A clinical practice review of percutaneous ethanol injection for thyroid nodules: state of the art for benign, cystic lesions

Percutaneous ethanol injection (PEI) is a widely used treatment option for cystic and predominantly cystic thyroid nodules. It has several advantages over other treatment modalities. Compared to surgery, PEI is less painful, can be performed in the outpatient setting, and carries less risk of transient or permanent side effects. Compared to other minimally invasive techniques such as radiofrequency ablation (RFA), PEI is less expensive and does not require specialized equipment. PEI performs well in the context of cystic nodules. PEI does not perform as well as other techniques in solid nodules, so its use as a primary treatment is limited to cystic and predominantly cystic thyroid nodules. However, PEI is also being explored as an adjunct treatment to improve ablation of solid nodules with other techniques. Here, we provide a clinical review discussing the genesis, mechanism of action, and patient selection with respect to ethanol ablation, as well as the procedure itself. Predictors of operative success, failure, and common adverse events are also summarized. Altogether, PEI allows impressive volume reduction rates with minimal complications. Several recent studies have also evaluated the long-term impact of PEI up to 10 years after treatment and revealed maintenance of robust treatment efficacy with no undesirable long-term sequelae. Thus, PEI remains the treatment of choice for benign but symptomatic cystic and predominantly cystic thyroid nodules.

RUNX1 methylation as a cancer biomarker in differentiating papillary thyroid cancer from benign thyroid nodules

Aim: It remains a challenge to accurately identify malignancy of thyroid nodules when biopsy is indeterminate. The authors aimed to investigate the abnormal DNA methylation signatures in papillary thyroid cancer (PTC) compared with benign thyroid nodules (BTNs). Methods: The authors performed genome profiling by 850K array and RNA sequencing in early-stage PTC and BTN tissue samples. The identified gene was validated in two independent case-control studies using mass spectrometry. Results: Hypomethylation of RUNX1 in PTC was identified and verified (all odds ratios: ≥1.50). RUNX1 methylation achieved good accuracy in differentiating early-stage PTC from BTNs, especially for younger women. Conclusion: The authors disclosed a significant association between RUNX1 hypomethylation and PTC, suggesting RUNX1 methylation as a potential biomarker for companion diagnosis of malignant thyroid nodules.

General Principles for the Safe Performance, Training, and Adoption of Ablation Techniques for Benign Thyroid Nodules: An American Thyroid Association Statement

Background: The primary goal of this interdisciplinary consensus statement is to provide a framework for the safe adoption and implementation of ablation technologies for benign thyroid nodules. Summary: This consensus statement is organized around three key themes: (1) safety of ablation techniques and their implementation, (2) optimal skillset criteria for proceduralists performing ablative procedures, and (3) defining expectations of success for this treatment option given its unique risks and benefits. Ablation safety considerations in pre-procedural, peri-procedural, and post-procedural settings are discussed, including clinical factors related to patient selection and counseling, anesthetic and technical considerations to optimize patient safety, peri-procedural risk mitigation strategies, post-procedural complication management, and safe follow-up practices. Prior training, knowledge, and steps that should be considered by any physician who desires to incorporate thyroid nodule ablation into their practice are defined and discussed. Examples of successful clinical practice implementation models of this emerging technology are provided. Conclusions: Thyroid ablative procedures provide valid alternative treatment strategies to conventional surgical management for a subset of patients with symptomatic benign thyroid nodules. Careful patient and nodule selection are critical to the success of these procedures as is extensive pre-procedural patient counseling. Although these emerging technologies hold great promise, they are not without risk and require the development of a unique skillset and environment for optimal, safe performance and consistent outcomes.

Preoperative platelet distribution width-to-platelet ratio combined with serum thyroglobulin may be objective and popularizable indicators in predicting papillary thyroid carcinoma

Objectives

The incidence of papillary thyroid carcinoma (PTC) has increased more rapidly than that of any other cancer type in China. Early indicators with high sensitivity and specificity during diagnosis are required. To date, there has been a paucity of studies investigating the relationship between preoperative platelet distribution width‐to‐platelet count ratio (PPR) and PTC. This study thus aimed to assess the diagnostic value of PPR combined with serum thyroglobulin (Tg) in patients with PTC.

Methods

A total of 1001 participants were included in our study. 876 patients who underwent surgery for nodular goiter were divided into the PTC group or benign thyroid nodule (BTN) group according to pathology reports, and 125 healthy controls (HCs) were included. Preoperative hemogram parameters and serum Tg levels were compared among three groups. Receiver operating characteristic (ROC) curve was used to evaluate the value of PPR combined with serum Tg for diagnosing PTC.

Results

Platelet distribution width (PDW) and PPR levels were higher in the PTC group than in the BTN and HC groups (both p < 0.05) but did not significantly differ between the BTN and HC groups. PDW and PPR levels significantly differed in the presence/absence of lymph node metastasis, the presence/absence of capsule invasion (p = 0.005), and TNM stages (p < 0.001). Multivariable analyses indicated that high serum Tg levels [adjusted odds ratio (OR), 1.007; 95% confidence interval (CI), 1.004–1.009; p < 0.001], high neutrophil‐to‐lymphocyte ratio (NLR,adjusted OR, 1.928; 95% CI, 1.619–2.295; p < 0.001), and high PPR (adjusted OR, 1.378; 95% CI, 1.268–1.497; p < 0.001) were independent risk factors for PTC. In ROC analysis, the areas under the curves (AUCs) of serum Tg, PDW, PPR, and NLR for predicting PTC were 0.603, 0.610, 0.706, and 0.685, respectively. PPR combined with serum Tg (PPR + Tg) had a higher diagnostic value (AUC, 0.738; sensitivity, 60%; specificity, 74.7%) compared with PDW + Tg (AUC, 0.656; sensitivity, 64.4%; specificity, 59.9%) and NLR + Tg (AUC, 0.714; sensitivity, 61.6%; specificity, 71.1%).

Conclusions

Preoperative PPR combined with serum Tg may be objective and popularizable indicators for effective predicting PTC.

The Year in Surgical Thyroidology: Recent Technological Developments and Future Challenges

Background: The field of surgical and interventional thyroidology is rapidly evolving. In the past few years, we have seen the introduction and establishment of many novel surgical adjuncts, techniques, and disruptive ablative technologies that have impacted the field. Methods: We identified the most influential articles on technological developments in surgical and interventional thyroidology that were published from September 1, 2020, to August 1, 2021. We searched three electronic databases and consulted experts. Results: Major findings are summarized. Continuous intraoperative nerve monitoring (cIONM) lowered the risk of early postoperative vocal cord palsy 1.8-fold and permanent palsy 29 · 4-fold compared with intermittent intraoperative nerve monitoring. Parathyroid autofluorescence yielded a diagnostic odds ratio (OR) of 228.9 for detection of parathyroid glands over visualization, with 96% sensitivity and 92% specificity. There was no significant difference in the incidence of major complications between the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transcervical thyroidectomy (1.5% vs. 2.1%, p = 0.75), and a higher body mass index did not lead to a significant increase in the odds of cumulative complication with TOETVA for the overweight (OR = 0.52 [95% confidence interval {CI} 0.17-1.58]) and obese groups (OR = 1.69 [CI 0.74-3.88]). Radiofrequency ablation (RFA) for benign thyroid nodules typically resulted in a 50-85% volume reduction with faster recovery times, less pain levels, and higher social and psychological well-being compared with conventional thyroidectomy at 15 months post-treatment, although physical well-being levels were higher in the conventional thyroidectomy group at this time. RFA for papillary thyroid microcarcinoma showed no significant difference in local tumor progression (1.8% vs. 3.3%, p = 0.209), lymph node metastasis (0.6% vs. 0.6%, p = 1.000), recurrence (1.2% vs. 2.4%, p = 0.244), and 4-year recurrence-free survival rates (98.2% vs. 97.0%, p = 0.223) when compared with transcervical lobectomy. Conclusions: cIONM, parathyroid autofluorescence, transoral vestibular approach thyroid surgery, and RFA for benign and malignant thyroid nodules are some of the latest additions to the surgeon's and interventionalist's armamentarium to manage thyroid disease. These technological advancements demonstrate promise to improve outcomes, decrease complications, and enhance a patient's quality of life, but further rigorous studies are needed to define their utility and value.

Ultrasound-guided microwave ablation of benign thyroid nodules: effects on inflammatory factors and thyroid function

OBJECTIVE

To explore the effects of ultrasound-guided microwave ablation on inflammatory factors and thyroid function in patients with benign thyroid nodules.

METHODS

A total of 150 patients with benign thyroid nodules treated in the Huazhong University of Science and Technology Union Shenzhen Hospital from January 2017 to December 2018 were selected as research participants, with 75 patients in each group. Patients in the control group received traditional surgery, while those in the study group were treated with ultrasound-guided percutaneous microwave ablation. The two groups were compared in terms of the following: clinical effect, quality of life scores, white blood cell count (WBC), hypersensitive-C-reactive-protein (hsCRP), tumor necrosis factor α (TNF-α), interleukin (IL)-6, epinephrine (E), norepinephrine (NE), visual analogue scale (VAS) scores, and serum levels of thyroid stimulating hormone (TSH), FT3, FT4, and TT4.

RESULTS

The total effective rate of the study group was significantly higher than that of the control group (96.00% vs. 77.33%). Before operation, there was no significant difference in WBC, VAS score, or the levels of hs-CRP, TNF-α, IL-6, E, and NE between the two groups (all P>0.05); After operation, WBC, and the levels of hs-CRP, TNF-α, IL-6, E, and NE increased significantly in both groups and were lower in the study group (all P<0.05). The nodule volume in the study group decreased with time. The serum levels of TSH, FT3, FT4, and TT4 in the study group were better than those in the control group (P<0.05). The study group obtained a lower incidence of postoperative complications than the control group (4.00% vs. 14.00%). In addition, the cosmetic score was higher and the symptom score was lower in the study group compared with the control group (all P<0.05).

CONCLUSION

In patients with benign thyroid nodules, the ultrasound-guided microwave ablation could effectively reduce nodule volume, preserve thyroid function, and improve the quality of patients' daily life. This is closely related to a reduced inflammatory response.

Effects of energy-based ablation on thyroid function in treating benign thyroid nodules: a systematic review and meta-analysis

BACKGROUND

Whether thyroid function would be affected by ablation remains controversial. This systematic review and meta-analysis aimed to investigate the effects of energy-based ablation on thyroid function in treating benign thyroid nodules.

METHODS

EMBASE, PubMed, Cochrane Library, and Web of Science databases were searched. The mean difference (MD) or standard MD (SMD) was applied to assess changes in thyroid function, thyroglobulin (Tg), and antibodies after ablation. RevMan version 5.3 was used for data synthesis.

RESULTS

Forty-two studies involving 6380 patients were eligible. The pooled results revealed significant decrease of 1-day thyroid-stimulating hormone (95% CI, -0.67 to -0.14), significant increase of 1-day, 1-week, and 1-month free thyroxine (95% CI, 1.57 to 5.28; 95% CI, 0.61 to 2.42; 95% CI, -0.76 to -0.15), 1-day and 1-week Tg level (95% CI, 0.40 to 0.81; 95% CI, 0.21 to 1.29), 6-month anti-thyroglobulin antibodies (95% CI, 0.02 to 0.26), 1- and 3-month thyroperoxidase antibody (95% CI, 0.02 to 0.22; 95% CI, 0.17 to 0.43), and 1-day, 1-, and 3-month thyrotrophin receptor antibody (95% CI, 0.10 to 0.43; 95% CI, 0.00 to 0.30; 95% CI, 0.13 to 0.36) after ablation. No statistically significant differences were found in these six indicators in the longer term. The results of subgroup analysis were similar to the pooled results. No significant publication bias was found.

CONCLUSIONS

Energy-based ablation was more likely to have negative effects on thyroid function and antibodies and led to transient increase in Tg level in the short term. However, most of the patients would not develop any thyroid dysfunction in the long-term follow-up.

Genome-Wide Histone H3K27 Acetylation Profiling Identified Genes Correlated With Prognosis in Papillary Thyroid Carcinoma

Thyroid carcinoma (TC) is the most common endocrine malignancy, and papillary TC (PTC) is the most frequent subtype of TC, accounting for 85–90% of all the cases. Aberrant histone acetylation contributes to carcinogenesis by inducing the dysregulation of certain cancer-related genes. However, the histone acetylation landscape in PTC remains elusive. Here, we interrogated the epigenomes of PTC and benign thyroid nodule (BTN) tissues by applying H3K27ac chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) along with RNA-sequencing. By comparing the epigenomic features between PTC and BTN, we detected changes in H3K27ac levels at active regulatory regions, identified PTC-specific super-enhancer-associated genes involving immune-response and cancer-related pathways, and uncovered several genes that associated with disease-free survival of PTC. In summary, our data provided a genome-wide landscape of histone modification in PTC and demonstrated the role of enhancers in transcriptional regulations associated with prognosis of PTC.

Long-Term Results of Ultrasound-Guided Radiofrequency Ablation of Benign Thyroid Nodules: State of the Art and Future Perspectives-A Systematic Review

Background

Nearly 20 years after the first feasibility study, minimally invasive ultrasound (US)-guided therapeutic techniques are now considered as a safe and effective alternative to surgery for symptomatic benign thyroid nodules. Radiofrequency ablation (RFA) is one of the most widely used treatment in specialized thyroid centers but, due to the relatively recent introduction into clinical practice, there are limited long-term follow-up studies. Aim of our work was to review the outcomes of RFA on solid nonfunctioning and on autonomous thyroid nodules (AFTN) on a long-time period for assessing the results in term of efficacy, complications, and costs and to compare them to the current indications of RFA.

Methods

A systematic review was performed using EMBASE and Medline library data between 2008 and 2021. Seventeen studies evaluated RFA for the treatment of benign solid (nonfunctioning or autonomous) thyroid nodules, with an at least 18 months of follow-up. Data extraction and quality assessment were performed by two endocrinologist according to PRISMA guidelines. Anthropometric data, safety and efficacy parameters were collected.

Results

The majority of the studies was retrospective study and reported 933 nodules, mostly solid. Baseline volume ranged between 6.1 ± 9.6 and 36.3 ± 59.8 ml. Local analgesia was used and the time duration of the treatment was between 5 ± 2 and 22.1 ± 10.9 min. The volume reduction rate at 12 months ranged from 67% to 75% for the nodule treated with a single procedure and reached to 93.6 ± 9.7% for nodules treated with repeat ablations. The regrowth rate at 12 months ranged from 0% to 34%.

Conclusion

All the studies under examination consistently validated the long-term clinical efficacy and the substantial safety of RFA for the treatment of benign thyroid nodules. Thermal ablation, however, is an operator-dependent technique and should be performed in centers with specific expertise. The selection of the patients should be rigorous because the nodule size and the structural and functional characteristics influence the appropriateness and the outcomes of the treatment. Future perspectives as the treatment of micro-papillary thyroid cancer or cervical recurrence need further investigations.

Ultrasonographic characteristics of thyroid nodule rupture after microwave ablation: Three case reports

RATIONALE

Thyroid nodule rupture is a rare complication after microwave ablation (MWA). The ultrasonographic characteristics, clinical course, treatment, or prognosis of thyroid nodule rupture after ablation have not been systematically summarized. Three cases with thyroid nodule rupture after MWA were reported in this study, including the characteristic ultrasound images before ablation and after rupture. Meanwhile, we investigated the etiology, diagnosis, treatment and prevention of the rupture. These findings can provide references for the future clinical practice.

PATIENTS CONCERNS

All 3 patients were pathologically diagnosed as benign thyroid nodules by core needle biopsy and then received 1 session of MWA.

DIAGNOSES

Fourteen days to 1 month after MWA later, all 3 patients presented with abrupt neck pain and swelling, and 1 of them had a fever. Ultrasound examinations shared common features that the rupture of thyroid capsule and a soft-tissue mass with unclear margin in front of the thyroid gland, which connected with the post-ablation nodule. Three patients were diagnosed as thyroid nodule ruptures.

INTERVENTIONS

All 3 patients received conservative management after the ruptures. With the treatment of intravenous antibiotics for 1 week, the neck swelling of patients 1 and 2 both disappeared. The aggravation of neck swelling was found in patient 3. Ultrasonography of the neck revealed irregular fluid echo in the soft-tissue mass, suggesting abscess formation. Aspiration and irrigation were performed. The neck swelling regressed gradually over another 2 weeks with the treatment of antibiotics. Two months after ablation, ultrasound examination showed that the mass had completely disappeared.

OUTCOMES

None of the 3 patients underwent open surgery due to thyroid nodule rupture. At 1-year follow-up, the volume reduction rate of thyroid nodules in 3 patients were as follows: 100%, 98.1% and 90.7%.

LESSONS

Nodule rupture is a rare but severe complication after MWA of the thyroid nodules. The diagnosis can be confirmed by clinical symptoms and ultrasound examination, and most nodule ruptures could be cured with conservative treatment. Grasping the characteristics of ultrasound imaging during the course of disease, and dynamically assessing course of disease progression by ultrasonography could avoid unnecessary imaging examinations or invasive procedures.

RFA and benign thyroid nodules: Review of the current literature

Benign thyroid nodules (BTNs) are commonly found in the general population. They are usually asymptomatic and their incidence has increased as a result of wide-spread use of ultrasound. Benign nodules are typically monitored clinically until they increase in size, resulting in compressive symptoms warranting surgery. However, although surgery is generally well-tolerated and of low-risk, it is associated with a small risk for several complications including hypothyroidism, nerve injury, hematoma, injury to other structures and wound infection. Recently, newer image-guided ablation techniques including radiofrequency ablation (RFA) have been introduced. RFA has a similar safety profile when compared to surgery and has shown promising results in challenging surgical candidates. Though several studies have been published in Asian and European countries on the efficacy of RFA, limited data is available on the North American population. The aim of the study is to review the current literature establishing the clinical outcomes and safety of RFA for benign nodules.

LEVEL OF EVIDENCE

V.

Horner's Syndrome During High-Intensity Focused Ultrasound Ablation for a Benign Thyroid Nodule

Objective

Horner's syndrome (HS) is a rare complication of high-intensity focused ultrasound (HIFU) and radiofrequency ablation for thyroid nodules. We present such a case and discuss how to avoid this complication in the future.

Methods

This case occurred during HIFU treatment of a benign thyroid nodule (BTN). Ultrasound and fine-needle aspiration cytology (FNAC) were performed before the procedure. Volume reduction was evaluated at 6 weeks, 3, 6, and 12 months. Technical success was ≥50% reduction at 6 months.

Results

A 30-year-old woman presented with a solitary symptomatic thyroid nodule. Her thyroid stimulating hormone was 1.16 (ref 0.4-3.6) μUI/mL), ultrasound found a 13 mL right-thyroid EU-TIRADS 4 nodule. Two FNACs were read as Bethesda II. The subsequent HIFU procedure was conducted with local 2% lidocaine anesthesia. The procedure was painful (visual analogic scale 10/10) and ipsilateral partial ptosis occurred during the procedure. Volume reduction at 12 months was 34.6% of the initial volume with persisting functional and cosmetic complaints, discomfort, and partial ptosis. As the volume reduction was ≤50%, the procedure was a technical failure. A new FNAC was read as Bethesda IV. A right lobectomy was performed without postoperative outcomes and without requiring hormonal replacement therapy. Pathological evaluation found no malignant cells.

Conclusion

HS is a rare complication of HIFU for management of BTNs. It may be symptomatic and have sequalae that persist for months. Severe neck pain may by associated, but further investigation is needed.

A Novel Strategy for Single-Session Ultrasound-Guided Radiofrequency Ablation of Large Benign Thyroid Nodules: A Pilot Cohort Study

Background: Ultrasound-guided radiofrequency ablation (RFA) of thyroid nodules (TNs) is a minimally invasive procedure that has been widely used to induce volume reduction in symptomatic solid benign TNs. The goal of this study was to investigate a novel therapeutic approach for single-session ablation of large thyroid nodules (LTNs, vol > 20 ml). Methods: We performed a pilot cohort study of 21 patients with symptomatic solid benign LTNs (vol > 20 ml), who accepted ultrasound-guided RFA treatment between September 2018 and November 2019. RFA was performed using an 18-gauge internally cooled electrode with ultrasonographic guidance in a single session combined with intraoperative hydrodissection and immediate contrast-enhanced ultrasound (CEUS) to optimize safety and efficacy. Nodule volume was evaluated before ablation and at 1, 3, and 6 months after initial ablation, and all patients were asked to assess the cosmetic score (from 1 to 4) and symptom score (from 0 to 10) before ablation and at every follow-up after ablation. Results: At the 6 month follow-up, there was significant nodule volume reduction, from 27.49 ml ± 7.9 (standard deviation) to 3.82 ml ± 5.02 (p = 0.001). Cosmetic signs (p = 0.001) and pressure symptoms (p = 0.001) were significantly improved. All patients underwent RFA without any major complications, and very few patients developed a change in voice (2/21). However, the changes subsided within 1 month. Almost half of the patients received an additional RFA (11/21) treatment to achieve complete ablation on the intraoperative immediate CEUS evaluation. Conclusion: RFA is effective for treating LTNs (vol > 20 ml) and controlling clinical symptoms with a low complication rate. Patients were satisfied with cosmetic sign and pressure symptom improvement. The intraoperative hydrodissection and immediate CEUS represent a novel therapeutic approach for single-session ablation of LTNs.

Benign thyroid nodules in pediatric patients: determining best practices for repeat ultrasound evaluations

Background The American Thyroid Association (ATA) recommendations for the follow-up of thyroid nodules with benign fine needle aspiration (FNA) cytology in children are largely based on adult data, despite well-characterized differences between thyroid nodules in adults and children. We aimed to determine the optimal time interval for repeat evaluation of an FNA-benign thyroid nodule in a pediatric patient. Methods This is a retrospective chart review of patients <19 years of age from 2003 to 2013 with a benign thyroid nodule by FNA cytology. Results We identified 43 patients with benign thyroid nodule cytology on FNA. The average age at diagnosis was 15.6 years, with female predominance (91%). Initial ultrasound (US) findings showed an average nodule size of 2.5 cm, 10% with calcifications, 37% hyperemia, 29% hypoechogenicity and 7% lymphadenopathy. Follow-up US was done in 42%. The first follow-up US occurred on average at 15 months after the initial US. Four patients had nodules with significant growth over time. One patient with papillary thyroid carcinoma (PTC) on final pathology initially had a decreasing nodule size, and then a subsequent increase in the nodule size after 4.5 years. Thyroid nodules were surgically removed in 33% with the final pathology showing a benign cytology in four patients, follicular adenoma in eight patients and PTC in two patients. Conclusions The majority of patients with benign thyroid nodules had no significant increase in nodule size in the first year of follow-up, including one patient who was subsequently found to have PTC. We recommend follow-up US at 1 year after initial presentation in low-risk pediatric patients with benign thyroid nodule cytology.

Effects of Metformin on TSH Levels and Benign Nodular Goiter Volume in Patients Without Insulin Resistance or Iodine Insufficiency

Objectives: To evaluate the impact of metformin (MTF) use on TSH levels, thyroid volume and volume of benign thyroid nodules (TNs). Additionally, to study if iodine status influences the outcomes. Methods: A total of 23 euthyroid patients (42 TNs) with benign thyroid nodules, diagnosed by fine needle aspiration biopsy, were randomly assigned to MTF or placebo (P) use for 6 months. Serum TSH, homeostatic model assessment for insulin resistance (HOMA-IR), and urinary iodine concentrations (UIC) were assessed. Ultrasound was used to evaluate TNs and thyroid volumes (TV) and their variations throughout the study. Diabetic patients, those undergoing levothyroxine replacement, and/or using thyroid- or insulin level-influencing drugs were excluded. Results: The sample consisted predominantly of patients without IR. Both intervention groups were similar regarding several confounding variables and showed a comparable median UIC. Serum TSH decreased significantly after MTF (-0.21 vs. 0.09 mUI/L in the P group; p = 0.015). At 6 months, no significant variations were found between groups with respect to TN volumes, TV, HOMA-IR, or body mass index (BMI). However, a tendency toward enlargement of TV with placebo (16.0%; p = 0.09) and a protective effect of MTF on growing TN (OR: 0.25; CI 0.05-1.20) was detected after excluding patients with IR (a lower UIC subgroup). The reduction on TSH levels with MTF maintained in the population without iodine insufficiency (-0.24 vs. +0.07 in the P group; p = 0.046) and was accentuated in those with excessive or more than adequate UIC (-0.69; p = 0.043). A protective effect of MTF on growing TN was suggested (OR: 0.11; IC: 0.02-0.84) in those with higher UIC. Conclusions: This study demonstrated that MTF caused a reduction in TSH levels in benign nodular goiter. This effect was more accentuated in patients with higher levels of UIC and was accompanied by a suggested protective effect on TN enlargement.

Microwave Ablation Compared With Laser Ablation for Treating Benign Thyroid Nodules in a Propensity-Score Matching Study

Objective: The efficacy and safety of percutaneous ultrasound-guided microwave and laser ablation (MWA and LA, respectively), for treating benign thyroid nodules (BTNs), were retrospectively compared. Methods: Patients (n = 318) underwent ablation of 328 BTNs. Confounding bias was reduced by propensity-score matching, and finally the MWA and LA groups each comprised 160 nodules. At baseline (before ablation), 3, 6, and 12 months, and every 6 months thereafter, the following were recorded: nodule volume reduction rate (VRR), neck symptom scores, cosmetic scores, complications, and side effects. Results: The baseline characteristics of the MWA and LA groups were comparable. The volumes of all nodules were less at all follow-ups relative to the baseline, as were the symptom and cosmetic scores at postoperative 6 months and thereafter (P < 0.01). At each follow-up, the overall VRRs of the MWA and LA groups were comparable. However, for nodules ≥13 mL, the VRR associated with LA at ≥6 months was significantly greater than that of MWA. The average ablation time for MWA was less than that of LA (P < 0.01). The overall incidences of major complications, minor complications, and side effects were 1.6, 2.2, and 18.4%, respectively, and there were no significant differences between the MWA and LA groups. Conclusion: Percutaneous ultrasound-guided MWA and LA are both safe and effective for the treatment of BTNs. Each can significantly reduce the nodule volume and improve the neck symptoms and appearance of patients, with a low incidence of adverse side effects. The efficiency of MWA is higher than that of LA. For nodules ≥13 mL, MWA may be preferred, but at 6 months and subsequent follow-ups the reduction in volume was greater in patients receiving LA.

Initial Ablation Ratio: Quantitative Value Predicting the Therapeutic Success of Thyroid Radiofrequency Ablation

BACKGROUND

The aims of this study were to determine a quantitative index, the initial ablation ratio (IAR), representing the amount of ablation, to predict therapeutic success and to evaluate the correlation between the IAR and volume reduction ratio (VRR).

METHODS

Among the patients who underwent radiofrequency ablation (RFA) for the treatment of benign thyroid nodules at the Withsim Clinic between April 2008 and December 2016, 130 patients with 134 nodules were included. The relationship between the IAR and VRR was analyzed at six months, 12 months, and the final follow-up. The relationship between the IAR and final VRR was also analyzed according to the initial nodule volumes.

RESULTS

The mean VRR was 78.7 ± 17.5% (range 23.3-100%) at a mean follow-up period of 22.6 ± 20.1 months (range 3-93 months). The mean IAR was 90.0 ± 11.6% (range 39.1-100%). The correlation coefficient between the IAR and final VRR was 0.65, which indicates a positive correlation (p < 0.001). When the IAR exceeded 70%, it tended to achieve 50% VRR in most cases.

CONCLUSIONS

The IAR is a quantitative indicator of how well the RFA procedures are performed, and it is highly correlated with the VRR. If the IAR is >70%, VRR of >50% may be expected after RFA.

Efficacy of Metformin for Benign Thyroid Nodules in Subjects With Insulin Resistance: A Systematic Review and Meta-Analysis

Background: To evaluate the effect of metformin therapy on decreasing benign thyroid nodule volume in subjects with insulin resistance (IR). Method: Randomized controlled trials (RCTs) and self-controlled trials for the meta-analysis published, before January 31, 2018 were selected from the PubMed, Cochrane Library, Embase, Web of Science, Chinese Biomedical Literature Database, National Knowledge Infrastructure, WANFANG and VIP Database. Pooled standard mean difference with 95% confidence interval was estimated by fixed- or random-effects model depending on heterogeneity. The risk of bias using the Cochrane Collaboration's tool was used to assess the quality of the RCTs contained. The quality of self-controlled studies was evaluated using the Methodological index for non-randomized studies (MINORS) method. Results: 7 studies (3 RCTs and 4 prospective self-controlled studies) with 240 patients were considered to be appropriate for the meta-analysis. The results of the meta-analysis indicated that the volume of thyroid nodule decreased significantly after metformin therapy (SMD -0.62, 95% CI -0.98 ~ -0.27). 6 studies reported the changes of the level of TSH. TSH levels decreased significantly after metformin therapy (SMD -0.27, 95% CI -0.47 ~ -0.07). The pooled data indicated an increase in FT3 level, and an unchanged FT4 level after metformin therapy (FT3, SMD 0.25, 95% CI 0.05 ~ 0.45; FT4, SMD -0.07, 95% CI -0.27 ~ 0.13). HOMA-IR levels decreased significantly after metformin therapy based on the pooled results of 3 RCTs and 3 prospective self-controlled studies (SMD -1.08, 95% CI -1.69 ~ -0.47). Conclusion: The meta-analysis demonstrated that metformin was safe and useful in shrinking benign thyroid nodules volume, improving thyroid function and IR. A large number of high-quality prospective studies still need to be carried out.

Safety of radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: a systematic review and meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to evaluate the safety of radiofrequency ablation (RFA) for the treatment of benign thyroid nodules and recurrent thyroid cancers.

MATERIALS AND METHODS

Ovid-MEDLINE, EMBASE, and Library of Cochrane databases were searched up to 12 July 2016 for studies on the safety of RFA for treating benign thyroid nodules or recurrent thyroid cancers. Pooled proportions of overall and major complications were assessed using random-effects modelling. Heterogeneity among studies was determined using the χ² statistic for the pooled estimates and the inconsistency index I².

RESULTS

A total of 24 eligible studies were included, giving a sample size of 2421 patients and 2786 thyroid nodules. 41 major complications and 48 minor complications of RFA were reported, giving a pooled proportion of 2.38% for overall RFA complications [95% confidence interval (CI): 1.42%-3.34%] and 1.35% for major RFA complications (95% CI: 0.89%-1.81%). There were no heterogeneities in either overall or major complications (I² = 1.24%-21.79%). On subgroup analysis, the overall and major complication rates were significantly higher for malignant thyroid nodules than for benign thyroid nodules (p = 0.0011 and 0.0038, respectively).

CONCLUSIONS

RFA was found to be safe for the treatment of benign thyroid nodules and recurrent thyroid cancers.

Vocal cord paresis following single-session high intensity focused ablation (HIFU) treatment of benign thyroid nodules: incidence and risk factors

BACKGROUND

Vocal cord paresis (VCP) may occur following high intensity focused ultrasound (HIFU) of thyroid nodules. We hypothesised its occurrence relates to the distance of the focus point (FP) of the HIFU beams from the recurrent laryngeal nerve (RLN) and the thermal power that this point received. Their relationships were examined.

METHODS

One hundred and three patients who underwent HIFU for symptomatic benign thyroid nodule from October 2015 to March 2017 were analysed. All treatment images were captured and were later watched by 2 reviewers to identify three FPs closest to the tracheoesophageal groove (TEG) on transverse sonographic view. TEG was taken as the RLN position. After identifying these FPs, their distance (mm) from the TEG, thermal power (W) used and depth from skin (mm) were recorded. These parameters were compared between those with and without VCP. VCP was defined as a cord with reduced or no movement.

RESULTS

Four (3.9%) patients suffered from a unilateral VCP afterwards but they all recovered fully within 6 weeks. There were no significant differences in baseline characteristics and treatment efficacy between the two groups. The distance from TEG (OR = 1.706, 95%CI = 1.001 to 2.915, p = 0.050) was the only significant factor for VCP. None of the other variables including thermal power were significant.

CONCLUSIONS

The incidence of VCP was 3.9% (4/103) and they completely recovered within 6 weeks. The distance between the FP and the TEG was the only related factor for VCP. The safe distance between FP and TEG should be ≥1.1 cm.

Radiofrequency ablation of benign thyroid nodules: depicting early sign of regrowth by calculating vital volume

OBJECTIVE

We evaluated long-term follow-up results of radiofrequency ablation of benign thyroid nodules to analyse the role of marginal vital tissue on nodule regrowth.

MATERIALS AND METHODS

We reviewed the medical records of 54 patients who underwent radiofrequency ablation between June 2008 and November 2013 with pressure symptoms, and/or cosmetic problems. All patients were followed up at least 12 months on three occasions. To evaluate an early sign of regrowth, three types of nodule volumes (total volume, ablated volume and vital volume) were measured and calculated using ultrasonography. Regrowth was defined as a more than a 50% increase in the total volume and vital volume increase was defined as a more than 50% increase compared to the previously reported smallest volume on ultrasonography.

RESULTS

The mean follow-up period was 39.4 ± 21.7 (range, 13-87) months. Vital volume increases occurred in 31 nodules (57.4%) and there was regrowth in 13 nodules (24.1%). The mean timing of the vital volume increase was 27.5 ± 18.5 months, and for regrowth it was 39.9 ± 17.5 months. Vital volume increase tended to precede regrowth.

CONCLUSION

Vital volume increase tended to occur earlier than regrowth and might be an early sign of regrowth in following-up after the radiofrequency ablation of benign thyroid nodules.

Evaluation of the safety and efficacy of radiofrequency ablation for treating benign thyroid nodules

Background: Radiofrequency ablation (RFA) is a relatively new procedure for treating benign thyroid nodules. The purpose of this study was to evaluate the safety and efficacy of RFA for treating benign thyroid nodules so as to serve as a reference for future clinical practice. Methods: This study retrospectively analyzed the clinical data of patients receiving percutaneous RFA for treating thyroid nodules from November 2014 to July 2015 in our medical center. One hundred and eight patients with a total of 380 nodules received ultrasound-guided RFA for treating thyroid nodules. Comparisons of the volume change of thyroid nodules before and after RFA treatment, post-treatment complication, and change of thyroid function, were carried out afterwards. Results: Before treatments, all patients received fine needle aspiration biopsy (FNA) which supported the diagnosis of benign tumor. There were 13 males and 95 females included in the study. Twenty-six cases (24.07%) had single nodule, and 82 cases (75.93%) had multiple nodules. Before treatments, the thyroid functions (FT3, FT4, and TSH) were normal originally or adjusted to normal range by endocrinology treatment. The preoperative nodules had minimum volume of 0.01mL, maximum volume of 70.89 mL, and mean volume of 1.02 ± 4.24mL. The volume of nodules one month and three months after RFA were 0.29 ± 0.72mL and 0.15 ± 0.87mL, respectively. In addition, volume reduction ratio (VRR) of nodules one month and three months after RFA were 64.12% and 85.54%, respectively. Both volume of nodules and VRR had statistically significant differences for pre-operative and post-operative comparison (P<0.05). Thyroid functions were in normal range after treatments, and there was no serious complications. Conclusions: Ultrasound-guided RFA treating benign thyroid nodules had the advantages of definite efficacy, safety, strong in control ability, no incision, less damage to surrounding normal tissues and no effect on thyroid function. It can be used as one of the main treatment methods for treating benign thyroid nodules.

Long- versus short-interval follow-up of cytologically benign thyroid nodules: a prospective cohort study

BACKGROUND

Thyroid nodules are common, and most are benign. Given the risk of false-negative cytology (i.e. malignancy), follow-up is recommended after 1-2 years, though this recommendation is based solely on expert opinion. Sonographic appearance may assist with planning, but is limited by large inter-observer variability. We therefore compared the safety and efficacy of long- versus short-interval follow-up after a benign initial aspiration, regardless of sonographic appearance.

METHODS

This study evaluated all patients referred to the Brigham and Women's Hospital Thyroid Nodule Clinic, between 1999 and 2010, with a cytologically benign nodule >1 cm and who had returned for follow-up sonographic evaluation. Despite standard clinical recommendations, variation in patient compliance resulted in variable follow-up intervals from time of initial aspiration to the first repeat evaluation. Main outcome measures included nodule growth, repeat fine needle aspiration (FNA), thyroidectomy, malignancy, and disease-specific mortality.

RESULTS

We evaluated 1,254 patients with 1,819 cytologically benign nodules, with a median time to first follow-up of 1.4 years (range, 0.5-14.1 years). The longer the follow-up interval, the more nodules grew and the more repeat FNAs were performed (P <0.001). The most clinical meaningful endpoints of malignancy or mortality, however, did not differ between the various follow-up intervals. The risk of a thyroidectomy (usually because of compressive symptoms) increased when time to first follow-up exceeded >3 years (4.9% vs. 1.2%, P = 0.0001), though no difference in malignancy risk was identified (0.2-0.8%, P = 0.77). No (0%) thyroid cancer-specific deaths were identified in either cohort.

CONCLUSIONS

While expert opinion currently recommends repeat evaluation of a cytologically benign nodule at 1-2 years, these are the first data to demonstrate that this interval can be safely extended to 3 years without increased mortality or patient harm. Nodule growth can be expected, though detection of malignancies is unchanged. While replication of these data in large prospective multicenter studies is needed, this extension in follow-up interval would reduce unnecessary visits and medical interventions for millions of affected patients worldwide, leading to healthcare savings. Please see related commentary article: http://dx.doi.org/10.1186/s12916-016-0559-9 and research article: http://dx.doi.org/10.1186/s12916-015-0419-z .

Avoiding unnecessary fine-needle aspiration cytology by accuractely predicting the benign nature of thyroid nodules using ultrasound

Objective:

The objective of this study was to describe a reliable ultrasound based index scoring system based on ultraound characteristics to identify benign thyroid nodules and avoid unnecessary fine needle aspiration cytology.

Materials and Methods:

Patients undergoing ultrasound-guided fine-needle aspiration cytology (FNAC) for thyroid nodules were evaluated prospectively. A total of 284 patients were evaluated from November 2005 to November 2011. There were 284 nodules. Any solid or partly solid focal nodule in the thyroid gland was included in the study. Cysts with no solid component were excluded. We used LOGIQ 9 (GE Healthcare) scanner equipped with a 10--14 MHz linear matrix transducer with color and power Doppler capability. Four US characteristics were evaluated, i.e., nodule margins, echo texture, vascularity, and calcification. Fine needle aspiration (FNA) was performed on all nodules. The nodules were labeled benign or suspicious using an ultrasound index score and the results compared with FNAC. Follicular neoplasms on fine-needle aspiration cytology were further assessed by excision biopsy and histology. Cytology/histology was used as the final diagnosis.

Results:

In total 284 nodules were analyzed. All the 234 nodules in US labeled benign category were proven to be benign on cytology/histology. Therefore the specificity of ultrasound in labeling a nodule benign was 100%. Twenty of the 50 nodules that were suspicious on US were malignant. The most significant US differentiating characteristics were nodule margins, vascularity, and microcalcification.

Conclusion:

Our results show that US can accurately characterize benign thyroid nodules using an index scoring system and therefore preclude FNAC in these patients.