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.

Radiofrequency Ablation for Benign Thyroid Nodules.

CONTEXT: Thermal ablative techniques of the thyroid have recently gained clinical traction as a therapeutic alternative that provides symptomatic relief and confers potential advantages over surgery. A truly multidisciplinary technique, thyroid ablation is currently performed by endocrinologists, interventional radiologists, otolaryngologists, and endocrine surgeons. Radiofrequency ablation (RFA), specifically, has seen widespread adoption, particularly in the treatment of benign thyroid nodules. This review summarizes current evidence on the application of RFA in benign thyroid nodules, and provides a start to finish overview of procedural preparation, performance, and outcomes. EVIDENCE ACQUISITION: A narrative review of literature focusing on RFA in the treatment of benign nodular disease was performed. Emphasis was placed on consensus statements, best practice guidelines, multi-institutional studies, and systematic reviews to summarize key concepts in candidacy, techniques, expectations, and outcomes. FINDINGS: RFA is increasingly recognized as a first-line treatment strategy in the management of symptomatic nonfunctional benign thyroid nodules. It can also be considered in functional thyroid nodules with small volumes or in patients ineligible for surgery. A targeted and efficacious technique, RFA results in gradual volume reduction that preserves the function of the surrounding thyroid parenchyma. Proper procedural technique, proficiency in ultrasound, and experience in ultrasound-guided procedures are instrumental to maintaining low complication rates and achieving successful ablation outcomes. CONCLUSIONS: In pursuit of a personalized approach, physicians across disciplines are increasingly incorporating RFA into their treatment algorithms, most commonly for benign nodules. As with any intervention, thoughtful selection and implementation ensure a safe procedure with optimal patient benefit.

US residents experiences with intraoperative nerve monitoring in thyroid and parathyroid surgery.

BACKGROUND: Understanding the patterns of IONM use and training among resident otolaryngologists is essential to ensure that the IONM skills and knowledge gained in residency are optimized for successful future practice of IONM. METHOD: An electronic survey was distributed to US-based OHNS residents. Questions evaluated resident experience, implementation, knowledge and understanding of IONM for endocrine surgeries. RESULTS: One hundred and seven OHNS residents participated, spanning all training levels and US geographic locations. The majority of residents received no didactic teaching on IONM (74.5%) nor had a clear troubleshooting algorithm in the event of a loss of signal (69.8%). The majority of residents were uncertain regarding the advantages/disadvantages of continuous versus intermittent IONM. CONCLUSION: The knowledge gap found in our survey study suggests that greater teaching of IONM principles for endocrine head and neck surgeries in OHNS residency programs would help to ensure successful utilization in future practice.

Endosulfan use and the risk of thyroid cancer: an ecological study.

Endosulfan, an organochlorine pesticide, has been understudied in the literature on thyroid cancer. The aim of this ecological study was to assess the correlation between endosulfan exposure and thyroid cancer incidence rates (IRs) in the United States (US). Age-adjusted thyroid cancer IRs per 100,000 people per state for the years 1999 to 2019 were obtained from the Center for Disease Control and Prevention (CDC). To assess the state-level use of endosulfan, data were obtained from the US Geological Survey (USGS). Endosulfan usage estimates (kilograms/acres cropland; quintiles) and thyroid cancer IRs were mapped together. The correlation between age-adjusted thyroid cancer IRs and statewide endosulfan use was calculated using the Spearman correlation. Overall endosulfan usage in the US trended downwards between 1992 and 2007 (T = -0.77; P < 0.001), while thyroid cancer IR trended upwards between 1999 and 2019 (T = 0.69; P < 0.001). There was a statistically significant correlation between 1992 endosulfan use and 2012 (r = 0.32; P = 0.03) and 2014 (r = 0.32; P = 0.03) thyroid cancer IRs. Although restrictions on endosulfan use seem effective, the potential impact of endosulfan exposure remains due to the persistent, semi-volatile, bioaccumulative, and biomagnifying properties of endosulfan metabolites in particular, indicating the need for future thyroid research of highly exposed populations.

Continuous intraoperative neuromonitoring of the recurrent laryngeal nerve by eliciting the laryngeal adductor reflex (LAR-CIONM).

The laryngeal adductor reflex (LAR) is a life-sustaining airway protective mechanism that serves to shield the lower airways from inhaled foreign bodies. Over the past half century, the LAR has been extensively investigated and its dysfunction has been linked to far-ranging pathologies, from dysphagia to sudden infant death syndrome. Over the past 6 years, specific electromyographic waves in the LAR response have been used to devise a methodology for monitoring the vagus and recurrently laryngeal nerves during surgical procedures. This methodology involves continuous intraoperative neuromonitoring of the laryngeal adductor reflex and isthus termed 'LAR-CIONM'. In this review paper, the physiology of the LAR will be summarized as it relates to LAR-CIONM and the technique of LAR-CIONM will be described. Applications of this technique and published outcomes of LAR-CIONM will be highlighted.

Correlation between Lindane Use and the Incidence of Thyroid Cancer in the United States: An Ecological Study.

The increasing rate of thyroid cancer may be attributable to endocrine disruptive chemicals. Lindane is a persistent organochlorine pesticide with endocrine disruptive properties that has been classified as carcinogenic to humans. The aim of this ecological study was to evaluate potential correlation between lindane exposure and thyroid cancer incidence in the United States (US). Data on statewide age-adjusted thyroid cancer incidence rate (per 100,000 people) was obtained from the Centers for Disease Control and Prevention for all US states for 2019. Lindane use estimates per cropland (kg/acres cropland) were then overlaid on the map of age-adjusted thyroid cancer incidence rate using ArcGIS. The trend of lindane use in the US between 1992 and 2007 was calculated using the Mann Kendall correlation test. The correlation between statewide lindane use and age-adjusted thyroid cancer incidence rates was calculated using Spearman correlation. Lindane use in the US decreased significantly between 1992 and 2007 (T = -0.617; p < 0.001). There was no statistically significant correlation between lindane use in 1992 and thyroid cancer incidence rate for any of the years between 1999 and 2019. Our results suggest that restrictions clearly seem to be effective in reducing lindane use, however, more research is needed for individual pesticides and thyroid cancer.

Radiofrequency ablation (RFA) compared to observation for benign thyroid nodules: emerging considerations for judicious use.

PURPOSE OF REVIEW: Radiofrequency ablation (RFA) for thyroid nodules confers tangible advantages over surgery, which include promising outcomes in the context of a minimally invasive procedure and the functional benefits of organ preservation. However, the ubiquity of benign nodules worldwide may spur the risk of misuse in cases where there is negligible gain over conventional surveillance. This review summarizes new developments in RFA and examines its judicious utilization in benign nodules. RECENT FINDINGS: RFA appears to be safe and effective for addressing compressive or cosmetic issues caused by benign functional and nonfunctional thyroid nodules. Volume regression occurs over 12 months, with some cases requiring multiple staged RFA procedures to achieve adequate shrinkage or to address regrowth. Complication rates including recurrent laryngeal nerve injury are reportedly low and are mitigated by strategic technical maneuvers, training, and experience. Consensus guidelines across international societies have emerged to better define appropriate patient candidates. Although association of overuse in analogous disciplines has been well established, no evidence of misuse in thyroid RFA has been described thus far. SUMMARY: Compelling multi-institutional data support RFA as first-line treatment for select benign thyroid nodules. Defining the nuances of patient selection and long-term surveillance are necessary to substantiate current observed results. Given the high incidence of thyroid nodules worldwide, it is important to emphasize that the majority of benign nodules will not require any intervention. Thorough consideration and careful implementation of recommended guidelines will hopefully lead to measurable benefit and avoid financial misuse.

Treatment of cystic thyroid nodules.

The optimal treatment option for cystic thyroid lesions depends on the composition of the lesion, prior interventions, and patient preference. Simple aspiration is a good initial diagnostic and treatment modality for thyroid lesions that are predominantly cystic. However, recurrence rates are high and, should fluid re-accumulate, further aspirations are unlikely to be effective. Ethanol ablation is an excellent first line treatment as it is relatively safe, well-tolerated, and simple to perform. It is at least as effective, if not more effective, than radiofrequency ablation (RFA) for simple cysts, and complex thyroid cysts with a solid component <20%. The efficacy of EA is inversely related to the percentage of solid component within any given lesion. There is some evidence that complex cysts with >20% solid component may have better long-term outcomes with RFA over EA, although EA is still a reasonable first line consideration. RFA salvage after EA is possible and effective, especially for complex nodules with larger solid components.

Trends for In- and Outpatient Thyroid Cancer Surgery in Older Adults in New York State, 2007-2017.

BACKGROUND: In view of the 2013 American Thyroid Association consensus statement on outpatient thyroidectomy, the present study assessed the trends and factors associated with thyroid cancer surgery setting in older adults, using the New York Statewide Planning and Research Cooperative System database. MATERIALS AND METHODS: There were 14,495 patients with surgically treated thyroid cancer in New York State between 2007 and 2017. Trends were plotted over time and stratified by surgery type. Significance of the trend was assessed using the Mann-Kendall test. Multivariable logistic regression was used to assess independent associations with surgical setting. RESULTS: The overall outpatient surgery rate significantly increased over time (correlation coefficient 0.82; P < 0.001), for both total thyroidectomy (P < 0.001) and lobectomy (P < 0.001). Factors associated with increased odds of inpatient surgery were medium- and high-volume hospitalization (adjusted odds ratio [ORadj] 2.12, 95% confidence interval [CI] 1.93-2.32; ORadj 1.69, 95% CI 1.55-1.85, respectively) versus low volume, undergoing total thyroidectomy (ORadj 1.75, 95% CI 1.61-1.90), as well as having Medicare insurance (ORadj 1.13, 95% CI 1.02-1.24) versus private insurance. CONCLUSIONS: The present study shows that outpatient thyroidectomy is increasingly favored over inpatient thyroidectomy over time in an older patient population. A clear changepoint following 2011 preceded the publication of the American Thyroid Association statement on outpatient thyroidectomy in 2013 and was likely associated with multiple publications reporting safety of outpatient thyroid surgery and clear economic benefits.

Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery.

BACKGROUND: Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon's ability to monitor the at-risk nerve. METHODS: The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation. RESULTS: Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve's value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes. CONCLUSIONS: The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided.

A comprehensive review of interventional ablation techniques for the management of thyroid nodules and metastatic lymph nodes.

Thyroidectomy remains the gold standard treatment for benign, symptomatic, or enlarging thyroid nodules, malignant nodules, and metastatic lymph node disease. However, in the past 2 decades, image-guided interventional techniques have emerged as promising alternative treatments for these conditions. Percutaneous ethanol ablation is now an accepted first-line treatment for recurring cystic thyroid nodules. Thermal ablation techniques such as high-intensity focused ultrasound, laser ablation, radiofrequency ablation, and microwave ablation have shown efficacy in producing a nodular volume reduction of greater than 50% that is maintained for several years with resolution of local compressive symptoms. There is also increasing evidence that these techniques can effectively treat papillary thyroid microcarcinomas and recurrent metastatic lymph node disease. Because these interventional ablation techniques are performed safely in an outpatient setting, are well tolerated, and the risk for needing thyroid hormone supplementation is negligible, they are becoming a popular alternative treatment to surgical resection. In this comprehensive review, we discuss each of these percutaneous interventions: the devices and techniques, the advantages and disadvantages of each energy, and summarize the outcomes published in the literature.

Trends in Diagnosis of Noninvasive Follicular Thyroid Neoplasm With Papillarylike Nuclear Features and Total Thyroidectomies for Patients With Papillary Thyroid Neoplasms.

Importance: Increasing detection of early-stage papillary thyroid neoplasms without improvements in mortality has prompted development of strategies to prevent or mitigate overtreatment. Objective: To determine adoption rates of 2 recent strategies developed to limit overtreatment of low-risk thyroid cancers: (1) a new classification, noninvasive follicular thyroid neoplasm with papillarylike nuclear features (NIFTP), and (2) hemithyroidectomy for selected papillary thyroid carcinomas (PTCs) up to 4 cm in size. Design, Setting, and Participants: This is a cross-sectional analysis of 3368 pathology records of 2 cohorts of patients from 18 hospitals in 6 countries during 2 time periods (2015 and 2019). Participating hospitals were included from the US (n = 12), Canada (n = 2), Denmark (n = 1), South Korea (n = 1), South Africa (n = 1), and India (n = 1). The records of the first 100 patients per institution for each year who underwent thyroid-directed surgery (hemithyroidectomy, total thyroidectomy, or completion thyroidectomy) were reviewed. Main Outcomes and Measures: Frequency of diagnosis of NIFTP, PTCs, and thyroidectomies during the study period. Results: Of the 790 papillary thyroid neoplasms captured in the 2019 cohort, 38 (4.8%) were diagnosed as NIFTP. Diagnosis of NIFTP was observed in the US, South Africa, and India. There was minimal difference in the total proportion of PTCs in the 2015 cohort compared with the 2019 cohort (778 [47.1%] vs 752 [44.5%]; difference, 2.6% [95% CI, -16.9% to 22.1%]). The proportion of PTCs eligible for hemithyroidectomy but treated with total thyroidectomy in the 2 cohorts demonstrated a decreasing trend from 2015 to 2019 (341 of 453 [75.3%] vs 253 of 434 [58.3%]; difference, 17.0% [95% CI, -1.2% to 35.2%]). Conclusions and Relevance: Results of this cohort study showed that the 2 mitigation strategies for preventing overtreatment of early-stage thyroid cancer have had mixed success. The diagnosis of NIFTP has only been applied to a small proportion of thyroid neoplasms compared with expected rates. However, more patients eligible for hemithyroidectomy received it in 2019 compared with 2015, showing some success with this deescalation strategy.

Radiofrequency ablation and related ultrasound-guided ablation technologies for treatment of benign and malignant thyroid disease: An international multidisciplinary consensus statement of the American Head and Neck Society Endocrine Surgery Section with the Asia Pacific Society of Thyroid Surgery, Associazione Medici Endocrinologi, British Association of Endocrine and Thyroid Surgeons, European Thyroid Association, Italian Society of Endocrine Surgery Units, Korean Society of Thyroid Radiology, Latin American Thyroid Society, and Thyroid Nodules Therapies Association.

BACKGROUND: The use of ultrasound-guided ablation procedures to treat both benign and malignant thyroid conditions is gaining increasing interest. This document has been developed as an international interdisciplinary evidence-based statement with a primary focus on radiofrequency ablation and is intended to serve as a manual for best practice application of ablation technologies. METHODS: A comprehensive literature review was conducted to guide statement development and generation of best practice recommendations. Modified Delphi method was applied to assess whether statements met consensus among the entire author panel. RESULTS: A review of the current state of ultrasound-guided ablation procedures for the treatment of benign and malignant thyroid conditions is presented. Eighteen best practice recommendations in topic areas of preprocedural evaluation, technique, postprocedural management, efficacy, potential complications, and implementation are provided. CONCLUSIONS: As ultrasound-guided ablation procedures are increasingly utilized in benign and malignant thyroid disease, evidence-based and thoughtful application of best practices is warranted.

The role of heavy metals in thyroid cancer: A meta-analysis.

INTRODUCTION: Metal ions are known to accumulate in the thyroid and some play an important role in the function and homeostatic mechanisms of the thyroid gland. Certain metal ions are known endocrine disruptors while others are classified to be carcinogenic. Although higher thyroid cancer incidence rates have been reported in regions with high metal levels in soil and drinking water, including volcanic regions, the effect of heavy metals on the thyroid is still poorly understood. To investigate the association between heavy metals and thyroid cancer, a comprehensive meta-analysis was performed to draw a more evidence-based conclusion for individual metal ions. MATERIAL AND METHODS: Nineteen studies were included in this meta-analysis, of which 9 studies reported blood metal ion levels, 8 studies reported tissue metal ion levels and 2 studies reported blood and tissue metal ion levels. The standardized mean difference (SMD) was calculated between thyroid cancer patients group and a control group (benign thyroid patients group or healthy controls group) per study. RESULTS: A significant positive SMD in manganese tissue levels between thyroid cancer patients and benign thyroid patients (SMD: 0.56 (95 % CI: 0.16, 0.95)) and a significant negative SMD in cobalt blood levels between thyroid cancer patients and healthy controls (SMD: -2.03 (95 % CI: -3.95, -0.10)) was found. No difference in levels of other metals in blood or thyroid tissue between thyroid cancer patients and non-thyroid cancer patients was noted. DISCUSSION AND CONCLUSION: The present meta-analysis therefore demonstrates the urgent need for future studies, especially given the increasing exposure of the general population to various environmental pollutants, including metal ions, and the thyroid cancer burden worldwide.

Clarifying optimal outcome measures in intermittent and continuous laryngeal neuromonitoring.

BACKGROUND: Intraoperative neuromonitoring (IONM) techniques have evolved over the past decade into intermittent IONM (I-IONM) and continuous IONM (C-IONM) modes of application. Despite many prior publications on both types of IONM, there remains uncertainty about what outcomes should be measured for each form of IONM. The primary objective of this paper is to define categories of benefit for I-IONM/C-IONM and to clarify and standardize their reporting outcomes. METHODS: Expert review consensus statement utilizing modified Delphi methodology. RESULTS: I-IONM provides diagnosis, classification, and prevention of nerve injury through accurate and early nerve identification. C-IONM provides real-time information on nerve functional integrity and thus may prevent some types of nerve injury but cannot assist in nerve localization. Sudden mechanisms of nerve injury cannot be predicted or prevented by either technique. CONCLUSIONS: I-IONM and C-IONM are complementary techniques. Future studies evaluating the utility of IONM should focus on outcomes that are appropriate to the type of IONM being utilized.

The short-latency R1 response of the electrical laryngeal adductor reflex contributes to airway protection by initiating glottic closure.

OBJECTIVE: The fundamental role of the short-latency (R1) laryngeal adductor reflex (LAR) response remains unclear with conflicting reports in the literature. This study's primary aim was to objectively determine whether the bilateral R1 response, which was elicited by electrical stimulation of the supraglottic mucosa, triggered bilateral glottis closure. METHODS: Video recording of the LAR in a prospective case series of patients undergoing trans-oral rigid laryngoscopy. The LAR was elicited by electrical stimulation of supraglottic mucosa. The LAR R1 and long-latency (R2) responses in laryngeal adductor musculature were correlated with mechanical vocal fold (VF) adduction in a time-locked manner. A high-speed camera recording 1057 frames per second was used to determine where in the LAR contractile closure the electrical R1 component occurred. RESULTS: Five patients were prospectively enrolled. The R1 response was present in all trials for all patients. The R2 response was recorded in four patients (80%). As assessed by the latency of the R1 response, electrical activation of the adductor muscles always preceded the mechanical onset of VF movement. VF adduction began near the middle of the R1 response in all trials for all patients. The R2 response of the LAR began after visible VF adduction for all patients. CONCLUSIONS: This study provides the first objective evidence that the bilateral R1 response of the electrically elicited LAR is the electrical event that initiates reflex airway closure. SIGNIFICANCE: These results suggest that under total intravenous anesthesia, the larynx preserves its capacity to elicit a LAR, thereby maintaining some protective functions that can prevent airway penetration.

Perioperative pain management and opioid-reduction in head and neck endocrine surgery: An American Head and Neck Society Endocrine Surgery Section consensus statement.

BACKGROUND: This American Head and Neck Society (AHNS) consensus statement focuses on evidence-based comprehensive pain management practices for thyroid and parathyroid surgery. Overutilization of opioids for postoperative pain management is a major contributing factor to the opioid addiction epidemic however evidence-based guidelines for pain management after routine head and neck endocrine procedures are lacking. METHODS: An expert panel was convened from the membership of the AHNS, its Endocrine Surgical Section, and ThyCa. An extensive literature review was performed, and recommendations addressing several pain management subtopics were constructed based on best available evidence. A modified Delphi survey was then utilized to evaluate group consensus of these statements. CONCLUSIONS: This expert consensus provides evidence-based recommendations for effective postoperative pain management following head and neck endocrine procedures with a focus on limiting unnecessary use of opioid analgesics.