Target Thyroid-stimulating Hormone Research Articles

Gender, FT4 levels, T stage, and BMI as predictors of TSH levels in thyroid cancer patients

BackgroundAfter initial treatment, levothyroxine (LT4) administration is necessary for thyroid cancer patients to achieve target thyroid-stimulating hormone (TSH) levels. However, the clinical efficacy of weight-based LT4 dosing has been suboptimal, highlighting the need to identify factors influencing the attainment of desired TSH levels and guide personalized treatment.MethodsWe constructed a retrospective cohort comprising 215 patients diagnosed with thyroid cancer. The identification of factors influencing the attainment of expected TSH levels was accomplished through univariate and multivariate logistic regression analyses. Subsequently, we developed a nomogram based on these prognostic factors and performed internal validation using the bootstrap resampling method.ResultsUnivariate and multivariate logistic regression analyses were conducted to analyze the clinical and demographic parameters. A nomogram was constructed using bootstrap resampling to predict the risk of TSH suppression failure, which was validated. The nomogram demonstrated moderate discrimination in estimating the risk of TSH suppression failure, with a Hosmer-Lemeshow test p-value of 0.393 and a bootstrapped calibrated C-index of 0.757 (95% CI 0.687-0.814). The calibration curve indicated good consistency of the model, and decision curve analysis suggested that the nomogram had clinical utility.ConclusionGender, preoperative serum free thyroxine (FT4) levels, T stage, and body mass index exhibit independent associations with the expected level of TSH. The established nomogram effectively predicts the risk of TSH suppression failure. Further research is warranted to investigate how these factors can be utilized in developing a personalized LT4 dosage calculator.

Assessing the impact of a dedicated referral and management algorithm in maternal hypothyroidism.

The significant risks of hypothyroidism during pregnancy can be mitigated through timely diagnosis and initiation of thyroxine to achieve a maternal euthyroid state. This study aimed to evaluate the efficiency of hospital endocrine services by assessing the rate of thyroxine commencement before the initial clinic appointment, the median gestational age at the first consultation, the rate of guideline-appropriate investigations, perinatal outcomes, and the proportion of referred patients who achieved their target thyroid-stimulating hormone (TSH) levels before and after implementing a dedicated referral and management pathway. A retrospective clinical audit was conducted using electronic medical records for the first fifty consecutive patients with hypothyroidism referred to the hospital clinic during two-time intervals: from April 1 to September 1, 2020 (pre-intervention) and from April 1 to September 1, 2021 (postintervention). Following the pathway implementation, there was no significant difference in the proportion of women with initially raised TSH who were prescribed thyroxine prior to the first clinic appointment (P=0.83). However, the first TSH measurement occurred earlier (median 5.5 vs. 6.5 weeks, P=0.011), and specialist reviews were conducted sooner (median 19 vs. 22 weeks, P=0.032). Significantly more women with elevated TSH underwent thyroid autoantibody testing postintervention (78% vs. 55.5%, P=0.035). There was no significant difference in perinatal outcomes. All women achieved their target TSH levels, with a median final TSH of 1.6 mIU/L (IQR: 1.2 to 2.3). While the proportion of referred patients achieving target TSH levels during pregnancy remained unchanged, certain measures of service efficiency improved. These included earlier TSH measurement, earlier endocrinologist review, and increased detection of thyroid autoantibodies.

Prognostic Implications of Maintaining the Target Thyroid-Stimulating Hormone Status Based on the 2015 American Thyroid Association Guidelines in Patients with Low-Risk Papillary Thyroid Carcinoma after Lobectomy: A 5-Year Landmark Analysis

Background: The 2015 American Thyroid Association guidelines recommend the maintenance of serum thyroid stimulating hormone (TSH) levels ≤2 mIU/L in patients with low-risk papillary thyroid carcinoma (PTC) who underwent lobectomy; however, the evidence is insufficient. We investigated the association between maintaining the TSH status at ≤2 mIU/L and tumor recurrence in patients with low-risk PTC who underwent lobectomy through a 5-year landmark analysis. Methods: Between 2010 and 2016, 662 patients with low-risk PTC were included. The postoperative TSH status was determined using the ‘TSH > 2 ratio’, which was calculated using the TSH test results during the 5-year follow-up. The optimal cutoff value of ‘TSH > 2 ratio’ for tumor recurrence was determined using a receiver operating characteristic curve analysis. Recurrence-free survival (RFS) was compared between the groups using Kaplan–Meier and Cox proportional hazard regression analyses. Results: Patients with ‘TSH > 2 ratio’ > 0.1833 (n = 498) had a worse RFS outcome compared to patients with ‘TSH > 2 ratio’ ≤ 0.1833 (n = 164; p < 0.001). ‘TSH > 2 ratio’ > 0.1833 was a significant risk factor for tumor recurrence after the 5-year landmark (hazard ratio: 4.795, 95% confidence interval: 2.102–10.937, p < 0.001). Conclusions: Maintaining TSH levels ≤ 2 mIU/L below a certain percentage among the total TSH tests during the 5-year follow-up period has a negative impact on tumor recurrence.

Adequate Dose of Levothyroxine for Thyroid-Stimulating Hormone Suppression after Total Thyroidectomy in Patients with Differentiated Thyroid Cancer.

The adequate dose of levothyroxine (LT4) for patients who have undergone total thyroidectomy (TT) for differentiated thyroid cancer (DTC) is uncertain. We evaluated the LT4 dose required to achieve mild thyroid-stimulating hormone (TSH) suppression in DTC patients after TT. The electronic medical records of patients who underwent TT for DTC and received mild TSH suppression therapy were reviewed. Linear regression analysis was performed to evaluate the association between LT4 dose (μg/kg) and an ordinal group divided by body mass index (BMI). We also evaluated the trend in LT4 doses among groups divided by BMI and age. In total, 123 patients achieved mild TSH suppression (0.1 to 0.5 mIU/L). The BMI variable was divided into three categories: <23 kg/m2 (n=46), ≥23 and <25 kg/m2 (n=30), and ≥25 kg/m2 (n=47). In the linear regression analysis, BMI was negatively associated with the LT4 dose after adjusting for age and sex (P<0.001). The LT4 doses required to achieve mild TSH suppression based on the BMI categories were 1.86, 1.71, and 1.71 μg/kg, respectively (P for trend <0.001). Further analysis with groups divided by age and BMI revealed that a higher BMI was related to a lower LT4 dose, especially in younger patients aged 20 to 39 (P for trend=0.011). The study results suggest an appropriate LT4 dose for mild TSH suppression after TT based on body weight in patients with DTC. Considering body weight, BMI, and age in estimating LT4 doses might help to achieve the target TSH level promptly.

A predictive model for L-T4 dose in postoperative DTC after RAI therapy and its clinical validation in two institutions.

To develop a predictive model using machine learning for levothyroxine (L-T4) dose selection in patients with differentiated thyroid cancer (DTC) after resection and radioactive iodine (RAI) therapy and to prospectively validate the accuracy of the model in two institutions. A total of 266 DTC patients who received RAI therapy after thyroidectomy and achieved target thyroid stimulating hormone (TSH) level were included in this retrospective study. Sixteen clinical and biochemical characteristics that could potentially influence the L-T4 dose were collected; Significant features correlated with L-T4 dose were selected using machine learning random forest method, and a total of eight regression models were established to assess their performance in prediction of L-T4 dose after RAI therapy; The optimal model was validated through a two-center prospective study (n=263). Six significant clinical and biochemical features were selected, including body surface area (BSA), weight, hemoglobin (HB), height, body mass index (BMI), and age. Cross-validation showed that the support vector regression (SVR) model was with the highest accuracy (53.4%) for prediction of L-T4 dose among the established eight models. In the two-center prospective validation study, a total of 263 patients were included. The TSH targeting rate based on constructed SVR model were dramatically higher than that based on empirical administration (Rate 1 (first rate): 52.09% (137/263) vs 10.53% (28/266); Rate 2 (cumulative rate): 85.55% (225/263) vs 53.38% (142/266)). Furthermore, the model significantly shortens the time (days) to achieve target TSH level (62.61 ± 58.78 vs 115.50 ± 71.40). The constructed SVR model can effectively predict the L-T4 dose for postoperative DTC after RAI therapy, thus shortening the time to achieve TSH target level and improving the quality of life for DTC patients.

Impact of Patient Age on Management of Hypothyroidism: A Survey of Physicians from Three Developing Regions

Abstract Background The thyroid-stimulating hormone (TSH) levels increase with age, and aiming for the same TSH target applicable in a younger population in older patients who are on replacement with thyroid hormones. Methods We assessed practice patterns regarding TSH goals and explored factors influencing physicians' decision-making when managing hypothyroidism. Multiple-choice questions in a case-based survey of a convenience sample of physicians practicing in relevant disciplines in three developing regions. Results Of the total 286, senior physicians represented 63% and mid-grades represented 27% of the respondents. Forty-one percent were endocrinologists, 19% were internists with endocrine interests, and 16% were family physicians. Over half (52%) practiced at a tertiary level and 42% had been in practice for over 20 years. Fifty percent of respondents had more than 20% of their patients over 65 years.Several attributes were factored into decision-making when managing hypothyroidism. Respondents took into account age (75%), preceded by the presence of cardiac arrhythmias (80%), pregnancy (79%), heart disease (78%), and patient symptoms (77%) when determining the treatment strategy. When presented with scenarios differing in patients' age, around 90% of physicians targeted a TSH ≤ 3.0 mIU/L in 30-year-old patients. Fifteen percent of respondents targeted a TSH of 1.6 to 3.0 mIU/L in octogenarians, but 78% targeted a TSH &gt; 3.1 to 5.0 mIU/L in this group. Regardless of sex, physician-reported TSH goal ranges (0.1–0.5, 0.6–1.5, 1.6–3.0, and 3.1–5.0 mIU/L) increased directly to patient age. Overall, respondents were less inclined to start treatment in 85-year-olds than in 70-year-old females with TSH of 6 mU/L (20% vs. 11%). Females with a TSH of 15 mU/L were more likely to get treated than those with a 6 mU/L TSH. Vital persons are more likely to be treated with thyroxine than vulnerable persons for the same TSH levels. Multivariate analysis showed that compared with endocrinologists, family physicians and other specialties were less likely to consider age in their clinical decisions, odds ratio (OR) 0.2 (95% confidence interval [CI] 0.1–0.7), p = 0.018, and OR 0.3 (95% CI 0.1–0.8), p = 0.013, respectively. Conclusion A consensus is needed on the role of patients' age in hypothyroidism management, the complexity of managing hypothyroidism in an older adult patient, and the variability in practice patterns among physicians. Addressing these challenges demands ongoing dialogue and collaboration among health care providers to improve patient care and outcomes in hypothyroidism management across different age groups.

Clinical inertia in thyrotropin suppressive therapy for low-risk differentiated thyroid cancer: A real-world experience at an endocrine center in Bangkok.

The management of low-risk differentiated thyroid cancer (DTC) has evolved over time toward treatment de-escalation. However, overtreatment with supraphysiological dose of levothyroxine (LT4) continues to be observed despite current clinical guideline. This study aimed to assess the actual thyrotropin suppressive therapy for low-risk DTC patients at an endocrine center in Bangkok. This retrospective study included patients with low-risk DTC who were regularly follow-up for at least 18 months at Theptarin Hospital between 2016 and 2022. The serum thyroid stimulating hormone (TSH) levels were stratified as TSH < 0.1 mIU/L; TSH 0.1 to 0.5 mIU/L; TSH 0.5 to 2.0 mIU/L; and TSH > 2.0 mIU/L. The initial risk stratification (IRS) and dynamic risk stratification were determined at 12 months of follow-up after completing the initial treatment and at the last visit. The clinical factors associated with overtreatment with LT4 were analyzed. A total of 102 patients (83.3% female, age at diagnosis 41.8 ± 13.6 years, mean tumor size 1.6 ± 1.0 cm) were evaluated with a mean follow-up of 5.9 years. The IRS classified 92.2% of patients after the initial treatment and 93.1% of patients at the last follow-up visit into the excellent response category. The mean LT4 daily dosage at the last follow-up was 121.3 ± 44.8 µg/day. Serum TSH levels were in an appropriate target range according to IRS in only 8.8% (9/102) of the patients and then improved to 19.6% (20/102) at the last follow-up visit. Further analysis showed that treating physicians with ≥10 years of practice was associated with severe TSH suppression therapy (TSH < 0.1 mIU/L). Despite the current clinical guideline recommendations and scientific evidences, less than one-fifth of low-risk DTC patients achieved the appropriate serum TSH target. While the proportion of an optimum LT4 suppressive had improved during the study period, further efforts are needed to overcome this clinical inertia.

Are resting metabolic rate and clinical symptoms affected by variation of serum thyroid stimulating hormone levels within the normal range in healthy and women with hypothyroidism? A case–control study

BackgroundIt is unclear whether variation in thyroid stimulating hormone (TSH) levels within the reference range affect energy expenditure and clinical symptoms and even within the normal range of TSH levels, resting energy expenditure may alter. The aim of the present study was to determine whether treated hypothyroid subjects and healthy subjects with a low-normal TSH range (0.3–2.3 mIU/L) have better clinical outcomes and increased energy expenditure than those with a high-normal TSH range (2.3–4.3 mIU/L). MethodsThis was a case-control study of 160 overweight/obese women with TSH levels across the reference range of 0.3-4.3 mU/l. Subjects were paired in four groups: healthy subjects with low-normal target TSH (n =40), healthy subjects with high-normal target TSH (n =40), subjects with treated hypothyroidism with low-normal target TSH (n =40), and subjects with treated hypothyroidism with high-normal target TSH (n =40). Resting energy expenditure (RMR), dietary intake, body composition, physical activity, and biochemical markers were assessed. ResultsSubjects with low-normal (≤2.3 mU/L) and high-normal (>2.3 mU/L) TSH levels did not differ in terms of RMR, serum T3 levels, and clinical symptoms except fatigue (P=0.013). However, serum fT4 levels were found to be significantly different between the study groups (P=0.002). Serum fT4 concentration was the highest in subjects with treated hypothyroidism with low-normal target TSH. ConclusionVariation in serum TSH levels within the reference range did not significantly affect REE and clinical symptoms except fatigue in healthy and women with hypothyroidism.

Effect of thyroid-stimulating hormone suppression on quality of life in thyroid lobectomy patients: interim analysis of a multicenter, randomized controlled trial in low- to intermediate-risk thyroid cancer patients (MASTER study).

Current clinical practices favor less or no thyroid-stimulating hormone (TSH) suppression for low- to intermediate-risk thyroid cancer patients who receive thyroid lobectomy. The association of TSH suppression on health-related quality of life (HR-QoL) in patients after thyroid lobectomy is not well studied. This study aimed to evaluate the effect of TSH suppression on patient HR-QoL after thyroid lobectomy. This study included patients enrolled in an ongoing, multicenter, randomized controlled study investigating the effects of TSH suppression. Patients were randomized to either the low-TSH group (TSH target range, 0.3-1.99 µIU/mL) or the high-TSH group (TSH target range, 2.0-7.99 µIU/mL). The HR-QoL, hyperthyroidism symptom, and depression symptom questionnaires performed preoperatively and 2 weeks and 3 months postoperatively were evaluated. Total of 669 patients (low-TSH group, 340; high-TSH group, 329) were included. Although total HR-QoL score changes were not different between the 2 groups, the high-TSH group had a significantly higher score in the physical domain at postoperative 3 months (P = 0.046). The 2 groups did not have significant differences in hyperthyroidism and depression scores. In the short-term postoperative period, the physical HR-QoL scores in thyroid lobectomy patients were better when they did not receive TSH suppression. This study suggests the importance of considering HR-QoL when setting TSH suppression targets in thyroid lobectomy patients.

Levothyroxine suppressive therapy in differentiated thyroid cancer treatment.

Levothyroxine therapy in management of diferentiated thyroid carcinoma (DTC) has been common practice for decades. Levothyroxine is being administered to patiens with DTC after total thyreoidectomy (with or without postopreative radioiodine treatment) not only to restore euthyroidism but to suppress the production of thyroid-stimulating hormone (TSH) as well because TSH is considered as a growth factor for thyroid follicular cells. However there has been a downside to this threatment recently. The main concerns are the known risks related to iatrogenic subclinical or even mild but clinicaly overt iatrogenic hyperthyroidism. Therefore individualized treatment approach aiming to balance between the risk of tumor recurence and the risks related to hypertyhroidism in view of pateints age, risk factors and comorbidities is essential. Close folow-up is therefore necessary with frequent dose adjustments according to target TSH values published in American Thyroid Association guidelines.

Relationship of Thyroid Function with Metabolic Parameters in Euthyroid Adults

Objective: Thyroid hormones have a significant effect on carbohydrate, lipid metabolism disorders, and insulin resistance (HOMA-IR) development. Vitamin D (25(OH)D) has been shown also can affect not only the musculoskeletal system, but also almost all tissues in the body, including the thyroid in recent years. In the study, we aim of this study is to investigate the relationship between the levels of thyroid-stimulating hormone (TSH) within the reference range and metabolic parameters in adults. Methods: 561 adult outpatients were divided into 2 groups low normal range (0.27-2.5 mIU/mL) and high normal range (2.5-4.2 mIU/mL) according to TSH, and HOMA-IR, 25(OH)D, and lipid levels were compared. Results: A statistically significant positive correlation was found between TSH and HOMA-IR in both the low normal range group (r = 0.123, p = 0.041) and the high normal range group (r = 0.196, p = 0.001). In the high normal range group, the relationship between TSH with vitamin D (r =-0.200, p =0.003), cholesterol (r =0.143, p =0.024), LDL cholesterol (r =0.154, p =0.018), non-HDL cholesterol (r = 0.134, p = 0.035) levels was statistically significant. Conclusion: Our study shows that high normal TSH levels in euthyroid adults are related to higher insulin resistance and lower 25(OH)D levels, and this interaction is a major contributor to dyslipidemia. Thyroid hormones explain the metabolic disorder in the early stages of T2DM. Therefore, we believe that screening TSH levels and determining the optimal TSH target will be beneficial.

Optimal thyrotropin level for low-risk papillary thyroid carcinoma after ultrasound-guided radiofrequency ablation

Purpose Maintaining an optimal thyroid stimulating hormone (TSH) level is important in the postoperative management of papillary thyroid carcinoma (PTC). However, there is little evidence for TSH target levels in patients undergoing radiofrequency ablation (RFA). This study aimed to determine the optimal TSH level for management in low-risk patients who underwent RFA. Methods This retrospective propensity score-matched cohort study included patients with low-risk PTC who underwent RFA from January 2014 to December 2018. The patients were categorized into two groups based on the range of TSH levels: low (≤2 mU/L) and high (>2 mU/L) TSH levels. Local tumor progression and disease-free survival (DFS) were compared between the low TSH and high TSH groups, using propensity score analyses based on patient- and tumor-level characteristics. Univariate analyses were performed to select risk factors for tumor progression. Results Overall, our study included 516 patients with low-risk PTC who underwent RFA with a long-term follow-up of 5-years. During follow-up, the overall incidence rate of local tumor progression was 4.8% (25/516), with no significant difference between the matched groups (7/106 [6.6%] vs. 5/53 [9.4%], p = 0.524). DFS did not differ between the two groups (p = 0.5). Moreover, TSH level was not regarded as a significant predictor of tumor progression after Cox analysis; primary tumor size was the only relevant risk factor. Conclusion This large propensity-matched study revealed no association between TSH levels and tumor progression. Thus, for patients with low-risk PTC who underwent RFA, the optimalTSH level is recommended at the euthyroid range.

Outcomes of Early Transition of Low-Risk Thyroid Cancer Patients from Specialist to Primary Care.

Background: Recently published clinical pathways for management of thyroid cancer outlined the criteria for transitioning low-risk patients to primary care within one to five years from diagnosis. However, discharge patterns among endocrinologists remain heterogeneous as there lacks a consensus regarding post-treatment care for thyroid cancer patients. Objective: This study described general characteristics and outcomes of thyroid cancer patients who were discharged from specialist care and transitioned to a primary care-based follow-up clinic. Methods: Thyroid cancer patients seen in the After Cancer Treatment Transition (ACTT) clinic at Women’s College Hospital (Toronto, Canada) were included in the study. Electronic medical records were reviewed between May and October 2021 to collect patient characteristics and outcomes. Descriptive statistics were calculated. Results: The study cohort included 148 thyroid cancer patients and 76% were female. All cases were papillary thyroid cancer and most diagnoses were classified as T2 (42%), N0 (55%), M0 (91%), and stage 1 (83%). Nearly all patients (n = 147) had complete thyroidectomy. Levels of thyroglobulin and thyroglobulin antibodies (TgAb) were low overall, with only 5% of the study cohort deemed TgAb positive. Mean levels of thyroid stimulating hormone (TSH) measured at 2 time points (1.37 mIU/L, 1.42 mIU/L) were within normal range. About 91% of the study cohort had normal TSH levels and 82% met target TSH levels. There were 2 cases of recurrence; however, investigation determined that they were not initially appropriate candidates for transition to primary care. Nearly 99% (n = 146) of patients had excellent response to therapy, showed no evidence of disease recurrence, and have not required re-referral to specialist care. Conclusions: These findings may reassure specialists that low-risk, stable thyroid cancer patients can be safely transitioned to primary care for post-treatment follow-up.

Body Weight as a Major Determinant Section of Thyroxine Sodium Dosage in the Treatment of Primary Hypothyroidism

Introduction: Several formulae have been proposed for optimising the dosage prerequisites of levothyroxine (LT4), and body weight and Body Mass Index (BMI) have been suggested to broadly dependent on the formulae range. Aim: To evaluate the role of body weight as a determinant of LT4 dosage in the treatment of primary hypothyroidism. Materials and Methods: The present study was a prospective observational study conducted at Outpatient Department (OPD) Endocrinology, Patna Medical College Hospital, Patna, Bihar, India, on 100 patients diagnosed with untreated primary hypothyroidism between February 2020 and January 2021. Demographic details, anthropometric measurements, vital signs, and details of types and dosage of treatment received were collected. LT4 dose requirement for each individual patient was then generated as mcg per kg/body weight per day. Estimation of serum Thyroid Stimulating Hormone (TSH), FT4, creatinine and thyroid peroxidase levels were carried out as per standard diagnostic protocols and the dosage adjustment was conducted based on target TSH levels. Population characteristics were expressed as mean±standard deviation. The Python version 3.4.5 with the package seaborn was used for statistical analyses and preparation of figures, distribution and correlation plots. Results: The study enrolled 100 individuals (88 women and 12 men) with mean age of 40.69 years (age range 17 to 72 years). A significant positive correlation was noted between the LT4 dose and total body weight (p-value &lt;0.001). The association was also significant when the LT4 dose was correlated with BMI (p-value &lt;0.001) and FT4 (p-value &lt;0.001). However, the correlation of Thyroid Peroxidase Antibodies (TPO Ab), TSH, height and age with the LT4 daily dose (p-value &gt;0.05) was found to be statistically non significant. Conclusion: There exist a significant positive correlation between LT4 dosage and body weight. Hence, body weight should be considered as a key determinant while prescribing LT4 therapy for the treatment primary hypothyroidism.

Liothyronine use in primary hypothyroidism - current concepts.

Hypothyroidism is an endocrine disorder whose management raises many challenges in clinical practice. Its standard treatment is levothyroxine (LT4). The goal of the treatment is to normalize signs and symptoms, as well as to achieve thyroid-stimulating hormone (TSH) concentrations within the reference range, on an individual basis. It is known that 5-10% of hypothyroid patients remain symptomatic, despite achieving the target TSH levels, which, in turn, affects their quality of life. After ruling out other causes of non-thyroid origin for this persistence, it is suggested that these patients could benefit from the use of liothyronine (LT3), added to LT4, especially if polymorphism of the deiodinase 2 (D2) genes is documented. There exist a variety of LT3 preparations, whose concentrations vary from 5 to 50 ug, with the recommended LT4/LT3 ratio of 13:1-20:1. The goals of combination therapy should be to achieve a physiological ratio of free triiodothyronine/free thyroxine (FT3/FT4) and non-suppression of TSH. Because there is currently no guide that makes evidence-based recommendations on the use of LT3 in primary hypothyroidism, more clinical studies are needed to be able to identify hypothyroid patients who may benefit from the use of LT3, by identifying new biomarkers.

Patterns of clinical management of hypothyroidism in adults: An electronic survey of physicians from the Middle East and Africa

Background: Hypothyroidism is a common endocrine disorder that is managed by a wide range of physicians. There are no data on the pattern of clinical management of hypothyroidism in the Middle East and Africa (MEA) region. Objectives: We sought to document current practices in the management of primary hypothyroidism in the MEA region and compare these with international recommendations and practices elsewhere. Materials and Methods: A convenience sample of physicians practicing in the MEA in relevant disciplines were invited to take a web-based survey consisting of previously validated multiple-choice questions dealing with investigation and treatment of an index case of overt primary hypothyroidism in general and in three special situations. Results: Out of complete 397 responses, 368 were eligible for inclusion in the analysis. The majority were endocrinologists and internal medicine specialists; 82.2% of them have been in clinical practice for 10 years or more. Overt hypothyroidism would be treated using L-T4 alone by 97.2% of respondents; 1.7% would use a combination of L-T4 and liothyronine (L-T3) therapy. The rate of replacement would be gradual (66.5%), an empiric dose, adjusted to achieve target levels (14.7%); or a calculated full replacement dose (18.5%). A target thyroid-stimulating hormone (TSH) of 2.0–2.9 mU/L was favored in the index case of overt hypothyroidism (by 34.4%) followed by a target of 3.0–3.9 mU/L (by 26.0%) of respondents. However, a target of 4.0–4.9 mU/L was the most commonly selected TSH target for an octogenarian (by 33.5% of respondents). Persistent hypothyroid symptoms despite achieving a target TSH would prompt testing for other causes by 86.9% of respondents, a change to L-T4 plus L-T3 therapy by 5.8%, and an increase in the thyroid hormone dose by 4.6%. Evaluation of persistent symptoms would include measurements of complete blood count (82.4%), complete metabolic panel (68.7%), morning cortisol (65.3%), Vitamin B12 levels (54.5%), and serum T3 levels (27.9%). Subclinical disease with a TSH 7.8 mU/L would be treated without further justification by 9.0% of respondents, or in the presence of positive thyroid peroxidase antibodies (65.3%), hypothyroid symptoms (65.0%), high low-density lipoprotein (51.7%), or a goiter (36.7%). The TSH target for a newly pregnant patient was 2.0–2.4 mU/L for 28.5% of respondents, with 15.8% preferring a TSH target of 1.5–1.9 mU/L. Thyroid hormone levels would be checked every 4 weeks during pregnancy by 62.9% and every 8 weeks by an additional 17.6%. A hypothyroid patient with a TSH of 0.5 mU/L who becomes pregnant would receive an immediate L-T4 dose increase by only 28.5% of respondents. Conclusions: The survey revealed that (1) nearly exclusive preference for L-T4 alone for therapy, (2) use of age-specific TSH targets for replacement therapy, (3) a low threshold for treating mild thyroid failure, (4) complacent and variable attention to TSH targets in the pregnant and prepregnant woman, and (5) a highly variable approach to both the rate and means of restoring euthyroid status for overt disease. Both alignments with and divergence from guidelines were detected. The results should help in directing focused educational activities in the region, providing a baseline for future monitoring of practices.

Thyroid function control among pregnant women following a therapeutic thyroidectomy.

The aim of this study was to assess the extent of thyroid function control among pregnant women who had previously undergone a therapeutic thyroidectomy. Retrospective cohort study. The largest health maintenance organization in Israel. All female patients who were pregnant between May, 2001 and September, 2012 and had a medical history of thyroid surgery. The thyroid-stimulating hormone (TSH) levels throughout the pregnancy were compared to recommended trimestral values. A multivariate analysis was performed to determine risk factors for not attaining TSH recommended range. A total of 477 females with a history of thyroid surgery had given 701 births during the study period. Forty-three percent (n = 203), had thyroidal malignancy. Nearly half of the women underwent total thyroidectomy (43.4%, n = 207). The women's TSH values were within the recommended range in only 60% (n = 350) of the pregnancies during the first trimester (0.1-2.5 mIU/L), in 61% (n = 335) during the second trimester (0.2-3 mIU/L), and in 70% (n = 338) during the third trimester (0.3-3 mIU/L). In multivariate analysis, women that underwent a total thyroidectomy due to a benign thyroid disease, were at the highest risk for not attaining target TSH levels. This very large cohort of pregnant women with a past history of thyroid surgery demonstrated a significant percentage of pregnancies with TSH values above the recommended range. Women that underwent a total thyroidectomy due to benign thyroid disease were at the highest risk for gestational hypothyroidism.

Long-term follow-up results of PTMC treated by ultrasound-guided radiofrequency ablation: a retrospective study

Objectives To confirm the long-term efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC). Methods We retrospectively reviewed data of 102 primary papillary thyroid carcinoma patients (82 women, 20 men; mean age: 43 [19] years) treated with radiofrequency ablation and thyroid-stimulating hormone (TSH) suppression therapy before December 2018. All patients were at high surgical risk or refused surgery. They were followed up at 1, 3, 6, 9, and 12 months and every 6–12 months thereafter using ultrasound and contrast-enhanced ultrasound. The volume and volume reduction ratio was calculated. Recurrence and lymph node or distant metastasis were evaluated. Results The mean initial tumor diameter was 0.50 (0.29) cm; the mean initial volume was 0.06 (0.09) mL. At 1, 3, 6, 9, 12, 24, 36, 48, and 60 months after RFA, complete resorption rates were 0, 0, 9.8 (10/102), 33.3 (34/102), 91.2 (93/102), 96.1 (98/102), 99 (101/102), 100, and 100%, respectively. Two patients had developed ipsilateral neck lymph node metastasis in regions IV and VI at 30- and 18-month follow-ups, respectively. After RFA, 3/102 patients (2.9%) developed hoarseness—the main side effect. No life-threatening or delayed complications occurred. The TSH value in the initial period was 0.06 (0.02) µIU/mL; the rate of reaching the TSH target was 85.7%. The TSH value at follow-up was 1.47 (0.91) µIU/mL; the compliance rate was 99.3%. Conclusions Ultrasound-guided RFA for PTMC is highly effective and safe. RFA can serve as a minimally invasive treatment for PTMC patients who refuse surgery or active surveillance.

Incremental value of post-high dose therapy I-131 scan over pre.therapy diagnostic I-131 scan in patients with differentiated thyroid cancer: Experience from a tertiary care centre in South India

Objective: Objective of this study is to establish the incremental value of post-high dose therapy I-131 whole body scintigraphy (WBS) over diagnostic pre-therapy I-131 WBS in the detection of radioiodine avid foci, staging and change in the management in patients with differentiated thyroid carcinoma post-total thyroidectomy. Methods: We retrospectively studied 93 post-total thyroidectomy patients with well differentiated thyroid cancer (mean age 47 [range 18–78] years; 72 females) who underwent diagnostic dose pre-therapy? I-131 WBS and post-high dose therapy? I-131 WBS from January 2017 to June 2018 were included. Discordance rate of pre-therapy? I-131 WBS findings with post-therapy? I-131 WBS was calculated. Results: Post-therapy I-131 WBS revealed additional radioiodine avid foci not detected on pre-therapy? I-131 WBS in 16 (17.2%) patients. Upstaging was more common in patients =55 years (8 of 23, 34.8%) when compared to patients Conclusion: Post-therapy? I-131 WBS revealed new foci in 17.2% patients and clinical upstaging occurred in 9.6% of patients compared to pre-therapy I-131 WBS. There is a significant improvement in the detection of radioiodine avid foci overall and also metastatic lymph nodes by doing post-therapy? I-131 WBS. We suggest that post-therapy? I-131 WBS should be routinely done as it had an incremental role over pre-therapy? I-131 WBS in establishing the true extent of tumour burden, in upstaging the disease and thereby planning adequate hormone suppression to attain target thyroid stimulating hormone levels.

Age-Related Serum Thyroid-Stimulating Hormone Reference Range in Older Patients Treated with Levothyroxine: A Randomized Controlled Feasibility Trial (SORTED 1)

Introduction: Serum thyroid-stimulating hormone (TSH) increases with age but target TSH is similar in younger and older hypothyroid patients on treatment. It is unknown if quality of life (QoL), hypothyroid symptoms and cardiovascular risk factors change in older hypothyroid patients treated to an age-appropriate reference range. Objective: To assess if a higher target serum TSH of 4.01–8.0 mU/L is feasible in, and acceptable to, older treated hypothyroid patients. Methods: A single-blind (participant) randomised controlled feasibility trial involving 48 hypothyroid patients aged ≥80 years on established and stable levothyroxine (LT4) therapy with serum TSH levels within the standard reference range (0.4–4.0 mU/L) was conducted. Standard (0.4–4.0 mU/L) or higher (4.1–8.0 mU/L) TSH target (standard TSH [ST] or higher TSH [HT] groups) LT4 for 24 weeks was administered. The outcome measures evaluated were thyroid function tests, QoL, hypothyroid symptoms, cardiovascular risk factors and serum marker of bone resorption in participants that completed the trial (n = 21/24 ST group, n = 19/24 HT group). Results: At 24 weeks, in the ST and HT groups, respectively, median (interquartile range) serum TSH was 1.25 (0.76–1.72) and 5.50 (4.05–9.12) mU/L, mean (± SD) free thyroxine (FT4) was 19.4 ± 3.5 and 15.9 ± 2.4 pmol/L, and daily LT4 dose was 82.1 ± 26.4 and 59.2 ± 23.9 µg. There was no suggestion of adverse impact of a higher serum TSH in the HT group with regard to any of the outcomes assessed. Conclusions: In hypothyroid patients aged ≥80 years on LT4 therapy for 24 weeks, there was no evidence that a higher target serum TSH was associated with an adverse impact on patient reported outcomes, cardiovascular risk factors or bone resorption marker over 24 weeks. Longer-term trials assessing morbidity and mortality outcomes and health-utility in this age group are feasible and should be performed.