Ultrasound-guided microwave ablation in the treatment of benign thyroid nodules in 435 patients

Comparison of clinical and patient-reported outcomes in patients with benign euthyroid solitary nodules after ultrasound-guided percutaneous microwave ablation and endoscopic thyroidectomy

BACKGROUND

Percutaneous ultrasound-guided microwave ablation (MWA) for benign solid thyroid nodules is the newest modality for treatment. However, the differences in treatment outcomes between MWA and endoscopic thyroidectomy vestibular approach (TOETVA) for patients with benign euthyroid solitary nodules remain unknown. We are sharing initial results from our prospective study.

METHODS

Prospective study between January 2022 and December 2023 was conducted and data were noted at 3 time points in patients planned for treatment (Preoperative, 1 week, and 12 months). Main outcome measures were clinical outcome and comparison of thyroid-related quality of life using the ThyPRO-39hin and swallowing-related quality of life using the SWAL-QoL.

RESULTS

Of the 36 included patients, 20 patients underwent TOETVA and 16 underwent MWA. Both the groups were comparable in terms of demographic and clinicopathological profiles. The nodule volume reduction rate of patients at 12 months after MWA was 75.10% and 100% for TOETVA. The mean preoperative ThyPRO-39hin and SWAL-QoL scores were comparable in all domains between the two groups. Mean ThyPRO-39hin and SWAL-QoL scores on postoperative day 7 were significantly better in the MWA group in domains impaired social life (p < 0.0001) and impaired daily life (p = 0.0002). However, at the end of 12 months, mean ThyPRO-39hin and SWAL-QoL scores became significantly better in the TOETVA group as compared to the MWA group.

CONCLUSION

Our findings suggest that transoral endoscopic thyroidectomy results in significant superior clinical outcome, thyroid-related quality of life, and swallowing-related quality of life in the long term.

[Local ablative procedures for treatment of thyroid nodules]

Thyroid nodules are very frequent in the iodine deficiency regions of central Europe and some of the affected patients are referred for definitive treatment, such as surgery and radioiodine treatment. In recent years nonsurgical and non-radioiodine techniques have been introduced to treat thyroid gland pathologies. These techniques include the probe-based techniques of radiofrequency, microwave and laser application. The only noninvasive technique is high-intensity focused ultrasound. All mentioned techniques have the goal to reduce the volume of the thyroid nodule by application of energy/heat. The knowledge of all techniques and their advantages and risks is necessary to help physicians and patients in making decisions for the appropriate method of treatment of thyroid nodules.

Comparison of the efficacy and safety of ultrasound-guided radiofrequency ablation and microwave ablation for the treatment of unifocal papillary thyroid microcarcinoma: a retrospective study

PURPOSE

This study aimed to compare the efficacy and safety of ultrasound-guided RFA and MWA in the treatment of unifocal PTMC.

METHODS

This retrospective study included 512 patients with 512 unifocal papillary thyroid microcarcinomas (PTMCs) who underwent RFA (n = 346) and MWA (n = 166) between January 2021 and December 2021. The volumes of the ablation areas were measured during follow-up, and the volume reduction rates were evaluated. The ablation duration, volume of hydrodissection, and ablation-related complications were also compared between the groups.

RESULTS

All lesions received complete ablation and no local or distant recurrences were observed in the two groups. A larger volume of isolation liquid was used for RFA than for MWA (p = 0.000). Hoarseness occurred in seven patients who underwent RFA (p = 0.102). At the 1-week follow-up, the mean volume of the areas ablated by RFA was smaller than that of the areas ablated by MWA (p = 0.049). During follow-ups at months 3, 9, 12, 15, and 18, the mean volumes of the ablated areas were larger in the RFA group than in the MWA group (all, p < 0.05). The mean volume of the ablated lesions increased slightly at the 1-week follow-up and then decreased at 1 month after ablation in both groups. The absorption curve of the ablated lesions in the RFA group was similar to that in the MWA group.

CONCLUSIONS

RFA and MWA are both efficient and safe methods for treating unifocal PTMC. They may be alternative techniques for patients who are not eligible or are unwilling to undergo surgery.

Microwave ablation for large benign thyroid nodules: a proposal for a new approach: "the fluid-motion technique"

INTRODUCTION

Most thyroid nodules are benign, and treatment is primarily indicated for patients with symptoms or cosmetic concerns related to nodular volume. Recently, there has been growing interest in nonsurgical and minimally invasive techniques for the treatment of symptomatic benign thyroid nodules, including microwave ablation (MWA).

AIMS

This study aims to evaluate the effectiveness, efficacy, and safety of ultrasound-guided uncooled MWA in the treatment of benign symptomatic thyroid nodules, using a new ablation technique called the "fluid-motion technique."

MATERIALS AND METHODS

From April 2021 to February 2023, a total of 150 patients with benign thyroid nodules were treated using MWA at the Endocrine Surgery Unit of Pederzoli Hospital, Peschiera del Garda (Italy), with 102 of them being followed-up for at least 6 months.

RESULTS

Before treatment, the mean major diameter was 38.4 ± 10.0 mm, and the mean volume was 13.6 ± 10.5 mL. At 1 month, the mean volume was 6.8 ± 6.2 mL, and at 3 months, it was 4.6 ± 4.1 mL. The mean Volume Reduction Rate (VRR) at 3 months was 61.1 ± 22.0%. Of the nodules, 17 (17%), 65 (66%), and 20 (19%) had volumes ≤ 10, 10.1-20, and ≥ 20.1 mL, respectively. For these nodules, the mean VRR at 3 and 6 months was 55.3 ± 16%, 63.4 ± 24.8%, 72 ± 26.9% and 68.0 ± 11.2%, 73.5 ± 18.3%, and 81.6 ± 15.8%, respectively.

CONCLUSION

Our study shows that ultrasound-guided MWA is an effective and safe minimally invasive treatment for benign thyroid nodules. The goal is to achieve a VRR that can reduce symptoms and improve cosmetic appearance.

Optimal design of aperiodic tri-slot antennas for the conformal ablation of liver tumors using an experimentally validated MWA computer model

OBJECTIVE

This study aims to demonstrate that the conformal microwave ablation (MWA) of liver tumors could be attained by optimizing the structure of an aperiodic tri-slot coaxial antenna, its insertion depth, and input power.

METHODS

A computational MWA model with an aperiodic tri-slot coaxial antenna operating at the frequency of 2.45 GHz was built and validated by both an ex vivo and a pilot in vivo experiment with porcine healthy livers. The validated in vivo computational MWA model implemented with a liver tumor was then used as a testbed to investigate the conformal ablation of liver tumors. Five liver tumors in different sizes and shapes were investigated. A genetic algorithm optimization method (NSGA-II) was used to optimize the structure of antenna, insertion depth of antenna, and microwave antenna input power for the conformal ablation of liver tumors.

RESULTS

The validation results showed that a good agreement in both the spatiotemporal temperature distribution and ablation zone was found between the computer model and the ex vivo experiments at both 45 W, 5 min and 60 W, 3 min treatments and the in vivo experiment at 45 W, 5 min treatment. The optimized simulation results confirmed that five cases of liver tumors in different sizes and shapes can be conformally ablated by optimizing the aperiodic tri-slot coaxial antenna, antenna insertion depth, and microwave antenna input power.

CONCLUSION

This paper demonstrates that the aperiodic tri-slot coaxial antenna can be optimized with the insertion depth and input power for the conformal ablation of liver tumors, regardless the size and shape of liver tumors.

Comparison of microwave alone and combined with ethanol ablation for different types of benign mixed thyroid nodules

OBJECTIVE

To evaluate the efficacy and safety of microwave ablation (MWA) plus ethanol ablation (EA) for different types of benign mixed thyroid nodules.

METHODS

A total of 81 patients with 81 benign mixed thyroid nodules were enrolled into the study; 39 were divided to the MWA group and 42 to the combined group (MWA combined with EA). Nodule ablation rate, volume reduction rate (VRR) and surgical complications of all patients were analyzed before and after treatment.

RESULTS

The mean ablation rate were 86.49 ± 6.68% and 90.09 ± 5.79% in the microwave and combined groups respectively, and the ablation rate of nodule decreased as the nodule volume increased. For nodules ≥15 ml in volume, the mean ablation rate of the combined group was higher than that of the microwave group (all P < 0.05). The mean VRR at 12 months postoperatively was 89.58 ± 4.32% in the microwave group and 92.92 ± 3.49% in the combined group, showing statistical significantly different between both arms (P = 0.001). The combined group decreased in volume more significantly than the microwave group for nodules with 20-50% or 50-80% cystic proportions or >15 ml in volume (all P < 0.05). The complication rate was 23.08% and 2.38% respectively.

CONCLUSION

MWA combined with EA is more effective than MWA for treating mixed thyroid nodules. MWA combined with EA may be the first approach for nodules with >20% cystic proportions or volume >15 ml.

Robotic system for magnetic resonance imaging-guided focused ultrasound treatment of thyroid nodules

BACKGROUND

Herein, a robotic system offering Magnetic Resonance-guided Focused Ultrasound (MRgFUS) therapy of thyroid nodules was developed.

METHODS

The robotic system offers linear motion in 2 PC-controlled axes that navigate a 3 MHz single-element focused transducer. The system, through a C-arm structure attaches to the table of Magnetic Resonance Imaging (MRI) scanners and couples to the neck of patients lying in the supine position. The MRI compatibility of the developed system was assessed inside a 3 T scanner. Benchtop and MRI feasibility studies evaluating the heating performance of the system were executed on excised pork tissue and on homogeneous and thyroid model agar-based phantoms.

RESULTS

The MRI compatibility of the system was successfully established. Grid sonications executed using robotic motion inflicted discrete and overlapping lesions on the excised tissue, while magnetic resonance (MR) thermometry successfully monitored thermal heating in agar-based phantoms.

CONCLUSIONS

The developed system was found to be efficient with ex-vivo evaluation. The system can perform clinical MRgFUS therapy of thyroid nodules and other shallow targets after further in-vivo evaluation.

Comparison of the Efficiency of Radiofrequency and Microwave Ablation Methods in the Treatment of Benign Thyroid Nodules

RATIONALE AND OBJECTIVES

To compare the efficacy of two thermal ablation techniques (radiofrequency vs microwave ablation) in the treatment of benign thyroid nodules.

MATERIALS AND METHODS

A total of 80 patients with 80 nodules underwent thermal ablation of thyroid nodules with either radiofrequency ablation (RFA) (23 females and 14 males; mean age 41 ± 9years) or microwave ablation (MWA) (28 females and 15 males; mean age 45 ± 11years). Ultrasound assessments were made at the 1st, 3rd, 6th, and 12th months after the ablation procedure.

RESULTS

The mean initial volume of the nodules (RFA: 15.6 mL [min 2.5-max 74]; MWA: 40 mL [min 2-max 205]) was statistically significantly different (P < .001). The following were the volume reduction rates of nodules at 1, 3, 6, and 12months, respectively: after RFA: 46.8 ± 13.5%, 62.9 ± 13.6%, 71.6 ± 11.9%, and 77.9 ± 10.3%. After MWA: 38.7 ± 12.5%, 54 ± 15.3%, 59.6 ± 12.5%, and 65 ± 11.3%. For all months, volume reduction rates in the RFA group were significantly higher than those in the MWA group (P < .05). One patient treated by RFA reported an abscess formation and another patient treated by RFA had a self-limiting hematoma, who recovered without any further treatment. Also, in the MWA group, one patient had abscess formation and another patient had transient recurrent nerve paralysis, who recovered with appropriate treatment.

CONCLUSION

Both methods are effective in treating benign thyroid nodules; however, RFA provides a better volume reduction.

Comparison of the effectiveness of lauromacrogol injection for ablation and microwave ablation in the treatment of predominantly cystic thyroid nodules: a multicentre study

PURPOSE

To compare the therapeutic efficacy and safety of microwave ablation (MWA) and lauromacrogol injection for ablation (LIA) for benign predominantly cystic thyroid nodules.

MATERIALS AND METHODS

In this retrospective study, 85 patients with predominantly cystic thyroid nodules (PCTNs) who underwent microwave ablation (MWA) or lauromacrogol injection for ablation (LIA) between June 2019 and August 2022 at three hospitals were included in our research. Forty-six patients were treated with microwave ablation, and thirty-nine patients were treated with lauromacrogol injection for ablation. The baseline characteristics, nodal volume, volume reduction rate (VRR), and incidence of postoperative complications were compared between these two groups.

RESULTS

After treatment, there were significant differences in the thyroid nodule volume and the volume reduction rate (VRR) at different follow-up times between the groups (p < 0.001). There were no significant differences in the nodal volume or the volume reduction rate (VRR) between the MWA group and the LIA group at 1, 3, 6, and 12 months (p > 0.05). Of note, no serious intraoperative or postoperative complications occurred in the corresponding group.

CONCLUSION

MWA and LIA are very effective and safe strategies for the treatment of predominantly cystic thyroid nodules. However, LIA is more advantageous in that it is less expensive and has a shorter length of hospital stay than MWA.

Analysis of risk factors for intra-cystic hemorrhage in microwave ablation of partially cystic thyroid nodules

Objective

The aim of this study is to identify risk factors of intra-cystic hemorrhage in microwave ablation of mixed solid and cystic microwave ablation s, and to design a preoperative nomogram to predict the risk value of intraoperative bleeding with the goal of individualizing the surgical approach toward different types of cystic and solid thyroid nodules.

Methods

A total of 241 patients with cystic-solid thyroid nodules who underwent ultrasound-guided percutaneous microwave ablation were retrospectively divided into a bleeding group and a non-bleeding group to compare the diameter, cystic proportion, cystic fluid nature, color Doppler flow imaging, Contrast-enhanced ultrasound (CEUS) findings, and operative methods. Based on univariate and multivariate analysis, the important risk factors of nodular intracapsular hemorrhage in the ablation procedure were projected to a nomogram for predicting the possibility of intraoperative hemorrhage in the thyroid cystic solid nodules.

Results

Intra-cystic hemorrhage was developed in 37 cases during the ablation of mixed thyroid nodules with a total incidence of 15% (37/241). Significant differences were found statistically between the two groups on the diameter of the lesions, CEUS findings, the cystic fluid ratio, and operative methods (P = 0.000, P = 0.001, P = 0.024, P = 0.002). The possibility of intraoperative nodular intracapsular hemorrhage was predicted by the model based on the risk factors with the accuracy of 81% and prediction consistency index (C-index) of 0.78.

Conclusion

A new and efficient prediction model was developed based on the identified risk factors for intracapsular hemorrhage during microwave ablation of mixed thyroid nodules, which will aid in the development of targeted surgical planning for different types of cystic thyroid nodules, thus reducing the risk of hemorrhage during ablation.

Safety and efficacy of microwave ablation for abdominal wall endometriosis: A retrospective study

Objectives

This retrospective study aimed to evaluate the safety and feasibility of ultrasound-guided microwave ablation in the treatment of abdominal wall endometriosis (AWE).

Background

AWE is a rare form of endometriosis that often results in cyclic abdominal pain. The current treatment algorithm for AWE is not well established. Microwave ablation technology is a promising new thermal ablation technique for treating AWE.

Methods

This was a retrospective study of nine women with pathologically proven endometriosis of the abdominal wall. All patients were treated with ultrasound-guided microwave ablation. Grey-scale and color Doppler flow ultrasonography, contrast-enhanced ultrasonography, and MRI were used to observe the lesions before and after treatment. The complications, pain relief, AWE lesion volume, and volume reduction rate were recorded 12 months after treatment to evaluate the treatment efficacy. Complications were classified according to the Common Terminology Criteria for Adverse Events and the Society of Interventional Radiology classification system.

Results

Contrast-enhanced ultrasound showed that all lesions underwent successful treatment with microwave ablation. The average initial nodule volume was 7.11 ± 5.75 cm³, which decreased significantly to 1.85 ± 1.02 cm³ at the 12-month follow-up with a mean volume reduction rate of 68.77 ± 12.50%. Periodic abdominal incision pain disappeared at 1 month after treatment in all nine patients. The adverse events and complications were Common Terminology Criteria for Adverse Events grade 1 or Society of Interventional Radiology classification grade A.

Conclusions

Ultrasound-guided microwave ablation is a safe and effective technique for the treatment of AWE, and further study is warranted.

Italian Guidelines for the Management of Non-Functioning Benign and Locally Symptomatic Thyroid Nodules

AIM

This guideline (GL) is aimed at providing a reference for the management of non-functioning, benign thyroid nodules causing local symptoms in adults outside of pregnancy.

METHODS

This GL has been developed following the methods described in the Manual of the National Guideline System. For each question, the panel appointed by Associazione Medici Endocrinology (AME) identified potentially relevant outcomes, which were then rated for their impact on therapeutic choices. Only outcomes classified as "critical" and "important" were considered in the systematic review of evidence and only those classified as "critical" were considered in the formulation of recommendations.

RESULTS

The present GL contains recommendations about the respective roles of surgery and minimally invasive treatments for the management of benign symptomatic thyroid nodules. We suggest hemithyroidectomy plus isthmectomy as the first-choice surgical treatment, provided that clinically significant disease is not present in the contralateral thyroid lobe. Total thyroidectomy should be considered for patients with clinically significant disease in the contralateral thyroid lobe. We suggest considering thermo-ablation as an alternative option to surgery for patients with a symptomatic, solid, benign, single, or dominant thyroid nodule. These recommendations apply to outpatients, either in primary care or when referred to specialists.

CONCLUSION

The present GL is directed to endocrinologists, surgeons, and interventional radiologists working in hospitals, in territorial services, or private practice, general practitioners, and patients. The available data suggest that the implementation of this GL recommendations will result in the progressive reduction of surgical procedures for benign thyroid nodular disease, with a decreased number of admissions to surgical departments for non-malignant conditions and more rapid access to patients with thyroid cancer. Importantly, a reduction of indirect costs due to long-term replacement therapy and the management of surgical complications may also be speculated.

Transvaginal ultrasound- and laparoscopy-guided percutaneous microwave ablation for adenomyosis has short- and long-term benefits: a single-center study

OBJECTIVES

Transvaginal ultrasound- and laparoscopy-guided percutaneous microwave ablation (TLPMA) is a minimally invasive alternative technique with low risk, fast recovery and few side effects. We aimed to evaluate the safety and long-term efficacy of TLPMA for treating adenomyosis.

METHODS

We included 79 patients with symptomatic adenomyosis who underwent TLPMA and 44 patients with adenomyosis who received the levonorgestrel-releasing intrauterine system (LNG-IUS). We evaluated the role of laparoscopy in TLPMA as well as the short- and long-term effects of TLPMA.

RESULTS

The mean age of the 79 patients who underwent TLPMA was 41.8 years. There was no difference in the mean age between the TLPMA and LNG-IUS groups. Laparoscopy could help to separate pelvic adhesions, provide a wide antenna path, and observe the uterine surface and bowel movement. No major complications were found in patients who underwent TLPMA. There was a significant post-treatment reduction in both the uterine and lesion volumes (p < 0.001). After a median follow-up duration of 36 months (range: 1-60 months), the uterine and lesion volumes remained stable. Additionally, most patients remained without dysmenorrhea, which confirms the long-term efficacy of TLPMA.

CONCLUSIONS

TLPMA is a feasible, minimally invasive technique for the treatment of adenomyosis, which significantly decreases the uterine and lesion volumes and has a good long-term effect.

Initial ablation radio predicting volume reduction from microwave ablation of benign thyroid nodules

OBJECTIVE

Our research sought to investigate the relationship between initial ablation ratio (IAR) and internal composition of benign thyroid nodules treated by microwave ablation (MWA).

MATERIALS AND METHODS

Patients who underwent MWA at the Affiliated Hospital of Jiangsu University from January 2018 to December 2022 were enrolled in our research. All the patients were followed up for at least one year. We analyzed the relationship between IAR at 1 month of solid nodules (solid >90%), predominantly solid nodules (90% >solid > 75%), mixed solid alongside cystic nodules (75% >solid > 50%) as well as volume reduction rate (VRR) at 1, 3, 6 and 12 months follow-up.

OBJECTIVE

The mean IAR of the solid nodules (solid >90%) was 94.32±7.87%,#x0025;, that of the predominantly solid nodules (90% >solid > 75%) and mixed solid alongside cystic nodules (75% >solid > 50%) were 86.51±6.66% and 75.19±4.97%,#x0025;, respectively. Almost all the thyroid nodules were significantly decreased in size after MWA. After 12 months of MWA treatment, the average volume of the aforementioned thyroid nodules decreased from 8.69±8.79 to 1.84±3.11 ml, 10.94±9.07 to 2.58±3.34 ml, 9.92±6.27 to 0.25±0.42 ml, respectively. The mean symptom and cosmetic scores of the nodules showed significant (p < 0.000) improvement. The rates of the complications or side effects of MWA against the above-mentioned nodule types were 8.3% (3/36), 3.2% (1/31) and 0% (0/36), respectively.

CONCLUSIONS

The application of the IAR to quantify the success rate of thyroid nodule microwaves in the short term demonstrated that IAR was related to the internal components of the nodule. Although the IAR was not high when the thyroid component was mixed solid and cystic nodules (75% >solid > 50%), the final therapeutic effect was still satisfactory.

Microwave Ablation Vs Traditional Thyroidectomy for Benign Thyroid Nodules: A Prospective, Non-Randomized Cohort Study

RATIONALE AND OBJECTIVES

To evaluate the efficacy of microwave ablation (MWA) for benign thyroid nodules (BTNs) and compare trauma and complication rates between MWA and traditional thyroidectomy for BTNs.

MATERIALS AND METHODS

84 patients with BTNs were recruited and followed up at 1, 3, 6, and 12months. 56 and 28 patients chose to undergo MWA (group A) and traditional thyroidectomy (group B), respectively. Efficacy was assessed by volume reduction rate (VRR) and therapeutic success rate (TSR) at each follow-up. Trauma was compared using inflammation response parameters, visual analog scale (VAS) scores, quality of life (QOL) and thyroid function measures at 1, 3, and 6 months. Complications rates were also compared.

RESULTS

The VRR was 80.70 ± 18.60%, and TSR was 91.70% at 6-months. Furthermore, the VRR increased to 90.45 ± 11.51%, and TSR increased to 100% at 12-months. C-reactive protein levels were significantly higher in group B on the first postoperative day (POD) (3.89 ± 0.86 mg/mL vs 3.39 ± 0.56 mg/mL, p = 0.002). Visual analog scale scores were significantly lower in group A on the first and second POD. Thyroid stimulating hormone levels were significantly lower in group A at three (1.71 ± 1.12uIU/mL vs 2.37 ± 1.24uIU/mL, p = 0.013) and 6-months (1.34 ± 0.70uIU/mL vs 1.97 ± 0.94uIU/mL, p = 0.002). There were no significant between-group differences in QOL and complication rates.

CONCLUSION

Microwave ablation shows acceptable and promising efficacy. Compared with thyroidectomy, MWA was associated with less trauma and comparable complication rates.

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.

Application of contrast-enhanced ultrasound in minimally invasive ablation of benign thyroid nodules

Objective

This study aimed to investigate the application value of contrast-enhanced ultrasound (CEUS) before and after minimally invasive ablation procedures for benign thyroid nodule(s) (BTN).

Methods

This prospective study included patients with BTNs scheduled to undergo ultrasound-guided minimally invasive ablation treatment. CEUS was performed before and after ablation (at 1 day, and 1, 6, and 12 months after ablation). Changes in microvascular perfusion and the volume of BTNs were noted and assessed.

Results

Sixty-two patients (62 BTNs), who underwent ablation procedures between June 2016 and August 2020, were included. All lesions were confirmed by biopsy, and histopathological results were obtained before ablation treatment. On preoperative CEUS, the lesions exhibited hyperenhancement (53.23%) or iso-enhancement (46.77%) during the arterial phase, and all lesions exhibited iso-enhancement in the venous and late phases. One day after ablation, none of the BTNs exhibited obvious enhancement on CEUS. One (1.61%) lesion was re-treated due to a nodule-like enhancement area detected by CEUS at the 6-month follow-up. The mean nodular volume reduction rate (VRR) at 1, 6, and 12 months follow-up demonstrated no significant difference between the two ablation groups (microwave ablation versus radiofrequency ablation). Twelve months after ablation, the mean (±SD) VRR of all BTNs was 60.3 ​± ​10.3%.

Conclusion

CEUS helped guide treatment decisions for BTNs before ablation treatment. Moreover, it could also be used to accurately and noninvasively evaluate treatment efficacy.

Long-term outcome of microwave ablation for benign thyroid nodules: Over 48-month follow-up study

OBJECTIVES

The short-term effects of microwave ablation (MWA) for the treatment of benign thyroid nodules (BTNs) were satisfactory in previous studies. However, as a slowly progressing disease, the long-term efficacy of MWA for BTNs at present is not clear. Our study aim was to assess the long-term results of MWA for BTNs after a 48-month follow-up.

METHODS

From June 2015 to September 2017, 148 patients had 148 BTNs. All patients were from the China-Japan Union Hospital of Jilin University. Careful ultrasound examinations were performed 1 day, 1 month, 3 months, 6 months, 12 months, and every 6 months after MWA. The volume, volume reduction rate (VRR), recurrence rate of the ablated area and thyroid function were recorded.

RESULTS

The mean volumes of the 148 nodules were 15.6 ± 9.4 cm³ (range: 1.3-48.9 cm³) and 0.6 ± 0.6 cm³ (range: 0-3.5 cm³) before and 48 months after MWA, respectively, with a nodule VRR of 96.9 ± 2.5% (range: 90.4-100%). Two patients (1.35%) had recurrence after MWA. Compared with thyroid function before MWA, no significant variation was observed after MWA. Five patients experienced complications (3.38%): two patients (1.35%) had bleeding, two patients (1.35%) had ear pain and toothache during MWA, and one patient (0.68%) had hoarseness after MWA. No cases of oesophageal injury, tracheal injury, infection, skin burns, etc., were reported during or after MWA.

CONCLUSIONS

Based on a long-term follow-up, MWA is an effective method for treating BTNs and is expected to be a potential first-line treatment.

Retrospective analysis of ultrasound-guided minimally invasive treatment of various thyroid cysts

PURPOSE

The aim of this article was to determine the efficacy and safety of the combined use of ethanol and microwave (MWA) to thyroid cysts and explore the differences of various cysts.

MATERIALS AND METHODS

A total of 136 patients and 142 thyroid cystic nodules and predominantly cystic nodules received combination therapy of ethanol and MWA between January 2016 and December 2019 in BeiJing Friendship Hospital. They were divided into different groups according to the size, and the characteristics of fluid aspirated. We compared the Initial size, treatment procedure, postoperative complications, and follow-up results to analyze the characteristics of different groups.

RESULTS

The combination treatments reduced the size of cysts by more than 93% with less complications at the end of follow-up. The treatment duration was longest in the colloid cysts (difference from the clear-fluid group, p < 0.01), the absolute volume of the clear-fluid group at the end of follow-up was the smallest (difference from the other two groups: P < 0.01).There were the similar mean volume reduction rate (VRR) between the large cysts and the small cysts (p > 0.05).

CONCLUSION

The combination treatments were applicable to all types of cysts. Understanding the characteristics of different cystic nodules and adopting different methods are helpful for us to carry out the minimally invasive treatment of cysts better.

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.

Factors related to the absorption rate of benign thyroid nodules after image-guided microwave ablation: a 3-year follow-up

PURPOSE

To assess the absorption rate and factors related to the development of benign thyroid nodules (BTNs) following image-guided microwave ablation (MWA).

MATERIALS AND METHODS

This retrospective study reviewed nodule efficacy in patients who underwent MWA of BTNs between January 2016 and January 2018. The endpoint was a third-year follow-up. Nodules were categorized into those showing complete absorption (volumes with less than 100% volume reduction ratio (VRR) and those showing partial absorption (100% VRR)). Univariable and multivariable regression analyses were carried out to identify variables that were associated with nodule absorption rates.

RESULTS

A total of 173 BTNs (median volume= 4.23 ml; 25-75 percentiles= 2.27-9.00 ml) from 173 patients were evaluated. 49.7% (86/173) of patients had nodules that became completely absorbed. The mean VRRs of all BTNs were 18.0%, 78.7%, 89.0%, 94.5%, and 97.1% at the 1-, 6-,12-, 24- and 36- month follow-ups. At the 3-year follow-up time point, nodule characteristics related to nodule VRR included nodule volume (adjusted odds ratio [AOR], 1.1 [95% CI: 1.0, 1.2]; p = 0.03) and nodule margin (AOR, 5.3 [95% CI: 1.8, 16.0]; p < 0.01). Treatment-related characteristics included energy per ml in nodular volume (AOR, 1.0 [95% CI: 1.0, 1.0]; p < 0.01) and blockage of peripheral flow (AOR, 3.3 [95% CI: 1.3 8.3]; p = 0.01).

CONCLUSIONS

US-guided image-guided MWA results in satisfactory long-term outcomes for the patients with BTNs. Factors related to nodule absorption rate were the volume and margin of the nodule, energy per ml in nodular volume and blockage of peripheral flow.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Efficacy on radiofrequency ablation according to the types of benign thyroid nodules

Percutaneous radiofrequency ablation (RFA) has been recommended as minimally invasive treatment for patients with symptomatic benign thyroid nodules (BTNs) because of the large number of clinical applications. This retrospective observational study sought to evaluate the clinical outcomes of RFA for BTNs. From 2014 to 2019, a sample size of 1289 patients treated by RFA were 262 ones with solid nodules and 1027 ones with cystic-solid nodule, respectively. The efficacy including the nodule maximal diameter reduction ratio (MDRR), the volume reduction ratio (VRR) and the cosmetic scores reduction ratio (CSRR). The results of the nodule MDRR and VRR in the cystic-solid nodule group were significantly better than those in the solid nodule group at the 3rd and 6th month, and the CSRR in the two groups showed statistically significant difference at the 3rd month. In a word, RFA is an effective method for symptomatic benign solid or cystic-solid nodules. The achieved MDRR and VRR in the cystic-solid nodule group were significantly better than those in the solid nodule group at the 3rd and 6th month.

A long-term retrospective study of ultrasound-guided microwave ablation of thyroid benign solid nodules

PURPOSE

To explore the clinical outcomes and safety of ultrasound-guided microwave ablation (MWA) for treating thyroid benign solid nodules during a three-year follow-up.

METHODS

A total of 53 patients with thyroid benign solid nodules with the largest diameter exceeding 2 cm were treated with US-guided MWA between January 2015 and December 2017. Nodule volume, the cosmetic score, and the symptom scores were evaluated before ablation and 1, 2, and 3 years after the operation. The characteristics of MWA and complications were also evaluated.

RESULTS

The thyroid nodule volume at each time point after ablation was significantly smaller than that before ablation (p < .05). The Symptom and Cosmetics score were significantly improved (p < .05). Hoarseness was the major complication, with an incidence of 1.89%. The original nodules volume was 7.28 ± 11.42 mL; the isolating fluid was 34.36 ± 13.35 mL; the ablation time was 188.77 ± 89.13s.

CONCLUSIONS

MMA is an effective and safe approach for reducing nodule volume and symptoms in patients with benign thyroid solid nodules.

A study on the efficacy of microwave ablation for benign thyroid nodules and related influencing factors

OBJECTIVES

To explore the efficacy of microwave ablation (MWA) in the treatment of benign thyroid nodules, and analyze related influencing factors.

METHODS

The clinical and ultrasound data of 115 patients with 115 benign thyroid nodules treated with MWA were retrospectively analyzed. The volume of nodules at 1, 3, 6, and 12 months after the procedure was obtained, and the volume reduction rate (VRR) at each time point was calculated. With VRR > 90% as the criterion for nodule cure, binary logistic regression was employed to screen the factors that affect the efficacy.

RESULTS

① At 1, 3, 6, and 12 months after the procedure, the volume of nodules continued to decrease, the VRR gradually increased, and the differences at each time point were statistically significant (p < 0.05). A total of 29 (25.21%) nodules disappeared completely at 12 months after the procedure; ② Multivariate stepwise logistic regression showed that there was a statistically significant difference for the internal component of nodules, enhancement mode, and immediate volume after the procedure in determining the ablation efficacy (p < 0.05); ③ The ROC curve was plotted for predicting the efficacy of MWA, with the results showing that the AUC, sensitivity, specificity, and accuracy were 0.82, 67.50, 88.00, 79.10%, respectively; ④ 11 cases (9.56%) had side effects, 10 cases (8.70%) had minor complications, and three cases (2.61%) had major complications.

CONCLUSION

MWA is safe and effective in the treatment of benign thyroid nodules. The internal component of nodules, enhancement mode, and immediate volume after the procedure are independent factors that affect the efficacy of ablation.

Microwave ablation of benign thyroid nodules: 3-year follow-up outcomes

PURPOSE

To evaluate the effectiveness of microwave ablation (MWA) for the treatment of thyroid nodules according to nodule composition.

MATERIALS AND METHODS

This study evaluated 171 patients with 180 benign thyroid nodules (BTNs) that had been treated with ultrasound-guided MWA. The volume reduction rate (VRR) of thyroid nodules and factors, which had an influence on the VRR, were assessed. Therapeutic success was defined as a >50% volume reduction at the 12-month follow-up. Multivariate regression analysis was used to identify independent predictors of VRR for BTNs after MWA treatment.

RESULTS

The mean diameter and volume of the nodules were 4.3 ± 1.3 cm and 18.9 ± 2.1 ml, respectively. The VRRs at the 1-, 3-, 6-, 12-, 24-, and 36-month follow-ups were 47.1%, 68.2%, 79.7%, 87.4%, 90.1%, and 93.2%, respectively. Of the 180 BTNs, there were 87 solid, 74 predominantly solid, and 19 predominantly cystic nodules. Solid nodules showed significantly lower VRRs compared with the predominantly solid and predominantly cystic nodules at the 1-, 3-, and 6-month follow-ups. For the multivariate regression analysis, the cyst component was an active prognostic factor for the VRR at the 1-, 3-, and 6-month follow-ups; the cyst component was not significantly associated with the VRR at the 12-, 24-, and 36-month follow-ups.

CONCLUSION

Our study suggested that ultrasound-guided MWA is an effective and safe procedure for the treatment of BTNs. Solid nodules indicate a lower VRR and less efficient than predominant solid nodules and predominant cystic nodules after MWA.

Conspicuousness and recurrence related factors of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules

Objective

Microwave ablation (MWA) is a minimally invasive technique for the treatment of benign thyroid nodules. The purpose of this study was to evaluate efficacy and safety of ultrasound-guided MWA in the treatment of benign thyroid nodules, and to find out the recurrence related factors, so as to provide reference for future clinical work.

Methods

This study retrospectively analyzed the patients who received ultrasound-guided MWA for benign thyroid nodules in our hospital from October 2018 to March 2020. A total of 214 patients were included in the study. We assessed thyroid volume changes (represented by volume reduction ratio VRR), the energy per 1 mL reduction in nodular volume (represented by energy volume ratio ΔE), the serum levels of free triiodide thyroid hormone (FT3), free thyroxine (FT4), thyrotropin (TSH) and complications after MWA treatment.

Results

There were a total of 306 nodules in 214 patients, including 183 (85.51%) females and 31 (14.49%) males. The median diameter and volume of the nodule were 33 mm and 8.01 mL. The VRR at 1 month, 3 months, 6 months and 12 months were 40.79%, 60.37%, 74.59% and 85.60%, respectively. In addition, MWA had a better ablation effect for small nodules (initial volume ≤ 10 mL). In recurrent studies, we found that ΔE was an independent risk factor for benign thyroid nodules (P < 0.05).

Conclusions

Ultrasound-guided MWA is effective and safe in the treatment of benign thyroid nodules. In addition, it has little damage to surrounding tissues and no effect on thyroid function. Especially, the nodules with smaller initial volume, the treatment is better. On the other hand, the energy per 1 mL reduction ΔE in nodular volume may be associated with nodular recurrence, which requires further follow-up for longer periods. At this stage, we consider that ultrasound-guided MWA can be used as one of the main clinical treatment methods for benign thyroid nodules.

Is partial ablation appropriate for benign thyroid nodules? A retrospective study with long-term follow-up after microwave ablation

OBJECTIVE

This retrospective study aimed to investigate the efficacy and safety of partial ablation (PA) for benign thyroid nodules (BTNs) using microwave ablation (MWA) in a long-term follow-up.

MATERIALS AND METHODS

Between February 2015 and April 2019, 236 patients with 236 BTNs (maximum diameter ≥2 cm) treated with ultrasound-guided MWA were enrolled. Contrast-enhanced ultrasound (CEUS) was performed within 3 d after ablation to determine whether there was residual tissue according to which the patients were assigned PA or complete ablation (CA). The volume reduction ratio (VRR) and complications were evaluated during follow-up.

RESULTS

Eighty-two patients were enrolled in the PA group, and 154 were enrolled in the CA group. Both groups achieved continuous reductions in nodule volume and increases in VRR within 2 years after ablation. Although the VRR of the PA group at 4 years was lower than that of the CA group (65.54 vs. 95.08%; p<.05), PA still achieved 'technical efficacy' with a volume reduction of more than 50%. The complication and side effect rates between the two groups showed no significant difference (p>.05).

CONCLUSIONS

Both PA and CA were safe and effective in reducing the volumes of BTNs in the long-term follow-up. For nodules with a large initial volume and dangerous location, PA with a small amount of residual tissue may be acceptable.

Modified percutaneous ethanol injection method combined with microwave ablation for the treatment of symptomatic, predominantly cystic, benign thyroid nodules: a retrospective study of 201 cases

OBJECTIVE

Percutaneous ethanol injection (PEI) and microwave ablation (MWA) are both important methods used in treating benign thyroid nodules. This study aimed to investigate the efficacy and safety of a modified PEI method combined with MWA for the treatment of symptomatic, predominantly cystic and benign thyroid nodules.

MATERIALS AND METHODS

This study included 201 patients who underwent treatment in our department between April 2015 and August 2018. Predominantly cystic thyroid nodules were treated by the modified PEI procedure, which included short-term boiling ethanol ablation (STBEA) and was combined with MWA. Complications, the volume reduction ratio (VRR), symptoms and cosmetic scores were recorded at 1, 3, 6 and 12 months after treatment and every 6 months thereafter.

RESULTS

No major complications were observed during or after the treatment. Ten patients (4.8%) experienced temporary voice change, which resolved within 3 months. Of 200 (97.6%) out of 205 nodules showed significant volume reduction at the final follow-up. Recurrence occurred for only 5 (2.4%) nodules. The mean thyroid nodule volume decreased from 17.40 ± 3.21 mL at baseline to 1.17 ± 0.37 mL at 12 months. The greatest VRR was observed within the first 3 months after treatment.

CONCLUSIONS

The modified PEI method combined with MWA is safe and effective for the treatment of predominantly cystic benign thyroid nodules and provides a shorter operating time and lower recurrence rate than traditional treatments.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of Microwave Ablation in the Treatment of Large (≥3 cm) Benign Thyroid Nodules

BACKGROUND

Large (≥3 cm) benign thyroid nodules usually cause clinical symptoms or cosmetic concerns and therefore require treatment. Microwave ablation (MWA) is a potential valid non-surgical treatment alternative, but there is a lack of evidence. Thus, this study is to evaluate the safety and efficacy of MWA in the treatment of large benign thyroid nodules.

METHODS

A retrospective study was conducted on 42 large benign thyroid nodules in 40 patients treated with MWA. We used the trans-isthmic approach and moving-shot technique to perform the procedure under ultrasound (US) guidance. Patients were followed by clinical and US examinations at 1, 3, 6, and 12 months after the MWA. Study outcomes were complications, volume reduction ratio (VRR), symptom and cosmetic scores, and the requirement of multiple MWA sessions.

RESULTS

There were 31 females and 9 males, with a median age of 46 years. The medians of largest diameter and volume of the nodules were 40 mm and 22 ml. Four (10%) minor complications were observed. The mean VRR was 75.1, 85.2, and 96.4% after 3, 6, and 12 months. The mean symptom and cosmetic scores dropped from 8.0 and 3.8 (before treatment) to 2.8 and 2.3 (at 12 months), respectively. Thirteen nodules (31%) required two MWA sessions.

CONCLUSIONS

MWA is safe, effective, and can be a good option to treat large benign thyroid nodules. More studies with large dataset and long follow-up are required to improve its safety and efficacy.

Comparative efficacy of different ultrasound-guided ablation for the treatment of benign thyroid nodules: Systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Percutaneous ablation is currently deemed an additionally treatment option for benign thyroid nodules in the world, but possibly different effect among the ablation modalities is not clear. So we aim to evaluate the efficacy and complications of thermal/chemical ablation by network meta-analysis.

MATERIALS AND METHODS

In the network meta-analysis, PubMed, EMBASE and the Cochrane Library databases were searched from 1980 to 2020. Studies of adults with thyroid benign nodules under percutaneous ablation therapy were included. Percentage mean volume change, symptom score change, cosmetic score change and complications were evaluated by network meta-analysis.

RESULTS

In the network meta-analysis, Radiofrequency Ablation(RFA) with 2 treatment sessions group was associated with the highest reduction for the mean volume change during 6-month follow-up (MD = 79.09 and 95% CrI:48.23-89.94). There is no significant difference in the incidence of complications. Subgroup analysis showed that 2 sessions of Radiofrequency Ablation (RFA) ranks the highest probability (surface under the cumulative ranking curve (SUCRA) values 77.9) of being the most efficacious treatment for solid or predominantly solid benign nodules. Ethanol ablation (EA) ranked first (SUCRA value 81.1) in the treatment for cyst or predominantly cyst benign nodules.

CONCLUSION

RFA appears to be superior to other US-guided percutaneous ablation in reducing benign thyroid nodule volume during short- and long-term follow-up. In the subgroup analysis, RFA with 2 treatment sessions showed the most significant effectiveness for solid benign thyroid nodules and EA showed more effectiveness to decrease the volume of cyst benign thyroid nodules.

The efficacy and safety of microwave ablation versus lobectomy for the treatment of benign thyroid nodules greater than 4 cm

PURPOSE

To evaluate the safety and effectiveness of microwave ablation (MWA) versus lobectomy for the treatment of benign thyroid nodules > 4 cm.

METHODS

We retrospectively analyzed the data of 48 patients who underwent MWA and 53 patients who underwent lobectomy to treat benign thyroid nodules > 4 cm. The patients were followed up for 12 months. The volume reduction ratio (VRR) was calculated. The operation time, incision length, hospitalization time, complications, thyroid function, symptoms, and cosmetic improvement were analyzed and compared between the two groups.

RESULTS

During the 12-month follow-up, the mean nodule volume in the MWA group was reduced from 36.1 ± 23.1 to 4.0 ± 4.1 ml, and the mean VRR of the nodules was 90 ± 5% in the MWA group, which was comparable with that in the surgery group. No significant postoperative change in thyroid function was observed in the MWA group. Compared with the surgery group, the incidence of complications and postoperative pain in the MWA group were lower, the operation time, incision length, and hospitalization time in the MWA group were shorter, and satisfaction with the esthetic results in the MWA group was greater.

CONCLUSION

MWA is safe and effective for the treatment of benign thyroid nodules > 4 cm. Moreover, MWA is associated with a faster recovery, fewer complications, better protection of thyroid function, and superior esthetic results relative to thyroid lobectomy.

Ablating Aspiration Needle Tract Prior to Microwave Ablation Can Improve Therapeutic Outcomes for Predominantly Cystic Thyroid Nodules

PURPOSE

To investigate whether ablating the aspiration needle tract could improve the safety and efficacy of ultrasound-guided microwave ablation (MWA) for predominantly cystic thyroid nodules.

MATERIALS AND METHODS

This retrospective study evaluated 41 predominantly cystic thyroid nodules that underwent MWA between June 2017 and August 2019. The nodules were stratified by different procedures into two groups: the aspiration needle tract was ablated before cyst fluid aspiration and MWA when treating 26 nodules in Group A, while the other 15 nodules in Group B underwent MWA directly after cyst fluid aspiration. Baseline characteristics, intervention time, hospital stays, nodules with intraoperative intracystic hemorrhage, and postoperative complications were compared between the two groups. Volume, volume reduction rate (VRR), compressive score (CS), and aesthetic score (AS) were evaluated during follow-up.

RESULTS

Both groups achieved decreases in volume, CS, and AS, as well as an increase in VRR. The volumes and VRRs in Group A at 1, 3, 6, and 12 months were significantly smaller and greater than those in Group B (p < 0.001). The incidence of intraoperative intracystic hemorrhage in Group A was significantly lower than that in Group B (p=0.035). Compared to Group B, hospital stays were much shorter in Group A (p=0.040). There were no significant differences in intervention time, cystic fluid volume or postoperative complications.

CONCLUSION

Aspiration needle tract ablation dramatically reduces the incidence of intraoperative intracystic hemorrhage and markedly improves the efficacy of MWA for predominantly cystic thyroid nodules.

Microwave Ablation of Visible Benign Thyroid Nodules with Different Internal Characteristics: A Comparative Study with Follow-up Results

PURPOSE

To investigate the effects of microwave ablation (MWA) on visible benign thyroid nodules (BTN) with different internal characteristics.

MATERIALS & METHODS

A total of 51 cases with 53 visible BTN were treated by ultrasound-guided percutaneous MWA. The 53 nodules were classified into three categories according to the internal characteristics, which were simple solid, mainly solid and mainly cystic nodules. Ultrasound examinations were performed to evaluate the volume shrinkage rations during follow-up. The thyroid functions and the cervical cosmetic scores were evaluated. The complications were observed during and after ablation.

RESULTS

A total of 53 symptomatic BTN were treated by MWA completely. The average volume of the nodules was 11.68 ± 10.16 ml, the volume reduction rates (VRR) at 1st, 3rd, 6th, 12th, and 18th months after ablation were 0.29 ± 0.27, 0.46 ± 0.25, 0.67 ± 0.19, 0.83 ± 0.10, and 0.92 ± 0.10, respectively. The VRR was significantly different among the three categories of lesions (p < 0.05). The symptoms of all patients were improved. Thyroid function indicators were fluctuated in normal range. There were no serious complications during and after the procedure.

CONCLUSION

MWA of visible BTN is safe and effective, and the short-time ablation effect is significantly different due to the internal characteristics of the nodule.

Thermal ablation for benign, non-functioning thyroid nodules: A clinical review focused on outcomes, technical remarks, and comparisons with surgery

Thermal ablation (TA) is a therapeutic option for benign, non-functioning thyroid nodules causing symptoms of compression and/or aesthetic concerns. TA was initially introduced as a treatment for patients who refused or were ineligible for surgery. In more recent years, the increase in the positive experiences of TA have paved the way for the idea that TA could be suggested as a first-line treatment. The present review was conceived to summarize the evidence achieved in this field, and to offer a clinical perspective on TA, with particular reference to the comparison between TA and surgery. We searched literature that was focused on two types of TA, laser (LA) and radiofrequency (RFA). The searched literature included short- mid-term prospective and retrospective studies, randomized trials, and meta-analyses that demonstrated a satisfactory volume reduction ratio (VRR), and benefits in cosmetic and symptoms scores. An important drawback of the use of TA, is the regrowth of a certain number of nodules, which necessitate further TA procedures or surgery. Long-term randomized controlled trials to evaluate the cost/effectiveness of TA vs surgery are not currently available. The selection of the nodule, the optimization of interventional techniques, and ultimately, a well-timed second treatment, are all factors that should be considered in a proactive strategy to prevent TA failure.

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.

Lever-elevating vs. liquid-isolating maneuvers during microwave ablation of high-risk benign thyroid nodules: a prospective single-center study

Aim: To compare the effects of the liquid-isolating maneuver and the lever-elevating maneuver in protecting cervical structures during microwave ablation for treating high-risk benign thyroid nodules.Methods: This prospectively study was approved by the Medical Ethics Committee of Panzhihua Central Hospital. A total of 174 patients were enrolled and randomly assigned to a liquid-isolating maneuver group (LIM, n = 87) or a lever-elevating maneuver group (LEM, n = 87). Operation time, postoperative voice change, time to recovery of baseline voice, peri-thyroid hematoma, neck tension, and intraoperative vasovagal reaction were assessed.Results: Operation time was greater in the LIM group than in the LEM group (44.75 ± 13.14 vs. 32.87 ± 10.84 min; p = .017).Voice changes were observed in 6 patients in the LIM group and 2 in the LEM group (6.9% vs. 2.3%, p = .278). The time to recovery of baseline voice was significantly greater in the LIM group compared with the LEM group (36.15 ± 10.24 vs. 24.48 ± 11.53 days, p = .014). The incidences of peri-thyroid hematoma and neck tension were higher in the LIM than in the LEM group (11.5% vs. 3.4%, 10.3% vs. 2.3%, p = .044 and p = .029). One patient (1.1%) in the LEM group and none of the patients in the LIM group experienced a vasovagal response (p = 1.000).Conclusion: The lever-elevating method is feasible and effective for the microwave ablation of benign thyroid nodules, with better protection of neck structures than observed with the liquid-isolating method.

Non-Surgical and Non-Radioiodine Techniques for Ablation of Benign Thyroid Nodules: Consensus Statement and Recommendation

Thyroid nodules and cysts are frequently diagnosed in Germany with a prevalence of about 20% in young adults reaching up to 70% in older adults. Surgery is the standard treatment of symptomatic nodules, nodules with suspicion of malignancy and thyroid cancer. Radioiodine treatment is applied for autonomously functioning nodules. During the last years new non-surgical and non-radioiodine techniques have been introduced to treat thyroid nodules. These techniques include ethanol/polidocanol treatment, radiofrequency, microwave, and laser ablation, and high frequency ultrasound ablation. A significant reduction in nodule size could be documented for these techniques in several studies, but long-term outcome data are missing. Until now, there is no general consensus regarding the appropriate indications for these methods. For this reason, the Thyroid Section (German Society for Endocrinology), the Thyroid Working Committee (German Society for Nuclear Medicine), and the German Association of Endocrine Surgeons (CAEK) for the German Society of General and Visceral Surgery (DGAV) reviewed the respective literature, discussed the pro and cons and developed a consensus statement and recommendation to help physicians and patients in their decision making.

Intracystic Hemorrhage and Its Management During Ultrasound-Guided Percutaneous Microwave Ablation for Cystic Thyroid Nodules

Background: Intracystic hemorrhage can present occasionally during ultrasound-guided percutaneous microwave ablation (PMWA) for cystic thyroid nodules. It can affect treatment outcome, can lead to ablation failure, and even conversion to open surgery. We aim to avoid such cases in the future by exploring their causes and management. Methods: From March 2017 to December 2019, we retrospectively studied 87 cystic thyroid nodules in 59 patients who underwent PMWA in the First Hospital of Jilin University. All patients were followed at 1, 3, 6, and 12 months after treatment. Results: All patients completed the treatment successfully. Nine cystic thyroid nodules presented with intracystic hemorrhage during the ultrasound-guided PMWA, giving an incidence of 10.3% (9/87 cysts). Larger cystic thyroid nodules were more likely to develop intracystic bleeding during ultrasound-guided PMWA. Intracystic hemorrhage resulted in significantly prolonged ablation time and had a negative effect on treatment outcome. No patients had other complications, but temporary post-operative pain and local swelling were more obvious in patients with intracystic hemorrhage. Conclusion: Intracystic hemorrhage is not rare during ultrasound-guided PMWA for cystic thyroid nodules. Doctors should pay more attention to it, learn to manage it and try to avoid it in clinical practice.

Pulsed high-power microwaves do not impair the functions of skin normal and cancer cells in vitro: A short-term biological evaluation

•

Pulsed high power microwave (MW) at a frequency 3.5 GHz was generated.

•

MW did not induce cell death in skin fibroblast normal cells and melanoma cells.

•

MW did not alter the morphology of melanoma cells.

•

Gene expression related to ATP synthesis and proliferation can get altered by MW.

•

MW selectively stimulated viability and proliferation of only melanoma cells.

Over the past few decades, microwave (MW) radiation has been widely used, and its biological effects have been extensively investigated. However, the effect of MW radiation on human skin biology is not well understood. We study the effects of pulsed high-power microwaves (HPMs) on melanoma (G361 and SK-Mel-31) and normal human dermal fibroblast (NHDF) cells. A pulsed power generator (Chundoong) was used to generate pulsed HPMs (dominant frequency: 3.5 GHz). For treatment 1, 5, 15, and 45 shots are given to cells in which the electromagnetic energy of 0.6 J was delivered to the cells at each trigger shot. Cell viability, proliferation rate, apoptosis, cell death, metabolic activity, and oxygen-free radical regulation were evaluated after the MW exposure at low and high doses. MW exposure increased the viabilities and proliferation rates of both melanoma cell lines in a dose-dependent manner, while no significant effects on the fibroblast cells were observed. We found an elevated level of ATP and mitochondrial activity in melanoma cells. Also, it was observed that MW exposure did not affect cell death in melanoma and fibroblast cells. A polymerase chain reaction analysis indicated that the MWs induced dose-dependent proliferation markers without affecting the cell cycle and apoptotic genes in the melanoma cells. Our findings show the differential effects of the MW radiation on the melanoma cells, compared to those on the fibroblast cells.

Ultrasound-Guided Percutaneous Microwave Ablation for Substernal Goiter: Initial Experience

OBJECTIVES

To preliminarily evaluate the safety, effectiveness, and feasibility of microwave ablation (MWA) for substernal goiter (SSG) in select patients and to provide a relevant treatment reference for further studies.

METHODS

From April 2017 to December 2017, 10 patients with SSG were treated by MWA. All patients were followed for at least 3 months to observe the therapeutic effects and complications. Therapeutic effects were assessed at follow-up for the relief of patients' symptoms, resolution of the cosmetic grade, and volume reduction rate (VRR) of SSG. Possibly related factors for the 3-month VRR of the nodules were analyzed.

RESULTS

The study included 9 female patients and 1 male patient with a mean age ± SD of 56.8 ± 10.1 years (range, 34-70 years). The mean volume of the nodules was 52.9 ± 27.9 mL (range, 23.7-122.6 mL). The nodule volume was significantly reduced at the 3-month follow-up (17.5 ± 9.5 mL; P < .05). The mean 3-month VRR of the index nodule was 66.7% ± 7.1%. A higher ablated portion-to-nodule ratio 1 day after MWA predicted a higher 3-month VRR (Spearman r = 0.646; P = .044). The mean symptom score (from 4.5 ± 1.7 to 1.5 ± 1.0; P = .005) and cosmetic grade (from 3.3 ± 0.5 to 2.2 ± 0.4; P = .004) declined significantly 3 months after the procedure. No complications or unexpected side effects were observed.

CONCLUSIONS

Our preliminary results support the effectiveness and safety of MWA for local control of SSG. This technology can be applied in select patients with SSG who are ineligible for surgery.