guideline, while 45.5% of demonstratedScan(+) Tg(+), 27.3% of patients demonstrated Scan(-) Tg(-); in the intermediate group, the figures were 2.3%and 90.0% while in the low risk group, they were 0.6% and 96.4%. In 9 of 11 patients with metastases (81.8%),stimulated serum Tg level at the time of radioiodine ablation therapy was over 10, however in 1 patient (9.1%)it was <2ng/mL and in one patient it was 2-10ng/mL (p=0.005). Aggressive subtypes of DTC were found in 8 of221 patients and serum Tg levels were ≤2ng/ml in 4 of these 8. Conclusions: We conclude that TSH-stimulatedserum thyroglobulin level at the time of ablation may not determine risk of recurrence. Therefore, DxWBSshould be performed at 8-12 months after ablation therapy.     

131I治疗儿童及青少年Graves病

抗甲状腺药物、手术、放射性碘是儿童及青少年Graes病的3种治疗方法.近60年的医疗实践证明,131I治疗是安全、有效的,应当作为首选治疗方法.     

Rising incidence of second cancers in patients with low-risk (T1N0) thyroid cancer who receive radioactive iodine therapy

BACKGROUND:

American Thyroid Association guidelines currently recommend the selective use of radioactive iodine (RAI) therapy in patients with well differentiated thyroid cancer (WDTC). Despite these guidelines, RAI ablation has been used routinely in all but the very lowest risk patients with thyroid cancer over the last 30 years. The objective of this study was to evaluate patterns of RAI use and elevated risk of secondary primary malignancies (SPM) in patients with low‐risk (T1N0) WDTC.

METHODS:

The Surveillance, Epidemiology, and End Results (SEER) database was used to analyze trends in RAI use over time in the United States. To determine the excess risk of SPM, the standardized incidence ratio (SIR) and excess absolute risk (EAR) of various cancers were calculated in the 2 cohorts. Between 1973 and 2007, 37,176 patients with WDTC were followed in the SEER Program, equating to 408,750 person‐years at risk (PYR). In total, 14,589 patients received RAI, and SPMs were observed in 3223 patients.

RESULTS:

During the study period, the rate of RAI use in patients with low‐risk (T1N0) WDTC increased from 3.3% to 38.1%. For low‐risk patients, the SIR of SPM was 1.21 (95% confidence interval [CI], 0.93‐1.54), and the EAR was 4.6 excess cases per 10,000 PYR. SPM with significantly elevated risk because of RAI were salivary gland malignancies (SIR = 11.13; 95% CI, 1.35‐40.2) and leukemia (SIR = 5.68; 95% CI, 2.09‐12.37). The excess risk of leukemia was significantly greater in patients aged <45 years (SIR = 5.32; 95% CI, 2.75‐9.30) compared with the excess risk in older patients (SIR = 2.26; 95% CI, 1.43‐3.39).

CONCLUSIONS:

The increased risk of a SPM in patients with low‐risk (T1N0) WDTC, along with a lack of data demonstrating improved survival outcomes with adjuvant RAI, provide a compelling argument in favor of rationing the use of RAI in this patient population. Cancer 2011;. © 2011 American Cancer Society.     

Management of thyroid eye disease in the United Kingdom: A multi-centre thyroid eye disease audit

This article aims to provide baseline data and highlight any major deficiencies in the current level of care provided for adult patients with thyroid eye disease (TED). We undertook a prospective, nonrandomized cross-sectional multicenter observational study. During a 3-month period June–August 2014, consecutive adult patients with TED who presented to nominated specialist eye clinics in the United Kingdom, completed a standardized questionnaire. Main outcome measures were: demographics, time from diagnosis to referral to tertiary centre, time from referral to review in specialist eye clinic, management of thyroid dysfunction, radioiodine and provision of steroid prophylaxis, smoking, and TED classification. 91 patients (mean age 47.88 years) were included. Female-to-male ratio was 6:1. Mean time since first symptoms of TED = 27.92 (73.71) months; from first visit to any doctor with symptoms to diagnosis = 9.37 (26.03) months; from hyperthyroidism diagnosis to euthyroidism 12.45 (16.81) months. First, 13% had received radioiodine. All those with active TED received prophylactic steroids. Seven patients who received radioiodine and did not have TED at the time went on to develop it. Then, 60% patients were current or ex-smokers. 63% current smokers had been offered smoking cessation advice. 65% patients had active TED; 4% had sight-threatening TED. A large proportion of patients (54%) were unaware of their thyroid status. Not enough patients are being provided with smoking cessation advice and information on the impact of smoking on TED and control of thyroid function.     

Management of paediatric thyroid carcinoma: recent experience with recombinant human thyroid stimulating hormone in preparation for radioiodine therapy

Background: Thyroid carcinoma in children is rare and raises unique management issues. Although metastatic disease is more common in this age group, prognosis remains good with appropriate treatment. The aim of the study was to report recent experience in the management of differentiated thyroid carcinoma in children, especially in the use of radioiodine after recombinant human thyroid stimulating hormone (rhTSH) stimulation. Methods: Eight patients, aged 5–17 years (five were boys) presented following total thyroidectomy for thyroid carcinoma between May 2003 and June 2005. Seven had papillary carcinoma and one had follicular carcinoma. Five had known lymph node metastases and one had pulmonary metastases at presentation. Four patients had previously received therapeutic irradiation for malignancy. All eight underwent diagnostic iodine scans, seven with rhTSH stimulation. Seven went on to receive radioiodine treatment as hospital inpatients, comanaged by the paediatric and nuclear medicine units. The dosage of ¹³¹I ranged from 1.5 to 3.7 × 10⁹ Bq. All except one were prepared by rhTSH stimulation. Results: Seven of eight patients had significant uptake in the neck on diagnostic scan and two had pulmonary abnormalities. Six of seven evaluable patients achieved complete thyroid ablation. Both patients with pulmonary abnormalities had scan resolution, although one of them only after a second radioiodine treatment. All patients had thyroxine replacement in doses to suppress TSH and all remain alive and well at time of carrying out this study. Conclusion: Optimal management of paediatric thyroid carcinoma necessitates a multidisciplinary approach. Radioiodine therapy under rhTSH is an effective and safe adjuvant treatment in this special subgroup.     

99mTc-MIBI甲状腺显像在胺碘酮所致甲状腺毒症鉴别诊断中的价值

目的 研究99mTc-MIBI甲状腺显像在胺碘酮所致甲状腺毒症（amiodarone-induced thyrotoxicosis,AIT）鉴别诊断上的价值。材料和方法 15例AIT患者在一周内均进行甲状腺吸碘率测定、甲状腺彩色多普勒超声和甲状腺99mTcO4-显像等常规检查,按照这些常规检查结果将AIT进行初始诊断分型（1型和2型）,1型AIT给予甲巯咪唑治疗,2型AIT给予强的松治疗。AIT分型的最终诊断按照患者的甲状腺毒症状态对治疗反应确定。所有患者在开始进行治疗前进行99mTc-MIBI甲状腺早期（15min）和延迟（60min）显像。结果 按照甲状腺常规检查,15例AIT患者的初始诊断分型分别为1型5例,2型10例。AIT最终诊断分型为1型4例,2型8例,另外3例患者按照初始分型（1型1例,2型2例）进行治疗的效果较差,在甲巯咪唑和强的松联合治疗后甲状腺功能恢复正常,因此归为混合型AIT。99mTc-MIBI 显像对于各型AIT均能正确区分,4例1型AIT患者的甲状腺都有明显的MIBI摄取和滞留,8例2型AIT患者甲状腺没有明显的MIBI摄取,3例混合型AIT的甲状腺有轻度的MIBI摄取。单独的CFDS将3例2型AIT和1例混合型AIT归为1型AIT。1型AIT均有可测量到的RAIU,但3例2型AIT和2例混合型AIT也有可测量到的RAIU。即使在RAIU和CFDS联合应用时,3例混合型AIT患者的分型仍不准确。结论 99mTc-MIBI甲状腺显像是有价值的AIT鉴别诊断工具,对于不同类型的AIT都能准确区分,特别是对于难治性的混合型AIT。