Management of simple nodular goiter: current status and future perspectives

Ultrasound-guided fine needle aspiration cytology and ultrasound examination of thyroid nodules in the UAE: A comparison

Background

Thyroid nodules are a common clinical finding and most are benign, however, 5–15% can be malignant. There is limited regional data describing the accuracy of ultrasound-guided fine needle aspiration (FNA) cytological examination compared to ultrasound examination of thyroid in patients who have undergone thyroid surgery.

Methods

A retrospective analysis of ultrasonographic (US) reports, FNA cytology reports and histopathology reports of 161 thyroid nodules presented at the endocrine center at Tawam hospital in Al Ain city, the United Arab Emirates during the period 2011–2019 was performed. US reports and images with FNA cytopathology reports and slides were reviewed by an independent radiologist and pathologist.

Results

In total, 40 nodules were reported as benign by US examination, while very low suspicious, low suspicious, intermediate suspicious and highly suspicious categories were reported in 21, 41, 14 and 45 nodules respectively. In addition, 68 nodules were reported as benign (Bethesda category II), while atypical follicular cells of unknown significance (Bethesda category III), follicular neoplasm (Bethesda category IV), suspicious for malignancy (Bethesda category V), and malignant (Bethesda category VI) categories were reported in 33, 9, 24 and 27 nodules respectively. The risk of malignancy for US benign nodules was 5%, while the risks of malignancy in very low suspicious, low suspicious, intermediate suspicious and highly suspicious nodules were 52%, 36%, 100% and 87%, respectively. The risk of malignancy for Bethesda category II was 3%, while the risks of malignancy in category III, IV, V and VI were 58%, 67%, 96% and 100%, respectively.

Conclusion

Thyroid FNA cytological examination and ultrasonography are key tools in predicting malignancy in thyroid nodules. Thyroid nodules with the diagnosis of Bethesda category III & IV run a high risk of malignancy thus more vigilance is required.

Long-Term Follow-Up of Thyroid Incidentalomas Visualized with 18F-Fluorodeoxyglucose Positron Emission Tomography-Impact of Thyroid Scintigraphy in the Diagnostic Work-Up

Our objective was to evaluate the frequency of malignancy in incidental thyroidal uptake on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in a cohort of Danish patients, and furthermore to evaluate the impact of thyroid scinti-graphy in the diagnostic work-up. All whole-body PET/CT reports from 1 January 2010 to 31 December 2013 were retrospectively reviewed and further analyzed if visually increased thyroidal FDG uptake was reported. Patient electronic files were searched for further thyroid evaluation. Of 13,195 18F-FDG-PET/CT scans in 9114 patients, 312 PET/CT reports mentioned incidental thyroid FDG-uptake, and 279 patients were included in the study (3.1%). The thyroid was further investigated in 137 patients (49%), and 75 patients underwent thyroid scintigraphy. A total of 57 patients had a thyroid biopsy and 21 proceeded to surgery. Surgical specimens displayed malignancy in 10 cases, and one thyroid malignancy was found by autopsy. Hence, 11 patients were diagnosed with thyroid malignancies among 279 patients with incidental thyroid 18F-FDG uptake (3.9%). In 34 patients, a biopsy was avoided due to the results of the thyroid scintigraphy. We conclude that patients with thyroid incidentalomas can benefit from further diagnostic work-up including a thyroid scintigraphy.

Thyroid Nodule Evaluation and Management in Older Adults: A Review of Practical Considerations for Clinical Endocrinologists

OBJECTIVE

Contextualizing the evaluation of older adults with thyroid nodules is necessary to fully understand which management strategy is the most appropriate. Our goal was to summarize available clinical evidence to provide guidance in the care of older adults with thyroid nodules and highlight special considerations for thyroid nodule evaluation and management in this population.

METHODS

We conducted a literature search of PubMed and Ovid MEDLINE from January 2000 to November 2020 to identify relevant peer-reviewed articles published in English. References from the included articles as well as articles identified by the authors were also reviewed.

RESULTS

The prevalence of thyroid nodules increases with age. Although thyroid nodules in older adults have a lower risk of malignancy, identified cancers are more likely to be of high-risk histology. The goals of thyroid nodule evaluation and the tools used for diagnosis are similar for older and younger patients with thyroid nodules. However, limited evidence exists regarding thyroid nodule evaluation and management to guide personalized decision making in the geriatric population.

CONCLUSION

Considering patient context is significant in the diagnosis and management of thyroid nodules in older adults. When making management decisions in this population, it is essential to carefully weigh the risks and benefits of thyroid nodule diagnosis and treatment, in view of older adults' higher prevalence of high-risk thyroid cancer as well as increased risk for multimorbidity, functional and cognitive decline, and treatment complications.

Comparative efficacy of different ultrasound-guided ablation for the treatment of benign thyroid nodules: Systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Percutaneous ablation is currently deemed an additionally treatment option for benign thyroid nodules in the world, but possibly different effect among the ablation modalities is not clear. So we aim to evaluate the efficacy and complications of thermal/chemical ablation by network meta-analysis.

MATERIALS AND METHODS

In the network meta-analysis, PubMed, EMBASE and the Cochrane Library databases were searched from 1980 to 2020. Studies of adults with thyroid benign nodules under percutaneous ablation therapy were included. Percentage mean volume change, symptom score change, cosmetic score change and complications were evaluated by network meta-analysis.

RESULTS

In the network meta-analysis, Radiofrequency Ablation(RFA) with 2 treatment sessions group was associated with the highest reduction for the mean volume change during 6-month follow-up (MD = 79.09 and 95% CrI:48.23-89.94). There is no significant difference in the incidence of complications. Subgroup analysis showed that 2 sessions of Radiofrequency Ablation (RFA) ranks the highest probability (surface under the cumulative ranking curve (SUCRA) values 77.9) of being the most efficacious treatment for solid or predominantly solid benign nodules. Ethanol ablation (EA) ranked first (SUCRA value 81.1) in the treatment for cyst or predominantly cyst benign nodules.

CONCLUSION

RFA appears to be superior to other US-guided percutaneous ablation in reducing benign thyroid nodule volume during short- and long-term follow-up. In the subgroup analysis, RFA with 2 treatment sessions showed the most significant effectiveness for solid benign thyroid nodules and EA showed more effectiveness to decrease the volume of cyst benign thyroid nodules.

Evaluating biochemical differences in thyroglobulin from normal and goiter tissues by infrared spectral imaging

Thyroglobulin is a glycoiodoprotein that is produced by thyroid follicular cells; it is stored in follicles in structures known as colloids. The main function of this protein is to stock the hormones triiodothyronine (T3) and thyroxine (T4) until the body requires them. This study aims to demonstrate that infrared spectral imaging with appropriate multivariate analysis can reveal biochemical changes in this glycoprotein. The results achieved herein point out biochemical differences in the colloid samples obtained from normal and goiter patients including glycosylation and changes in the secondary conformational structure. We have presented the first spectral histopathology-based method to detect biochemical differences in thyroid colloids, such as TG iodination, glycosylation, and changes in the secondary structure in normal and goiter patients. The observed changes in the colloids were mainly due to the alterations in amide I and amide II (secondary conformation of proteins) and there is a correlation with different glycosylation between normal and goiter tissues.

Determining an energy threshold for optimal volume reduction of benign thyroid nodules treated by radiofrequency ablation

OBJECTIVES

Radiofrequency ablation (RFA) is effective in reducing the volume of benign thyroid nodules. However, what parameters can influence the response to RFA is still unclear. The present study aimed to (1) investigate which ultrasound and technical parameters are potential determinants of the volumetric reduction; (2) develop a dose-response model, and (3) analyze the effects of RFA on ultrasound features.

METHODS

In this retrospective study, three institutions treated patients with benign thyroid nodules according to the same protocol. The technical parameters were power and energy. The 1-year volume reduction ratio (VRR) was the reference standard of the response. The correlations of different parameters with VRR were analyzed and the association between several parameters and a VRR above 50% studied by uni- and multivariate analyses. The probit regression estimated the probability to achieve an effective response.

RESULTS

One hundred fifteen patients were enrolled. The median power was 50 W and median total delivered energy 27,531 J. At 1-year follow-up, the median VRR was 64.0% and 87 (75.7%) nodules showed a VRR above 50%. Among all parameters, only baseline volume, total energy, and energy per volume were independently associated to a VRR > 50% (p = 0.001, p = 0.0178, p < 0.001 respectively). The probit regression analysis demonstrated that delivering 756 J/ml and 2670 J/ml gave a probability of VRR > 50% in 50% and 99% of patients, respectively.

CONCLUSIONS

Considering the baseline nodular volume and delivering the adequate energy per volume allow optimizing technical and clinical success.

KEY POINTS

• The effectiveness of radiofrequency ablation in treating benign thyroid nodules is negatively correlated to the volume of the nodule and positively correlated to the energy delivered per volume. • When planning the treatment, the total energy to deliver can be calculated by using a simple formula: nodular volume × 2670 J.

Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: A 2020 THESIS Questionnaire Survey of Members of the Swedish Endocrine Society

BACKGROUND

The standard treatment of hypothyroidism is levothyroxine (LT-4). However, there are several controversies regarding treatment of hypothyroid patients.

AIM

To investigate the Swedish endocrinologists' use of thyroid hormones in hypothyroid and euthyroid individuals.

METHODS

Physician members of the Swedish Endocrine Society (SEF) were invited by e-mail to participate in an online survey investigating this topic.

RESULTS

Out of the eligible 411 members, 116 (28.2%) responded. The majority (98.9%) stated that L-T4 is the treatment of choice. However, around 50% also prescribed liothyronine (L-T3) or a combination of L-T4+L-T3 in their practice. Combination therapy was mostly (78.5%) used in patients with persistent hypothyroid symptoms despite biochemical euthyroidism on L-T4 treatment. Most respondents prescribed L-T4 tablets and did not expect any major changes with alternative formulations such as soft-gel capsules or liquid formulations in situations influencing the bioavailability of L-T4. In euthyroid patients, 49.5% replied that treatment with thyroid hormones was never indicated, while 47.3% would consider L-T4 for euthyroid infertile women with high thyroid peroxidase (TPO) antibody levels.

CONCLUSION

The treatment of choice for hypothyroidism in Sweden is L-T4 tablets. Combination therapy with L-T4+L-T3 tablets was considered for patients with persistent symptoms despite biochemical euthyroidism. Soft-gel capsules and liquid solutions of L-T4 were infrequently prescribed. Swedish endocrinologists' deviation from endocrine society guidelines merits further study.

Thyroid Nodules Located in the Lower Pole Have a Higher Risk of Malignancy than Located in the Isthmus: A Single-Center Experience

PURPOSE

The aim of our study is to investigate whether thyroid nodules (TNs) localization has value as a predictor of malignancy. Ultrasonography provides very valuable information in the evaluation of TNs, but it does not correlate perfectly with histopathologic findings. Therefore, studies that will include new diagnostic methods that can improve these unknowns can be welcomed gratefully.

METHODS

This study was carried out retrospectively in a tertiary care center from September 2016 to January 2020. The study included 862 adult patients who have one or more nodules. Ultrasonography of characteristics of nodules such as echogenicity, content, margins, calcifications, size, and localization was recorded. Fine-needle aspiration biopsy (FNAB) was performed on dominant and suspicious 1142 nodules.

RESULTS

The patients were composed of 692 (80.3%) females and 170 (19.7%) males. Compared to nodules located in the isthmus; the malignancy risk increased 8.39 (OR: 8.39 (2.34-30.12), p = 0.001) times in the lower pole, 4.27 (OR: 4.27 (1.16-15.72), p = 0.029), times in the middle pole, 8.09 (OR: 8.09 (2.11-30.94), p = 0.002) times in the upper pole, and 7.63 (OR: 7.63 (1.95-29.81), p = 0.003) times in the nodules covering the whole of the lobe. Although the most nodular location was in the middle pole, the risk of malignancy was less than that in the lower and upper poles.

CONCLUSIONS

Unlike the other localization studies, we found a higher risk of malignancy in the lower and similarly upper thyroid poles. Besides well-defined malignancy indicators in the literature and guidelines, localization information is promising for this purpose in the future.

The diagnostic value of ultrasonography in detection of different types of thyroid nodules

Background

This article discusses the importance of high frequency ultrasonography in detection of different types of thyroid nodules considering only the histopathological examination of the surgical specimens as the final diagnosis. We studied 50 patients referred to ENT clinic with a thyroid nodule. Ultrasonography and ultrasound-guided fine-needle aspiration biopsy were done to all the patients. Thyroid surgery was done according to FNAB results.

Result

From 50 thyroid specimens, the US could predict the malignancy in 18 specimens. By histopathology, only 16 specimens were malignant, and 34 were benign thyroid disease. The sensitivity, specificity, and accuracy of US were 100%, 94.12%, and 96% respectively. The most suspicious ultrasongraphic feature was microcalcification followed by taller than wider (T ˃ W).

Conclusion

High frequency ultrasound is a very important tool to predict the malignant possibility during thyroid nodule evaluation.

The Role of Nuclear Medicine in the Clinical Management of Benign Thyroid Disorders, Part 1: Hyperthyroidism

Benign thyroid disorders, especially hyper- and hypothyroidism, are the most prevalent endocrine disorders. The most common etiologies of hyperthyroidism are autoimmune hyperthyroidism (Graves disease, GD), toxic multinodular goiter (TMNG), and toxic thyroid adenoma (TA). Less common etiologies include destructive thyroiditis (e.g., amiodarone-induced thyroid dysfunction) and factitious hyperthyroidism. GD is caused by autoantibodies against the thyroid-stimulating hormone (TSH) receptor. TMNG and TA are caused by a somatic activating gain-of-function mutation. Typical laboratory findings in patients with hyperthyroidism are low TSH, elevated free-thyroxine and free-triiodothyronine levels, and TSH-receptor autoantibodies in patients with GD. Ultrasound imaging is used to determine the size and vascularity of the thyroid gland and the location, size, number, and characteristics of thyroid nodules. Combined with lab tests, these features constitute the first-line diagnostic approach to distinguishing different forms of hyperthyroidism. Thyroid scintigraphy with either radioiodine or ^99mTc-pertechnetate is useful to characterize different forms of hyperthyroidism and provides information for planning radioiodine therapy. There are specific scintigraphic patterns for GD, TMNG, TA, and destructive thyroiditis. Scintigraphy with ^99mTc-sestamibi allows differentiation of type 1 from type 2 amiodarone-induced hyperthyroidism. The radioiodine uptake test provides information for planning radioiodine therapy of hyperthyroidism. Hyperthyroidism can be treated with oral antithyroid drugs, surgical thyroidectomy, or ¹³¹I-iodide. Radioiodine therapy is generally considered after failure of treatment with antithyroid drugs, or when surgery is contraindicated or refused by the patient. In patients with TA or TMNG, the goal of radioiodine therapy is to achieve euthyroid status. In GD, the goal of radioiodine therapy is to induce hypothyroidism, a status that is readily treatable with oral thyroid hormone replacement therapy. Dosimetric estimates based on the thyroid volume to be treated and on radioiodine uptake should guide selection of the ¹³¹I-activity to be administered. Early side effects of radioiodine therapy (typically mild pain in the thyroid) can be handled by nonsteroidal antiinflammatory drugs. Delayed side effects after radioiodine therapy for hyperthyroidism are hypothyroidism and a minimal risk of radiation-induced malignancies.

Computer aided diagnosis of thyroid nodules based on the devised small-datasets multi-view ensemble learning

With the development of deep learning, its application in diagnosis of benign and malignant thyroid nodules has been widely concerned. However, it is difficult to obtain medical images, resulting in insufficient number of data, which contradicts the large amount of data required for acquiring effective deep learning diagnostic models. A multi-view ensemble learning based on voting mechanism is proposed herein to boost the performance of the models trained by small-dataset thyroid nodule ultrasound images. The method integrates three kinds of diagnosis results which are obtained from 3-view dataset which is composed of thyroid nodule ultrasound images, medical features extracted based on U-Net output and useful features selected by mRMR from the statistical features and texture features. To obtain preliminary diagnosis results, the images are utilized for training GoogleNet. For improving the results, supplementary methods were proposed based on the medical features and the selected features. To analyze the contribution of these features and acquire two groups of diagnosis results, the designed Xgboost classifier is utilized for obtaining two groups of features respectively. Subsequently, the boosting final results are obtained through majority voting mechanism. Furthermore, the proposed method is utilized to diagnose sequence images (the images extracted by frame from videos) to solve the poor results caused by slight differences. Finally, better final results are obtained for both of the normal dataset and the sequence dataset (consisting of sequence images). Compared with the accuracies obtained by only training deep learning models with small datasets, the diagnostic accuracies of the above two datasets are improved to 92.11% and 92.54% respectively by utilizing the proposed method.

Treating thyroid nodules by radiofrequency: is the delivered energy correlated with the volume reduction rate? A pilot study

OBJECTIVE

Radiofrequency ablation (RFA) was proven as effective in reducing thyroid nodules' volume. However, whether technical procedure aspects could influence the volume reduction rate (VRR) has not been clarified. This retrospective pilot study aimed to analyze the correlation of RFA power, duration, and energy with VRR.

METHODS

During the period from June to December 2018 two primary-care centers treated benign thyroid nodules of adult outpatients according to the same RFA procedure. Technical parameters to be investigated were the following: median power (P_median), effective time of treatment (T_eff), energy calculated as P_median × T_eff (E_calc), and energy delivered per mL as Kcal × 4184 × nodule's volume (E_del). Continuous variables were analyzed by the Mann-Whitney test. Data of 1-year posttreatment follow-up were collected on December 2019 and the correlation of the above parameters with VRR was analyzed by linear regression.

RESULTS

Forty-one nodules were included and their 1-year VRR was 66.6%. RFA was performed with a P_median of 55 W, T_eff 10.24 min, E_calc 31,380 J, and E_del 1473 J/mL. E_del was significantly correlated with VRR (p = 0.014) while P_median, T_eff, and E_calc not. A strong correlation of E_del with VRR was found in nodules <10 mL (p = 0.001) while no significant correlation was observed in nodules >10 mL.

CONCLUSIONS

This study showed that the energy delivered with RFA is the only technical parameter significantly correlated with the VRR of thyroid nodules.

GWAS of thyroid stimulating hormone highlights pleiotropic effects and inverse association with thyroid cancer

Thyroid stimulating hormone (TSH) is critical for normal development and metabolism. To better understand the genetic contribution to TSH levels, we conduct a GWAS meta-analysis at 22.4 million genetic markers in up to 119,715 individuals and identify 74 genome-wide significant loci for TSH, of which 28 are previously unreported. Functional experiments show that the thyroglobulin protein-altering variants P118L and G67S impact thyroglobulin secretion. Phenome-wide association analysis in the UK Biobank demonstrates the pleiotropic effects of TSH-associated variants and a polygenic score for higher TSH levels is associated with a reduced risk of thyroid cancer in the UK Biobank and three other independent studies. Two-sample Mendelian randomization using TSH index variants as instrumental variables suggests a protective effect of higher TSH levels (indicating lower thyroid function) on risk of thyroid cancer and goiter. Our findings highlight the pleiotropic effects of TSH-associated variants on thyroid function and growth of malignant and benign thyroid tumors.

Evidence-Based Data About Prevalence and Risk of Malignancy of Thyroid Incidentalomas Detected by Different PET Radiopharmaceuticals

Background:

To date, several meta-analyses and systematic reviews have reported data about the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals.

Objective:

This article aims to summarize the published evidence-based data about the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals.

Methods:

A comprehensive computer literature search of systematic reviews and meta-analyses published up to July 2019 in PubMed/MEDLINE and Cochrane library databases regarding the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals was carried out.

Results:

We have summarized the data about prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals (fluorine-18 fluorodeoxyglucose, radiolabelled choline and prostate-specific membrane antigen) taking into account 8 evidence-based articles.

Conclusion:

Evidence-based data demonstrated that thyroid incidentalomas detected by different PET radiopharmaceuticals are not infrequent and their risk of malignancy is not negligible, in particular if focal pattern is evident at PET, thus requiring further clinical and instrumental evaluation.

Machine Learning Prediction of Radiofrequency Thermal Ablation Efficacy: A New Option to Optimize Thyroid Nodule Selection

BACKGROUND

Radiofrequency (RF) is a therapeutic modality for reducing the volume of large benign thyroid nodules. If thermal therapies are interpreted as an alternative strategy to surgery, critical issues in their use are represented by the extent of nodule reduction and by the durability of nodule reduction over a long period of time.

OBJECTIVE

To assess the ability of machine learning to discriminate nodules with volume reduction rate (VRR) < or ≥50% at 12 months following RF treatment.

METHODS

A machine learning model was trained with a dataset of 402 cytologically benign thyroid nodules subjected to RF at six Italian Institutions. The model was trained with the following variables: baseline nodule volume, echostructure, macrocalcalcifications, vascularity, and 12-month VRR.

RESULTS

After training, the model could distinguish between nodules having VRR <50% from those having VRR ≥50% in 85% of cases (accuracy: 0.85; 95% confidence interval [CI]: 0.80-0.90; sensitivity: 0.70; 95% CI: 0.62-0.75; specificity: 0.99; 95% CI: 0.98-1.0; positive predictive value: 0.95; 95% CI: 0.92-0.98; negative predictive value: 0.95; 95% CI: 0.92-0.98).

CONCLUSIONS

This study demonstrates that a machine learning model can reliably identify those nodules that will have VRR < or ≥50% at 12 months after one RF treatment session. Predicting which nodules will be poor or good responders represents valuable data that may help physicians and patients decide on the best treatment option between thermal ablation and surgery or in predicting if more than one session might be necessary to obtain a significant volume reduction.

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.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Elastography for the diagnosis of high-suspicion thyroid nodules based on the 2015 American Thyroid Association guidelines: a multicenter study

BACKGROUND

An accurate diagnosis for high-suspicion nodules based on the 2015 American Thyroid Association (ATA) guidelines would reduce unnecessary invasive examinations. Elastography is a useful tool for discriminating benign and malignant thyroid nodules. The aim of this study is to investigate the diagnostic efficiency of elastography for high-suspicion thyroid nodules based on the 2015 ATA guidelines in the Chinese population.

METHODS

Thyroid nodules with high-suspicion characteristics based on the 2015 ATA guidelines were subjected to conventional ultrasound (US) and ultrasound strain elastography (USE) examinations at 12 hospitals from 4 geographic regions across China. Cytology/histology of thyroid nodules was used as a reference method. Receiver operating characteristic (ROC) curves were plotted to evaluate the diagnostic performance of the elasticity score (ES) and strain ratio (SR). Logistic regression analysis was used to determine the predictors of malignancy.

RESULTS

Overall, a total of 1445 thyroid nodules (834 malignant, 611 benign) from 12 centers were included in the final analysis. The areas under the curve of the ES and SR were 0.828 and 0.732, respectively. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the ES were 92.4, 60.7, 79.0, 76.3 and 85.5%, respectively, and those of the SR were 81.1, 50.1, 68.9, 65.9 and 67.9%, respectively. The combination of the Thyroid Imaging Reporting and Data System (TI-RADS) and ES led to a significant increase in the sensitivity and NPV (97.1 and 91.9%, respectively) compared with the TI-RADS alone. Logistic regression analysis showed that microcalcifications (OR = 5.290), taller than wide (OR = 12.710), irregular margins (OR = 10.117), extrathyroidal extension (ETE; OR = 6.412), the ES (OR = 3.741) and the SR (OR = 1.083) were independent predictors of malignant thyroid nodules. The sensitivity, specificity, accuracy, PPV and NPV of the ES were all superior in nodules ≥1 cm than in those < 1 cm (95.0% vs 90.4, 68.8% vs 56.8, 85.9% vs 74.4, 85.2% vs 69.9, and 87.8% vs 84.2%, respectively).

CONCLUSIONS

Elastography combined with the ES is a valuable tool for the assessment of high-suspicion thyroid nodules based on the 2015 ATA guidelines, especially in nodules ≥1 cm.

Radiofrequency ablation of functioning and non-functioning thyroid nodules: a single institution 12-month survey

PURPOSE

Radiofrequency (RF) treatment has played an increasing role in the management of benign thyroid nodules in recent years. The aim of this retrospective study was to evaluate the efficacy of RF treatment on volume reduction in functioning and non-functioning thyroid nodules.

PATIENTS AND METHODS

We reviewed the medical records of patients who had thyroid nodule RF ablation at our department between August 2017 and May 2018. Patients underwent a periodical follow-up with ultrasound examinations and thyroid function tests at 1, 3, 6 and 12 months from RF. Complications were assessed using the reporting standards of Interventional societies.

RESULTS

43 patients were submitted to thyroid nodule RF ablation treatment. Patients were subdivided into two groups, those with functioning (17 patients) or non-functioning nodules. At baseline (i.e. pre-RF treatment), the two groups of patients were superimposable for gender, age, BMI, nodule volume and maximum nodule diameter. The volume reduction of all 43 nodules was 69.1 ± 17.3% (range 26.0-94.5%) with no difference between functioning and non-functioning lesions (72.9 ± 18.1% vs 66.7 ± 16.7%, p = 0.254). A total energy delivered per nodule was 16.5 ± 6.8 kJ, with no difference between functioning and non-functioning lesions (14.5 ± 7.2 kJ vs. 18.2 ± 6.3 kJ, p = 0.083, respectively). No major complications were observed.

CONCLUSIONS

Radiofrequency ablation is a clinically effective and safe outpatient treatment in patients with benign nodules. In particular, we showed that a single treatment is effective in restoring euthyroidism in patients with autonomously functioning thyroid nodules.

Diagnostic value of shear wave sonoelastography in differentiation of benign from malignant thyroid nodules

PURPOSE

To study the efficacy of shear wave elastography (SWE), using both qualitative and quantitative methods, alone and in conjunction with other B-mode features.

METHOD

117 patients with 123 nodules were studied both by conventional ultrasonography and SWE. Size, echogenicity, margins, internal calcification (micro- or macro-calcification), composition, shape and color Doppler were assessed for each nodule. The elasticity was assessed both qualitatively and quantitatively. Velocity in the ROI (Region of Interest) was calculated in the stiffest portions for 3 times, and maximum and mean velocity were obtained. ROC curve was analyzed to calculate the best cut-off value of the SWV (Shear Wave Velocity). Univariate logistic regression was used to examine the maximum and mean SWV as discrete variables and the results were compared to key variables of conventional US (Ultrasound) features.

RESULT

123 nodules in 117 patients were evaluated. Poor margins, hypoechogenicity, micro-calcification, color Doppler grades III and IV, color map grades IV and V, maximum and minimum velocity had significant correlation with malignancy. The highest Nagelkerke R2 belonged to maximum and mean velocity (R2 = 41.2 and 39 respectively) which propose them as the strongest predictors of malignancy. The best cut-off point for differentiation of benign from malignant nodules was 3.63 m/s for maximum velocity (sensitivity of 90 %, specificity of 78.2 %,) and 3.44 m/s for mean velocity (sensitivity of 90 %, specificity of 76.4 %).

CONCLUSION

The Real-time SWE is a promising test for the preoperative malignancy risk stratification of patients and maximum velocity has the strongest predictive value for both conventional and elastography variables.

Genetic interaction analysis of VEGF-A rs3025039 and VEGFR-2 rs2071559 identifies a genetic profile at higher risk to develop nodular goiter

CONTEXT

Nodular goiter in patients from areas of iodine deficiency is due to the growth of follicular and endothelial cells, involving different vascular-related growth factors in its pathogenesis.

OBJECTIVE

The aim of our study was to examine the association of known single polymorphisms of vascular endothelial growth factor-A [VEGF-A], VEGF receptor-2 [VEGFR-2] and hypoxia-inducible factor-1α [HIF-1α] genes or their genetic interactions with the risk of nodular goiter development.

PATIENTS AND METHODS

116 normal subjects, without any thyroid disease, and 108 subjects with nodular goiter [subjects with goiter and at least one thyroid nodule of > 1 cm of maximum size and in absence of signs of autoimmunity] were selected from a homogeneous population living in a mild iodine deficiency geographic area. Analyses were performed on germline DNA obtained from blood samples and VEGF-A rs3025039, VEGFR-2 rs2071559, and HIF-1αrs11549465 SNPs were investigated by real-time PCR technique. The multifactor dimensionality reduction [MDR] methodology was applied to investigate the genetic interaction between SNPs. Hardy-Weinberg equilibrium was performed.

RESULTS

None of the studied polymorphisms were individually associated with a higher risk to develop nodular goiter [P > 0.05]. The combination of the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms had the highest accuracy of 0.58 [P = 0.018] and the interaction of some genotypes was significantly associated with the risk of nodular goiter development.

CONCLUSIONS

Our results support a genetic interaction between the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms as a predictor of the risk to develop nodular goiter in subjects coming from an area with mild iodine deficiency.

Causes of misdiagnoses by thyroid fine-needle aspiration cytology (FNAC): our experience and a systematic review

Objective

FNA is a simple, safe, cost-effective and accurate diagnostic tool for the initial screening of patients with thyroid nodules. The aims of this study were to determine the diagnostic utility of FNAC performed in our institution, assess the cytomorphologic features that contribute to diagnostic errors and propose improvement measures.

Methods

A total of 2781 FNACs were included in the study, and 1122 cases were compared with their histological diagnoses. We retrospectively reexamined our discordant (both false-negative and false-positive) cases and performed a systematic review of previous studies on causes of misdiagnoses.

Results

When DC V and DC VI were both considered cytologic-positive, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were 98.3, 30.9, 94.9, 58.3 and 93.5%, respectively. If DC VI was considered cytologic-positive, the sensitivity, specificity, PPV, NPV and diagnostic accuracy of FNAC were 98.0, 84.0, 99.4, 58.3, and 97.5% respectively. The main cause of false-negative diagnoses was sampling error (13/15, 86.7%), while interpretation error led to the majority of the false-positive diagnoses (38/47, 80.9%). Overlapping cytological features in adenomatous hyperplasia, thyroiditis and cystic lesions were the major factors contributing to interpretation errors, while the size and number of nodules may have led to false-negative diagnoses because of heterogeneity and unsampled areas.

Conclusions

The sensitivity and PPV of thyroid FNAC in our institution were higher than those in the published data, while the specificity and NPV were lower. Regarding the FNA category DC V, a frozen section analysis during diagnostic lobectomy is necessary. Multiple passes should be performed in various parts of a large nodule or from different nodules to reduce the risk of false-negative findings. Cytopathologists should strengthen their criteria for the identification of adenomatous hyperplasia, thyroiditis and cystic lesions to avoid false-positive diagnoses. NIFTP has little effect on diagnostic accuracy and the distribution of diagnostic errors.

Radiofrequency Ablation on Autonomously Functioning Thyroid Nodules: A Critical Appraisal and Review of the Literature

Background: Thyroid nodules are an extremely common occurrence, as their prevalence in the general population is estimated to range between 50 and 70%. Some of these nodules are autonomously functioning such that they can cause hyperthyroidism over time. In this case, surgery and radioiodine represent the standard of care. Nevertheless, patients might have contraindications or be unwilling to undergo these treatments. Minimally-invasive ultrasound-guided techniques, such as laser and radiofrequency ablation (RFA), have been recently introduced into clinical practice as an alternative treatment for symptomatic benign thyroid nodules. Due to their efficacy and tolerability, these techniques have become increasingly available and their usage has been extended also to autonomously functioning thyroid nodules (AFTN). Methods: In this narrative review, we will describe the studies reporting the therapeutic effects of RFA on AFTN, the studies reporting how RFA compares to the other treatment modalities, as well as the current indications for the use of RFA in patients with AFTN. For this purpose, a comprehensive literature search was independently conducted by three investigators on PubMed, EMBASE, and the Cochrane Library from inception up to February 2020 to identify published articles concerning the effects of RFA on AFTN. Results and Conclusions: Current consensus statements and guidelines support the notion that RFA should be regarded as a first-line therapy for non-functioning benign thyroid nodules, while it remains a valid second-line option for AFTN treatment in case of contraindications or patient unwillingness to undergo surgery or radioiodine.

Efficacy of thermal ablation in benign non-functioning solid thyroid nodule: A systematic review and meta-analysis

BACKGROUND

Image-guided thermal ablations are commonly used in the treatment of thyroid nodules. Radiofrequency ablation (RFA) and laser ablation are the most commonly used. Here we aimed to obtain solid evidence of the long-term efficacy of RFA and laser ablation in benign non-functioning solid thyroid nodules (BNFSTN).

METHODS

PubMed, CENTRAL, Scopus, and Web of Science were searched until March 2019. Studies reporting the effectiveness of RFA or laser ablation in patients with BNFSTN in terms of volume reduction rate (VRR), compressive symptoms and cosmetic concerns were included. Complications were also assessed.

RESULTS

Out of 963 papers, 12 studies on RFA and 12 on laser ablation were included, assessing 1186 and 2009 BNFSTNs, respectively. Overall, VRR at 6, 12, 24, and 36 months was 60%, 66%, 62%, and 53%. VRR of RFA was 68%, 75%, and 87%, respectively. VRR of laser ablation was 48%, 52%, 45%, and 44%, respectively. Baseline volume of nodules undergone RFA was significantly smaller compared to laser ablation (20.1 ± 22.4 versus 24.6 ± 23.6 ml; p < 0.01). Nodules smaller than 30 ml obtained better outcomes than larger ones. A significant reduction in compressive symptoms and cosmetic concerns was found after RFA.

CONCLUSIONS

This meta-analysis showed that both RFA and laser ablation are able to obtain a significant volume reduction in BNFSTNs. A significant volume reduction is already evident at 6 months after thermal ablation and results are stable over the time.

Features and outcome of differentiated thyroid carcinoma associated with Graves' disease: results of a large, retrospective, multicenter study

BACKGROUND

Whether differentiated thyroid cancer (DTC) occurring concomitantly with Graves' disease (GD) is more aggressive and bound to a less favorable outcome is controversial.

OBJECTIVE

Aim of this multicenter retrospective study was to compare baseline features and outcome of DTC patients with GD (DTC/GD+) or without GD (DTC/GD-).

PATIENTS

Enrolled in this study were 579 patients referred to five endocrine units (Cagliari, Pavia, Pisa, Siena, and Varese) between 2005 and 2014: 193 patients had DTC/GD+ , 386 DTC/GD-. Patients were matched for age, gender and tumor size. They underwent surgery because of malignancy, large goiter size, or relapse of hyperthyroidism in GD.

RESULTS

Baseline DTC features (histology, lymph node metastases, extrathyroidal extension) did not differ in the two groups, except for multifocality which was significantly more frequent in DTC/GD+ (27.5% vs. 7.5%, p < 0.0001). At the end of follow-up (median 7.5 years), 86% of DTC/GD+ and 89.6% DTC/GD- patients were free of disease. Patients with persistent or recurrent disease (PRD) had "biochemical disease" in the majority of cases. Microcarcinomas were more frequent in the DTC/GD+ group (60% vs. 37%, p < 0.0001) and had an excellent outcome, with no difference in PRD between groups. However, in carcinomas ≥ 1 cm, PRD was significantly more common in DTC/GD+ (24.4% vs. 11.5%; p = 0.005). In the whole group, univariate and multivariate analyses showed that GD+ , lymph node involvement, extrathyroidal invasion, multifocality and tall cell histotype were associated with a worse outcome. Female gender and microcarcinomas were favorable features. No association was found between baseline TSH-receptor antibody levels and outcome. Graves' orbitopathy (GO) seemed to be associated with a better outcome of DTC, possibly because patients with GO may early undergo surgery for hyperthyroidism.

CONCLUSIONS

GD may be associated with a worse outcome of coexisting DTC only if cancer is ≥ 1 cm, whereas clinical outcome of microcarcinomas is not related to the presence/absence of GD.

A novel computerised quantification of thyroid vascularity in the differentiation of malignant and benign thyroid nodules

Purpose

Only five percent of thyroid nodules are malignant. It is important to find reliable and at the same time non-invasive methods to identify high-risk nodules. The aim of this study was to determine the diagnostic validity of a morphologic feature-oriented approach of ultrasound study for the identification of malignant thyroid nodules.

Material and methods

Seventy-one thyroid nodules in 71 consecutive patients were evaluated with both ultrasonography (US) and US-assisted fine needle aspiration biopsy (FNAB). Thyroid grey-scale and power Doppler US were performed, and a Windows-based software was designed to process power Doppler US (PDUS) images that were recorded directly by the US device. We provided a histogram graph of coloured pixels and calculated the Malignancy Index to identify the probability of malignancy for each thyroid nodule.

Results

Thirty-six nodules (50.7%) were determined to be malignant in FNAB. Area under the receiver operating curve was 0.91 (95% CI: 0.85-0.98) for PDUS-based malignancy index in differentiating malignant thyroid nodules from benign ones. The best cut-off point for malignancy index was determined to be 0.092, with a sensitivity of 86.1% and specificity of 80% in identifying malignant nodules.

Conclusions

This PDUS-driven malignancy index using a contour-finding algorithm approach could accurately and reliably differentiate malignant and benign thyroid nodules. As a pre-FNAB assessment, the malignancy index may be able to reduce the number of patients with nodular thyroid disease undergoing this invasive procedure.

Growth rates of malignant and benign thyroid nodules in an ultrasound follow-up study: a retrospective cohort study

Background

Thyroid nodules are frequently detected by cervical ultrasound examinations. In follow-up studies, malignant as well as benign nodules may exhibit an increase in size.

The objective of our investigation was to test whether histologically determined malignant and benign thyroid nodules show differences in growth rates above a defined significance level.

Methods

A retrospective ultrasound cohort follow-up study from 4 to 132 months included 26 patients with differentiated carcinomas and 26 patients with adenomas of the thyroid gland. Significance levels were determined by intra- and interobserver variations of volumetric measurements in 25 individuals.

Results

Intra- and interobserver volumetric measurements were highly correlated (r = 0.99 and r = 0.98, respectively), with variations of 28 and 40%, respectively. The growth rates of malignant and benign nodules did not show differences with respect to two sonographic measurements (d = − 0.04, 95%CI(P): 0.41–0.85, P = 0.83). Using shorter increments and multiple measurements, growth rates of malignant nodules revealed significantly higher values (d = 0.16, 95%CI(P): 0.02–0.04, P = 0.039).

Conclusions

The growth rates of benign and malignant thyroid nodules do not appear to differ using two sonographic volumetric measurements. However, due to temporal changes in cellular proliferation and arrest, malignant nodules may exhibit higher growth rates with multiple assessments and shorter increments.

A comparative analysis of diffusion-weighted imaging and ultrasound in thyroid nodules

BACKGROUND

Diffusion-weighted imaging (DWI) and ultrasound are commonly used methods to examine thyroid nodules, but their comparative value is rarely studied. We evaluated the utility of DWI and ultrasound in differentiating benign and malignant thyroid nodules.

METHODS

A total of 100 patients with 137 nodules who underwent both DWI and ultrasound before operation were enrolled. The T1 and T2 signal intensity ratio (SIR) of each thyroid nodule was calculated by measuring the mean signal intensity divided by that of paraspinal muscle. The apparent diffusion coefficient (ADC) value and the SIR of benign and malignant thyroid nodules were analyzed by two-sample independent t tests. The sensitivity, specificity, and accuracy of DWI and ultrasound were compared with chi-square tests.

RESULTS

There was no significant difference in the SIR between benign and malignant thyroid nodules. The ADC value was significantly different. At the threshold value was 1.12 × 10^- 3 mm²/s, the maximum area under the curve was 0.944. The sensitivity, specificity, and accuracy were 84.9, 92.2, and 87.6% respectively. The corresponding values of ultrasound diagnosis were 90.1, 80.4, and 86.9%.

CONCLUSIONS

Ultrasound has high sensitivity in differentiating benign and malignant thyroid nodules, and the ADC value has high specificity, but there is no statistical difference in sensitivity or specificity between the two modalities. DWI and ultrasound each have their own advantages in differentiating benign and malignant thyroid nodules.

Association of adiposity with thyroid nodules: a cross-sectional study of a healthy population in Beijing, China

BACKGROUND

The relationship between thyroid nodules (TNs) and adiposity is controversial. This paper describes a cross-sectional investigation performed to determine the existence of any such relationship. To assess adiposity, body mass index (BMI) and visceral fat area (VFA) were utilized.

METHODS

Between January 1, 2017 and March 3, 2019. Three thousand five hundred thirty four healthy people were examined using thyroid ultrasonography, visceral fat and anthropometric measurements, laboratory tests and questionnaire interview. Binary logistic regression analyses were used.

RESULTS

Of the 3534 healthy subjects, 58.69% (2074/3534) of the subjects had TNs. A total of 55.91% (1976/3534) had BMI ≥ 25 kg/m² and 39.67% (1402/3534) had VFA ≥ 100 cm². After adjustment to address confounders, BMI-based overweight and obesity levels only correlated with higher risk TNs when used as a continuous variable (OR = 1.031, 95% CI: 1.008-1.055, P = 0.008), while VFA was both a continuous variable (OR = 1.003, 95% CI: 1.000-1.005, P = 0.034) and a categorical variable (OR = 1.198, 95% CI: 1.014-1.417, P = 0.034) associated with significantly elevated risk of TNs. Analyzing the subgroups, BMI ≥ 25 kg/m² (OR = 1.500, 95% CI: 1.110-2.026, P = 0.008) was significantly correlated with TN risk in individuals with TG ≥ 1.7 mmol/L. VFA ≥ 100 cm² correlated with the TN risk irrespective of age (< 50 years: OR = 1.374, 95% CI: 1.109-1.703, P = 0.004; ≥ 50 years: OR = 1.367, 95% CI: 1.063-1.759, P = 0.015) and in the following subgroups: women (OR = 4.575, 95% CI: 2.558-8.181, P = 0.000), FBG ≥ 6.1 mmol/L (OR = 1.522, 95% CI: 1.048-2.209, P = 0.027), and TG ≥ 1.7 mmol/L (OR = 1.414, 95% CI: 1.088-1.838, P = 0.010).

CONCLUSIONS

Adiposity correlates with TNs. To assess TN risk in Chinese individuals, VFA is better than BMI.

The effect of retinoic acid in the ability of cold solid thyroid nodule to take up radioactive iodine: A preliminary study

One of the treatment options for benign thyroid nodules is radioactive iodine (RAI). However, this treatment is more effective for hot/warm solid thyroid nodules. Cold thyroid solid nodules are characterized by the lack of iodine uptake compared to normal thyroid tissue. Oral retinoic acid (RA) is a synthetic derivative of Vitamin A. The effect of RA on the uptake of RAI is still controversial. The aim of this study was to evaluate the effect of RA in the ability of a cold solid thyroid nodule to take up RAI. Individuals with a cold solid thyroid nodule based on ultrasonography and thyroid scintigraphy were included. Participants with liver dysfunction, smokers, and pregnant patients were excluded from the study. Each participant underwent thyroid uptake scintigraphy twice (pre- and post-RA consumption) using 35–37 MBq NaI-131. Participants consumed RA at a dose of 1 mg/kg body weight (BW) followed with 1.5 mg/kg BW. This study was approved by Dr. Hasan Sadikin General Hospital Ethic Committee. A total of 12 cold thyroid solid nodules were evaluated. The mean percentage of the nodule uptake value pre- and post-intervention was 1.11% and 0.62%, respectively (P = 0.004), while normal thyroid tissue uptake values pre- and post-intervention were 27.57% and 13.40%, respectively (P = 0.002). The percentage alteration of nodules and normal thyroid tissue uptake value were 42.4% and 51.5% lower, respectively (P = 0.354). This study showed that RA reduces the ability of cold solid thyroid nodule, as well as normal thyroid tissue, to take up RAI.

Long-Term Efficacy of a Single Session of RFA for Benign Thyroid Nodules: A Longitudinal 5-Year Observational Study

CONTEXT

Radiofrequency ablation (RFA) of benign thyroid nodules has been gaining consensus. However, no solid information on its long-term efficacy is available.

OBJECTIVE

To analyze the long-term results of single-session RFA.

DESIGN

Retrospective longitudinal observational study.

SETTING

Primary care center.

PATIENTS OR OTHER PARTICIPANTS

Adult outpatients who underwent a single-session RFA and posttreatment follow-up of least 3 years.

INTERVENTION

Ultrasound-guided RFA was performed after local anesthesia by "moving-shot" technique. RFA was performed with a median power of 55W and a median time of 14 minutes with an internally cooled 18-gauge electrode with an active 10-mm tip.

MAIN OUTCOME MEASURES

Objective (trend of nodule volume) and subjective (compressive and cosmetic concerns) response to RFA were evaluated. Continuous variables were analyzed by the Wilcoxon and ANOVA test and their correlations by using the Spearman test. Categorical variables were compared by Pearson χ2 test.

RESULTS

Two hundred and fifteen patients were included. An early significant reduction of nodule volume was found at 1 year, lasting up to 5 years. A 67% nodule shrinkage was observed at the end of the observation period. The best response was recorded in nodules below 10 mL (79% reduction early and 81% at 5 years). Patients' symptoms were significantly reduced.

CONCLUSIONS

This study, by demonstrating a durable shrinkage of benign thyroid nodules treated by RFA with an improvement of subjective symptoms, establishes the reliability of RFA as alternative to surgery in the management of thyroid nodules, thus representing a remarkable novelty for clinical practice.

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.

Preoperative vitamin D levels do not relate with the risk of hypocalcemia following total thyroidectomy. A cohort study

BACKGROUND

Hypocalcemia is the most common complication following total thyroidectomy. Few factors may relate with increased risk of postoperative hypocalcemia. Preoperative vitamin D values have been evaluated in few studies, but reports present conflicting data. Aim of our study is to evaluate the association of preoperative vitamin D values and hypocalcemia following total thyroidectomy.

METHODS

A retrospective analysis of patients undergoing total thyroidectomy in our department of endocrine surgery between November 2012 and November 2015 was performed.

RESULTS

Mean age of patients was 56.2 years (±14.0) and sex ratio (F:M) was 4.3:1. Sixty-four patients (17.4%) had preoperative vitamin D insufficiency (x<25 nmol/L), 138 patients (37.5%) vitamin D deficiency (25<x<50 nmol/L) and 166 patients (45.1%) vitamin D sufficiency (x>50 nmol/L). Following total thyroidectomy for both benign and malignant pathology, 66 patients (17.9%) had symptomatic hypocalcemia (x<2.0 mmol/L) requiring medical treatment (group 1), 64 patients (17.4%) biochemical hypocalcemia (2<x<2.1 mmol/L) not requiring treatment (group 2) and 238 patients (64.7%) had normal levels (x>2.1 mmol/L, group 3). Mean postoperative PTH value was 25.4 pg/ml (range 2-61). No statistical correlation between postoperative serum calcium and preoperative vitamin D values (R=-0.001, P=0.9849) was found nor associations were found regarding age, sex, type of thyroid disease or BMI.

CONCLUSIONS

In our cohort of patients, preoperative vitamin D levels were not associated with a higher risk of hypocalcemia following total thyroidectomy. Postoperative PTH appears to be the most sensible item to predict the risk of postoperative symptomatic hypocalcemia.

Graves' disease, multinodular goiter and subclinical hyperthyroidism

Subclinical hyperthyroidism is a common clinical entity, defined by serum TSH below the reference range, with normal FT4 and FT3 levels in an asymptomatic patient. Whether or not subclinical hyperthyroidism should be treated remains a matter of debate. Cross-sectional and longitudinal population-based studies demonstrate association of subclinical hyperthyroidism with risk of atrial fibrillation and osteoporosis, and with cardiovascular and all-cause mortality. However, there are no randomized clinical trials addressing whether long-term health outcomes are improved by treating subclinical hyperthyroidism; in the absence of evidence one way or the other, it seems appropriate to use decision trees taking account of TSH concentration and presence of risk factors (age>65 years or post-menopause, osteoporosis and cardiac disease).

Long-term outcome following laser therapy of benign cystic-solid thyroid nodules

OBJECTIVE

Laser therapy (LT) is considered a safe and effective procedure for inducing thyroid nodule necrosis, fibrosis and shrinkage. Little is known about long-term efficacy of LT in benign complex thyroid nodules, which we report here.

DESIGN AND METHODS

One hundred and ten euthyroid outpatients (28 men and 82 women; median age 48 years (range 17-82)) with a recurrent cytologically benign cystic (≥2 mL cyst volume) thyroid nodule causing local discomfort were assigned to LT. LT was performed after complete cyst aspiration and under continuous ultrasound (US) guidance. Nineteen patients (17 within 6 months) had surgery after LT. The median follow-up for the remaining 91 patients was 45 months (range: 12-134).

RESULTS

The overall median nodule volume in the 110 patients decreased from 9.0 mL (range: 2.0-158.0) to 1.2 mL (range: 0.0-85.0) (P < 0.001) at the final evaluation, corresponding to a median reduction of 85% (range: -49 to 100%). Remission of the cystic part (volume ≤1 mL) was obtained in 82 of 110 (75%) patients after LT. The median cyst volume decreased from 6.3 mL (range: 2.0-158.0) to 0.0 mL (range: 0.0-85.0) (P < 000.1), corresponding to a median reduction of 100% (range: -49 to 100%). These results correlated with a significant decrease in pressure as well as cosmetic complaints. Side effects were restricted to mild local pain.

CONCLUSION

US-guided aspiration and subsequent LT of benign recurrent cystic thyroid nodules results in a satisfactory long-term clinical response in the majority of patients. LT constitutes a clinically relevant alternative to surgery in such patients.

[Prevalence of thyroid abnormality: a comparison of ambulatory claims data with data from a population-based study]

BACKGROUND

Billing diagnoses are used for quality assurance, estimates of prevalence and resource allocation. Validity studies showed relevant limitations. In Germany, there are no population-based data on the agreement of outpatient billing diagnoses with clinical data of thyroid disorders.

OBJECTIVES

The study investigated the agreement of ICD-diagnosed thyroid nodules, goitre, hyperthyroidism, hypothyroidism and thyroiditis with clinical and self-reported data from the population-based cohort study called the Study of Health in Pomerania (SHIP).

MATERIALS AND METHODS

Billing data from the Association of Statutory Health Insurance Physicians Mecklenburg-Vorpommern were linked on an individual level for the period from 2002-2016 with data from SHIP. The agreement was evaluated using sensitivity, specificity and positive and negative predictive value (PPW, NPW). Data were weighted to ensure population representativeness.

RESULTS

The data of 5746 participants were analysed (46% male, average age 55 years, SD [standard deviation] ± 15, min: 20 years, max: 93 years). Based on clinical data, 63% (3451/5511, missing values n = 235) and based on billing data 25% (1421/5746) of the participants had thyroid disorders. The sensitivity was 12-36%, the specificity was 84-98%, the PPW was highest for thyroid nodules (75%) and hypothyroidism (70%) and the NPW was between 63 and 94%, depending on the investigated thyroid disorder.

CONCLUSIONS

Thyroid disorders are common and often undiagnosed. Billing data have a low sensitivity to identify clinically relevant thyroid disorders.

Evaluation of malignancy with thyroid imaging reporting and data system (TI-RADS) in thyroid nodules with persistent nondiagnostic cytology

Background/aim

We aimed to evaluate the utility of thyroid imaging reporting and data system (TI-RADS) in prediction of malignancy in thyroid nodules with persistent nondiagnostic (ND) cytology.

Materials and methods

A total of 246 thyroid nodules which were surgically removed and had at least two fine-needle aspirations (FNAs) with ND cytology were included in this study. Ultrasonography features and TI-RADS scores were recorded.

Results

Of 246 nodules, 218 (88.6%) had benign and 28 (11.4%) had malignant final histopathology. Frequencies of taller than wide shape, solidity, hypoechogenicity, microcalcifications, and presence of irregular borders were similar between benign and malignant nodules (P > 0.05). The number of nodules categorized as TI-RADS 3, 4a, 4b, and 4c were 12 (4.9%), 53 (21.5%), 104 (42.3%), and 77 (31.3%), respectively. There was not any nodule in TI-RADS 5 category. Malignancy rates of categories 3, 4a, 4b, and 4c were 0%, 13.2%, 9.6%, 14.3%, respectively. No significant differences were detected in TI-RADS categories between benign and malignant nodules (P > 0.05).

Conclusion

In this study, we did not demonstrate any suspicious ultrasound (US) finding predictive for malignancy in thyroid nodules with persistent ND cytology and did not determine any difference between malignant and benign nodules regarding TI-RADS scores. Whereas, we found that thyroid nodules in 4a, 4b, and 4c TI-RADS categories had higher malignancy rates than those previously reported in ND cytology. We think that TI-RADS categories in thyroid nodules with persistent ND cytology can be helpful in treatment decision.

The Impact of Post-thyroidectomy Paresis on Quality of Life in Patients with Nodular Thyroid Disease

Objective

To investigate the impact of postoperative paresis on disease-specific quality of life (DSQoL) after thyroidectomy in patients with benign nodular thyroid disease.

Study Design

Observational study.

Setting

University hospital.

Subjects and Methods

Patients were evaluated before and 3 weeks and 6 months after surgery in an individual prospective cohort study using videolaryngostroboscopy (VLS), voice range profile, voice handicap index (VHI), multidimensional voice program, maximum phonation time (MPT), and auditory perceptual evaluation. Changes in DSQoL were assessed by the Thyroid-specific Patient-Reported Outcome measure. Cohen’s effect size was used to evaluate changes.

Results

Sixty-two patients were included, 55 of whom completed all examinations. Three weeks after surgery, a blinded VLS examination showed signs of paresis of either the recurrent laryngeal nerve or the external branch of the superior laryngeal nerve (RLN/EBSLN) in 13 patients (24%). A paresis corresponded to a 12 ± 28 point increase in VHI ( P = .002) and was associated with a significant 4.3 ± 7.5 semitone decrease in the maximum fundamental frequency ( P < .001) and a 5.3 ± 8.2 dB reduction in maximum intensity. Further, it was associated with a 4.5 ± 11.2 second reduction in MPT ( P = .001) and an increase of 0.40 ± 1.19 in grade, 0.42 ± 1.41 in roughness, and 0.36 ± 1.11 in breathiness. Signs of postoperative RLN/EBSLN paresis correlated with an 11.0-point ( P = .02) poorer improvement in goiter symptoms at both 3 weeks and 6 months after surgery.

Conclusion

Signs of RLN/EBSLN paresis after thyroidectomy were associated with less pronounced improvement in goiter symptoms in patients with thyroid nodular disease. However, thyroidectomy was associated with an overall improved DSQoL by 6 months after surgery.

Minimally-invasive treatments for benign thyroid nodules: a Delphi-based consensus statement from the Italian minimally-invasive treatments of the thyroid (MITT) group

Benign thyroid nodules are a common clinical occurrence and usually do not require treatment unless symptomatic. During the last years, ultrasound-guided minimally invasive treatments (MIT) gained an increasing role in the management of nodules causing local symptoms. In February 2018, the Italian MIT Thyroid Group was founded to create a permanent cooperation between Italian and international physicians dedicated to clinical research and assistance on MIT for thyroid nodules. The group drafted this list of statements based on literature review and consensus opinion of interdisciplinary experts to facilitate the diffusion and the appropriate use of MIT of thyroid nodules in clinical practice. (#1) Predominantly cystic/cystic symptomatic nodules should first undergo US-guided aspiration; ethanol injection should be performed if relapsing (level of evidence [LoE]: ethanol is superior to simple aspiration = 2); (#2) In symptomatic cystic nodules, thermal ablation is an option when symptoms persist after ethanol ablation (LoE = 4); (#3) Double cytological benignity confirmation is needed before thermal ablation (LoE = 2); (#4) Single cytological sample is adequate in ultrasound low risk (EU-TIRADS ≤3) and in autonomously functioning nodules (LoE = 2); (#5) Thermal ablation may be proposed as first-line treatment for solid, symptomatic, nonfunctioning, benign nodules (LoE = 2); (#6) Thermal ablation may be used for dominant lesions in nonfunctioning multinodular goiter in patients refusing/not eligible for surgery (LoE = 5); (#7) Clinical and ultrasound follow-up is appropriate after thermal ablation (LoE = 2); (#8) Nodule re-treatment can be considered when symptoms relapse or partially resolve (LoE = 2); (#9) In case of nodule regrowth, a new cytological assessment is suggested before second ablation (LoE = 5); (#10) Thermal ablation is an option for autonomously functioning nodules in patients refusing/not eligible for radioiodine or surgery (LoE = 2); (#11) Small autonomously functioning nodules can be treated with thermal ablation when thyroid tissue sparing is a priority and ≥80% nodule volume ablation is expected (LoE = 3).

Ultrasound-guided fine needle aspiration of thyroid nodules with on-site cytological examination: Diagnostic efficacy, prevalence, and factors predicting for Bethesda category I results

BACKGROUND AND OBJECTIVE

Ultrasound-guided fine needle aspiration of thyroid nodules with on-site cytological examination may decrease the number of Bethesda categoryI cytologies. The study objective was to evaluate our second-year experience with this procedure to analyze diagnostic efficacy, prevalence, and factors predicting for Bethesda categoryI results.

PATIENTS AND METHOD

A retrospective study was conducted of 279 nodules from 233 patients. Ultrasound -guided fine needle aspiration was performed according to the 2015 criteria of the American Thyroid Association. A specimen of each aspiration was air-fixed on site before Diff-Quik staining and microscopic examination to assess its suitability; otherwise, nodule aspiration was repeated up to 5times. Diagnostic efficacy was assessed based on sensitivity and specificity on the cytological categories BethesdaII and BethesdaVI.

RESULTS

Diagnostic sensitivity and specificity were both 100%, 5.4% Bethesda categoryI results were obtained, and variables independently associated were age (4.7% increase per year of life) and nodule volume (2.3% increase per each 1mL of volume).

CONCLUSIONS

Ultrasound-guided fine needle aspiration of thyroid nodules with on-site cytological examination allows for a high diagnostic efficacy and has been shown to be a highly relevant procedure because it has a very low rate of cytological results of Bethesda categoryI, whose risk has been higher in older subjects and with larger nodules.

Duration of Hyperthyroidism and Lack of Sufficient Treatment Are Associated with Increased Cardiovascular Risk

BACKGROUND

Cardiovascular disease remains the most prevalent cause of death in hyperthyroidism. However, the impact on cardiovascular events of varying thyroid status and of treatment remains unclarified. The aims of this study were to investigate the association between hyperthyroidism and cardiovascular events in treated and untreated hyperthyroid individuals, as well as exploring the impact of cumulative periods of hyperthyroidism as a proxy for undertreatment on cardiovascular events.

METHOD

This was a case-control study nested within a population-based cohort of individuals attending health services in Funen County, Denmark, in the period from 1995 to 2011. Data on comorbidities and mortality were collected from The Danish National Patient Register and The Danish Register of Causes of Death. Participants were 275,467 individuals with at least one serum thyrotropin (TSH) measurement in the study period. Hyperthyroidism was defined as at least two measurements of decreased serum TSH within six months, separated by at least 14 days. Incident cases of cardiovascular disease (myocardial infarction, atrial fibrillation, heart failure, stroke, and cardiovascular death) were matched with controls. Conditional logistic regression analyses were performed to calculate odds ratios (OR) for exposure to hyperthyroidism, adjusting for preexisting comorbidities.

RESULTS

A total of 20,651 individuals experienced a cardiovascular event (9.5% incidence rate 13.2/1000 person-years [confidence interval (CI) 13.0-13.4]) compared to euthyroid individuals, conditional logistic regression showed increased cardiovascular risk in untreated hyperthyroid patients (OR = 1.25 [CI 1.06-1.48], p = 0.007) but not in treated hyperthyroid patients (OR = 1.04 [CI 0.90-1.22], p = 0.57)]. The OR for cardiovascular events per six months of decreased TSH was 1.09 ([CI 1.05-1.14], p < 0.001) in treated hyperthyroid individuals, and 1.10 ([CI 1.05-1.15], p < 0.001) in untreated hyperthyroid individuals.

CONCLUSIONS

The risk of cardiovascular disease was found to be increased in untreated hyperthyroid patients, and the duration of decreased TSH associated with increasing risk of cardiovascular outcomes in both treated and untreated hyperthyroid individuals. This suggests that increased cardiovascular risk is driven not only by lack of treatment but also by insufficient therapy. The results support timely treatment and careful monitoring of hyperthyroid patients in order to reduce cardiovascular risk.

The Impact of Esophageal Compression on Goiter Symptoms before and after Thyroid Surgery

INTRODUCTION

Benign nodular goiter may be associated with swallowing difficulties, but insight into the associated pathophysiology is limited. The aim of this study was to investigate the effect of surgery on the degree of esophageal compression, and its correlation to swallowing difficulties.

METHODS

Esophageal compression and deviation were evaluated blindly on magnetic resonance imaging (MRI) of the neck, prior to and 6 months after thyroid surgery for symptomatic benign goiter. Goiter symptoms and swallowing difficulties were measured by the Goiter Symptom Scale of the Thyroid-Specific Patient-Reported Outcome (ThyPRO) questionnaire. Cohen's d was used for evaluating effect sizes (ES).

RESULTS

Sixty-four patients completed the study. Before surgery, median goiter volume was 57 (range 14-642) mL. The smallest cross-sectional area of the esophagus (SCAE) increased from a median of 95 (47-147) to 137 (72-286) mm² (ES = 1.31, p < 0.001). Median esophagus width increased from 15 (range 10-21) to 17 (range 12-24) mm (ES = 0.94, p < 0.001) after surgery, while no statistically significant change was observed for the sagittal dimension (anterior-to-posterior), thus reflecting an increasingly ellipsoid esophageal shape. Median esophageal deviation decreased moderately after surgery from 4 (0-23) to 3 (0-10) mm (ES = 0.54, p = 0.005). The goiter symptom score improved considerably from (mean ± SD) 40 ± 21 to 10 ± 10 points (ES = 1.5, p < 0.001) after surgery, and the improvements were associated with improvements in SCAE (p = 0.03).

CONCLUSIONS

In patients with goiter, thyroidectomy leads to substantial improvements in esophageal anatomy, as assessed by MRI, and this correlates with improved swallowing symptoms. This information is valuable in qualifying the dialogue with goiter patients, before deciding on the mode of therapy. Clinicaltrials.gov (NCT03072654).

The assessment of radio-adaptive response in graves' hyperthyroidism patients following radioactive iodine uptake

Low doses of radiation affect the response of cells to higher doses; this phenomenon is called radio-adaptive response, which leads to increased resistance to subsequent higher doses. We have investigated the adaptive response using 0.37 MBq priming dose of I-131 followed by 296-444 MBq challenging dose in peripheral human lymphocyte cells. The study was performed on 42 patients with Graves' disease and 29 healthy adult persons as a control group. The patients were divided into two groups. In the first group, patients were referred for radioactive iodine therapy with a specific dose, and iodine was given to them on the day of referral. In the second group, patients were referred for radioactive iodine uptake and radioactive iodine therapy, and iodine uptake was initially performed, then 24 h later, iodine therapy was done. In both groups, 1 month after treatment, blood samples were taken to cytokinesis-block micronucleus (MN) assay. The number of MN in binuclear lymphocyte cells was counted as an end point test. The mean frequency of MN in first, second, and control groups was 75.86 ± 12.68, 71.45 ± 12.56, and 20.06 ± 7.30, respectively. Our results showed that the frequency of total chromosome aberration in both radiation groups was higher than controls. However, in the first group was higher than another group, but their difference was not statistically significant. According to the results, we cannot approve the hypothesis that 0.37 MBq I-131 administration before iodine therapy could induce a radio-adaptive response in lymphocytes of Graves' patients.

The Impact of Goiter and Thyroid Surgery on Goiter Related Esophageal Dysfunction. A Systematic Review

Background: Patients with goiter referred for thyroidectomy report swallowing difficulties. This might be associated with esophageal compression and deviation as this is present in a significant number of patients. Studies on how goiter and subsequently its treatment affect the esophagus are sparse and point in various directions. Our aim was to investigate, through a systematic review, the impact of goiter and thyroidectomy on esophageal anatomy, esophageal physiology, and subjective swallowing dysfunction. Methods: The search period covered 1 January 1975 to 1 July 2018, using the scientific databases PubMed and EMBASE. Inclusion criteria were adult patients with goiter who were either observed or underwent thyroidectomy. Search terms were variations of the terms for goiter, esophagus, swallowing, and dysphagia. From an initial 3,040 titles, 55 full text evaluations led to the final inclusion of 27 papers. Seventeen papers investigated, prospectively, the impact of thyroidectomy on the esophagus, while five observational and five retrospective studies were also included. Results: Esophageal anatomy impairment: Esophageal deviation occurred in 14% and esophageal compression in 8-27% of goiter patients. The prevalence increased with goiter size and with the extent of substernal extension. The smallest cross-sectional area of the esophagus increased by median 34% after thyroidectomy. Esophageal physiology changes: Goiter patients had increased esophageal transit time, positively correlated with goiter size, but unrelated to esophageal motility disturbances. Decrease in the upper esophageal sphincter pressure occurred early after surgery, and normalized within 6 months. Swallowing related patient-reported outcomes: Evaluated by validated questionnaires, swallowing symptoms worsened in the early period after thyroidectomy, but improved after 6 months, as compared to baseline. Conclusions: Thyroidectomy relieved patients with goiter from dysphagia, within 6 months of surgery probably via increase in the cross-sectional area of the esophagus. Attention to the impact by goiter on the esophagus is needed, and balanced and individualized information about the potential benefits and risks of thyroid surgery is crucial in the management of patients with goiter.

Epidemiology of hyperthyroidism in Iran: a systematic review and meta-analysis

Background

Hyperthyroidism is a systemic disorder that causes severe morbidity and is even fatal. Several studies have been performed in Iran to determine the epidemiologic properties of hyperthyroidism; however, they did not use a systematic approach or meta-analysis to evaluate the results. Therefore, this systematic review and meta-analysis aimed to evaluate the epidemiologic data on hyperthyroidism in Iran.

Methods

In order to find all relevant papers published by October 2017, we searched both international (Web of Science, Scopus, PubMed, Embase, and Cochrane library) and Persian databases (Scientific Information Database, Magiran, and Barekat Knowledge Network System). Meta-analysis was performed using metaprop random effects analysis for prevalence and metaprop fix effect analysis for incidence by Stata statistical software. I² was used for the demonstration of heterogeneity.

Results

Of 7667 published papers or conference proceeding, 7448 studies were removed after eliminating duplicates and reviewing titles/abstracts. Finally, after reviewing 219 full texts, 18 papers met the inclusion and exclusion criteria. The pooled prevalence of total, overt, and subclinical hyperthyroidism in general population were 2.43% (95% CI: 0.23-4.63%), 0.69% (95% CI: 0.21-1.18%), and 1.52% (95% CI: 0.14-2.89%), respectively. The pooled annual incidence of total hyperthyroidism was 2.2 (95% CI: 1.1-3.3) per 1000 population: 0.8 (0.1-1.4) and 1.3 (0.4-2.2) per 1000 population for overt and subclinical hyperthyroidism, respectively.

Conclusions

This is the first systematic review and meta-analysis, which investigated the epidemiology of hyperthyroidism in Iran. It seems that the prevalence and incidence of hyperthyroidism among the general population in Iran is similar to that in other parts of the world.

Changes in Swallowing Symptoms and Esophageal Motility After Thyroid Surgery: A Prospective Cohort Study

INTRODUCTION

Swallowing difficulties, the pathophysiology behind which is incompletely understood, have been reported in 47-83% of goiter patients referred for thyroidectomy. We aimed at examining the influence of thyroid surgery on swallowing symptoms and esophageal motility.

METHODS

Thirty-three patients with benign nodular goiter undergoing thyroid surgery were included. All completed high-resolution esophageal manometry examinations and the goiter symptom scale score, assessed by the thyroid-specific patient-reported outcome measure. The evaluations were performed before and 6 months after surgery.

RESULTS

Before surgery, the goiter symptom score was median 39 points (range 2-61), which improved to median five points (range 1-52) after surgery (p < 0.001). The motility parameters were within the limits of normal swallowing physiology, both before and after surgery. Only the upper esophageal sphincter (UES) pressure increased significantly from 70.6 ± 27.7 to 87.7 ± 43.2 mmHg after surgery (p = 0.04). Using regression analyses, there was no significant correlation between change in goiter symptoms and weight of the removed goiter, motility parameters, or motility disturbances. However, patients undergoing total thyroidectomy experienced a larger reduction in pressure in the area of the UES and former thyroid gland after surgery in comparison with patients undergoing less extensive surgery.

CONCLUSIONS

Goiter symptoms improved significantly after thyroidectomy, but without correlation to esophageal motility disturbances. This information is essential when interpreting dysphagia in patients with nodular goiter, and when balancing patients' expectations to surgical goiter therapy.

REGISTRATION NUMBER

NCT03100357 ( www.clinicaltrials.org ).

Risk Assessment and Hydrodissection Technique for Radiofrequency Ablation of Thyroid Benign Nodules

Purpose: This retrospective study aimed to explore the importance of risk assessment and hydrodissection pre-treatment for radiofrequency ablation of thyroid nodules and initially establish the concept of thyroid nodule risk assessment and the corresponding ablation norms.

Method: Based on the specific location of thyroid nodules, risk assessment and the corresponding preventive measures for thyroid ablation were established. During the period of 2015.10-2017.5, a total of 382 patients were enrolled to compare the safety and efficacy of the ablation for patients with or without risk assessment and the corresponding preventive measures. Statistical analysis encompassed Independent T test for continuous variables and Fisher's exact test/Chi-square test for categorical variables.

Result: Of all 382 patients, 188 patients underwent ablation with risk assessment and the corresponding preventive measures before ablation and 194 without, respectively. The patient characteristics, risk grading, ablation time, thyroid function after ablation and the complete ablation rate showed no statistical differences exsisted between two groups (P>0.05). The complication in very high risk nodules was avoided in the group of patients with risk assessment and preventive measures before ablation.

Conclusion: It is a very safe and effective way to carry out radiofrequency ablation after pre-treatment of thyroid nodules by hydrodissection technique according to risk assessment. It will provide clinicians with greater help in the ablation treatment of thyroid nodules, and improve the safety of the thyroid ablation.