Microwave Ablation Compared With Laser Ablation for Treating Benign Thyroid Nodules in a Propensity-Score Matching Study

Comparison of Ultrasound-Guided Percutaneous Microwave Ablation and Conventional Thyroidectomy in the Treatment of Papillary Thyroid Microcarcinoma: Meta-Analysis

Purpose: To perform a meta-analysis of clinical trials comparing percutaneous microwave ablation (PMWA) guided by ultrasound with conventional thyroidectomy for the management of papillary thyroid microcarcinoma (PTMC), analyzing feasibility, safety, and long-term efficacy, and to provide clinical guidance for the treatment selection of PTMC. Methods: Embase, PubMed, Cochrane Library, Web of Science, CNKI, VIP Database, and Wanfang Database were systematically searched to identify clinical studies of PMWA or thyroidectomy for PTMC up to December 2023. The relevant data from the articles were extracted, and the data analysis was performed using RevMan 5.4 software. Results: A total of 442 articles were identified and subsequently screened based on the inclusion and exclusion criteria, 9 clinical studies involving a total of 1577 patients were included, with 788 patients in the PMWA group and 789 patients in the surgery group. Following data extraction and statistical analysis, in comparison to the surgery group, the PMWA group had shorter operation time [mean differences (MD) = -36.36; 95% CI -55.66 to -17.06; P = .0002], shorter hospital stay (MD = -3.93; 95% CI -5.55 to -2.30; P < .00001), less intraoperative bleeding (MD = -21.25; 95% CI -27.36 to -15.15; P < .00001), and lower hospital costs (MD = -1.00; 95% CI -1.33 to -0.66; P < .00001), all with statistical significance. The comparison of postoperative complications revealed a lower incidence of complications in the PMWA group compared to the surgery group [relative risk (RR) = 0.29; 95% CI 0.21 to 0.40; P < .00001], with statistical significance. Thyroid-related hormone analysis showed that the free triiodothyronine (MD = 0.61; 95% CI 0.33 to 0.90; P < .00001) and free thyroxine (MD = 1.81; 95% CI 0.94 to 2.68; P < .0001) levels in the PMWA group were higher than those in the traditional surgery group, while the levels of thyroid-stimulating hormone were lower than those in the traditional surgery group (MD = -7.63; 95% CI -10.25 to -5.01; P < .00001), with statistically significant differences, indicating that PMWA had a smaller impact on thyroid function. In 2 studies, there were no statistically significant disparities in postoperative recurrence or lymph node metastasis (LNM) between the 2 cohorts (RR = 0.70; 95% CI 0.33 to 1.50; P = .36). There were no statistically significant differences in physiological health score between different groups and different time points before and after treatment (P > .05); However, the mental component score and the total score of the Medical Outcomes Study (MOS) item short-form health survey were significantly elevated in the ablation group compared to the excision group post-treatment (P < .05). Conclusion: For patients with low-risk PTMC with definitive diagnosis and precise risk stratification, PMWA can be selected. PMWA treatment for patients with PTMC is comparable to conventional surgical treatment and has the advantages of minimal trauma, rapid recovery, no scarring, and fewer complications, which are superior to open surgery to a certain extent. For patients with ambiguous preoperative diagnosis and uncertainty regarding LNM status, surgical intervention is the optimal choice.

Comparison of ultrasound-guided microwave ablation, laser ablation, and radiofrequency ablation for the treatment of elderly patients with benign thyroid nodules: A meta-analysis

BACKGROUND

A new minimally invasive technique, ultrasound-guided thermal ablation has become one of the treatment methods for benign thyroid nodules. This study aims to evaluate the efficacy and safety of laser ablation (LA), radiofrequency ablation (RFA), and microwave ablation (MWA) in the treatment of elderly patients with benign thyroid nodules.

METHODS

PubMed, Web of Science, and Cochrane Library were searched for qualified randomized controlled studies (RCTs) issued from establishing databases to March 2022. After screening and evaluating the article quality, the data on nodular volume reduction rate (VRR) and the incidence of complications after thermal ablation were extracted and analyzed by RevMan 5.3 and Stata l4.0.

RESULTS

The meta-analysis included seven articles with 3055 participants. We found that LA, RFA, and MWA could markedly reduce the volume of benign thyroid nodules. LA was superior to RFA and MWA in reducing the volume of benign thyroid nodules in 6 months of follow-up (all P < 0.05). LA, RFA, and MWA can be safely implemented in patients with benign thyroid nodules. The incidence of significant complications after the RFA group was enhanced compared with that in the MWA (P < 0.05), and the incidence of secondary complications after RFA was slightly higher than that of LA (P < 0.05).

CONCLUSION

LA, RFA, and MWA can markedly reduce the volume of benign thyroid nodules in elderly patients and can safely treat benign thyroid nodules.

Assessing the relative effectiveness of various ultrasound-guided ablation techniques for treating benign thyroid nodules: A systematic review and network meta-analysis

BACKGROUND

Benign thyroid nodules (BTNs) represent a prevalent clinical challenge globally, with various ultrasound-guided ablation techniques developed for their management. Despite the availability of these methods, a comprehensive evaluation to identify the most effective technique remains absent. This study endeavors to bridge this knowledge gap through a network meta-analysis (NMA), aiming to enhance the understanding of the comparative effectiveness of different ultrasound-guided ablation methods in treating BTNs.

METHODS

We comprehensively searched PubMed, Embase, Cochrane, Web of Science, Ovid, SCOPUS, and ProQuest for studies involving 16 ablation methods, control groups, and head-to-head trials. NMA was utilized to evaluate methods based on the percentage change in nodule volume, symptom score, and cosmetic score. This study is registered in INPLASY (registration number 202260061).

RESULTS

Among 35 eligible studies involving 5655 patients, NMA indicated that RFA2 (radiofrequency ablation, 2 sessions) exhibited the best outcomes at 6 months for percentage change in BTN volume (SUCRA value 74.6), closely followed by RFA (SUCRA value 73.7). At 12 months, RFA was identified as the most effective (SUCRA value 81.3). Subgroup analysis showed RFA2 as the most effective for solid nodule volume reduction at 6 months (SUCRA value 75.6), and polidocanol ablation for cystic nodules (SUCRA value 66.5).

CONCLUSION

Various ablation methods are effective in treating BTNs, with RFA showing notable advantages. RFA with 2 sessions is particularly optimal for solid BTNs, while polidocanol ablation stands out for cystic nodules.

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.

Minimally Invasive Treatments of Benign Thyroid Nodules: A Network Meta-Analysis of Short-Term Outcomes

Background: Image-guided thermal ablation interventions are novel thermal-based modalities used for the treatment of benign thyroid nodules. Methods: We conducted a systematic review and a Bayesian network meta-analysis, examining studies using thermal ablation interventions in the treatment of benign nodular thyroid disease (PROSPERO CRD42022367680). The primary endpoints included volume reduction rate (VRR), and symptomatic score and cosmetic score improvement. Secondary endpoints included vocal disturbances, laryngeal nerve palsy, hypothyroidism, and nodular regrowth (defined by increased nodular volume of >50% for thermal ablation or new nodules arising in remaining thyroid tissue conventional surgery [CS]). Results: We included 16 studies (3 randomized controlled trials [RCTs] and 13 comparative case series), describing radiofrequency ablation (RFA), laser ablation (LA), microwave ablation (MWA), high-intensity focus ultrasound (HIFU), and CS, respectively. The review included data from 4112 patients followed for a mean of 11.9 months. Meta-analyses showed no significant differences among RFA, LA, MWA, HIFU, and CS regarding any of the primary endpoints of VRR, symptomatic score, and cosmetic score. In examining the surface under the cumulative ranking area (SUCRA) ranking, CS (SUCRA, 98.49), LA (SUCRA, 51.58), and MWA (SUCRA, 57.0) were identified as the three interventions that were most likely to result in the largest VRR, symptomatic and cosmetic score reduction. RFA, relative risk (RR) 0.19 [95% credibility interval (CI): 0.06 to 0.48], LA RR 0.23 [CI: 0.06 to 0.79], and MWA RR 0.25 [CI: 0.09 to 0.60] were associated with the greatest reduction in risk for postintervention vocal complications compared with CS, with RFA (SUCRA, 61.62) being ranked as the highest in safety. RFA RR 0.05 [CI: 0.00 to 0.40] and MWA RR 0.16 [CI: 0.02 to 0.73] were associated with a reduced risk of transient laryngeal nerve injury compared with CS. RFA RR 0.00 [CI: 0.00 to 0.00] and MWA RR 0.00 [CI: 0.00 to 0.03] were associated with a reduced risk of hypothyroidism occurrence compared with CS, with RFA (SUCRA, 99.86) yielding the highest safety ranking. RFA was associated with a reduced risk for nodular regrowth RR 0.09 [CI: 0.00 to 0.85], compared with CS. Conclusion: We have comprehensively reviewed the published literature on the efficacy and safety of thermal ablation modalities for benign thyroid nodules. Important research gaps remain regarding a paucity of both long-term data and high-quality RCTs.

Multiple overlapping microwave ablation in benign thyroid nodule: a single-center 24-month study

Objective

This study aimed to evaluate the safety and long-term efficacy using the multiple overlapping ablation technique with a novel non-cooled microwave system in benign symptomatic thyroid nodules.

Methods

This prospective cohort single-center study collected complication data from the start of the procedure to 30 days postoperatively and evaluated the safety and effectiveness with a follow-up of 24 months. Ultrasound examinations were performed to determine the volume shrinkage during follow-up. Thyroid function cosmetic and symptoms scores and satisfaction degree were evaluated.

Results

A total of 30 symptomatic benign thyroid nodules were treated by microwave ablation using a power between 15 and 30 W depending on the size of the nodule to be treated. The volume reduction rates in months 1, 3, 6, 9, 12, and 24 after ablation were 32, 59, 67, 69, 73, and 81%, respectively. The mean symptom score and mean cosmetic score before treatment were 4 and 3, respectively, while after treatment they dropped to 3 and 1, respectively. Thyroid function indicators fluctuated in the normal range and those with hyperthyroidism recovered to normal parameters. One case of temporary laryngeal paralysis occurred postoperatively and fully recovered in less than 3 months.

Conclusions

The novel microwave ablation system presented herein can help achieve good clinical success rate in benign thyroid nodules with a satisfying safety profile. The microwave ablation performed with the multiple overlapping ablation technique could be a good alternative to surgery and radiofrequency ablation in the management of benign thyroid nodules.

Outcomes of laser-induced thermotherapy for thyroid nodules at the West Vascular Center, Ukraine

Thyroid nodules are common, occurring in 50-60% of healthy patients. Currently, there are no effective conservative treatment options for nodular goiter, and surgery can have limitations and potential complications. The purpose of this study was to evaluate the efficacy, tolerability, and long-term results of using sclerotherapy and laser-induced interstitial thermotherapy (LITT) to treat benign thyroid nodules. A retrospective analysis was conducted on 456 patients with benign nodular goiter who received LITT. The volume of the nodular goiter was measured at 1, 3, 6, and 12 months post-treatment, and a repeated fine needle aspiration (FNA) with the cytological examination was performed to verify the structure of the nodular goiter in the long term. The results showed that LITT was an effective method for treating nodular mass (nodules), as evidenced by a decrease in the volume of NG by 51-85% after 6-12 months. FNA results 2-3 years after LITT showed no thyrocytes, only connective tissue, indicating the efficacy of LITT for benign thyroid nodules. LITT is highly effective in most cases, often resulting in the disappearance or significant decrease in nodular formations.

Meta-analysis of the efficacy and safety of thermal ablation for treating large benign thyroid nodules

OBJECTIVE

Many large benign thyroid nodules have symptoms and cosmetic problems. This study consisted of a meta-analysis to accurately assess the effect of thermal ablation on these nodules.

METHODS

The PubMed, Embase, Web of Science, and Scopus databases were systematically searched for retrospective or prospective studies of thermal ablation since June 1, 2021. The weighted mean differences of the measures were analysed before and after treatment.

RESULTS

A total of 10 eligible studies were included. By comparing the initial nodule volume with the nodular volume after thermal ablation, we found that the volume reduction rate was increased significantly after 1 month (SMD = 0.453, 95% CI: 0.323-0.583, p &lt; .001), 3 months (SMD = 0.655, 95% CI: 0.563-0.747, p &lt; .001), 6 months (SMD = 0.691, 95% CI: 0.607-0.774, p &lt; .001), and 12 months (SMD = 0.694, 95% CI: 0.583-0.803), p &lt; .001). The nodular volume was also found to decrease significantly, after 1 month (SMD = 2.381, 95% CI: 1.278-3.485, p &lt; .001), 3 months (SMD = 5.071, 95% CI: 2.386-7.756, p &lt; .001), 6 months (SMD = 5.363, 95% CI: 2.765-7.962, p &lt; .001), and 12 months (SMD = 8.194, 95% CI: 2.113-14.274), p &lt; .001). Symptom score (SMD = 4.419, 95% CI: 2.573-6.265, p &lt; .001)and cosmetic score (SMD = 4.245, 95% CI: 2.566-5.359, p &lt; .001) were reduced after thermal ablation.

CONCLUSIONS

Thermal ablation could become an alternative to manage large benign thyroid nodules.

Efficacy of radiofrequency and laser thermal ablation in solving thyroid nodule-related symptoms and cosmetic concerns. A systematic review and meta-analysis

Several studies have showed good/excellent results of thermal-ablation (TA) to reduce volume of benign thyroid nodule (TN). Nevertheless, no systematic review has reported information about clinical achievements with TA. Being the latter of high interest, this systematic review was undertaken to achieve high evidence about the efficacy of TA in reducing TN-related symptoms and cosmetic concerns. Radiofrequency (RFA) and laser (LA) therapies were considered. A comprehensive literature search of online databases was performed on January 2022 looking for studies reporting clinical results obtained by RFA or LA in terms of VAS (namely, Visual Analogic Scale) and cosmetic concerns. Initially, 318 records were found and 14 were finally included in the meta-analysis. VAS data were available in all RFA studies and the pooled mean reduction was of 3.09 points with significant heterogeneity. Cosmetic score data were available in 11 RFA studies and the pooled mean reduction was of 1.45 with significant heterogeneity. Regarding LA studies, 4 series reported VAS data and the pooled mean reduction was of 2.61 points with significant heterogeneity. The analysis of LA data about cosmetic concerns was not performed due to data paucity. Importantly, heterogeneities were not explained by meta-regression analyses using several covariates (i.e., baseline TN volume, follow-up duration, volume reduction rate). This systematic review showed that clinical data about TN TA efficacy are sparse and affected by high unexplained inconsistency. International societies should give indication about how we should clinically select and evaluate patients undergoing TN TA.

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.

A 5-year follow-up study on the efficacy and safety of ultrasound-guided laser ablation in elderly patients with papillary thyroid microcarcinoma: A retrospective, single-center study from China

OBJECTIVE

The aim of this study is to evaluate the long-term efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) for the treatment of elderly patients with papillary thyroid microcarcinoma (PTMC).

METHODS

From September 2015 to April 2017, 38 elderly patients with PTMC confirmed through fine-needle aspiration biopsy (FNAB) were treated with PLA. Before the treatment, the location and volume of the nodule together with the patients' symptoms were evaluated. Twenty-four hours after the treatment, contrast-enhanced ultrasound (CEUS) was performed to evaluate the completeness of the ablation. To evaluate the volume of the ablation area and recurrence or metastasis, ultrasound examination was performed at 1, 3, 6, and 12 months after the treatment and every 6 months thereafter. FNAB was performed for any suspicious recurrence or metastasis lesions.

RESULT

The ablation of all the 38 patients was all achieved completely as confirmed by CEUS. No obvious complications were found. The success rate of single ablation was 100%. The average follow-up time was 64.58 ± 5.29 months (60-78 months). By the time of the last follow-up, 31 (81.58%) ablation lesions disappeared completely and seven (18.42%) ablation lesions showed scar-like changes. The volume of nodules was 40.69 ± 16.45 mm³ before operation, which decreased to 0.22 ± 0.76 mm³ by the end of 42 months, and all nodules disappeared 4 years after ablation (P < 0.01). At 6, 12, 18, 24, 30, 36, and 42 months after ablation, the average volume reduction rates (VRRs) were 12.09%, 31.21%, 50.9%, 72.06%, 84.79%, 95.65%, and 100%, respectively. Of all the patients enrolled, one patient (2.6%) had local recurrence and was treated with PLA again. No regrowth of treated nodule or lymph node metastasis and distant metastases was detected.

CONCLUSION

Ultrasound-guided PLA is effective and safe for the treatment of elderly patients with PTMC who are ineligible for surgery.

The value of ultrasound guided laser ablation in papillary thyroid recurrence carcinoma: A retrospective, single center study from China

OBJECTIVE

The efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) for treating recurrent papillary thyroid cancer nodules (RPTCNs).

METHODS

A retrospective study was conducted in 43 patients with single recurrent thyroid cancer which was diagnosed by fine needle aspiration biopsy (FNAB). The extent of ablation was assessed by contrast-enhanced ultrasound (CEUS) 24h after PLA. At baseline (before ablation), 6, and 12 months, and every 6 months thereafter, the following were recorded: nodule maximum diameter, volume reduction rate (VRR), complications, and side effects.

RESULT

All 43 patients were successfully treated with PLA without serious complications. All patients underwent CEUS 24 hours after PLA treatment, and all achieved complete ablation. The success rate of single ablation was 100%. The average follow-up time was 23.47 ± 6.50 months, 12 ~ 36 months. At the last follow-up, 32 (74.4%) ablation lesions disappeared completely and 11 (25.6%) ablation lesions showed scar-like changes. No lymph node metastasis was found during follow-up. The maximum diameter and volume of nodules decreased from 5.1 ± 1.4 mm, 86.22 ± 20.46 mm³ before operation to 0.73 ± 1.1 mm, 1.02 ± 1.92 mm³ at the end of observation (P < 0.01). The average volume reduction rates (VRR) at 6, 12, 18, 24, 30 and 36 months after ablation were 11.92%, 60.64%, 82.26%, 90.96%, 93.7% and 97.79% respectively. No regrowth of treated nodule and distant metastases were detected. One patient (2.3%) had local recurrence and was treated with PLA again.

CONCLUSION

Ultrasound-guided PLA appears to be effective and safe for treating unifocal RPTCNs in selected patients who are ineligible for surgery, which is suitable for clinical application and promotion.

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.

Ultrasonography-guided radiofrequency ablation for the treatment of T2N0M0 papillary thyroid carcinoma: a preliminary study

PURPOSE

To evaluate the efficacy and safety of ultrasonography (US)-guided radiofrequency ablation (RFA) for treating T2N0M0 papillary thyroid cancer (PTC).

METHODS

This retrospective study was approved by the ethics committee of Chinese PLA General Hospital (S2019-211-01). Twelve patients with T2N0M0 PTC (five men and seven women with a mean age of 41.0 ± 9.2 years (range, 21-61 years)), who were not eligible for or refused surgery, were included in our study. RFA was performed with the moving-shot technique, and the ablation area exceeded the tumor edge by at least 3 mm. US was performed before RFA, immediately, 1, 3 , 6 and 12 months after RFA, and every 6-12 months thereafter.

RESULTS

All tumors were ablated as planned. The mean follow-up duration was 24.1 ± 6.9 months (range, 13-33 months). The tumor volume decreased significantly from 4.4 ± 2.8 ml to 0.3 ± 0.5 ml, and the volume reduction rate (VRR) was (93.7 ± 7.6)% at the final follow-up with two tumors (16.7%) disappearing. New or recurrent tumors were not found, and no local or distant metastasis were detected during follow-up. No life-threatening or delayed complications were observed.

CONCLUSION

RFA may be a potential alternative to surgery for the management of T2N0M0 PTC in select patients, especially for those who are ineligible for surgery.

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.

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.

A Nomogram to Predict Regrowth After Ultrasound-Guided Radiofrequency Ablation for Benign Thyroid Nodules

OBJECTIVE

To develop and validate a nomogram to predict regrowth for patients with benign thyroid nodules undergoing radiofrequency ablation (RFA).

METHODS

A total of 200 patients with 220 benign thyroid nodules who underwent RFA were included in this respective study. After RFA, patients were followed up at 1, 3, 6, and 12 months, and every 12 months thereafter. Regrowth was defined as an increase in nodule volume 50% over the previously recorded smallest volume. A nomogram was developed based on the variables identified by multivariate logistic regression and the model performance was evaluated by discrimination(concordance index) and calibration curves.

RESULTS

The incidence of regrowth was 13.64% (30/220) after a mean follow-up period of 27.43 ± 17.99 months. Multivariate logistic regression revealed initial volume (OR = 1.047, 95%CI 1.020-1.075), vascularity (OR = 2.037, 95%CI 1.218-3.404), and location close to critical structure (OR = 4.713, 95%CI 1.817-12.223) were independent factors associated with regrowth. The prognostic nomogram incorporating these three factors achieved good calibration and discriminatory abilities with a concordance index of 0.779 (95%CI 0.686-0.872).

CONCLUSIONS

A prognostic nomogram was successfully developed to predict nodule regrowth after RFA, which might guide physician in stratifying patients and provide precise guidance for individualized treatment protocols.

Thermal Ablation of Benign Thyroid Nodules and Papillary Thyroid Microcarcinoma

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