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

American Association of Clinical Endocrinology Disease State Clinical Review: The Clinical Utility of Minimally Invasive Interventional Procedures in the Management of Benign and Malignant Thyroid Lesions

OBJECTIVE

The objective of this disease state clinical review is to provide clinicians with a summary of the nonsurgical, minimally invasive approaches to managing thyroid nodules/malignancy, including their indications, efficacy, side effects, and outcomes.

METHODS

A literature search was conducted using PubMed and appropriate key words. Relevant publications on minimally invasive thyroid techniques were used to create this clinical review.

RESULTS

Minimally invasive thyroid techniques are effective and safe when performed by experienced centers. To date, percutaneous ethanol injection therapy is recommended for recurrent benign thyroid cysts. Both ultrasound-guided laser and radiofrequency ablation can be safely used for symptomatic solid nodules, both toxic and nontoxic. Microwave ablation and high-intensity focused ultrasound are newer approaches that need further clinical evaluation. Despite limited data, encouraging results suggest that minimally invasive techniques can also be used in small-size primary and locally recurrent thyroid cancer.

CONCLUSION

Surgery and radioiodine treatment remain the conventional and established treatments for nodular goiters. However, the new image-guided minimally invasive approaches appear safe and effective alternatives when used appropriately and by trained professionals to treat symptomatic or enlarging thyroid masses.

Ultrasound-Guided Thermal Ablation of Thyroid Nodules: Technicalities Progress and Clinical Applications, Especially in Malignant Thyroid Nodules

Thyroid nodules are commonly encountered in health care practice. They are usually benign in nature, with few cases being malignant, and their detection has increased in the adult population with the help of ultrasonography. Thyroidectomy or surgery is the first-line treatment and traditional method for thyroid nodules; however, thyroidectomy leaves permanent scars and requires long-term use of levothyroxine after surgery, which makes patients more reticent to accept this treatment. Thermal ablation is a minimally-invasive technique that have been employed in the treatment of benign and malignant thyroid nodules nodules, and have been shown to be effective and safe. Several studies, including long-term, retrospective, and prospective studies, have investigated the use of ablation to treat benign thyroid nodules and malignant thyroid nodules, including papillary thyroid carcinoma. Here, we review the recent progress in thermal ablation techniques for treating benign and malignant nodules, including their technicalities, clinical applications, pitfalls and limitations, and factors that could affect treatment outcomes. Special in-depth elaboration on the recent progress of the application of thermal ablation therapy in malignant thyroid nodules.

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.

Comparison of radiofrequency ablation and microwave ablation for benign thyroid nodules: A systematic review and meta-analysis

PURPOSE

To compare the effectiveness and safety of radiofrequency ablation (RFA) and microwave ablation (MWA) for the treatment of benign thyroid nodules (BTNs).

METHODS

PubMed, Embase and Cochrane databases were searched up to September 11, 2020. Volume reduction rate (VRR), symptomatic and cosmetic scores analysed by standardized mean difference (SMD), and complications analysed by risk difference (RD) were performed to evaluate the efficacy and safety of RFA and MWA for treating BTNs.

RESULTS

Five eligible studies were included. 899 patients with 956 BTNs and 869 patients with 938 BTNs received RFA and MWA, respectively. RFA and MWA have the similar pooled 3-month (56.0% vs. 53.9%, p = .668) and 6-month (80.8% vs. 74.9%, p = .080) VRRs. But RFA showed a significantly higher VRR than MWA after 12 months (86.2% vs. 80.0%, p = .036). The pooled symptomatic and cosmetic scores decreased significantly after 6 and 12 months in both RFA and MWA. The improvements of symptoms were equivalent between two groups at 6 (SMD: 1.17 vs. 1.12, p = .930) and 12 (SMD: 1.46 vs. 1.45, p = .930) months. No significant differences in cosmetic scores were found between two groups at 6 (SMD: 0.87 vs. 0.94, p = 0. 334) and 12 (SMD: 1.21 vs. 1.15, p = 0. 872) months. Major (RD = -0.02, P = .107) and minor (RD = 0.00, p = .661) complications did not significantly differ between RFA and MWA.

CONCLUSIONS

RFA and MWA are effective and safe treatment modalities for BTNs. But RFA showed a superior 12-month VRR. RFA may have a better long-term effect on volume reduction of nodules compared with MWA.

[The "hot" thyroid gland carcinoma and a critical look at thermal ablation]

Hot and hyperfunctioning thyroid gland nodules are currently treated primarily by radioiodine or surgical resection. In recent years local thermal ablation as an alternative therapeutic modality is increasingly recommended. This article reports the case of a patient with a hot thyroid nodule, which was resected and turned out to be follicular thyroid cancer. In this context it appears to be necessary to critically question thermal ablation as an alternative treatment option for thyroid nodules, particularly since the current recommendations are weak with low or even very low evidence. Radioiodine or surgery remains the first-line treatment for hot and hyperfunctioning thyroid nodules but malignancy in a hot thyroid nodule also needs to be considered.

Update of Radiofrequency Ablation for Treating Benign and Malignant Thyroid Nodules. The Future Is Now

Thermal and chemical ablation are minimally invasive procedures that avoid removal of the thyroid gland and target symptomatic nodules directly. Internationally, Radiofrequency ablation (RFA) is among one of the most widely used thermal ablative techniques, and is gaining traction in North America. Surgery remains the standard of care for most thyroid cancer, and in the right clinical setting, Active Surveillance (AS) can be a reasonable option for low risk disease. Minimally invasive techniques have emerged as an alternative option for patients deemed high risk for surgery, or for those patients who wish to receive a more active treatment approach compared to AS. Herein, we review the literature on the safety and efficacy of RFA for treating benign non-functioning thyroid nodules, autonomously functioning thyroid nodules, primary small low risk thyroid cancer (namely papillary thyroid cancer) as well as recurrent thyroid cancer.

Comparison of ultrasound-guided thermal ablation and conventional thyroidectomy for benign thyroid nodules: a systematic review and meta-analysis

Objective: To compare the safety and efficacy of ultrasound-guided thermal ablation and conventional thyroidectomy for benign thyroid nodules (TNs) by performing a systematic review and meta-analysis.Methods: We searched PubMed, Embase, Web of Science and Cochrane Library databases for clinical trials from the date of their inception to 1 April 2019. Two investigators independently examined the trials to select qualified studies, extracted relevant information and assessed the risk of bias according to the Cochrane Collaboration checklist (Oxford, UK). The primary study outcomes were safety (hoarseness, hypothyroidism and postoperative pain) and efficacy (symptom improvement, postoperative cosmetic effects and hospitalization time). This study is registered with PROSPERO (CRD42019125643).Results: Seven studies involving 1289 patients were included. The results demonstrated that the incidences of hoarseness [odds ratio (OR) 0.33, 95% confidence interval (95% CI) (0.14, 0.79)], hypothyroidism [risk difference (RD) -0.31, 95% CI (-0.34, -0.28)] and postoperative pain [OR 0.35, 95% CI (0.25, 0.49)] were lower, and the hospitalization time was shorter [standard mean difference (SMD) -4.01, 95% CI (-4.22, -3.81)], in the thermal ablation group than in the conventional thyroidectomy group, and postoperative cosmetic effects were better [relative risk (RR) ratio 1.12, 95% CI (1.01, 1.24)] (p < 0.05). For symptom improvement, the difference was not statistically significant.Conclusions: This study shows that for benign TNs, ultrasound-guided thermal ablation may have potential advantages in terms of safety, cosmetic effects and shorter hospitalization time compared with conventional thyroidectomy, while symptom improvement is the same.

2020 European Thyroid Association Clinical Practice Guideline for the Use of Image-Guided Ablation in Benign Thyroid Nodules

Standard therapeutic approaches for benign thyroid lesions that warrant intervention are surgery for cold and either surgery or radioiodine for autonomously functioning thyroid nodules (AFTN). Image-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for selected clinical conditions. Due to mounting scientific evidence and widening availability, ETA considered it appropriate to develop guidelines for the use of TA in adult patients. TA procedures are well tolerated, but a dedicated training of the operators is required and information on possible complications needs to be shared with the patients. The following factors should be considered when weighing between observation, surgery, and TA for benign thyroid nodules. In solid non-hyperfunctioning nodules, TA induces a decrease in thyroid nodule volume, paralleled by improvement in symptoms. Nodule re-growth is possible over time and may necessitate repeat treatment, or surgery, in a dialogue with the patient. In AFTN, radioactive iodine is the first-line treatment, but TA may be considered in young patients with small AFTN due to higher probability of restoring normal thyroid function and avoidance of irradiation. In cystic nodules, ethanol ablation (EA) is the most effective and least expensive treatment. TA may be considered for cystic lesions that relapse after EA or have a significant residual solid component following drainage and EA. TA should be restricted to benign lesions that cause symptoms or cosmetic concern. Presently, laser and radiofrequency ablation are the most thoroughly assessed techniques, with similar satisfactory clinical results. Microwaves and high-intensity focused ultrasound therapy options remain to be fully evaluated.

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.

Which needle in the treatment of thyroid nodules?

Thyroid nodules are a common finding in general population, with a prevalence of 20% to 70% at ultrasound (US) examination. Many of them are benign but treatment can be necessary to relief compressive symptoms. In the last years, percutaneous ablations have achieved amazing development in the treatment of thyroid nodules as they provide a minimally invasive but effective approach. We aimed to summarize the main aspects related to treatment of thyroid nodules with radiofrequency ablation (RFA), focusing on the use of different types of needles. A narrative review was performed and all papers analyzed reported good results in terms of nodule's size reduction and symptoms relief. No major complications have been reported, even though needles of bigger size seemed related with major risks of post-procedural local edema. Thus, thinner internally cooled multi tined needles [18-19 Gauge (G)] rather than larger needles (14 G) seem to have better results and less complications.

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.

Percutaneous laser ablation for benign thyroid nodules: a meta-analysis

Purpose

To evaluate percutaneous laser ablation in treating benign thyroid nodules, we conducted a meta-analysis based on summarizing existing researches.

Materials and Methods

A literature search for clinical trial was performed in PubMed, Cochrane Library and Excerpt Medica Database. The qualities of included studies were evaluated. We calculated the indexes with mean difference. Heterogeneity and publication bias were tested and explored. We performed subgroup analyses and sensitivity analysis further.

Results

A total of 19 researches and 2137 patients were included in this meta-analysis. The pooled estimates of nodule volume were statistically significant after percutaneous laser ablation for 1 month, 3 month, 6month, 12month, 24month and 36month(P < 0.05). The pooled estimate of thyroid-stimulating hormone was statistically significant after percutaneous laser ablation for 1 and 12 month (P = 0.008 and P = 0.03). The pooled estimate of free triiodothyronine was no statistically significant after percutaneous laser ablation for all follow-up intervals. The pooled estimate of free tetraiodothyronin was statistically significant after percutaneous laser ablation1 month (P = 0.004). The pooled estimate of thyroglobulin was statistically significant after percutaneous laser ablation 24 month (P = 0.04). The heterogeneity was found and the source of heterogeneity was explored in nodule volume for 6 and 12 month. No publication bias was found.

Conclusions

This meta-analysis demonstrated that percutaneous laser ablation was safe and useful in shrinking benign thyroid nodules volume, improving thyroid function, relieving symptoms of pressure and esthetic, especial for hyper-vascular benign thyroid nodules. Larger number of high-quality prospective studies still needs to be performed.

Ultrasound-navigated radiofrequency ablation of thyroid nodules with integrated electromagnetic tracking: comparison with conventional ultrasound guidance in gelatin models

PURPOSE

A thyroid-like gelatin model was used to determine potential superiority of a new navigation system for ultrasound (US)-guided electrode insertion called EchoTrack, featuring a US probe with an integrated electromagnetic field generator, in comparison with conventional US when performing radiofrequency ablation.

METHODS

In order to compare 20 navigated ablations with 20 ablations under conventional US guidance, a thyroid-like gelatin model was used. In each group, 10 in-plane and 10 out-of-plane punctures were performed. Metal seeds measuring 8.5 [Formula: see text] 1.8 mm served as ablation targets. The number of redirections until final electrode placement, targeting accuracy and electrode placement time were measured.

RESULTS

The number of redirections could be significantly ([Formula: see text]) reduced from 2.7 ± 1.3 in the conventional group to 0.2 ± 0.5 in the EchoTrack group. Accuracy increased from 3.9 ± 4.7 to 2.0 ± 1.9 mm. The total placement time increased from 39 ± 20.5 to 79.2 ± 26 s.

CONCLUSIONS

EchoTrack is able to reduce the redirections needed to place the electrode in comparison with conventional US and provides high placement accuracy. Our new navigation system has high potential to reduce the risk of harming critical structures and to improve guidance during ablation of difficult nodules, as treatment planning as well as the safety of out-of-plane punctures are improved.