High-intensity focused ultrasound (HIFU) therapy for benign thyroid nodules: a 3-year retrospective multicenter follow-up study

Efficacy of HIFU for the treatment of benign thyroid nodules: a systematic review and meta-analysis

OBJECTIVE

Thyroid nodules are common and sometimes associated with cosmetic issues. Surgical treatment has several disadvantages, including visible scarring. High-intensity focused ultrasound (HIFU) is a recent noninvasive treatment for thyroid nodules. The present study aims to evaluate the effectiveness and safety of HIFU for the treatment of benign thyroid nodules.

METHODS

We searched PubMed, Embase, and Cochrane Library for studies evaluating the outcomes of HIFU for patients with benign thyroid nodules. We conducted a meta-analysis by using a random effects model and evaluated the volume reduction ratio, treatment success rate, and incidence of treatment-related complications.

RESULTS

Thirty-two studies were included in the systematic review. Only 14 studies were used in the meta-analysis because the other 18 involved data collected during overlapping periods. The average volume reduction ratios at 3, 6, and 12 months after treatment were 39.02% (95% CI: 27.57 to 50.47%, I2: 97.9%), 48.55% (95% CI: 35.53 to 61.57%, I2: 98.2%), and 55.02% (95% CI: 41.55 to 68.48%, I2: 99%), respectively. Regarding complications, the incidences of vocal cord paresis and Horner's syndrome after HIFU were 2.1% (95% CI: 0.2 to 4.1%, I2: 14.6%) and 0.7% (95% CI: 0 to 1.9%, I2: 0%), respectively.

CONCLUSIONS

HIFU is an effective and safe treatment option for patients with benign thyroid nodules. However, the effects of HIFU on nodules of large sizes and with different properties require further investigation. Additional studies, particularly randomized controlled trials involving long-term follow-up, are warranted.

CLINICAL RELEVANCE STATEMENT

Surgical treatment for thyroid nodules often results in permanent visible scars and is associated with a risk of bleeding, nerve injury, and hypothyroidism. High-intensity focused ultrasound may be an alternative for patients with benign thyroid nodules.

KEY POINTS

• The success rate of HIFU treatment for thyroid nodules is 75.8% at 6 months. Average volume reduction ratios are 48.55% and 55.02% at 6 and 12 months. • The incidence of complications such as vocal fold paresis, Horner's syndrome, recurrent laryngeal nerve palsy, hypothyroidism, and skin redness is low. • HIFU is both effective and safe as a treatment for benign thyroid nodules.

High-intensity focused ultrasound for benign thyroid nodules: Systemic review and meta-analysis

BACKGROUND

High-intensity focused ultrasound (HIFU) is a less invasive option offered for the treatment of large, compressive, benign thyroid nodules.

METHODS

Observational studies of more than five participants using HIFU in the management of benign thyroid nodules from 2000 to 2021 were identified using predefined inclusion criteria. The primary outcome was an estimate of the effectiveness of HIFU.

RESULTS

Out of 158 studies reviewed, 8 articles were included with 297 patients and 300 nodules. HIFU significantly reduced nodule volume from 1 to 24 months following therapy (weighted mean difference [WMD], 47.68, 95 % confidence interval [CI], 34.13-59.66, p < 0.0001) and achieved favorable success rates (risk ratio [RR], 1.49, 95 % CI, 1.15-1.84, p < 0.001) for 50 % volume reduction.

CONCLUSIONS

HIFU appears to be a feasible, safe, and effective treatment modality for patients with benign thyroid nodules. Future research, including randomized controlled trials, is needed to determine therapy optimization, and patient selection to identify the potential role of this new therapy.

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.

[Clinical Approach for Thyroid Radiofrequency Ablation]

Radiofrequency ablation (RFA) is a non-surgical treatment for symptomatic, benign thyroid nodules. This treatment works by heating and destroying the nodule tissue, which results in reduction of its size and alleviation of the symptoms involved. RFA is indicated for nodules which are confirmed to be benign on two or more cytological or histological examinations, and which result in clinical symptoms requiring medical treatment. It is associated with good short-term outcomes on one-year follow-up; however, 20%-30% of the nodules regrow after more than three years. Therefore, on the basis of long-term follow-up, management of regrowth is key to patient care following RFA. Regrowth is more likely to occur in nodules that are large in size prior to RFA, and in those with high or increased vascularity. Recently, new techniques such as hydrodissection, artery-first ablation, and venous ablation have been introduced to inhibit regrowth. In addition, appropriate criteria for additional RFA should be applied to manage regrowth and prolong its therapeutic effects. RFA is essentially an alternative to surgery; therefore, the ultimate goal of this procedure is to avoid surgery permanently, rather than to achieve temporary effects.

Horner's Syndrome and Lymphocele Following Thyroid Surgery

Horner’s syndrome (HS), caused by lesions of the 3-neuron oculosympathetic nerve pathway (ONP), includes the triad: blepharoptosis, miosis and anhidrosis (ipsilateral with ONP damage). Thyroid−related HS represents an unusual entity underling thyroid nodules/goiter/cancer−HS (T-HS), and post-thyroidectomy HS (Tx-HS). We aim to overview Tx-HS. This is a narrative review. We revised PubMed published, full-length, English papers from inception to November 2022. Additionally, we introduced data on post-thyroidectomy lymphocele/chylous leakage (Tx-L), and introduced a new pediatric case with both Tx-HS and Tx-L. Tx-HS: the level of statistical evidence varies from isolated case reports, studies analyzing the large panel of post-thyroidectomy complications reporting HS among the rarest side effects (as opposite to hypocalcemia), or different series of patients with HS due to various disorders, including T-HS/Tx-HS. Tx-HS is related to benign or malignant thyroid conditions, regardless the type of surgery. A pre-operatory rate of T-HS of 0.14%; a post-operatory rate of Tx-HS between 0.03% and 5% (mostly, 0.2%) are identified; a possible higher risk on endoscopic rather than open procedure is described. Incomplete HS forms, and pediatric onset are identified, too; the earliest identification is after 2 h since intervention. A progressive remission is expected in most cases within the first 2−6 months to one year. The management is mostly conservative; some used glucocorticoids and neurotrophic agents. One major pitfall is an additional contributor factor like a local compression due to post-operatory collections (hematoma, cysts, fistula, Tx-L) and their correction improves the outcome. The prognostic probably depends on the severity of cervical sympathetic chain (CSC) lesions: indirect, mild injury due to local compressive masses, intra-operatory damage of CSC like ischemia and stretching of CSC by the retractor associate HS recovery, while CSC section is irreversible. Other iatrogenic contributors to HS are: intra-operatory manipulation of parathyroid glands, thyroid microwave/radiofrequency ablation, and high-intensity focused ultrasound, and percutaneous ethanol injection into thyroid nodules. Tx-L, rarely reported (mostly <0.5%, except for a ratio of 8.3% in one study), correlates with extended surgery, especially lateral/central neck dissection, and the presence of congenitally—aberrant lymphatic duct; it is, also, described after endoscopic procedures and chest-breast approach; it starts within days after surgery. Typically low-fat diet (even fasting and parental nutrition) and tube drainage are useful (as part of conservative management); some used octreotide, local sealing solutions like hypertonic glucose, Viscum album extract, n-Butyl-2-cyanoacrylate. Re-intervention is required in severe cases due to the risk of lymphorrhoea and chylothorax. Early identification of Tx-HS and Tx-L improves the outcome. Some iatrogenic complications are inevitable and a multifactorial model of prediction is still required, also taking into consideration standardized operatory procedures, skillful intra-operatory manipulation, and close post-operatory follow-up of the patients, especially during modern era when thyroid surgery registered a massive progress allowing an early discharge of the patients.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Thermal ablation

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

Horner syndrome after thyroid-related surgery: a review

BACKGROUND

Horner syndrome (HS) is caused by damage to the cervical sympathetic nerve. HS is a rare complication after thyroidectomy. The main manifestations of HS include miosis and ptosis of the eyelids, which seriously affect esthetics and quality of life. At present, there is a lack of research on HS after thyroidectomy, and its etiology is not completely clear. This review aimed to evaluate how to reduce the incidence of HS and promote the recovery from HS as well as to provide a reference for the protection of cervical sympathetic nerves during surgery.

RESULTS

HS caused by thyroid surgery is not particularly common, but it is still worthy of our attention. After searching with "Horner Syndrome," "Thyroid" as keywords, a total of 22 related cases were screened in PubMed. The results showed that open surgery, endoscopy, microwave ablation, and other surgical methods may have HS after operation. In addition, the statistics of 1213 thyroid surgeries in our hospital showed that the incidence of HS after endoscopic surgery (0.39%) was slightly higher than that after open surgery (0.29%). Further, this review analyzed potential causes of HS after thyroidectomy, so as to provide a theoretical basis for reducing its incidence.

CONCLUSION

Preventing HS during thyroidectomy is a difficult problem. The close and highly variable anatomical relationship between the thyroid and cervical sympathetic nerves increases the risk of sympathetic nerve damage during thyroidectomy. Surgery and the use of energy equipment are also closely related to the occurrence of HS.

Safety and Efficacy of Ultrasound-Guided Radiofrequency Ablation for Benign Nonfunctional Thyroid Nodules in Children: A Retrospective Study of 62 Patients with Over Four Years of Follow-Up

Background: Image-guided radiofrequency ablation (RFA) for benign nonfunctional thyroid nodules in adults has been shown to be effective and safe, but few trials address the use of RFA in children. Therefore, this study was designed to assess the efficacy and safety of RFA application to benign nonfunctional thyroid nodules in children. Methods: A retrospective study of RFA for 70 benign nonfunctional thyroid nodules in 62 children with four-year follow-up was conducted. Volume reduction ratio (VRR), technique efficacy, regrowth rate, symptom score, and cosmetic score were calculated to evaluate the efficacy. Complications and side effects were recorded. Logistic regression analysis was performed to identify risk factors, and subgroup analyses were performed. Results: Patients were followed up for at least four years (59.1 ± 10.5 months, range 48-85 months). After RFA treatment, the VRR and technique efficacy rates were highest at the first year^* (77.5% and 91.4%, respectively) but decreased by four years (55.1% and 81.4%, respectively). The symptom score decreased from 4.0 ± 2.1^* to 0.8 ± 1.6 (Z = -6.82, p < 0.001), and the cosmetic score decreased from 3.3 ± 0.7 to 1.3 ± 0.9 (Z = -7.0, p < 0.001).^* The nodule regrowth rate was 22.9%, of which 56.3% of cases represented loss of efficacy. In the cases of loss of efficacy, 66.7% had greater volume than their initial presentation. Patients who received a second RFA treatment due to loss of efficacy lost efficacy again. Bilateral nodules, low vascularity, and low cystic components were independent risk factors correlating with technique efficacy. Bilateral nodules correlated with low VRR, low efficacy rate, and high regrowth rate. Nodules with a higher proportion of cystic components had higher VRR. The overall complication rate was 4.8%. Conclusions: RFA was effective in reducing the volume of benign nonfunctional thyroid nodules in children, providing significant symptomatic relief with a good safety profile during short- and long-term follow-up. RFA is a good minimally invasive treatment modality for selected pediatric patients, and it may not be appropriate for the treatment of bilateral thyroid nodules in children.

The efficacy and safety of high-intensity focused ultrasound in the treatment of benign thyroid nodules: A systematic review and meta-analysis from 1990 to 2021

INTRODUCTION

To date, there have only been 2 systematic reviews, and 1 systematic review and meta-analysis on high-intensity focused ultrasound (HIFU) for benign thyroid nodules. The present systematic review and meta-analysis seeks to evaluate the efficacy and safety of HIFU in the treatment of benign thyroid nodules.

METHODS

Pubmed, Embase and Cochrane databases were searched for relevant studies from 1990 to 2021. Nine studies were included in the systematic review and 6 in the meta-analysis. Pooled volume reduction rates (VRRs) at 3, 6 and 24 months after HIFU were assessed.

RESULTS

This systematic review and meta-analysis showed that pooled VRRs at 3, 6, and 24 months after HIFU were 42.14 (95% confidence interval [CI] 28.66-55.62, I2=91%), 53.51 (95% CI 36.78-70.25, I2=97%) and 46.89 (95% CI 18.87-74.92, I2=99%), respectively. There was significant heterogeneity in the pooled VRRs at 3, 6 and 24 months after HIFU. No studies recorded complete disappearance of the nodules. Common side effects included pain, skin changes and oedema. There were no major complications except for transient vocal cord paralysis and voice hoarseness (0.014%) and transient Horner syndrome (0.5%).

CONCLUSION

HIFU may be an effective and safe alternative treatment modality for benign thyroid nodules. Larger clinical trials with longer follow-up are needed to evaluate the effectiveness of HIFU in treating benign thyroid nodules.

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.

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.

Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives

Ultrasound has been established as a baseline imaging technique for thyroid nodules. The main advantage of adding CEUS is the ability to assess the sequence and intensity of vascular perfusion and hemodynamics in the thyroid nodule, thus providing real-time characterization of nodule features, considered a valuable new approach in the determination of benign vs. malignant nodules. Original studies, reviews and six meta-analyses were included in this article. A total of 624 studies were retrieved, and 107 were included in the study. As recognized for thyroid nodule malignancy risk stratification by US, for acceptable accuracy in malignancy a combination of several CEUS parameters should be applied: hypo-enhancement, heterogeneous, peripheral irregular enhancement in combination with internal enhancement patterns, and slow wash-in and wash-out curve lower than in normal thyroid tissue. In contrast, homogeneous, intense enhancement with smooth rim enhancement and "fast-in and slow-out" are indicative of the benignity of the thyroid nodule. Even though overlapping features require standardization, with further research, CEUS may achieve reliable performance in detecting or excluding thyroid cancer. It can also play an operative role in guiding ablation procedures of benign and malignant thyroid nodules and metastatic lymph nodes, and providing accurate follow-up imaging to assess treatment efficacy.

The Role of CEUS in the Evaluation of Thyroid Cancer: From Diagnosis to Local Staging

Ultrasound often represents the first diagnostic step for thyroid nodule evaluation in clinical practice, but baseline US alone is not always effective enough to achieve thyroid nodule characterization. In the last decades new ultrasound techniques, such as CEUS, have been introduced to evaluate thyroid parenchyma as recommended by EFSUMB guidelines, for use in clinical research field, although its role is not yet clear. Several papers show the potential utility of CEUS in the differential diagnosis of benign and malignant thyroid nodules and in the analysis of lymph node involvement in neoplastic pathology. Therefore, we carried out an evaluation of the literature concerning the role of CEUS in three specific areas: the characterization of the thyroid nodule, the evaluation of minimally invasive treatment and loco-regional staging of the lymph node in proven thyroid cancer. According to evidence reported, CEUS can also play an operative role in nodular thyroid pathology as it is able to guide ablation procedures on thyroid nodule and metastatic lymph nodes, to assess the radicality of surgery, to evaluate disease relapse at the level of the margins of ablated regions and to monitor the clinical evolution of necrotic areas in immediate post-treatment setting.

Symptomatic aseptic necrosis of benign thyroid lesions after microwave ablation: risk factors and clinical significance

BACKGROUND

Symptomatic aseptic necrosis (SAN) followed by nodule rupture is a kind of severe complications after thermal ablation for benign thyroid nodules (BTN). No studies are available to evaluate its pathologic process, clinical manifestations, risk factors and effectiveness of therapies after microwave ablation (MWA).

METHODS

From 2012 to 2019, 398 patients who received MWA for BTN were retrospectively reviewed. Clinical data included baseline patient characteristics, imaging features (internal vascularity and the proportion of the solid component), ablation power and time, complications and prognosis were collected and documented.

RESULTS

Ten patients (2.51%) experienced post-MWA SAN, eight patients with nodule rupture and the other two without. The mean time from MWA to SAN symptom was 8.6 days and to rupture was 16.3 days. The initial symptoms of SAN patients were neck bulging, swelling and discomfort. Patients would go through nodule rupture once the nodule contents extended into the extrathyroidal area with the discontinuity of the anterior thyroid capsule, and fistula formed unavoidably in this condition. Incision drainage was effective for rupture and early treatment of non-steroidal anti-inflammatory drug might cure the early-stage SAN. Multivariate analysis showed sex (OR = 0.13; 95% CI: 0.03, 0.61; p=.03) was the risk factor leading to SAN and males were more vulnerable to SAN.

CONCLUSION

SAN after MWA came earlier and initially illustrated as neck bulging, swelling and discomfort. Early detection and early treatment might prevent the rupture of nodules. Once the breakdown of thyroid capsule occurred, rupture of ablated nodules out of skin was unavoidable and invasive procedures might be the most effective treatment.

Long-Term Outcomes of Thermal Ablation for Benign Thyroid Nodules: The Issue of Regrowth

Thermal ablation (TA) for benign thyroid nodules (BTNs) is widely accepted as an effective and safe alternative to surgery. However, studies on the long-term outcomes of TA have reported problems with nodule regrowth and symptom recurrence, which have raised the need for adequate control of regrowth. Therefore, a more complete TA with a longer-lasting treatment effect may be required. In this study, we review and discuss long-term outcomes and regrowth of BTNs following TA and evaluate factors affecting the long-term outcomes. We also discuss the management of regrowth based on long-term outcomes.