Radiofrequency ablation of benign thyroid nodules does not affect thyroid function in patients with previous lobectomy

Thermal Ablation of Thyroid Nodules, From the AJR "How We Do It" Special Series

Ablation has been shown to be an effective option for treatment of well-selected patients with thyroid nodules, particularly benign nodules, and thermal ablation is being increasingly used for this purpose. The general approach to thermal ablation of the thyroid will be familiar to interventional radiologists who perform ablation in other tissues; however, thermal ablation of the thyroid has additional unique considerations. In this review, we provide evidence-based and real-world guidance on the performance of thermal ablation for the treatment of patients with thyroid nodules, drawing on our collective experience and clinical practice. We describe patient selection, ablation modalities, equipment, general procedural approach, additional technical considerations, and postprocedural follow-up. We discuss various clinical scenarios; give tips on performing specific portions of the procedure; and highlight a range of relevant anatomic, biochemical, and clinical factors as a guide for interventional radiologists in establishing a successful thyroid ablation practice.

Improvement in thyroid-specific quality of life following radiofrequency ablation of benign thyroid nodules: A USA study

BACKGROUND

Radiofrequency ablation is an effective minimally invasive technique for benign thyroid nodules, with European and Asian studies reporting improved quality of life following treatment. We aimed to assess the thyroid-related quality of life of patients with benign thyroid nodules treated with radiofrequency ablation in the United States.

METHODS

This is a prospective single-institution study of patients treated with radiofrequency ablation over a 4-year period. Nodule characteristics and Thyroid-Related Patient-Reported Outcome (ThyPRO)-39 scores were assessed at baseline, 3 months post-procedure, and last follow-up (range: 3-12 months). Wilcoxon signed-rank test was used to assess differences in scores before and after radiofrequency ablation with standardized effect size analysis.

RESULTS

A total of 56 patients with 76 nodules were treated. The median volume reduction ratio at 1, 3, 6, and 12 months was 44.9% (interquartile range: 27.3-57.3), 65.2% (53.5-73.1), 69.7% (63.5-81.9), and 79.6% (66.2-88.9), respectively. At 3-month follow-up, significant improvement (P < .05) was observed for goiter symptoms (28.9 vs 10.8), anxiety (30.7 vs 19.3), and appearance (29.9 vs 10.8). At last follow-up, significant improvement (P < .05) was observed for goiter symptoms (28.9 vs 8.9), anxiety (30.7 vs 22.3), appearance (29.9 vs 10.8), and overall quality of life (30.3 vs 11.1). Effect sizes were moderate for appearance (standardized effect size 0.5-0.8) at last follow-up.

CONCLUSION

In the largest US study to date assessing quality of life following radiofrequency ablation, we observed an expected volume reduction ratio and improvements in thyroid-specific quality of life, particularly in the goiter, anxiety, and appearance domains.

Surgical and Pathological Challenges in Thyroidectomy after Thermal Ablation of Thyroid Nodules

Background: Thermal ablation is a minimally invasive treatment for benign thyroid nodules, but its impact on subsequent thyroidectomy and pathological evaluation is uncertain. This study investigates whether preoperative ablation complicates thyroidectomy and poses challenges for pathological diagnosis. Study Design: This retrospective cohort study used prospectively collected institutional registry data on patients with benign thyroid nodules who underwent thyroidectomy after prior radiofrequency ablation. Perioperative outcomes, including thyroidectomy difficulty scale (TDS) and macroscopic adhesion score (MAS), were compared with a control group without prior ablation. Histopathological and cytological changes within the ablated zone and periphery were also evaluated. Results: This study included 165 patients, with 145 in the nonablation group and 20 in the postablation group (17 females, mean age 53.4 years, mean nodule size 4.4 cm, mean interval between ablation and thyroidectomy 29.5 months). Compared with the nonablation group, the ablation group had longer operative time (99.5 vs. 69.5 minutes, p < 0.05), higher TDS (9 vs. 6, p < 0.05), more severe MAS (anterior 50.0% vs. 16.6%, p < 0.05; posterior: 35.0% vs. 16.6%, p < 0.05), and increased incidental parathyroidectomies (10.7% vs. 1.6%, p < 0.05). Histopathologically, the ablated area showed acellular hyalinization (95%), coagulative necrosis (60%), and chronic inflammation (85%). Both central and peripheral regions displayed cytological alterations (nuclear enlargement, focal chromatin clearing, and clear-cell change). Challenges in defining tumor capsule integrity were noted in eight follicular neoplasms, complicating the diagnosis of three follicular carcinomas and two follicular tumors of uncertain malignant potential. Conclusions: Thermal ablation of thyroid nodules may be associated with increased surgical difficulty and adhesion formation during subsequent thyroidectomy. Additionally, ablation-induced tissue alterations can potentially complicate pathological diagnosis. However, due to the small number of study cases, further confirmatory research is needed.

Investigating the optimal maximum diameter of benign thyroid nodules for thermal ablation on the basis of complete disappearance rate

OBJECTIVE

Thermal ablation (TA) is a safe and effective treatment for benign thyroid nodules (BTNs). However, there has been no consensus on the optimal maximum diameter (MD) of BTNs for TA. This study aimed to identify the optimal MD of BTNs for TA based on complete disappearance rate after TA.

MATERIALS AND METHODS

This retrospective study included 639 BTNs treated with TA from June 2014 to January 2022. The complete disappearance rate of BTNs after TA was summarized, related influencing factors were explored, and the optimal MD of BTNs for TA was identified.

RESULTS

At the final follow-up (median: 40 months, range: 24-95 months), the overall volume reduction rate was 95.4 ± 9.0%, and 50.5% of the BTNs (323/639) completely disappeared. The MD was significantly negatively correlated with complete disappearance (odds ratio 0.89, 95% confidence interval 0.87-0.92; p < 0.001). Calcification, comet-tail artifacts, multilocular cysts, and composition of BTNs, as well as diabetes were negatively correlated with complete disappearance. Restricted cubic spline indicated that an MD of 25.0 mm was the optimal threshold of BTNs for TA, which was confirmed by subgroup logistic regression analysis. Compared with BTNs with MD ≤ 25.0 mm, those with MD > 25.0 mm had a greater complication rate (6.5% vs. 2.4%, p = 0.012).

CONCLUSIONS

The MD of BTNs was negatively correlated with complete disappearance after TA; an MD > 25.0 mm indicated a reduced likelihood of complete disappearance compared with an MD ≤ 25.0 mm. An MD of 25.0 mm is an appropriate threshold of BTNs for TA on the basis of complete disappearance rate.

Assessing the efficacy of thyroid nodule radiofrequency ablation using patient-reported outcome measures

BACKGROUND

Radiofrequency ablation has recently emerged as an alternative treatment for thyroid nodules. Most studies are centered on volume reduction, whereas a few have assessed symptom improvement mainly with nonstandardized metrics. As experience in the United States is growing, we aim to assess the efficacy of radiofrequency ablation in treating benign thyroid nodules using the validated Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease.

METHODS

This is a prospective study of a newly established radiofrequency ablation program at a single tertiary referral center in 2022. Patients who underwent radiofrequency ablation were evaluated using the Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease, a validated metric ranging from 0 to 100 at baseline, 2 weeks, 3 months, and 6 months. In addition, a thyroid ultrasound was done at those intervals to assess size and volume reduction. Procedure complications were evaluated as well.

RESULTS

A total of 25 patients underwent radiofrequency ablation during the study period for a total of 32 nodules treated; 84% were female with a mean age of 51 years. The baseline mean nodule volume and largest dimension were 13 ± 11 mL and 3.4 ± 1 cm, respectively. A significant change in the Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease compressive score was seen at 3 months (38.9 ± 26.4 to 21.0 ± 21.4; P = .004) and 6 months (32.7 ± 19.9 to 17.5 ± 21.0; P = .02) but not at 2 weeks (41.0 ± 22.7 to 36.1 ± 21.9; P = .28). Significant volume and size reductions were seen at all 3-time points. Two complications occurred.

CONCLUSION

Our initial results of the thyroid radiofrequency ablation program find that it effectively alleviates symptoms by reducing nodule size in patients with symptomatic benign thyroid nodules.

[Effective and Safe Application of Radiofrequency Ablation for Benign Thyroid Nodules]

Radiofrequency ablation (RFA) has been a representative, non-surgical treatment for benign thyroid nodules that cause cosmetic problems or compression symptoms. The procedure of RFA should be performed effectively and safely. This review discusses the patient selection, pre-procedure evaluation and planning, principles, devices, techniques, and complications with reference to the guidelines and research on thyroid RFA. In particular, this review will devote to introduce RFA techniques and to provide practical help in the implementation of this procedure.

Analysis of 5 years' experience of a head and neck surgeon with radiofrequency ablation for benign thyroid nodule

PURPOSE

This study reports the long-term efficacy, safety, complications and management of radiofrequency ablation (RFA) for benign thyroid nodule performed over 5 years by a head and neck surgeon.

MATERIALS AND METHODS

We studied 287 consecutive patients who underwent RFA between March 2011 and January 2021. Pre- and postoperative thyroid nodule volumes were measured and volume reduction rate was calculated using ultrasonography (USG). Subjective symptom scores and cosmetic scores were investigated. Complications and their managements were analyzed. Complications and their management were investigated. Follow-up USG was performed at 6 and 12 months after RFA, and annually thereafter.

RESULTS

The mean volume reduction was 75.2 ± 23.8 % after 6 months and 91.9 ± 14.8 % after 5 years. All of nodule volume, and the cosmetic and symptom scores, decreased significantly postoperatively, and these scores were maintained to 5 years. Minor complications occurred in 15 of 287 (5.2 %) patients; there were no major complications. Injection laryngoplasty was performed for three patients with vocal cord paralysis. Two patients underwent open thyroid surgery because of nodule regrowth.

CONCLUSIONS

RFA is a safe and effective treatment without major complication for more than five years. Minor complications were managed by the head-and-neck surgeon personally.

Uncooled Microwave Ablation as a Treatment Option to Preserve Thyroid Function in Patients with Benign Thyroid Nodules

Objective:

The objective is to evaluate the long-term efficacy and safety of uncooled MWA for the treatment of benign thyroid nodules and its long-term effect on thyroid functions.

Material and Methods:

The study was conducted on 40 patients with 40 nodules. They were treated between September 2019 and December 2020. Nodules’ volumes, thyroid functions (triiodothyronine, free thyroxine, thyrotropin) and anti-thyroid peroxidase and anti-thyroglobulin antibodies were measured before treatment and at 3rd, 6th and 12th month following the treatment. Volume reduction rates and changes in clinical findings were evaluated.

Results:

The mean volume reduction rate was 49.88, 65.3, and 79.06% at 3rd, 6th, and 12th month, respectively. Antibody levels and thyroid function tests have remained within normal limits and were not exhibited significant change during follow-ups (p > 0.05), except for a significant increase in free thyroxin level at 12th-month (p = 0.007). Subjective symptoms and cosmetic scores were significantly improved all follow-up (p < 0.0001). The only complication was a first-degree skin burn in a patient.

Conclusion:

In conclusion, uncooled microwave ablation is an effective and safe method for the treatment of benign thyroid nodules and preserves thyroid function.

Efficacy and safety of ultrasound-guided radiofrequency ablation for papillary thyroid microcarcinoma: a systematic review and meta-analysis

BACKGROUND

We comprehensively evaluate the efficacy and safety of US-guided radiofrequency ablation (RFA) in the treatment of papillary thyroid microcarcinoma (PTMC) via a systematic review and meta-analysis.

METHODS

We searched the PubMed, Embase and Cochrane Library databases for studies published during the time between the establishment of the database through October 2021. We included a 10 non-randomized controlled trial (non-RCT) that reported the application of US-guided RFA in PTMC. The sample size of patients totaled 1279. We evaluated the ablation efficacy by analyzing the volume reduction rate (VRR), complete disappearance rate (CDR) and recurrence rate of PTMC treated by RFA. We analyzed all data using STATA version 15.1 (Stata Corporation, College Station, TX).

RESULTS

Our pooled results proved RFA treatment significantly reduces the volume of tumors (Weighted Mean Difference [WMD] = -103.20, 95% CI: -111.93 - -94.48, p = 0.000). We also found the VRR at 12 months after RFA was 93.27% (95% CI: 84.68-101.86), and the CDR at 12 months after RFA was 64% (95% CI: 39-89%). Additionally, pooled results showed the incidence of mPTC residue in ablation area, newly discovered mPTC and lymph node metastases after RFA treatment were respectively 0.3% (95% CI: -0.1-0.7%), 2.5% (95% CI: 1.1-3.9%) and 1.0% (95% CI: 0.2-1.9%), and the incidence of complications after RFA treatment was 1.8% (95% CI: 0.7-3.2%).

CONCLUSIONS

US-guided RFA is effective and safe for treating PTMC. It could be an excellent alternative to the existing treatment options.

Radiofrequency ablation versus reoperation for benign thyroid nodules that developed after previous thyroid surgery

PURPOSE

To compare the clinical outcomes of radiofrequency ablation (RFA) versus reoperation for benign thyroid nodules that developed after previous thyroid surgery.

METHODS

A total of 53 patients with 53 benign nodules developed after previous thyroid surgery were evaluated in this retrospective study. Eighteen patients were treated by RFA (RFA group) and 35 patients underwent reoperation (reoperation group). The efficacy, safety, thyroid function, blood loss, hospitalization, total treatment time, and cost were compared between the two groups.

RESULTS

In the RFA group, the mean volume decreased significantly from 12.78 ± 17.57 ml to 0.94 ± 1.01 ml (p = 0.043) with a volume reduction rate of 85.27 ± 14.35% and significant improvement in symptom and cosmetic scores (all p = 0.001). Therapeutic efficacy was achieved with a single session in all thyroid nodules. The total treatment time (6.12 ± 3.17 min vs. 110.26 ± 44.41 min, p < 0.001), blood loss (0 ml vs. 82.58 ± 105.55 ml, p < 0.001) and hospitalization(0 days vs. 9.66 ± 4.28 days, p < 0.001) were significantly lower in the RFA group than those in reoperation group, but the costs of treatment were similar(2262.12 ± 221.54 USD vs. 2638.04 ± 1062.90 USD, p = 0.081). The incidence of complications was significantly higher in the reoperation group than in the RFA group(31.43 vs. 0%, p < 0.001). Furthermorre, 65.17% of patients developed hypothyroidism after reoperation, whereas the thyroid function of the patients in the RFA group was unaffected.

CONCLUSION

For patients with benign thyroid nodules developed after previous thyroid surgery, RFA can be considered as a safe and effective alternative to reoperation with advantages of maintenance of intact thyroid function and low incidence of complications.

Efficacy and safety of ultrasound-guided radiofrequency ablation for low-risk papillary thyroid microcarcinoma in patients aged 55 years or older: a retrospective study

PURPOSE

To evaluate the efficacy and safety of radiofrequency ablation for low-risk papillary thyroid microcarcinoma (PTMC) in patients aged 55 years or older.

METHODS

This retrospective study included 95 patients aged 55 years or older who underwent radiofrequency ablation (RFA) for PTMCs between June 2014 and January 2019. Incidence and duration of postoperative complications were recorded and evaluated. Tumor volume and volume reduction rate (VRR) changes were calculated. Patients were also closely monitored for tumor recurrence, regrowth, and lymph node metastasis.

RESULTS

All nodules were completely ablated. The mean initial volume of the ablated thyroid nodules was 107.27 ± 99.10 mm³, and the volume decreased significantly during the follow-up time. The VRR in 1st, 3rd, 6th, 12th, 18th, 24th and 36th month were -591.64 ± 623.65%, -170.89 ± 319.51%, 9.74 ± 128.43%, 77.99 ± 45.26%, 99.35 ± 3.61%, 99.45 ± 3.05% and 99.78 ± 1.54%, respectively. No patient had any life-threatening complications. One patient had lymph node metastasis and one had a recurrence; both underwent a second radiofrequency ablation treatment and achieved satisfactory treatment results.

CONCLUSIONS

Our study suggests that radiofrequency ablation is a safe and effective option for low-risk PTMC in patients aged 55 years or older who are at a high risk of general anesthesia and postoperative complications or those who refuse surgery.

Radiofrequency ablation and thyroid nodules: updated systematic review

PURPOSE

In the thyroid gland, radiofrequency ablation (RFA) is being applied to both benign nodules and cancers internationally, while interest is also growing in the West. Benign thyroid nodules (BTNs) may be candidates for intervention when symptoms develop. For differentiated thyroid cancers (DTC), surgery is currently the first-line treatment. However, for candidates with high surgical risk or those who refuse to undergo repeated surgery, newer techniques such as RFA are an option. Surgery is associated with complications including hypothyroidism, voice change, hypocalcemia, and a scar. RFA has been used in Asian and European institutions as an alternative to surgery, but is relatively new in North America. Although RFA is not associated with significant complications, few randomized control trials have assessed its efficacy. The studies to date suggest a low rate of severe complications and a small need for thyroid hormone replacement following RFA. Further large-scale studies focusing on a Western population are needed. The aim of this review is to evaluate the evidence with respect to the current studies and data about the safety and efficacy of radiofrequency ablation for the management of BTNs and DTC.

METHODS

We systematically searched the PubMed/MEDLINE, EMBASE, Clinical Queries, and Web of Science databases, for articles published up to April 30th, 2020.

RESULTS

Total of 75 studies that met the inclusion criteria were included in the review. Thirty-five studies focused on RFA use for solid nodules, 12 studies on predominantly cystic nodules, 10 for autonomously functioning thyroid nodules, and 18 studied were published on differentiated thyroid cancer.

CONCLUSIONS

RFA seems to be an effective and safe alternative to surgery in high-risk surgical patients with thyroid cancers and for selected BTNs. Additional trials with longer follow-up in North American patients are needed to validate its full role in the armamentarium of thyroid ologists.

Current Status and Challenges of US-Guided Radiofrequency Ablation of Thyroid Nodules in the Long Term: A Systematic Review

BACKGROUND

US-guided minimally-invasive techniques, such as radiofrequency ablation (RFA) have emerged as an alternative treatment for benign and malignant thyroid nodules. This systematic review aims to provide an overview on the long-term outcomes of US-guided RFA in patients with benign and malignant thyroid nodules.

METHODS

We systematically searched PubMed/MEDLINE, EMBASE, and Scopus to identify articles reporting the outcomes of thyroid RFA after a follow-up of at least 3 years.

RESULTS

A total of 20 studies met the inclusion criteria and were included in the review. In patients with benign thyroid nodules, RFA significantly reduced nodule volume and this was generally maintained for the following 5 years. However, a small but not negligible proportion of nodules regrew and some of them required further treatments over time. In patients with malignant nodules, RFA has been used not only to treat differentiated thyroid cancer (DTC) neck recurrences, but also to treat papillary thyroid microcarcinoma (PTMC). In most patients with PTMC, RFA led to complete disappearance of the tumor. When it was compared to surgery, RFA was not inferior in terms of oncologic efficacy but it had a lower complication rate. However, RFA did not allow for final pathology, disease staging and accurate risk stratification.

CONCLUSIONS

US-guided RFA significantly reduces benign thyroid nodules and destroys most PTMC, and this is generally maintained for at least 5 years after the initial treatment. Further studies addressing the risk of regrowths in patients with benign thyroid nodules, as well as the risk of recurrence in patients with PTMC are needed.

Efficacy and safety of radiofrequency ablation for benign thyroid nodules in patients with previous thyroid lobectomy

Background

Radiofrequency ablation (RFA) is recommended for the treatment of benign thyroid nodules. However, data on the clinical role of RFA for benign thyroid nodules in patients with history of thyroid lobectomy are insufficient. The purpose of this study was to evaluate the efficacy and safety of radiofrequency ablation (RFA) for benign thyroid nodules in patients who had previously undergoing thyroid lobectomy.

Methods

From May 2015 to October 2018, a total of 20 patients (19 females, 1 male, mean age 49.50 ± 14.26 years, range 22–74 years) with 20 benign thyroid nodules (mean volume 15.04 ± 21.17 ml, range 0.40–69.67 ml) who had undergone previous thyroid lobectomy were included in this retrospective study. Patients were followed up at 3, 6, 12 months after RFA and every 12 months thereafter by ultrasound, clinical evaluation and thyroid function. Volume, volume reduction rate (VRR), symptom score and cosmetic score were evaluated.

Results

During the mean follow-up time of 21.24 ± 16.41 months, the mean nodule volume decreased significantly from 15.04 ± 21.17 ml to 1.29 ± 1.17 ml (P = 0.018) with a mean VRR of 85.41 ± 12.17%. Therapeutic success was achieved in a single session for all thyroid nodules. The symptom score (P = 0.001) and cosmetic score (P = 0.001) were both significantly reduced at the last follow-up. The levels of free triiodothyronine (fT3), free thyroxine (fT4) and thyroid stimulating hormone were not significantly different at the last follow-up from those prior to treatment (all P > 0.05). No life-threatening complications or sequelae occurred after RFA.

Conclusions

As a minimally invasive modality, RFA was a safe, effective, and thyroid function-preserving option for patients with symptomatic benign thyroid nodules after a previous lobectomy.

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.

Thyroid dysfunction following radiofrequency ablation for benign thyroid nodules: more likely to occur within one-week and in high-risk population

BACKGROUND

Radiofrequency ablation (RFA) has been recommended as the treatment for benign thyroid nodules (BTNs) by some guidelines. However, detailed follow-up instructions for thyroid function about the timing and affected populations after RFA are lacked due to insufficient researches. This 12-month prospective study aimed to evaluate the incidence and risk factors of thyroid dysfunction at different time points after RFA, especially within 1 week that previous studies didn't concern.

METHODS

Seventy-five euthyroid patients who underwent RFA for symptomatic BTNs were enrolled (ChiCTR-INR-16007884). The incidence of thyroid dysfunction within 1 week, at 1, 6, and 12 months after RFA was evaluated. The risk factors for different types of thyroid dysfunction in the different terms were further analyzed.

RESULTS

Within 1 week after RFA, the incidence of thyroid dysfunction was as high as 36.00% unexpectedly, and only overt thyrotoxicosis and subclinical thyrotoxicosis occurred, which were significantly associated with the low-normal baseline thyrotropin (TSH) level (p = 0.001) and high ablation volume ratio (p = 0.008). From 1 to 12 months (the long term), the incidence dropped significantly and remained low (8.00-12.00%); and thyroid dysfunction presented as overt thyrotoxicosis, subclinical thyrotoxicosis, and subclinical hypothyroidism. The long-term thyrotoxicosis group had more cases with diabetes and lower baseline TSH levels. The long-term subclinical hypothyroidism group had more cases with positive thyroid peroxidase antibodies, higher baseline TSH levels, and higher ablation volume ratios.

CONCLUSIONS

After the RFA of BTNs, thyroid dysfunction was more likely to occur within 1 week and in populations with risk factors.

Thermal Ablation of Benign Thyroid Nodules and Papillary Thyroid Microcarcinoma

Due to the increasing rates of physical examination and application of advanced ultrasound machines, incidences of benign thyroid nodules (BTNs) and papillary thyroid microcarcinoma (PTMC) were dramatically up-regulated in recent years. Thermal ablation (TA) has been widely used and regarded as a safe and effective method to eliminate or reduce BTNs and recurrent low-risk PTMC. However, conclusions using TA to treat primary PTMC are controversial. Recently, several long-term and prospective studies on TA treatment of BTNs and primary PTMC have been reported. Here, we review current literatures and progress on TA treatment of BTNs and PTMC and underline the way to get the best treatment outcomes, providing a comprehensive insight into the research progresses in this field.

Radiofrequency Thermal Ablation of Benign Thyroid Nodules: The Correlation Between Ultrasound Nodule Characteristics and Results

Background. The aim of this observational study was to investigate for which nodules a better response to radiofrequency thermoablation (RFA) for nonfunctioning benign thyroid nodules is likely. Methods. Aesthetic score, compressive score, and volume of 32 benign nodules from 32 patients were registered during follow-up at baseline, 1, 3, 6, and 12 months. Results. A volume reduction rate (VRR) of 72.56% at 12 months after the procedure (P = .009) was registered. A significant (P < .001) improvement in the compressive and aesthetic scores was observed. Nodules with a baseline volume <20 mL had VRRs at 3 and 6 months that were significantly greater than those with volume >20 mL (P = .037). Conclusions. RFA was shown to be a safe and effective procedure for the management of benign thyroid nodules and that there is a correlation between the initial size of the nodule and the response to treatment.

Novel Approaches for Treating Autonomously Functioning Thyroid Nodules

Benign thyroid nodules are exceedingly common in the adult population. Only a small percentage of nodules are toxic or autonomously functioning thyroid nodules (AFTNs). The options clinicians have for treating the symptoms of hyperthyroidism include anti-thyroidal medications, radioactive iodine, or surgery. Depending on the patient population treated, these options may not be suitable or have inherent risks that are undesirable to the patient. On the other hand, untreated hyperthyroidism can lead to osteoporosis, atrial fibrillation, emotional lability, and neurological consequences. Thus, we present a review of two novel safe and effective approaches for treating AFTN; one surgical (transoral endoscopic thyroid surgery) and one non-surgical (radiofrequency ablation), as a means for expanding our treatment armamentarium.

The injury of recurrent laryngeal nerve and thyroid regeneration after irreversible electroporation ablation of most part of thyroid gland-an experimental study on swine model

To study the thyroid regeneration and injury of recurrent laryngeal nerve after irreversible electroporation (IRE). 12 pigs were divided into three groups: six pigs underwent IRE, other pigs were used as controls. IRE was performed near tracheoesophageal groove, to ablate most part of thyroid gland. Parathyroid and thyroid function, recurrent laryngeal nerve injury and thyroid computed tomography (CT) imaging were regularly investigated. The histopathology results were analyzed to detect thyroid regeneration. Masson's trichrome method for collagen and immunohistochemistry were performed for Soluble protein-100 (S100) and neurofilaments on nerve section. In IRE group, there were no symptoms of recurrent laryngeal nerve-related injury. No abnormalities of recurrent laryngeal nerve were shown on hematoxylin-eosin (HE) staining, Masson's trichrome staining, Neurofilament (NF) staining and S100 staining. There were no significant changes for thyroid and parathyroid function in all pigs. Immediately after IRE, CT showed hypoattenuation in the ablated thyroid gland and it became swelling. 14 days after IRE, thyroid CT showed hetergenous attenuation in the electroporation zone, and the size and attenuation of thyroid gland were normal after two months. There was cell apoptosis in the thyroid gland after IRE. Seven and 14 days after IRE, there was fragmentation of nucleus within the follicle, and some follicles were empty. Two months later, complete regeneration of thyroid tissue was shown. IRE was shown to be both effective and safe with complete regeneration of thyroid tissue and preservation of the function and structure of the recurrent laryngeal nerve.

Value of monopolar and bipolar radiofrequency ablation for the treatment of benign thyroid nodules

Only a few thyroid nodules are perceived as functional or optically disturbing. If there is a need for action, surgical intervention is the long-term standard by which thermoablative procedures (radiofrequency-, laser-, microwave ablation, high intensity focused ultrasound) must be measured against in terms of safety, effectiveness and patient satisfaction. Prior to intervention assessment of the dignity of the nodule by ultrasound-guided fine needle aspiration is essential for cold and warm nodules, as is the confirmation of an inconspicuous cervical lymph node status. The short-term treatment results of these newer interventions in terms of nodule volume reduction and symptomatic improvement are promising and the general complication rate of the procedures is low. Since functional thyroid parenchyma is preserved, maintaining normal thyroid status is the rule. The procedure is usually performed on an outpatient basis, under local anesthesia and monitoring. The subsequent convalescence is usually very short. Most studies are available on monopolar radiofrequency ablation. Several professional societies have defined indications for radiofrequency ablation (RFA), but these need to be further refined based on practical experience and literature. An acceptable long-term recurrence rate still has to be proven for practically all thermoablative methods, for monopolar RFA limited long-term data are encouraging so far. The recurrence rate as well as patient satisfaction will provide the basis for a meaningful overall cost-benefit analysis in the future.

Radiofrequency Ablation of Thyroid Nodules: A Long-Term Prospective Study of 24 Patients

PURPOSE

To evaluate the volume reduction rate (VRR) of thyroid nodules over a long period of time after radiofrequency (RF) ablation treatment in both solid and mixed nodules; to determine ablation parameters; and to evaluate complications and success rates and safety of RF ablation.

MATERIAL AND METHODS

In this prospective study, 24 patients (83% females and 17% males; age 50.17 ± 13.6 years) underwent ultrasound-guided percutaneous RF ablation of benign thyroid nodules with radiologic follow-up at 1, 3, 6, 12, 24, and 36 months after treatment. All patients presented with compressive or cosmetic complaints and with Thyroid Imaging Reporting and Data System 1 or 2 nodules under ultrasound and were confirmed to be Bethesda Category II after 2 fine-needle aspirations.

RESULTS

A total of 24 nodules (54.2% solid, 37.5% solid predominance, and 8.3% cystic predominance) were included in this study. Significant results in VRR (%) were found at 24 months and 36 months of 69.92 ± 19.23 and 76.84 ± 15.92, respectively. Furthermore, a logarithmic relationship was found when VRR was plotted over time, in both solid and mixed nodules. No correlations were found with any of the ablation parameters. The success rate reached 72.22% at 12 months, and the total complication rate was 16.67% (12.5% minor complications and 4.2% major complications-1 laryngeal nerve palsy), reaching an 83.3% safety.

CONCLUSIONS

RF ablation can be an alternative treatment modality in the management of benign symptomatic thyroid nodules. The results show that it is a safe and effective treatment if trans-isthmic approach and moving-shot techniques are correctly followed.

2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Image-guided chemical and thermal ablations for thyroid disease: Review of efficacy and complications

Image-guided ablation of thyroid disease is increasingly being commonly reported. Techniques including ethanol injection and thermal ablation using radio-frequency, laser, and microwave devices have been described. Minimally invasive approaches to the management of benign cystic, solid, and functional thyroid nodules as well as both primary and recurrent thyroid malignancy have been reported. The purpose of this article is to review the current evidence relating to image-guided ablation of thyroid disease with a focus on clinical outcomes and complication rates for patients treated with this minimally invasive approach.

Monopolar Radiofrequency Ablation of Thyroid Nodules: A Prospective Austrian Single-Center Study

BACKGROUND

Monopolar radiofrequency ablation is currently deemed an exotic treatment option for benign thyroid nodules in many central European countries. The aim of this study was to evaluate prospectively the safety and efficacy of this method in a large patient cohort following its introduction in Austria.

METHODS

Peri- and post-interventional complications were analyzed for 277 patients. Efficacy was determined for 300 and 154 nodules at 3 and 12 months post treatment, respectively. All treatments were performed with an internally cooled 18G radiofrequency electrode using a free-hand, "moving-shot" technique following subcutaneous and local perithyroidal anesthesia.

RESULTS

Mean patient age (SD) was 52 ± 12.9 years (75% female), and overall mean baseline nodule volume (SD) was 13.8 ± 15.9 mL. Nodules were visible in 62.8% of patients, 40% had a symptom score ≥4 on a 10-point visual analogue scale, and 14.4% had hyperthyroidism. Mean overall nodule volume reduction rates (VRR) at 3 and 12 months were 68 ± 16% and 82 ± 13%, respectively (p < 0.001). At 12 months, 81% of nodules exhibited a VRR of ≥70%, with 10%, 6%, and 2% of nodules showing VRRs of 60-70%, 50-60%, and ≤50%, respectively. Subgroup analysis according to baseline nodule size (≤10 mL to >30 mL) or baseline nodule composition (solid, mixed, cystic) revealed significantly higher VRRs for smaller and cystic nodules. Moreover, nodule shrinkage was accompanied by significantly improved symptom and cosmetic scores after 3 and 12 months (p < 0.001). Of 32 hyperthyroid patients, 27 (84%) were euthyroid, four had subclinical hyperthyroidism, and one had subclinical hypothyroidism at last follow-up. Post-procedural complications were absent in 83% of patients, minimal in 12.9%, moderate and reversible in 3.2% (1.8% voice change, 0.7% hyperthyroidism, 0.3% wound infection treated with antibiotics, 0.3% epifascial hematoma), and irreversible in 0.7% (one case with hypothyroidism and one with a wound infection treated by surgery).

CONCLUSIONS

It is concluded that a single treatment course with monopolar radiofrequency ablation is both safe and highly effective in terms of nodule volume reduction, relief of local symptoms, and (in patients with hyperthyroidism) restoration of euthyroid function. In no case was a prescription of thyroid medication required among those patients who were euthyroid at baseline.

Update on the role of ultrasound guided radiofrequency ablation for thyroid nodule treatment

Thyroid nodules can be frequently detected in general population, most of them are benign, however malignant cases are rising in the past decades. Ultrasound (US) is the most common imaging modality to assess thyroid nodular lesions, plan patient work-up and guide minimally invasive treatment. The present review paper has been researched to evaluate the current status of radiofrequency ablation (RFA) treatment in order to evaluate indications, techniques, complications, limitations and outcome assessment in benign solid, partially cystic nodules and recurrent malignant nodules. RFA comparison with other ablation techniques has been provided as well. US guided Radiofrequency ablation has been proved to be effective and safe in cases of benign thyroid nodules and a promising treatment method alternative to surgery for patients with recurrent papillary thyroid cancer. It's major role lies in significant reduction of thyroid nodule mean volume and improvement of the patient symptoms. However, future multicenter studies are warranted to better clarify the multi-parametric patient selection criteria and evaluate RFA technique efficacy, advantages and limitations in the variety of thyroid nodular disease.

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

US-Guided Percutaneous Radiofrequency versus Microwave Ablation for Benign Thyroid Nodules: A Prospective Multicenter Study

Compared with microwave ablation (MWA), percutaneous radiofrequency ablation (RFA) and laser ablation (LA) have been recommended as minimally invasive treatments for patients with symptomatic benign thyroid nodules (BTNs) because of the large number of clinical applications. This prospective multicenter study sought to evaluate the clinical outcomes of RFA and MWA for BTNs. In eight participating institutions, the total number of 1252 patients treated by RFA and MWA were 649 ones with 687 BTNs and 603 ones with 664 BTNs, respectively. The clinical outcomes including the nodular maximal diameter reduction ratio (MDRR), the nodular volume reduction ratio (VRR), and the incidence of complications were compared to evaluate the efficacy and safety of the two techniques. The results for the nodular MDRR and VRR in the RFA group were significantly better than those in the MWA group at 6 months and later follow-up, and the major complication rates of 4.78% and 6.63% in RFA and MWA groups showed no statistically significant differences. In conclusion, both RFA and MWA are safe and effective techniques for selected patients with symptomatic BTNs. The achieved MDRR and VRR in the RFA group were greater than those in the MWA group at 6 months and later follow-up.

Complications Following Radiofrequency Ablation of Benign Thyroid Nodules: A Systematic Review

OBJECTIVE

This systematic review examined whether radiofrequency ablation (RFA) is a safe treatment modality for benign thyroid nodules (BTNs).

DATA SOURCES

PubMed, Embase, and the Cochrane Library database were searched for articles that (a) targeted human beings and (b) had a study population with BTNs that were confirmed by fine-needle aspiration cytology and/or core needle biopsy.

STUDY SELECTION

Thirty-two studies relating to 3409 patients were included in this systematic review.

RESULTS

Based on literatures, no deaths were associated with the procedure, serious complications were rare, and RFA appears to be a safe and well-tolerated treatment modality. However, a broad spectrum of complications offers insights into some undesirable complications, such as track needle seeding and Horner syndrome.

CONCLUSIONS

RFA appears to be a safe and well-tolerated treatment modality for BTNs. More research is needed to characterize the complications of RFA for thyroid nodules.

Radiofrequency ablation for benign thyroid nodules

Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

Radiofrequency ablation for treatment of benign thyroid nodules: A PRISMA-compliant systematic review and meta-analysis of outcomes

BACKGROUND

Thyroid nodules (TNs) usually appearing in the general population have the potential possibility of malignant transformation and common problems of jugular oppression such as dyspnea and hoarseness. We performed this meta-analysis to evaluate the efficiency of radiofrequency ablation (RFA) for the treatment of benign TNs in accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements.

METHODS

Published literatures were retrieved from PubMed, Embase, Web of Science, and Scopus up to January 27, 2016. Pooled standard mean difference with 95% confidence interval was estimated by fixed- or random-effects model depending on heterogeneity, which was calculated using the Cochran Q, τ, and I statistics. The quality of the articles was evaluated by the Newcastle-Ottawa scale.

RESULTS

Meta-analysis of data from 1090 patients with 1406 benign TNs in 20 articles showed that with the subgroup stratified by nodule volume, they were significantly decreased at 1, 3, 6, 12, and the last follow-up months, when comparing post-RFA with the initial nodule volume. In addition, the volume also notably declined by cold and hot nodules. By subgrouping into the largest diameter, symptom score, cosmetic score, thyrotropin, triiodothyronine, free thyroxine level, and vascularity, the pooled data indicated that there was a decrease in largest diameter, symptom score, cosmetic score, triiodothyronine level, and vascular scale, an unchanged free thyroxine, and an increased thyrotropin level after RFA. The publication bias for this particular study is presented in the following groups: nodule volume reduction at 6 months and last follow-up month after RFA and symptom score.

CONCLUSION

In summary, by pooling of these studies we recommended that RFA indeed has the advantages in improving outcomes and providing better prognosis for patients with benign TNs.

Laser Thermal Ablation of Thyroid Benign Nodules

Thermal ablation therapies for benign thyroid nodules have been introduced in recent years to avoid the complications of traditional methods such as surgery. Despite the little complications and the reportedly acceptable efficacy of thermal ablation methods, quite few medical centers have sought the potential benefits of employing them. This paper provides an introduction to the literature, principles and advances of Percutaneous Laser Ablation therapy of thyroid benign nodules, as well as a discussion on its efficacy, complications and future. Several clinical research papers evaluating the thermal effect of laser on the alleviation of thyroid nodules have been reviewed to illuminate the important points. The results of this research can help researchers to advance the approach and medical centers to decide on investing in these novel therapies.

Volume reduction of benign thyroid nodules 3 months after a single treatment with high-intensity focused ultrasound (HIFU)

Background

High-intensity focused ultrasound (HIFU) is a promising, non-invasive technique in treating benign thyroid nodules (TNs). The aim of this study was to evaluate the efficacy of HIFU to induce clinically meaningful shrinkage in benign predominantly solid TNs and to identify variables that influence or predict the magnitude of TN volume reduction.

Methods

For each of ten subjects, HIFU treatment was conducted on a single nodule. Nodular volume was measured sonographically at baseline and at 3 months post-procedure. Nodular function and early treatment assessment was done scintigraphically.

Results

Median nodular volume reduction was 0.7 ml absolute and 48.8% relative to pre-interventional size (p < 0.05). Absolute shrinkage was negatively correlated with the average treatment depth (τ = −0.61, p < 0.05). Absolute nodular volume was positively correlated with the scintigraphic nodular uptake reduction (τ = 0.66, p < 0.05).

Conclusions

HIFU treatment of benign predominantly solid TNs appears to be safe and effective for inducing nodular shrinkage. Despite potential for improvement, a single treatment session with HIFU is already a viable alternative to more standard methods. The feasibility of multiple HIFU treatments requires further investigation. Due to the small sample size, the findings of this analysis need conformation by larger studies.

Radiofrequency ablation for autonomously functioning thyroid nodules: a multicenter study

BACKGROUND

The purpose of this study is to validate the generalizability of the efficacy and safety of radiofrequency (RF) ablation for treating autonomously functioning thyroid nodules (AFTN) in a large population multicenter study.

METHODS

This study included 44 patients from 5 institutions who refused or were not suitable for surgery or radioiodine therapy. Twenty-three patients were affected by a toxic nodule and 21 by a pretoxic nodule. RF ablation was performed using an 18-gauge, internally cooled electrode. Nodule volume, thyroid function, scintigraphy, symptom/cosmetic scores, and complications were evaluated before treatment and during each follow-up.

RESULTS

The mean follow-up period was 19.9±12.6 months. The mean nodule volume was initially 18.5±30.1 mL and significantly decreased after treatment at 1 month (11.8±26.9 mL, p<0.001) and the last month (4.5±9.8 mL, p<0.001). Significant improvement of triiodothyronine, free thyroxine, and thyrotropin was observed at the last follow-up. Regarding scintigraphy, 35 hot nodules became cold or were normal when scanned and 9 decreased uptake, although they remained hot nodules. The mean symptom and cosmetic scores were significantly reduced at the last follow-up. No major complications were encountered.

CONCLUSIONS

This multicenter study validated the efficacy and safety of RF ablation for treating AFTN; RF ablation can be considered an alternative to surgery or radioiodine therapy.

Radiofrequency ablation is a thyroid function-preserving treatment for patients with bilateral benign thyroid nodules

PURPOSE

To evaluate the efficacy and safety of radiofrequency (RF) ablation for treatment of bilateral thyroid nodules as well as preservation of thyroid function.

MATERIALS AND METHODS

Between January 2007 and October 2012, 18 patients (16 women and 2 men; mean age, 49.9 y; median age, 44 y; age range, 27-81 y) with bilateral thyroid nodules treated by RF ablation were included in this study. The inclusion criteria included bilateral thyroid nodules, pressure symptoms or cosmetic problems, cytologic confirmation of benignancy without atypical cells, and patient refusal of surgery. We used an RF generator (Cool-tip RF system [Covidien, Boulder, Colorado] or SSP-2000, Taewoong Medical Co, Ltd [Gyeonggi-do, Republic of Korea]) and an 18-gauge internally cooled electrode with 1-cm active tips (Cool-tip [Covidien] or Well-Point RF electrode [Taewoong Medical Co, Ltd]). RF ablation was conducted using the moving shot technique and a trans-isthmic approach. RF ablation was performed in separate sessions for nodules in each lobe. Follow-up ultrasound examinations were performed at 1-6 months, 6-12 months, and during the last month of follow-up. The diameter and volume of the nodule and clinical problems including cosmetic and symptom scores were evaluated before and after the procedure.

RESULTS

The mean initial nodule size was 4.1 cm ± 1.9, although there was a significant decrease by the time of the last follow-up examination (range, 1-48 mo; mean, 18.1 mo ± 12.8; P < .001, 2.5 cm ± 1.4). The initial nodule volume was 24.4 mL ± 32.2 and was decreased at the last follow-up (6.3 mL ± 19.0, P < .001), with a mean volume reduction of 75.9% ± 19.0. The symptom (P < .001) and cosmetic (P < .001) scores were decreased. Serum hormone levels did not differ significantly before treatment and at the last follow-up (P > .05).

CONCLUSIONS

RF ablation improves cosmetic problems and symptoms and preserves thyroid function in patients with bilateral thyroid nodules.

Vascular and interventional radiology radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: literature review

Thermal radiofrequency ablation is a relatively new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. Different recommendations are necessary for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus.

A short review of basic head and neck interventional procedures in a general radiology department

Image-guided interventional procedures provide a safe way to diagnose and treat a variety of head and neck abnormalities. The procedure time is usually short, and most procedures can be performed on an outpatient basis. Knowledge about strengths and weaknesses, efficacy, potential complications, and pitfalls of these procedures allows the best treatment to be chosen for a particular lesion type. This review discusses some of the commonly performed interventional radiology procedures in a general radiology department in the management of patients with neoplastic diseases in the head and neck region.

Combination therapy consisting of ethanol and radiofrequency ablation for predominantly cystic thyroid nodules

SUMMARY

Predominantly cystic thyroid nodules are often aspirated before radiofrequency ablation to enhance its efficacy; however internal bleeding during the aspiration is a problem. We evaluated the feasibility and safety of ethanol ablation to control internal bleeding that occurred during preparatory aspiration. Between September 2010 and August 2011, 11 of 40 predominantly cystic nodules bled internally during fluid aspiration before radiofrequency ablation. To control the bleeding, 99% ethanol was injected. The efficacy of ethanol in controlling bleeding, final nodule volume and complications were assessed. Control of the bleeding by ethanol ablation and subsequent radiofrequency ablation was feasible in all patients. Ninety-one percent (10/11) could be treated in 1 session. The mean nodule volume dropped from 17.1 to 4.3 mL (P < .018). There were no major complications. Ethanol ablation and radiofrequency ablation combination therapy is a feasible and safe technique for treating predominantly cystic thyroid nodules that exhibit internal bleeding during preparatory aspiration.

Use of radiofrequency ablation in benign thyroid nodules: a literature review and updates

Successful thermal ablation using radiofrequency has been reported in various tumors including liver or kidney tumors. Nonsurgical minimally invasive ablative therapy such as radiofrequency ablation (RFA) has been reported to be a safe and efficient treatment option in managing symptomatic cold thyroid nodules or hyperfunctioning thyroid nodules. Pressure and cosmetic symptoms have been shown to be significantly improved both in the short and long terms after RFA. For hyperfunctioning thyroid nodules, RFA is indicated for whom surgery or radioiodine are not indicated or ineffective or for those who refuse surgery or radio-iodine. Improvement of thyroid function with decreased need for antithyroid medications has been reported. Complication rate is relatively low. By reviewing the current literature, we reported its efficacy and complications and compared the efficacy of RFA relative to other ablative options such as ethanol ablation and laser ablation.