Prevalence of normal TSH value among patients with autonomously functioning thyroid nodule

Image-guided Thermal Ablation as a Promising Approach to Both Nontoxic and Toxic Autonomously Functioning Thyroid Nodules

RATIONALE AND OBJECTIVES

Although thermal ablation has been recommended as an alternative therapy option for autonomously functioning thyroid nodules (AFTN), current clinical evidence mainly focuses on toxic AFTN. This study aims to evaluate and compare the efficacy and safety of thermal ablation (percutaneous radiofrequency ablation or microwave ablation) in treating nontoxic and toxic AFTN.

MATERIALS AND METHODS

AFTN patients who received a single session of thermal ablation with a follow-up period ≥12 months were recruited. Changes in nodule volume and thyroid function, and complications were evaluated. Technical efficacy was defined as the maintenance or restoration of euthyroidism with a volume reduction rate (VRR) ≥80% at the last follow-up.

RESULTS

In total, 51 AFTN patients (age: 43.8±13.9 years, female: 88.2%) with a median follow-up period of 18.0 (12.0-24.0) months were included, where 31 were nontoxic (nontoxic group), and 20 were toxic (toxic group) before ablation. The median VRR was 96.3% (80.1%-98.5%) and 88.3% (78.3%-96.2%) in the nontoxic and toxic groups, respectively, and the respective euthyroidism rates were 93.5% (29/31, 2 evolved to toxic) and 75.0% (15/20, 5 remained toxic). The corresponding technical efficacy was 77.4% (24/31) and 55.0% (11/20, p=0.126). Except for one case of stress-induced cardiomyopathy in the toxic group, no permanent hypothyroidism or other major complications occurred in both groups.

CONCLUSION

Image-guided thermal ablation is efficacious and safe in treating AFTN, both nontoxic and toxic. Recognition of nontoxic AFTN would be helpful for treatment, efficacy evaluation, and follow-up.

Clinical value of molecular markers as diagnostic and prognostic tools to guide treatment of thyroid cancer

OBJECTIVE

Advances in our understanding of the molecular biology of thyroid tumours is being rapidly translated into their clinical management. This review summarizes the current use of molecular testing in thyroid tumours, focusing on their usefulness as diagnostic and prognostic tools to guide treatment with consideration of present limitations.

DESIGN

Considerations about molecular testing applications for the diagnosis and treatment of thyroid tumours are divided into four sections/roles: (1) evaluating cytologically indeterminate thyroid nodules; (2) guiding extent of surgery in indeterminate thyroid nodules; (3) completing histological characterization of thyroid tumours and (4) identifying actionable mutations in advanced progressive thyroid cancers.

RESULTS

Genomic testing can improve the presurgical malignancy risk assessment in indeterminate thyroid nodules. However, a prior in-depth analysis of institutional quality and outcomes of sonographical, cytological and histological characterization of thyroid tumours is necessary. Presently, it remains uncertain whether knowing the molecular profile of a cytologically indeterminate thyroid nodule might be advantageous to modify the extent of initial surgery. Molecular characterization of thyroid tumours can be a valuable adjunct to morphological diagnosis in some challenging cases, such as in low-risk follicular cell-derived neoplasms, or rare tumours. Finally, as selective kinase inhibitors are available, molecular testing in locally advanced/metastatic progressive thyroid cancers should also be integrated into the institutional clinical management pathway to improve outcomes and limit toxicity.

CONCLUSIONS

Molecular testing needs to be implemented into the local evidence-based clinical management thyroid nodule/cancer pathways to improve its diagnostic and prognostic value and to optimize cost-effectiveness.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : What is the role of functional imaging and isotopic treatment?

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the role of thyroid scintigraphy in the diagnosis of autonomous thyroid nodules, nuclear medicine in nodules with indeterminate cytology and iodine treatment for autonomous thyroid nodules.

Distribution of Functional Status of Thyroid Nodules and Malignancy Rates of Hyperfunctioning and Hypofunctioning Thyroid Nodules in Germany

AIM

Thyroid scintigraphy enables the depiction of the functional status of thyroid nodules (TNs) with both, ^99mTc-pertechnetate and ¹²³Iodine. The functional status is relevant for diagnostic procedures for the differentiation of benign and malignant TNs. The aim of this study was to examine the current frequencies of hyper-, hypo- and isofunctioning TNs in Germany and to estimate the risk of malignancy with regard to functional status.

METHODS

In 11 study centers, a minimum of 100 nodules per center were consecutively enrolled between July 2019 and April 2020. Inclusion criteria were: newly diagnosed nodule, nodule' size of 10 mm or more, thyroid scintigraphy. Exclusion criteria were: completely cystic TNs, patients with prior radioiodine therapy or thyroid surgery. The risk of malignancy was estimated for hyper- and hypofunctioning TNs.

RESULTS

Overall, 849 patients (72 % women) with 1262 TNs were included. Patients' age ranged from 18 to 90 years. Most TNs were hypofunctioning (n=535, 42%) followed by isofunctioning TNs (n=488, 39%) and hyperfunctioning TNs (n=239, 19%). When only TNs with a maximum size of 2 cm or more were considered the rate of hyperfunctioning and hypofunctioning TNs increased (to 27% and 49%) while isofunctioning TNs decreased. Only one of all hyperfunctioning TNs was malignant. In hypofunctioning nodules, the malignancy rate was estimated at 10%.

CONCLUSION

In Germany, the proportion of hyperfunctioning TNs is approximately 20% and increases in larger TNs to up to 27%. Due to the low risk of malignancy in hyperfunctioning TNs, no further procedures to rule out malignancy are necessary. The risk of malignancy of hypofunctioning TNs is significantly higher. Thus, a thyroid scintigraphy is a useful diagnostic tool in Germany.

Radioactive Iodine for the Treatment of Subclinical Thyrotoxicosis Grade 1 and 2: Outcome of up to 18-Year Follow Up

BACKGROUND

Subclinical thyrotoxicosis (SCT) is associated with significant morbidity and mortality, specifically increased risk of atrial fibrillation and cardiovascular death. The management is ill-defined due to the scarcity of randomised controlled studies. Some clinicians recommend radioiodine (RAI) treatment however its long-term outcome is unknown. Therefore, further data is needed to provide robust evidence-based guidelines.

METHODS

A prospective, single-protocol analysis of the outcome of SCT patients (Grade 1; 0.1-0.4 mIU/L and Grade 2; <0.1 mIU/L) treated with mean dose of 427 MBq of I¹³¹, followed up for up to 18 years. Thyroid function tests were measured at 4-6 weeks, 3-, 6-, and 12-months post-RAI, and annually thereafter. Cure was defined as achieving a euthyroid/hypothyroid state.

RESULTS

Seventy-eight patients with a median age of 68 years (range 36-84) and varying aetiology [55 toxic multinodular goitre (TMNG), 10 toxic nodule (TN) and 13 Graves' disease (GD)] were followed up for a median period of 7.5 years (range 1-18). The cure rate was 100%. The rates of hypothyroidism in TMNG, TN and GD were 23.6%, 30% and 38.5% respectively. The median time to hypothyroidism was 6 and 12 months in GD and TMNG/TN respectively. No differences in outcome between Grade 1 versus Grade 2 were observed.

CONCLUSION

RAI using single mean dose of 427 MBq is effective and safe, irrespective of aetiology or grade of TSH suppression. GD patients become hypothyroid within the first year, whilst TMNG/TN for up to 9-years. Thus after 12 months of follow up, annual thyroid function monitoring is advised.

Prevalence and Treatment Outcomes of Marine-Lenhart Syndrome in Japan

INTRODUCTION

Marine-Lenhart syndrome (MLS) is now understood to be a combination of Graves' disease and autonomously functioning thyroid nodule(s) (AFTNs). The prevalence of the syndrome and suitable treatments for those living in iodine-sufficient areas are uncertain.

OBJECTIVES

We aimed to investigate the prevalence, treatment, and prognosis of MLS in Japan, an iodine-sufficient area.

METHODS

This study involved patients who visited our hospital between February 2005 and August 2019. Among patients with both thyrotoxicosis and thyroid nodule(s) larger than 10 mm, MLS and isolated AFTNs were diagnosed based on serum thyroid-stimulating hormone receptor antibody levels and scintigraphy using radioiodine or technetium-99m and thyroid uptake.

RESULTS

Twenty-two patients were found to have MLS, compared to 372 with isolated AFTNs and 8,343 with Graves' disease, during the period. Therefore, the rate of MLS cases was 0.26% among all patients with Graves' disease (22/8,343). Treatments and outcomes were assessed for cases of MLS (n = 18) and isolated AFTNs (n = 269). Antithyroid drugs (ATDs) were withdrawn in 27.8% of cases in the MLS group and 10.3% in the isolated AFTN group. There was no significant difference in the clinical outcome after ATD withdrawal between the 2 groups. However, the rate of hypothyroidism after radioactive iodine (RAI) administration was significantly higher in the MLS group than in the isolated AFTN group (42.9 vs. 9.0%, p = 0.005) despite similar doses of RAI.

CONCLUSIONS

The prevalence of MLS among patients with Graves' disease was 0.26% in Japan. RAI therapy induces hypothyroidism more frequently than in those with AFTNs probably because RAI is taken up in the surrounding Graves' tissues.

2021 European Thyroid Association Guidelines for the Management of Iodine-Based Contrast Media-Induced Thyroid Dysfunction

Given the fact that a large number of radiological examinations using iodine-based contrast media (ICM) are performed in everyday practice, clinicians should be aware of potential ICM-induced thyroid dysfunction (TD). ICM can induce hyperthyroidism (Hyper) or hypothyroidism (Hypo) due to supraphysiological concentrations of iodine in the contrast solution. The prevalence of ICM-induced TD varies from 1 to 15%. ICM-induced Hyper is predominantly found in regions with iodine deficiency and in patients with underlying nodular goiter or latent Graves' disease. Patients at risk for ICM-induced Hypo include those with autoimmune thyroiditis, living in areas with sufficient iodine supply. Most cases of ICM-induced TD are mild and transient. In the absence of prospective clinical trials on the management of ICM-induced TD, an individualized approach to prevention and treatment, based on patient's age, clinical symptoms, pre-existing thyroid diseases, coexisting morbidities and iodine intake must be advised. Treatment of ICM-induced Hyper with antithyroid drugs (in selected cases in combination with sodium perchlorate) should be considered in patients with severe or prolonged hyperthyroid symptoms or in older patients with underlying heart disease. It is debated whether preventive therapy with methimazole and/or perchlorate prior to ICM administration is justified. In ICM-induced overt Hypo, temporary levothyroxine may be considered in younger patients with symptoms of Hypo, with an underlying autoimmune thyroiditis and in women planning pregnancy. Additional clinical trials with clinically relevant endpoints are warranted to further aid in clinical decision-making in patients with ICM-induced TD.

Molecular Imaging for Thyrotoxicosis and Thyroid Nodules

After exclusion of exogenous iodine overload, radioiodine uptake (RAIU) testing with 123I or 131I enables the accurate evaluation and quantification of iodine uptake and kinetics within thyroid cells. In addition, scintigraphic evaluation with 123I or 99mTc-pertechnetate (99mTc04-) provides the topographic distribution of thyroid cell activity and allows the detection and localization of ectopic thyroid tissue. Destructive thyrotoxicosis is characterized by abolished or reduced uptake whereas productive thyrotoxicosis (i.e., hyperthyroidism "sensu strictu") is characterized by high RAIU with scintigraphically diffuse (i.e., Graves disease and diffuse thyroid autonomy) or focal (i.e., autonomously functioning thyroid nodules [AFTN]) overactivity. Accordingly, RAIU or thyroid scintigraphy are widely used to differentiate different causes of thyrotoxicosis. In addition, several radiopharmaceuticals are also available to help in differentiating benign from malignant thyroid nodules and inform clinical decision making. In fact, AFTNs can be safely excluded from fine-needle aspiration biopsy while either 99mTc-methoxyisobutylisonitrile (MIBI) and 18F-FDG may complement the work-up of cytologically indeterminate cold nodules and contribute to reducing the need for diagnostic lobectomies/thyroidectomies. Finally, RAIU studies are also useful for calculating the administered therapeutic activity of 131I to treat hyperthyroidism and euthyroid multinodular goiter. All considered, thyroid molecular imaging allows us to characterize molecular/functional aspects of different thyroid diseases, even before clinical symptoms become manifest and remains integral to properly managing such conditions. Our present paper summarizes basic concepts, clinical applications, and potential developments of thyroid molecular imaging in patients affected by thyrotoxicosis and thyroid nodules.

Radioiodine therapy of thyroid autonomy

Radioiodine therapy (RIT) of thyroid functional autonomy (TFA) is rapidly evolving, though it has been recognized for decades as a very effective treatment of toxic nodular varieties. Indeed, TFA is a frequent cause of persistent subclinical hyperthyroidism, which should be regarded as a new metabolic syndrome, with well-established adverse cardio-vascular consequences. Sensitive TSH assays and multiparametric ultrasounds are not accurate enough to reliably diagnose TFA and identify its main variants, unifocal, multifocal (UFA/MFA) and disseminated autonomy (DISA). Modern diagnostic tools are extensively presented and rely upon Thyroid Scan imaging and quantification. A new relationship allows predicting at baseline, an excess of 123I uptake as compared to the TSH stimulation in compensated TFA. Suppressed TS are useful with either isotope, otherwise. Diagnosis of the DISA variant is presented as compared to Graves' disease. Dosimetry has some specificity in TFA work-up. Indeed, the spatial distribution of the dose is as important as the mean value itself and can be eventually controlled by adjusting the TSH level with the smart use of LT3 or antithyroid drug therapy (ATD). A review of the different ways to determine the target mass from anatomical to functional approaches is presented. Main clinical and dosimetric published results of RIT are summarized according to clinical goals. Endogenous TSH stimulation using an ATD preparation has promising results in reducing big autonomously functioning goiters. Finally, we report preliminary successful results of preventive RIT using short term LT3 suppression in compensated TFA, with low administered activities and low rate of hypothyroidism.

Microwave ablation of symptomatic benign thyroid nodules: Short- and long-term effects on thyroid function tests, thyroglobulin and thyroid autoantibodies

OBJECTIVE

Microwave ablation therapy has been attracting great attention due to its advantages such as low complication rate, good cosmetic results and effective nodule shrinking. Although the effect of thermal ablation therapy on the nodule volume reduction rate has been shown several studies, a limited number of papers have been reported for the effects of microwave ablation (MWA) on thyroid function tests. The aim of this study was to investigate the short- and long-term effects of MWA therapy on thyroid function tests (TFTs), thyroglobulin (Tg) and thyroid autoantibodies in euthyroid patients.

DESIGN, PATIENTS AND MEASUREMENTS

Demographic data of the patients, TFTs, Tg, thyroid autoantibodies and thyroid volume of the nodules were recorded before the procedure and follow-up. Any differences in serum thyroid hormone levels were investigated in pre-, post- and 6-month follow-up periods before and after MWA.

RESULTS

The difference between all thyroid hormone levels at pre MWA and 24 h after MWA was statistically significant (p < .001). FT3 (4.62) pmol/L and FT4 (10.81) pmol/L median levels increased significantly (p < .001), while thyrotropin (TSH) levels decreased at 24 h after MWA (p < .001). Thyroid antibodies levels were not statistically different at 6-month (p > .05), whereas Tg levels decreased (p < .001) compared to pre MWA.

CONCLUSIONS

While no significant effect was observed at 6 month, the effect of MWA on thyroid function tests was prominent at 24 h.

Biochemical follow-up of nonfunctioning benign thyroid nodules

OBJECTIVE

For the biochemical follow-up of benign thyroid nodules, some authors recommend periodic lifelong measurement of thyroid-stimulating hormone (TSH) to assess for the development of toxic nodules over time. The purpose of this retrospective study was to assess the incidence of thyroid dysfunction over time in patients with benign thyroid nodule(s), with a normal TSH at diagnosis and to identify any factors that may predict biochemical dysfunction over time.

METHODS

Medical records of patients with the diagnosis of thyroid nodule(s) between January 2011 and August 2014 were reviewed. Patients who had TSH measurement within 1 year of initial diagnostic ultrasound (US) were included.

RESULTS

One-hundred fifty-seven patients identified with thyroid nodule(s) satisfied inclusion criteria. At a median follow-up of 45 (34-63) months, 13 (8.3%) patients developed thyroid dysfunction. The mean initial TSH in the group which developed subclinical hyperthyroidism (0.65 mIU/mL) was statistically different from the group that did not develop thyroid dysfunction (1.37 mIU/mL, P: 0.007). More patients with TSH <1 mIU/L developed thyroid dysfunction as compared to subjects with TSH ≥1 mIU/L (P: .022). There was no significant difference in the incidence of thyroid dysfunction on the basis of gender, race, smoking status, TPO Ab positivity and number of nodules at diagnosis.

CONCLUSIONS

We recommend re-examining the current practice and clinical utility of frequent TSH monitoring in all patients with thyroid nodules, particularly if initial TSH level is ≥1 mIU/L.

Serum thyroid stimulating hormone level for predicting utility of thyroid uptake and scan

BACKGROUND

Thyroid uptake and scan (TUS) is a clinical tool used for differentiation of thyrotoxicosis etiologies. Although guidelines recommend ordering a TUS for evaluation of low TSH levels, no specific value is defined. This study aimed to determine a TSH cutoff at which TUSs yield a greater likelihood of successful determination of etiology to avoid unnecessary testing.

METHODS

This was a retrospective study on 137 patients seen by an endocrinologist who underwent TUS for evaluation of low TSH (<0.4 μU/mL). A receiver operating curve analysis was performed to determine the TSH cutoff with maximal sensitivity and specificity for prediction of diagnostic utility.

RESULTS

Ninety percent of TUSs (n = 123) led to a diagnosis, while 10% (n = 14) were inconclusive or normal. Diagnoses included Graves' diseases (52%), toxic multinodular goiter (19%), thyroiditis (12%), and solitary toxic adenoma (7%). The median TSH value was 0.008 μU/mL (IQR 0.005, 0.011), and the median free T4 value was 1.7 μU/mL (IQR 1.3, 2.8). The ROC analysis produced an area under the curve of 0.86. The optimal TSH cutoff value was 0.02 μU/mL (sensitivity 80%, specificity 93%) for prediction of diagnostic yield.

CONCLUSION

This study demonstrates that TSH is a useful predictor of the utility of TUS in yielding an etiology of thyrotoxicosis. Our analysis showed that TUS had a greater likelihood of determining an etiology when TSH was ≤0.02 μU/mL. This information can help clinicians avoid unnecessary cost and patient time burden when TUS is unlikely to aid in determining the etiology of thyrotoxicosis.

Thyroid scintigraphy in the era of fine-needle aspiration cytology

PURPOSE

To evaluate whether thyroid scintigraphy would alter the clinical management of patients referred for fine-needle aspiration cytology (FNA).

METHODS

We reviewed the medical and imaging records of patients referred to our Department between 2016 and 2019. All the patients had to take a serum thyrotropin test administered in our hospital at least two months before the FNA; where the TSH level was ≤1.5 mIU/L, the patients were subjected to a scan and subsequently to FNA, where indicated. We selected only healthy patients with no previous history of thyroid disease, who were not taking any drugs and who had a TSH level of ≤1.5 mIU/L. We excluded patients with multinodular goitre.

RESULTS

A total of 176 patients were analysed. A total of 67/176 patients (38%) showed a serum of TSH ≤ 0.27 mIU/L. Scintigraphy identified a hot nodule in 142 lesions (80.7%), a warm nodule in 8 lesions (4.5%) and a cold nodule in 26 lesions (14.8%). The ROC curve analysis indicated that a TSH value of ≤0.42 mIU/L identified patients with hyperfunctioning nodules with a sensitivity of 65% and a specificity of 77%. All patients with cold and warm nodules were submitted to FNA: 22/26 (85%) and 5/8 (63%) lesions showed suspected malignancy or were compatible with malignancy, respectively.

CONCLUSION

Speculating on our data, if we had subjected our patients to FNA as indicated by the 2015 ATA guidelines, we would have subjected 117 patients to cytology, from whom 83 had undetected hot nodules. Conversely, by adopting scintigraphy for all patients with TSH ≤ 1.5 mIU/L, 109 patients have avoided FNA. However, our study was performed in a region with a history of mild iodine deficiency. Therefore, we cannot claim that our observation is valid for patients born and living in areas with sufficient iodine uptake. We recommend thyroid scintigraphy for treating single thyroid nodules in euthyroid patients born and living in regions with an iodine deficiency, when TSH levels are below 1.5 mIU/L before FNA.

Ultrasound systems for risk stratification of thyroid nodules prompt inappropriate biopsy in autonomously functioning thyroid nodules

OBJECTIVE

Ultrasound (US) risk stratification systems (RSSs) have been developed to reduce the number of unnecessary fine-needle aspiration (FNA) biopsies in patients with thyroid nodules. Autonomously functioning thyroid nodules (AFTN) account for 5%-10% of palpable lesions and are very rarely malignant. The present study was undertaken to investigate how RSSs classify AFTNs and whether RSSs are able to avoid unnecessary FNA biopsies in such cases.

METHODS

Patients with AFTN who had undergone US, scintigraphy and thyroid function evaluation from December 2016 to December 2017 were selected. US images were retrospectively reviewed and AFTN reclassified according to AACE/ACE/AME, ACR-TIRADS, ATA, BTA, EU-TIRADS, K-TIRADS and TIRADS. Risk class and indication for FNA were assessed.

RESULTS

A number of 87 AFTNs from 85 consecutive patients were enrolled. A median diameter of 22 mm (range 10-59) was found, with an ovoid isoechoic nodule being the most frequent US presentation. When AFTNs were reclassified according to US RSSs, the most common categories were low and intermediate risk. AFTNs were assessed as being at high risk/high suspicion/malignant in 1%-9%, with good agreement among AACE/ACE/AME, ATA, EU-TIRADS, K-TIRADS and TIRADS. Remarkably, FNA was indicated in 27%-90% of AFTNs. A statistically significant difference among the systems was found; 8% of cases were nonclassifiable by one or more US RSS.

CONCLUSIONS

Ultrasound RSSs prompt inappropriate FNA in a significant number of patients with AFTN.

Fusion iENA Scholar Study: Sensor-Navigated I-124-PET/US Fusion Imaging versus Conventional Diagnostics for Retrospective Functional Assessment of Thyroid Nodules by Medical Students

In conventional thyroid diagnostics, the topographical correlation between thyroid nodules (TN) depicted on ultrasound (US) in axial or sagittal orientation and coronally displayed scintigraphy images can be challenging. Sensor-navigated I-124-PET/US fusion imaging has been introduced as a problem-solving tool for ambiguous cases. The purpose of this study was to investigate the results of multiple unexperienced medical students (MS) versus multiple nuclear medicine physicians (MD) regarding the overvalue of I-124-PET/US in comparison to conventional diagnostics (CD) for the functional assessment of TN.

METHODS

Out of clinical routine, cases with ambiguous findings on CD were selected for I-124-PET/US fusion imaging. Sixty-eight digital patient case files (PCF) of 34 patients (CDonly and CD+PET/US PCF) comprising 66 TN were provided to be retrospectively evaluated by 70 MD and 70 MS, respectively. A total of 2174 ratings (32.9 per TN) were carried out: 555 ratings (8.4 per TN) for CDonly and 532 ratings (8.1 per TN) for CD+PET/US by each MD and MS.

RESULTS

Functional assessment revealed 8.5%/11.7% (n.s.) (16.4%/25.8% (p = 0.0002)), 41.8%/28.5% (p < 0.0001) (23.9%/17.9% (p = 0.0193)), 36.0%/30.5% (n.s.) (57.3%/53.9% (n.s.)), and 13.7%/29.4% (p < 0.0001) (2.4%/2.4% (n.s.)) hyperfunctioning, indifferent, hypofunctioning, and not rateable TNs for CDonly (CD+PET/US) and MD/MS, respectively. The respective rating confidence was indicated as absolute certain, quite certain, equivocal, uncertain, and not rateable in 11.7/3.4% (p < 0.0001) (44.9%/38.9% (p = 0.0541), 51.9%/26.7% (p < 0.0001) (46.2%/41.5% (n.s.)), 21.6%/29.0% (p = 0.0051) (6.2%/14.8% (p < 0.0001)), 1.1%/11.5% (p < 0.0001) (0.2%/2.3% (p = 0.0032)), and 13.7%/29.4% (p < 0.0001) (2.4%/2.4% (n.s.)) by MD/MS, respectively. There was a significant difference in the diversity of the observers' functional assessment of TN (MD 0.84 vs. MS 1.02, p = 0.0006) and the respective confidence in functional assessment (MD 0.93 vs. MS 1.16, p < 0.0001) between MD and MS on CDonly, whereas CD+PET/US revealed weaker differences for both groups (MD 0.48 vs. MS 0.47, p = 0.57; and MD 0.66 vs. MS 0.83, p = 0.0437). With the additional application of I-124-PET/US, the rating diversity of both MD and MS markedly tends towards more consistency (p < 0.0001 in each case).

CONCLUSION

The additional application of sensor-navigated I-124-PET/US fusion imaging significantly influenced the functional assessment of TN positively, especially for unexperienced observers.

Prevalence of hyperfunctioning thyroid nodules among those in need of fine needle aspiration cytology according to ATA 2015, EU-TIRADS, and ACR-TIRADS

PURPOSE

Given the large number of patients with thyroid nodules, improvement of the specificity of current ultrasound-based thyroid nodule classification systems (ATA, EU-TIRADS, and ACR-TIRADS) is warranted to reduce the number of diagnostic thyroidectomies. Thyroid scintigraphy has been shown to demonstrate hyperfunctional nodules, associated with a low malignancy risk, in euthyroid patients. However, it is not known if thyroid scintigraphy could improve specificity of current classification systems. The aim of this study, therefore, was to determine the frequency of hyperfunctional nodules among those nodules in need of fine needle aspiration cytology (FNA) according to current classification systems and to test if nodule functional status is associated with sonographic features.

METHODS

Five hundred sixty-six euthyroid patients (TSH 0.55-4.20 μU/ml) presenting for thyroid nodule workup including thyroid sonography and scintigraphy at our department between 09/2013 and 02/2018 were included in this retrospective study. All nodules > 10 mm were classified according to ATA, EU-TIRADS, and ACR-TIRADS and correlated to their functional status as assessed by 99mTc-pertechnetate scintigraphy.

RESULTS

Ultrasound detected 1029 thyroid nodules ≥ 10 mm, including 545 nodules ≥ 15 mm. Prevalence of hyperfunctional nodules among those with recommendation for FNA according to ATA 2015, EU-TIRADS, and ACR-TIRADS was 6.4%, 6.9%, and 6.5% for nodules ≥ 10 mm and 7.2%, 7.6%, and 7.5% only considering nodules ≥ 15 mm. No sonographic feature was correlated to hyperfunctionality of nodules.

CONCLUSION

In euthyroid patients, thyroid scintigraphy demonstrates hyperfunctionality, which cannot be predicted by ultrasound, in up to 6.9% of nodules in need of FNA according to ultrasound-based classifications. Given the known low risk of malignancy in hyperfunctional nodules, thyroid scintigraphy can lower the frequency of fine needle aspirations and-potentially-the frequency of diagnostic hemithyroidectomies in euthyroid patients.

Can ultrasound systems for risk stratification of thyroid nodules identify follicular carcinoma?

BACKGROUND

Ultrasound (US) risk stratification systems (RSSs) have been developed to reduce the number of unnecessary fine needle aspirations (FNAs) of thyroid nodules. These systems were designed primarily to identify papillary thyroid carcinomas, thus their performance on follicular thyroid carcinoma (FTC) is debatable. The present study was undertaken to investigate the accuracy of RSSs in selecting FTCs for FNA.

METHODS

Patients with FTC who underwent US examinations between 2012 and 2018 in 2 institutions were selected. US images were reviewed retrospectively, and FTCs were reclassified according to the American Association of Clinical Endocrinologist/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME), American College of Radiology (ACR-TIRADS), 2015 American Thyroid Association, British Thyroid Association, European Thyroid Association, Korean Society of Thyroid Radiology and Korean Society of Radiology, and Thyroid Imaging Reporting and Data System (TIRADS). Risk class and indication for FNA were assessed.

RESULTS

Forty-five FTCs from 45 consecutive patients were included in the study. The median tumor diameter was 32 mm (range, 11-100), and ovoid isoechoic nodule with or without lobulated margins was the most frequent presentation. When FTCs were classified according to RSSs, the most common categories were intermediate and high risk, though 1 case in 3 was not classifiable. FTCs were classified as high risk/high suspicion/malignant in 11% to 74% of cases, with a statistically significant difference among the systems. FNA was indicated in 69% to 100% of cases, with good agreement among AACE/ACE/AME, ACR-TIRADS, and TIRADS.

CONCLUSION

Current RSSs show high performance in selecting FTCs for FNA. This result is mainly due to the dimensional RSSs cutoffs indicating FNA. On the contrary, given the reported unsuspicious echo-structural presentation of FTC and the recognized limitation of cytological assessment to detect it, caution is advised when using US to manage cytologically indeterminate nodules.

I-124-PET/US Fusion Imaging in Comparison to Conventional Diagnostics and Tc-99m Pertechnetate SPECT/US Fusion Imaging for the Function Assessment of Thyroid Nodules

The purpose of this study is to investigate I-124 positron emission tomography (PET)/ultrasound (US) fusion imaging for function assessment of thyroid nodules. In 70 patients, 201 lesions were examined with conventional diagnostics (CD) (thyroid US, laboratory findings and Tc-99m pertechnetate scintigraphy), Tc-99m pertechnetate single photon emission computed tomography (SPECT) and I-124 PET/computed tomography (CT). Subsequently, US fusion imaging (SPECT/US and PET/US) was performed by three experienced investigators. Patients referred for thyroid diagnostics in a clinical routine setting were included in this study if CD produced equivocal results. PET/US was superior to CD and SPECT/US in 96% and 86%, respectively, and ambiguous findings in CD were clarified by PET/US in 96% of the 70 patients. Regarding nodule-based function assessment, 10% (66%), 39% (14%) and 71% (4%) of the 201 lesions were rated with absolute certainty (equivocal or uncertain) using CD, SPECT/US and PET/US, respectively (p < 0.001). PET/US has the potential to improve the function assessment of thyroid nodules in comparison to CD.

Performance of 18F-FDG PET/CT in Selecting Thyroid Nodules with Indeterminate Fine-Needle Aspiration Cytology for Surgery. A Systematic Review and a Meta-Analysis

Thyroid nodules with indeterminate fine-needle aspiration cytology (FNA) represent a major challenge in clinical practice. We conducted a systematic review and meta-analysis evaluating the ability of hybrid imaging using fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to appropriately select these nodules for surgery. PubMed, CENTRAL, Scopus, and Web of Science were searched until July 2019. Original articles reporting data on the performance of ¹⁸F-FDG PET/CT in thyroid nodules with indeterminate FNA were included. Summary operating points including 95% confidence interval values (95% CI) were estimated using a random-effects model. Out of 786 retrieved papers, eight studies evaluating 104 malignant and 327 benign thyroid nodules were included. The pooled positive and negative likelihood ratios (LR+ and LR-) and diagnostic odds ratio (DOR) of ¹⁸F-FDG PET/CT were 1.7 (95% CI: 1.4-2.0), 0.4 (95% CI: 0.2-0.7), and 3.5 (95% CI: 1.7-7.1), respectively. No heterogeneity was found for LR+ and DOR. In patients with thyroid nodules with indeterminate FNA, ¹⁸F-FDG PET/CT has a moderate ability to correctly discriminate malignant from benign lesions and could represent a reliable option to reduce unnecessary diagnostic surgeries. However, further studies using standardized criteria for interpretation are needed to confirm the reproducibility of these findings.

Radioisotope imaging for discriminating benign from malignant cytologically indeterminate thyroid nodules

The risk of malignancy in thyroid nodules with indeterminate cytological classification (Bethesda III-IV) ranges from 10% to 40%, and early delineation is essential as delays in diagnosis can be associated with increased mortality. Several radioisotope imaging techniques are available for discriminating benign from malignant cytologically indeterminate thyroid nodules, and for supporting clinical decision-making. These techniques include iodine-123, technetium-99m-pertechnetate, technetium-99m-methoxy-isobutyl-isonitrile (technetium-99m-MIBI), and fluorine-18-fluorodeoxyglucose (fluorine-18-FDG). This review discusses the currently available radioisotope imaging techniques for evaluation of thyroid nodules, including the mechanism of radiotracer uptake and the indications for their use.

Real-time elastography in autonomously functioning thyroid nodules: relationship with TSH levels, scintigraphy, and ultrasound patterns

BACKGROUND

Real-time elastography has been proposed to increase the sensitivity of ultrasound and improve the detection of thyroid nodules at risk of malignancy. To date sparse data on real-time elastography assessment of autonomously functioning thyroid nodules exist. Here, we investigated the potential role of real-time elastography in autonomously functioning thyroid nodule assessment. Specifically, the correlation between serum hormones and real-time elastography score, as well as other clinical and ultrasound features, was analyzed.

METHODS

Patients with autonomously functioning thyroid nodule identified by I-123 scintigraphy from September 2015 to July 2016 and undergoing ultrasound, real-time elastography, and thyroid function evaluation were selected. All autonomously functioning thyroid nodule were classified as RTE I (prevalence of red or green color with blue in up to 25% of the nodule area), RTE II (blue in 25-75%), or RTE III (blue in more than 75%). The association between suppressed thyroid stimulating hormone and patient's age, nodule's size, ultrasound presentation, and real-time elastography scoring was analyzed by Odds Ratio in univariate fashion and multivariate model.

RESULTS

A number of 47 subjects with single autonomously functioning thyroid nodule were enrolled. Median age of 63 years, median size of 2.0 cm, and suppressed thyroid stimulating hormone levels in 32% of cases were found. Those nodules classified by ultrasound at high risk underwent fine-needle aspiration cytology and cancer was excluded. At real-time elastography evaluation, a 45% of autonomously functioning thyroid nodule had a hard appearance (RTE III) and had thyroid stimulating hormone significantly lower than the other (p < 0.0001). A model of multivariate logistic regression including nodule's size, ultrasound characteristics, and elastographic presentation showed that only RTE III was significantly associated with suppressed thyroid stimulating hormone (Odds Ratio of 50).

CONCLUSIONS

Autonomously functioning thyroid nodule may have variable elasticity at real-time elastography examination, being hard score associated with reduced/suppressed thyroid stimulating hormone. For clinical practice, the presence of autonomously functioning thyroid nodule should be considered in patients with hard lesions. Also, as quoted by the most recent ATA guidelines, elastography should not be accounted for risk stratification of thyroid nodules.

When Is Thyroidectomy the Right Choice? Comparison between Fine-Needle Aspiration and Final Histology in a Single Institution Experience

OBJECTIVES

The aim of this study was to compare SIAPEC-IAP-based cytological reports with their corresponding histological diagnoses to establish when thyroidectomy is the right choice in the management of thyroid diseases.

STUDY DESIGN

This is a retrospective review of all the consecutive thyroidectomies/lobectomies performed at Maria Vittoria Hospital during the 10-year period between January 2005 and December 2015. Patients who underwent both fine-needle aspiration (FNA) and surgical procedures in our institution were included in the study.

RESULTS

A total of 260 patients underwent both FNA and a thyroid surgical procedure at Maria Vittoria Hospital; 111 (42.69%) had a malignant histological report. The final cytological diagnosis was nondiagnostic (TIR-1) in 19 cases (7.31%), benign (TIR-2) in 83 cases (31.92%), indeterminate (TIR-3) in 96 cases (36.92%), suspicious for malignancy (TIR-4) in 22 cases (8.46%), and diagnostic for malignancy (TIR-5) in 40 cases (15.38%). Among the 96 cases with TIR-3 cytology, after the review, 44 (16.92%) were classified as TIR-3A and 52 (20%) as TIR-3B. The prevalence of malignancy among TIR-3A cases was 20.45% (9/44) and among TIR-3B cases 53.85% (28/52). The difference was statistically significant (p = 0.0007).

CONCLUSIONS

Our data suggest that follow-up alone is not sufficient in TIR-3A patients given the high prevalence of malignancy within that diagnostic category (20.45%) and the low sensitivity (75.68%) and specificity (59.32%) in the distinction between TIR-3A and TIR-3B. Regarding patients with a multinodular goiter and TIR-2 at FNA, the surgical approach should not be excluded.

Searching for the most effective thyrotropin (TSH) threshold to rule-out autonomously functioning thyroid nodules in iodine deficient regions

The purpose of this study is to evaluate the distribution of thyrotropin (TSH) values in patients with autonomously functioning thyroid nodules and to set a TSH threshold above which thyroid scintigraphy would be obviated. Four hundred fifty one patients were included in the present study. Inclusion criteria were age > 18 years, TSH levels between 0.40 and 4.0 mIU/L, detection of a single solid or predominantly solid thyroid nodule >10 mm in the longest diameter. Thyroid ultrasound and thyroid scintigraphy with ^99mTc-pertechnetate were performed concurrently in all patients. Among 451 enrolled patients, 173 (38 %) had an autonomously functioning thyroid nodules, of which 137 (79 %) with a normal TSH level. Demographic data and nodules' volume were not significantly different in patients with autonomously functioning thyroid nodules and non-functioning nodules, respectively. However, TSH levels were nonetheless significantly lower in patients with autonomously functioning thyroid nodules compared to those with non-functioning nodules (p < 0.001). Adopting a TSH cutoff level at 2.38 mUI/L, all autonomously functioning thyroid nodules were correctly identified (i.e., 100 % sensitivity) with a 100 % negative predictive value. Our study showed a very high prevalence of autonomously functioning thyroid nodules in mildly iodine-deficient regions and confirmed that serum TSH is not an effective screening test to diagnose an autonomously functioning thyroid nodules. Our data add arguments in favor of the first-line use of thyroid scintigraphy to assess thyroid nodules, at least in iodine deficient areas. As all scintigraphically detected autonomously functioning thyroid nodules had a TSH level below 2.38 mUI/L, a thyroid scintigraphy should be omitted when higher TSH values are found in patients carrying a thyroid nodule.

Early detection of biochemically occult autonomous thyroid nodules

OBJECTIVE

Autonomously functioning thyroid areas may be associated with subclinical or overt hyperthyroidism, but may exist even in the presence of normal TSH. This study was aimed at comparing the rate of autonomously functioning areas and their cardiac sequelae in patients with nodular goitre studied with the usual and a novel approach.

DESIGN AND METHODS

In total 490 adult outpatients with thyroid nodular goitre, living in a mild iodine-deficient area, were selected in our referral centre for thyroid diseases from 2009 to 2014 on the basis of a suspicion of thyroid functional autonomy. They were divided in three groups according to a non-conventional approach (excessive response to thyroxine treatment: group 1) or conventional approach (low/normal TSH with clinical suspicion or low TSH: groups 2 and 3). All patients of the study with the suspicion of thyroid functional autonomy underwent thyroid scan with radioactive iodine (I¹³¹) uptake (RAIU).

RESULTS

The percentage of confirmed thyroid functional autonomy was 319/490, being significantly higher in group 3 than in groups 1 and 2 (81.5 vs 64.7 vs 52.6%; chi-square P < 0.0001). However, the diagnosis with non-conventional approach was made at a significant earlier age (P < 0.0001). Cardiac arrhythmias as well as atrial fibrillation were similarly detected by conventional and non-conventional approaches (chi-square test: P = 0.2537; P = 0.8425).

CONCLUSIONS

The hyper-responsiveness to thyroxine treatment should induce the suspicion of thyroid functional autonomy at an early stage, allowing to detect autonomous functioning areas in apparently euthyroid patients.

Higher TSH can be used as an additional risk factor in prediction of malignancy in euthyroid thyroid nodules evaluated by cytology based on Bethesda system

Recently, it has been suggested that thyrotropin (TSH) concentration can be used as a marker for prediction of thyroid malignancy. In this study, we aimed to investigate the association between TSH levels and prediction of malignancy in euthyroid patients with different Bethesda categories. The data of 1433 euthyroid patients with 3206 thyroid nodules who underwent thyroidectomy were screened retrospectively. The preoperative cytology results, thyroid function tests, thyroid autoantibodies, and presence of histopathological Hashimoto's thyroiditis (HT) were recorded. Of the 1433 patients, 585 (40.8 %) had malignant and 848 (59.2 %) had benign histopathology. Malignant group had smaller nodule size, elevated TSH levels, and higher rate of presence of HT compared to benign group (p < 0.001, all). Cytology results of 3206 nodules were as follows: 832 nondiagnostic (ND), 1666 benign, 392 atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 68 follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), 133 suspicious for malignancy (SM), and 115 malignant. Both SM and malignant cytology groups had higher TSH levels than other 4 Bethesda categories (p < 0.05, all). Benign cytology group had significantly lower TSH levels compared to other cytology groups (p < 0.05, all). Patients with malignant final histopathology in ND and AUS/FLUS cytology groups had significantly higher TSH levels compared to patients with benign final histopathology (p < 0.05, all). Moreover, TSH levels showed to increase from Bethesda categories II to VI. In addition to cytology, higher TSH levels can be used as a supplementary marker in prediction of malignancy in certain Bethesda categories.

Is there still a role for thyroid scintigraphy in the workup of a thyroid nodule in the era of fine needle aspiration cytology and molecular testing?

Thyroid scintigraphy is now rarely used in the work-up of a thyroid nodule except in the presence of a low TSH value. Therefore, autonomously functioning thyroid nodules (AFTNs) with a normal TSH value are diagnosed only in the rare medical centers that continue to use thyroid scan systematically in the presence of a thyroid nodule. In this review, we discuss the prevalence of AFTN with a normal TSH level and the possible consequences of performing fine needle aspiration cytology (FNAC) in an undiagnosed AFTN. We also discuss the risk of malignant AFTN which may be higher than previously stated.