A feasibility study of microwave ablation for papillary thyroid cancer close to the thyroid capsule

Management of low-risk papillary thyroid cancer. Minimally-invasive treatments dictate a further paradigm shift?

BACKGROUND

Current management options for PTMC include lobo-isthmectomy and active surveillance (AS). Recently, ultrasound-guided minimally invasive procedures (MITs) are offered as a nonsurgical therapy for PTMC because they do not require hospitalization and general anaesthesia, and do not result in loss of thyroid function or cosmetic damage. MITs are reported to consistently provide, mostly in large retrospective series of patients, a rapid, safe, and cost-effective way to eradicate low-risk thyroid malignancies. However, conclusive data from well-conducted prospective studies on the histologically-proven completeness of tumor ablation and the long-term clinical advantages versus AS are still lacking.

OBJECTIVES

This study aimed to evaluate the efficacy and safety of ultrasound-guided minimally invasive treatments (MITs) for PTMC in comparison to traditional surgical methods and active surveillance, and to assess their role in current clinical practice.

METHODS

A structured literature review was conducted using keywords related to PTMC, MIT, and comparative techniques. Studies were evaluated based on treatment modality, patient selection, follow-up duration, complication rates, and clinical outcomes.

RESULTS

MITs have shown promising results in the management of PTMC. These treatments offer several advantages over surgery, such as reduced use of surgical resources, lower costs, minimal work disruption, and fewer major complications. However, there are still limitations, including the need for long-term surveillance and the potential risk of incomplete tumor ablation.

CONCLUSIONS

MITs represent a promising non-surgical option for managing low-risk PTMC, especially for patients ineligible for or refusing surgery. Despite favorable outcomes, more robust prospective data are needed to confirm their long-term benefits and completeness of tumor ablation. Interdisciplinary discussions and thorough patient education on the advantages and limitations of MITs are crucial for informed decision-making.

Comparison of Micro-flow Imaging and Contrast-Enhanced Ultrasound in Ultrasound-Guided Microwave Ablation of Benign Thyroid Nodules

OBJECTIVE

The study described here was aimed at ascertaining the utility of micro-flow imaging (MFI) during ultrasound (US)-guided microwave ablation (MWA) of thyroid nodules by contrasting its effectiveness with that of contrast-enhanced ultrasound (CEUS).

METHODS

Seventy-three patients with eighty-eight thyroid nodules who underwent US-guided MWA were included in our study from January 2020 to June 2023. Thirty-five patients underwent CEUS during the MWA process, and thirty-eight patients underwent MFI during the MWA process. We compared the two groups' baseline characteristics, tumor volume (V), volume reduction rate (VRR), complications and clinical characteristics.

RESULTS

Both groups exhibited similar outcomes with respect to V and VRR at 1, 3, 6, 12 and 18 mo after MWA (p > 0.05). Consistency was observed with respect to post-operative complications, supplementary ablation times and surgical duration (p > 0.05). It is worth noting that the MFI group had lower treatment costs compared with the CEUS group (11,337.64 ± 80.93 yuan for the MFI group versus 12,971.23 ± 254.89 yuan for the CEUS group, p < 0.05).

CONCLUSION

In the MWA procedure for thyroid nodules, MFI is similar to CEUS with respect to safety and efficacy. Simultaneously, it offers the advantage of reducing surgical expenses, which lessens the economic burden for patients.

Radiofrequency ablation for solitary T1N0M0 papillary thyroid carcinoma in the danger triangle area: a preliminary analysis

OBJECTIVES

To evaluate the feasibility, efficacy, and safety of radiofrequency ablation (RFA) for solitary T1N0M0 papillary thyroid carcinoma (PTC) in the danger triangle area.

METHODS

94 participants (mean age 44.45 ± 13.08; 73 females) with solitary T1N0M0 PTC in the danger triangle area who underwent percutaneous RFA at the hospital from January 2018 to April 2020 were retrospectively analyzed. Key ablation procedures included sufficient paratracheal fluid isolation, low-power, and short active tip (5 mm working electrode). Tumor size changes at different time points after RFA, technical success rates, tumor disappearance, disease progression, and complications were recorded and compared.

RESULTS

Contrast-enhanced ultrasonography revealed that complete tumor ablation was performed with a 100% success rate in these patients. Post-ablation, the maximum diameter and volume of the ablation zone increased at the first and third month (p < 0.001), followed by a gradual decrease in size, without significant difference by the 6th month. The tumor disappearance rate was 76.59% (72/94), with higher rates in the T1a group compared to the T1b group (80% [64/80] VS57.1% [8/14], p < 0.001). There were no local recurrences. The incidence of new lesions and LNM was 3.2% (3/94), limited to the T1a subgroup. Further ablation was successfully applied to all new lesions and LMN. Mild voice changes were the only complication, with a rate of 3.2% (3/94), resolved within 4 months after RFA.

CONCLUSIONS

Sufficient paratracheal fluid isolation combined with a low-power, short active tip radiofrequency ablation strategy is a safe and effective method for treating solitary T1N0M0 PTC in the danger triangle area.

Efficacy and safety of ultrasound-guided radiofrequency, microwave and laser ablation for the treatment of T1N0M0 papillary thyroid carcinoma on a large scale: a systematic review and meta-analysis

BACKGROUND

To analyze the efficacy and safety of radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LA) in T1N0M0 papillary thyroid carcinoma (PTC) patients by evaluating data on several outcomes on a large scale.

MATERIALS AND METHODS

Literature searches were conducted in PUBMED, EMBASE and the Cochrane Library for studies of thermal ablation (TA) for treating T1N0M0 PTC. Data on the volume reduction rate (VRR) at the 12-month follow-up and final follow-up, complete disappearance rate, local recurrence rate, lymph node metastasis rate, and complication rate of RFA, MWA and LA were evaluated separately. RFA effects were compared between T1aN0M0 and T1bN0M0 patients.

RESULTS

A total of 36 eligible studies were included. RFA presented superior efficacy than MWA in 12-month VRR. At the final follow-up, the difference was slight in subgroups, showing a significant reduction. The complete disappearance rate of LA (93.00%) was higher than that of RFA (81.00%) and MWA (71.00%). Additionally, the local recurrence rate pooled proportions of MWA and RFA were both 2.00%, lower than that of the LA group (3.00%). There was no event of distant metastasis. The lymph node metastasis rates were similar, as RFA (1.00%) had the lowest. For minor complication rates, the pooled proportions of RFA (3.00%) were smaller than those of LA (6.00%) and MWA (13.00%). T1aN0M0 lesions presented with better outcomes than T1bN0M0 lesions.

CONCLUSION

RFA, MWA and LA were reliable in curing PTC, and RFA presented advantages in most outcomes. T1aN0M0 patients may experience fewer side effects than T1bN0M0 patients.

Ultrasound-guided thermal ablation for papillary thyroid microcarcinoma: the devil is in the details

Thermal ablation (TA) has harvested favorable outcomes in treating low-risk papillary thyroid microcarcinoma (PTMC). Preoperative assessment, intraoperative procedures and postoperative follow-up are all closely linked with the success and safety of TA on PTMC. However, many details in these aspects have not been systematically reviewed. This review firstly described the influence of preoperative assessment, especially for the risk of lymph node metastasis (LNM), as well as the molecular testing on the selection of TA for PTMC. Besides, we also summarized the experiences in treating special PTMC cases by TA, like multifocal lesions, PTMC located in the isthmus or adjacent to the dorsal capsule. At last, we discussed the follow-up strategies, the influence of the thyroid-stimulating hormone (TSH) level on the prognosis of PTMCs, and the management for recurrent cases. In conclusion, the procedures during the entire perioperative period should be standardized to improve the outcomes of TA in treating PTMC patients.

Microwave ablation of solitary T1N0M0 papillary thyroid carcinoma: A case report

BACKGROUND

The gold standard treatment for papillary thyroid carcinoma is total thyroidectomy and indications for microwave thermal ablation for primary thyroid cancers have not yet been clearly established However, some patients refuse surgery and others have no indication for it, for example patients under palliative care as in this case, or cannot undergo surgery, based on their comorbidities. These indications are described in the most recent Korean, North American and European guidelines. Laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective, so the choice should be based on the specific competences and resources of the pertaining centers. These indications are Percutaneous minimally-invasive techniques; they can be useful to stop disease progression and as an alternative to surgery in patients with contraindication or who refuse surgery. We present a case of a thyroid papillary carcinoma with 17 mm effectively treated with microwave thermal ablation and without recurrence after one year of follow up.

CASE SUMMARY

The authors present a case of a 71-years-old patient with a left lobe papillary thyroid carcinoma with 13 mm × 17 mm × 13 mm, with no indication for thyroid surgery given the context of another cancer in palliative treatment. Microwave thermoablation was performed on December 2021. Four months later he repeated computed tomography (CT) scan, which showed that the tumor had disappeared. Six months after ablation he underwent a positron emission tomography/CT-fluorodeoxyglucose scan, which didn't show any evidence of hypermetabolic tumor lesions.

CONCLUSION

This case shows microwave thermoablation can be a safe and effective alternative to surgery in patients with no conditions to undergo surgery or when they refuse it. By treating the tumor, with this minimally invasive technique, we are stopping its growth and avoiding disease progression.

Microwave ablation of solitary T1N0M0 papillary thyroid carcinoma: A case report

BACKGROUND

The gold standard treatment for papillary thyroid carcinoma is total thyroidectomy and indications for microwave thermal ablation for primary thyroid cancers have not yet been clearly established However, some patients refuse surgery and others have no indication for it, for example patients under palliative care as in this case, or cannot undergo surgery, based on their comorbidities. These indications are described in the most recent Korean, North American and European guidelines. Laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective, so the choice should be based on the specific competences and resources of the pertaining centers. These indications are Percutaneous minimally-invasive techniques; they can be useful to stop disease progression and as an alternative to surgery in patients with contraindication or who refuse surgery. We present a case of a thyroid papillary carcinoma with 17 mm effectively treated with microwave thermal ablation and without recurrence after one year of follow up.

CASE SUMMARY

The authors present a case of a 71-years-old patient with a left lobe papillary thyroid carcinoma with 13 mm × 17 mm × 13 mm, with no indication for thyroid surgery given the context of another cancer in palliative treatment. Microwave thermoablation was performed on December 2021. Four months later he repeated computed tomography (CT) scan, which showed that the tumor had disappeared. Six months after ablation he underwent a positron emission tomography/CT-fluorodeoxyglucose scan, which didn’t show any evidence of hypermetabolic tumor lesions.

CONCLUSION

This case shows microwave thermoablation can be a safe and effective alternative to surgery in patients with no conditions to undergo surgery or when they refuse it. By treating the tumor, with this minimally invasive technique, we are stopping its growth and avoiding disease progression.

Thyroid cancer

The past 5-10 years have brought in a new era in the care of patients with thyroid cancer, with the introduction of transformative diagnostic and management options. Several international ultrasound-based thyroid nodule risk stratification systems have been developed with the goal of reducing unnecessary biopsies. Less invasive alternatives to surgery for low-risk thyroid cancer, such as active surveillance and minimally invasive interventions, are being explored. New systemic therapies are now available for patients with advanced thyroid cancer. However, in the setting of these advances, disparities exist in the diagnosis and management of thyroid cancer. As new management options are becoming available for thyroid cancer, it is essential to support population-based studies and randomised clinical trials that will inform evidence-based clinical practice guidelines on the management of thyroid cancer, and to include diverse patient populations in research to better understand and subsequently address existing barriers to equitable thyroid cancer care.

Clinical outcomes of ultrasound-guided radiofrequency ablation for solitary T1N0M0 papillary thyroid carcinoma: A retrospective study with more than 5 years of follow-up

BACKGROUND

Ultrasound-guided radiofrequency ablation (RFA) has been used in patients with papillary thyroid carcinoma (PTC) who refuse surgery or active surveillance. However, the long-term outcomes are still limited. This study aimed to evaluate the clinical outcomes of RFA for solitary T1N0M0 PTC in a large cohort over a more than 5-year follow-up period.

METHODS

This retrospective study included 358 patients with solitary T1N0M0 PTC who were treated with RFA and followed for at least 5 years. The bipolar RFA procedure was performed using hydrodissection technique, transisthmic approach, and moving-shot technique. The primary outcomes were disease progression, including lymph node metastasis (LNM), recurrent tumor, persistent tumor, and distant metastasis. The secondary outcomes were volume reduction rate, complete disappearance rate, complications, and delayed surgery.

RESULTS

During a mean follow-up period of 75.5 ± 9.7 months, the overall disease progression was 5.0%. The incidence of LNM, recurrent tumor, and persistent tumor was 1.4%, 3.1%, and 0.6%, respectively. There were no significant differences in the disease progression (5.0% vs. 5.5%, p = 1.000), LNM (1.3% vs. 1.8%, p = .568), recurrent tumor (3.3% vs. 1.8%, p = .872), persistent tumors (0.3% vs. 1.8%, p = .284), and 5-year recurrence-free survival rates (95.4% vs. 96.4%, p = .785) in the T1a and T1b groups. Volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. No complications occurred. No patients underwent delayed surgery because of anxiety.

CONCLUSIONS

RFA is an effective and safe alternative for patients with T1N0M0 PTC and can offer a minimally invasive curative option for patients who refuse surgery or active surveillance.

PLAIN LANGUAGE SUMMARY

During a mean follow-up period of 75.5 ± 9.7 months, the overall papillary thyroid carcinoma disease progression was 5.0%. The volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. The T1a and T1b groups had similar incidence of disease progression and 5-year recurrence-free survival rates. No patients experienced complications or underwent delayed surgery because of anxiety.

Microwave Ablation for Papillary Thyroid Microcarcinoma with and without US-detected Capsule Invasion: A Multicenter Prospective Cohort Study

Background Microwave ablation (MWA) has achieved favorable results in the treatment of papillary thyroid microcarcinoma (PTMC) confined in glandular parenchyma. However, studies on the outcome of MWA for PTMC with US-detected capsular invasion remain unclarified in the literature. Purpose To compare the feasibility, effectiveness, and safety of MWA in the treatment of PTMC with and without US-detected capsular invasion. Materials and Methods Participants from 12 hospitals with a PTMC maximal diameter of 1 cm or less without US- or CT-detected lymph node metastasis (LNM) who planned to undergo MWA were enrolled in this prospective study between December 2019 and April 2021. All tumors were evaluated with preoperative US and were divided into those with and those without capsular invasion. The participants were observed until July 1, 2022. The primary end points, including technical success and disease progression, and the secondary end points, including treatment parameters, complications, and tumor shrinkage during follow-up, were compared between the two groups, and multivariable regression was performed. Results After exclusion, 461 participants (mean age, 43 years ± 11 [SD]; 337 women) were included: 83 with and 378 without capsular invasion. After one participant with capsular invasion aborted MWA because of technical failure, 82 participants with and 378 participants without capsular invasion (mean tumor volume, 0.1 mL ± 0.1 vs 0.1 mL ± 0.1; P = .07) were analyzed with a mean follow-up period of 20 months ± 4 (range, 12-25 months) and 21 months ± 4 (range, 11-26 months), respectively. In those with and those without capsular invasion, comparable technical success rates were achieved (99% [82 of 83] vs 100% [378 of 378], P = .18), with one and 11 complications, respectively (1% [one of 82] vs 3% [11 of 378], P = .38). There was no evidence of differences in disease progression (2% [one of 82] vs 1% [four of 378]; P = .82) or tumor shrinkage (mean, 97% ± 8 [SD] vs 96% ± 13; P = .58). Conclusion Microwave ablation was feasible in the treatment of papillary thyroid microcarcinoma with US-detected capsular invasion and showed comparable short-term efficacy with or without the presence of capsular invasion. © RSNA, 2023 Clinical trial registration no. NCT04197960 Supplemental material is available for this article.

Thermal ablation for cervical lymph node metastasis from papillary thyroid carcinoma: A meta-analysis

BACKGROUND

Traditionally, surgery has been the standard treatment for cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC). However, thermal ablation is currently recommended by several guidelines. This study aimed to evaluate the efficacy and safety of thermal ablation for lymph node metastasis in patients with PTC.

METHODS

We searched PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases until March 2022 to collect studies on thermal ablation (including radiofrequency, microwave, and laser ablations) for cervical lymph node metastasis from PTC.

RESULTS

A total of 190 patients were included, ranging from 5 to 39 in each study, with a sex ratio (male/female) ranging from 1/4 to 17/20, an average age ranging from 15.6 ± 3.0 to 62.3 ± 13.2 (yr), and a total of 270 cervical lymph nodes, ranging from 8 to 98. The follow-up results showed that thermal ablation significantly reduced the maximum diameter and volume of metastatic lymph nodes in PTC (P < .01). The pooled complete disappearance rate was 86% (95% confidence interval 79% to 93%). Thyroglobulin levels were significantly lower after surgery (P < .01). No major complications occurred, and the combined voice change rate was as low as 1% [CI 0% to 3%].

CONCLUSION

Our meta-analysis showed that thermal ablation is an effective and safe method for the treatment of cervical lymph node metastases from PTC. Considering the limitations of this study, more prospective, multicenter, large-sample studies are needed in the future.

A clinical study on microwave ablation of multifocal (≤ 3) T1N0M0 papillary thyroid carcinoma

OBJECTIVE

To evaluate the feasibility, efficiency, and safety of microwave ablation (MWA) for T1N0M0 multifocal (≤ 3) papillary thyroid carcinoma (PTC).

METHODS

This was a retrospective study, and patients who underwent MWA for multifocal (≤ 3) PTC were reviewed between October 2016 and December 2020. After ablation, the changes in tumor size and volume, as well as the rate of technical success, tumor disappearance, disease progression, and complications were assessed.

RESULTS

There were a total of 57 cases enrolled in the present study, which included 18 males and 39 females. The mean age was 44 ± 11 years (22-66 years); the mean follow-up time was 18 ± 11 months (6-48 months). Complete ablation was achieved in all enrolled cases. Therefore, the technical success rate was 100%. Due to expanding ablation, the MD and volume of the ablation zone, as well as the VRR, increased at the 1st and 3rd months after ablation and decreased at 12 and 18 months after ablation (p < 0.05 for all). The total complete tumor disappearance rate was 43.9% (25/57), including 54% (24/44) in the T1a subgroup vs. 7.7% (1/13) in the T1b subgroup (p = 0.003). The total disease progression rate was 7% (4/57), including 9.1% (4/44) in the T1a subgroup vs. 0% (0/13) in the T1b subgroup (p = 0.142). The overall complication rate was 5.3% (3/57), including 6.8% (4/44) in the T1a subgroup vs. 0% (0/13) in the T1b subgroup (p = 0.206).

CONCLUSION

This preliminary study indicates that MWA is a safe and effective treatment for T1N0M0 multifocal (≤ 3) PTC.

KEY POINTS

• MWA is a promising alternative method for T1N0M0 multifocal (≤ 3) PTC.

Research Review of Thermal Ablation in the Treatment of Papillary Thyroid Carcinoma

Background

Minimally invasive treatment of thyroid tumors has become increasingly common, but has mainly focused on benign thyroid tumors, whereas thermal ablation of thyroid cancer remains controversial. Clinical studies analyzing the efficacy of thermal ablation of papillary thyroid carcinoma (PTC) have been conducted in several countries to verify its safety. Here, we screened and reviewed recent studies on the efficacy and safety of thermal ablation of PTC as well as psychological assessment, patient prognosis, recurrence, and factors affecting ablation.

Summary

The most significant controversy surrounding ablative treatment of PTC centers on its effectiveness and safety, and >40 studies have been conducted to address this issue. The studies include papillary thyroid microcarcinoma (PTMC) and non-PTMC, single PTC and multiple PTC, and controlled studies of ablative therapy and surgical treatment. In general, ablation techniques can be carefully performed and promoted under certain conditions and with active follow-up of postoperative patients. Ablation is a promising alternative treatment especially in patients who are inoperable.

Conclusions

Clinical studies on PTC ablation have provided new perspectives on local treatment. However, because PTC grows very slowly, it is an indolent tumor; therefore, studies with larger sample sizes and extended post-procedure follow-ups are necessary to confirm the investigators’ hypotheses.

Microwave ablation vs. surgery for papillary thyroid carcinoma with minimal sonographic extrathyroid extension: a multicentre prospective study

OBJECTIVES

Minimal extrathyroid extension (mETE) was removed from the TNM staging system. This study was designed prospectively to compare the safety and efficacy of microwave ablation (MWA) versus surgery for treating T1N0M0 papillary thyroid carcinomas (PTC) with sonographically detected mETE.

METHODS

From December 2019 to April 2021, 198 patients with T1N0M0 mETE-PTCs evaluated by preoperative ultrasound from 10 hospitals were included. Ninety-two patients elected MWA, and 106 patients elected surgery for treatment. MWA was performed using extensive ablation with hydrodissection. Surgery consisted of lobectomy with ipsilateral central lymph node dissection (CLD), lobe and isthmus excision with ipsilateral CLD and total thyroidectomy with ipsilateral CLD. The rates of technical success, cost, oncologic outcomes, complications and quality of life of the two groups were assessed.

RESULTS

The follow-up times for the MWA and surgery groups were 12.7 ± 4.1 and 12.6 ± 5.0 months, respectively. The technical success rate was 100% for both groups. Oncological outcomes of the two groups were similar during the follow-up (all p > 0.05). The MWA group had a shorter operation time, less blood loss and lower costs (all p < 0.001). Three complications (3.3%) were reported in the MWA group and 4 (3.8%) in the surgery group (p = 0.846). The surgery group had higher scores for scar problems and anxiety (p < 0.001 and p = 0.003, respectively).

CONCLUSIONS

Microwave ablation was comparable in the short term to surgery in terms of treatment safety and efficacy in selected patients with T1N0M0 mETE-PTC detected by ultrasound.

KEY POINTS

• Microwave ablation is comparable to surgery in the safety and short-term efficacy for PTCs with sonographically detected mETE. • Thermal ablation is technically feasible for mETE-PTC treatment. • Patients with mETE-PTC have similar quality of life in the two groups, except for worse scar problems and anxiety in the surgery group.

Over than three-year follow-up results of thermal ablation for papillary thyroid carcinoma: A systematic review and meta-analysis

BACKGROUND

This study is a meta-analysis based on evidence-based medicine to explore the long-term (≥3 years) efficacy of thermal ablation in the treatment of papillary thyroid carcinoma (PTC).

METHODS

We searched the PubMed, Embase, and Cochrane Library databases for studies published during the time between the establishment of the databases through June 2022. We included 13 non-randomized-controlled trials (non-RCTs) that reported the application of ultrasound-guided thermal ablation in PTC. We excluded studies that were repeated publications, research without full text, contained incomplete information, lacked data extraction, involved animal experiments, reviews, and systematic reviews. STATA 15.1 software was used to analyze the data.

RESULTS

Tumor volume after thermal ablation at 3-year follow-up was significantly lower than pre-ablation (standardized mean difference [SMD] = -1.06, 95% CI: -1.32~-0.80). The pooled results indicated that the maximum diameter after thermal ablation at 3-year follow-up was significantly lower than pre-ablation (SMD = -1.93, 95% CI: -12.13~-1.73). The pooled results indicated that volume reduction rate (VRR) after thermal ablation at 3-year follow-up was 98.91% (95% CI: 97.98-99.83%), and complete disappearance rate (CDR) after thermal ablation at 3-year follow-up was 83% (95% CI: 67-94%). In addition, the incidence of newly discovered mPTC and lymph node metastases after thermal ablation was 0.3% (95% CI: 0.0-1.0%) and 0.0% (95% CI: 0.0-0.0%), respectively.

CONCLUSION

Overall, the long-term (≥3 years) efficacy of ultrasound-guided thermal ablation in the treatment of PTC was significant, with favorable disease progression. Ultrasound-guided thermal ablation can be considered an alternative approach for patients with PTC who refuse surgery or are unable to undergo surgery.