Thermal Ablation for the Management of Papillary Thyroid Microcarcinoma in the Era of Active Surveillance and Hemithyroidectomy

Long-term clinical outcomes of thermal ablation for benign thyroid nodules and unresolved issues: a comprehensive systematic review

Thermal ablation is widely accepted as an effective and safe method for treating benign thyroid nodules. Many studies reporting short-term results have consistently demonstrated the efficacy and safety of thermal ablation. However, as the clinical application of thermal ablation grows and follow-up periods extend, long-term clinical outcomes of thermal ablation have revealed several issues, including regrowth and diagnosis of malignancy in ablated lesions. In this systematic review, we analyze the long-term clinical outcomes of thyroid thermal ablation, focusing on regrowth, delayed surgery, and the potential for malignancy after thermal ablation and propose solutions to address these unresolved issues and enhance the management of benign thyroid nodules through thermal ablation.

Three-year follow-up results of radiofrequency ablation for low-risk papillary thyroid microcarcinomas: Systematic review and meta-analysis

OBJECTIVES

Confidence in long-term treatment results of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) is required in comparison with surgery and active surveillance (AS). The objective of this meta-analysis is to report more than three years of follow-up results of radiofrequency ablation for PTMCs.

METHODS

Ovid PUBMED, COCHRANE, and EMBASE databases were searched through Nov 19, 2023, for studies reporting outcomes in patients with PTMC treated with radiofrequency ablation and followed up for more than 3 years. The standard mean difference of the tumor volume before and after therapy, tumor recurrence, lymph node (LN) metastasis, distant metastasis, complications, and the pooled volume reduction rates (VRRs) at 1, 3, 6, 12, 24, 36, and 48 months after radiofrequency ablation were assessed. Data were extracted and methodological quality was assessed independently by two radiologists according to the PRISMA guidelines.

RESULTS

Eight studies, involving 2131 patients, met the inclusion criteria through database searches. The overall VRR was 99.81 % (95 % CI: 99.68, 99.95) in the last follow-up. During a mean pooled follow-up of 46.59 months, 69 patients experienced local PTMC recurrence, with 8 cases within the ablation area. Additionally, 44 patients were diagnosed with newly discovered PTMC, and 17 patients exhibited lymph node metastases. Among the patients with PTMC recurrence, 3 were under active surveillance while 59 underwent additional RFA. The pooled mean complication rate was 2.80 %, with no instances of life-threatening or delayed complications.

CONCLUSIONS

Radiofrequency ablation proves to be an effective local tumor control method for low-risk PTMC patients, resulting in clinically significant and enduring volume reduction. The rate of regrowth and retreatment requirement post-RFA was notably lower, positioning RFA as a compelling alternative to existing treatment options.

Comparison between thermal ablation and surgery in low risk papillary thyroid carcinoma: a prospective study

Objective

To conduct a comparative analysis of the efficacy, safety, and impact on quality of life outcomes between thermal ablation and surgical interventions in patients diagnosed with papillary thyroid carcinoma (PTC).

Methods

A prospective study was undertaken, enrolling patients with PTC ≤5mm who underwent radiofrequency ablation (RFA), laser ablation (LA), or surgery, for analysis of efficacy and safety outcomes. The Thyroid Cancer-Specific Quality of Life questionnaire was administered to all patients before treatment and at 3, 6, and 12 months post-treatment.

Results

A total of 162 eligible patients were included in the study. Major complications were not observed in the RFA and LA groups, while five cases were reported in the surgery group, although no statistically significant differences were observed. Minor complications were documented in two, three, and 14 patients in the RFA, LA, and surgery groups, respectively, with no significant variances noted. Surgical duration and hospitalization time were notably shorter in the thermal ablation groups. At the final follow-up, complete disappearance of nodules was seen in 71.4% of cases treated with RFA and 71.0% of cases managed with LA, with no significant disparities between the groups. Both RFA and LA exhibited similar effects on quality of life, with thermal ablation techniques showing better functional outcomes in comparison to surgery. Across all groups, adverse effects were most pronounced at the 3-month post-treatment mark but gradually reverted to baseline levels in the thermal ablation group, contrasting with the surgery group.

Conclusions

For PTC ≤5mm, both RFA and LA exhibited similar cancer control outcomes and superior quality of life on par with surgery, while minimizing complications. These findings underscore the promise of RFA and LA as potential standard treatments for small PTCs, subject to further confirmation in future studies.

Ultrasound-guided radiofrequency ablation for the treatment of papillary thyroid carcinoma: a review of the current state and future perspectives

Papillary thyroid carcinoma (PTC) is a highly prevalent cancer that typically exhibits indolent behavior and is associated with a favorable prognosis. The treatment of choice is surgical intervention; however, this approach carries the risk of complications, including scarring and loss of thyroid function. Although active surveillance can mitigate the risk of PTC overtreatment, the possibility of tumor growth and metastasis can elicit anxiety among patients. Ultrasoundguided thermal ablation has emerged as a safe and effective alternative for individuals who are ineligible for or decline surgery. This article provides a review of the clinical research on radiofrequency ablation as a treatment for PTC, offering a thorough examination of its efficacy, safety, and future perspectives.

A nomogram for predicting adverse pathologic features in low-risk papillary thyroid microcarcinoma

BACKGROUND

Identifying risk factors for adverse pathologic features in low-risk papillary thyroid microcarcinoma (PTMC) can provide valuable insights into the necessity of surgical or non-surgical treatment. This study aims to develop a nomogram for predicting the probability of adverse pathologic features in low-risk PTMC patients.

METHODS

A total of 662 patients with low-risk PTMC who underwent thyroid surgery were retrospectively analyzed in Qilu Hospital of Shandong University from May 2019 to December 2021. Logistic regression analysis was used to determine the risk factors for adverse pathologic features, and a nomogram was constructed based on these factors.

RESULTS

Most PTMC patients with these adverse pathologic features had tumor diameters greater than 0.6 cm (p < 0.05). Other factors (age, gender, family history of thyroid cancer, history of autoimmune thyroiditis, and BRAFV600E mutation) had no significant correlation with adverse pathologic features (p > 0.05 each). The nomogram was drawn to provide a quantitative and convenient tool for predicting the risk of adverse pathologic features based on age, gender, family history of thyroid cancer, autoimmune thyroiditis, tumor size, and BRAFV600E mutation in low-risk PTMC patients. The areas under curves (AUC) were 0.645 (95% CI 0.580-0.702). Additionally, decision curve analysis (DCA) and calibration curves were used to evaluate the clinical benefits of this nomogram, presenting a high net benefit.

CONCLUSION

Tumor size > 0.60 cm was identified as an independent risk factor for adverse pathologic features in low-risk PTMC patients. The nomogram had a high predictive value and consistency based on these factors.

Thyroid ultrasound and its ancillary techniques

Ultrasound (US) of the thyroid has been used as a diagnostic tool since the late 1960s. US is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters. However, the characterization of thyroid nodules by US remains challenging. The introduction of Thyroid Imaging Reporting and Data Systems (TIRADSs) has improved diagnostic accuracy of thyroid cancer significantly. Newer techniques such as elastography, superb microvascular imaging (SMI), contrast enhanced ultrasound (CEUS) and multiparametric ultrasound (MPUS) expand diagnostic options and tools further. In addition, the use of artificial intelligence (AI) is a promising tool to improve and simplify diagnostics of thyroid nodules and there is evidence that AI can exceed the performance of humans. Combining different US techniques with the introduction of new software, the use of AI, FNB as well as molecular markers might pave the way for a completely new area of diagnostic accuracy in thyroid disease. Finally, interventional ultrasound using US-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for benign as well as malignant thyroid diseases.

Novel and Advanced Ultrasound Techniques for Thyroid Thermal Ablation

Thyroid radiofrequency ablation and microwave ablation are widely adopted minimally invasive treatments for diverse thyroid conditions worldwide. Fundamental skills such as the trans-isthmic approach and the moving shot technique are crucial for performing thyroid ablation, and advanced techniques, including hydrodissection and vascular ablation, improve safety and efficacy and reduce complications. Given the learning curve associated with ultrasound-guided therapeutic procedures, operators need training and experience. While training models exist, limited attention has been given to ultrasound maneuvers in ablation needle manipulation. This article introduces two essential maneuvers, the zigzag moving technique and the alienate maneuver, while also reviewing the latest ultrasound techniques in thyroid ablation, contributing valuable insights into this evolving field.

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.

Significant dysregulation of lipid metabolism in patients with papillary thyroid carcinoma after thyroidectomy

Introduction

Thyroidectomy and thyrotropin suppressive therapy is the widely used surgical treatment for papillary thyroid carcinoma (PTC) patients. However, systematic metabolic changes of post-operative PTC patients were rarely reported.

Methods

Here, untargeted metabolomic detection of cohorts from PTC before (t0) and 1-month-after (t1) thyroidectomy, were performed to characterize circulating metabolic signatures after surgical treatment.

Results

Our results showed PTC patients exhibited lower thyroid stimulating hormone degree, higher total thyroxine, and significant lipid-related metabolic alternations after thyroidectomy, which included 97 upregulations (including 93 lipids) and 5 downregulations (including 2 lipids and 3 nucleotides). Enrichment of metabolic pathways mainly included biosynthesis of fatty acids, purine metabolism, and linoleic acid metabolism. We also demonstrated that differential surgical approaches (hemi- and total thyroidectomy) and post-operative complication phenotypes (insomnia, fatigue), might lead to characteristic metabolic signatures.

Discussion

This study revealed dynamic changes of metabolite characteristics of PTC patients after surgical treatment, which were associated with clinical thyroid function parameters, surgical approaches, and complication occurrence. It enlightened us to pay more attention on the post-operative metabolic dysregulation of PTC patients and their long-term qualities of life, so as to provide cautious clinical decisions on surgical choices, treatments, and follow-up details.

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

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

Rigorous radiofrequency ablation can completely treat low-risk small papillary thyroid carcinoma without affecting subsequent surgical management

OBJECTIVE

Minimally invasive therapies are gaining interest because of the indolence and excellent prognosis of low-risk papillary thyroid carcinoma (PTC). This study aimed to evaluate the outcomes of radiofrequency ablation (RFA) for low-risk PTC and to determine the effects of ablation on subsequent surgical management.

METHODS

A medical record review was conducted including patients with low-risk PTC who underwent surgery after RFA from July 2015 to July 2021. Demographic characteristics, tumor characteristics, ablation procedures, surgical findings, and pathological changes were reviewed for all patients. The primary outcomes were surgical and pathological changes in post-ablation patients.

RESULTS

Of the 10 patients with 11 PTCs, 9 (90%) were women; the median (SD) patient age was 41.5 (8.2) years. The maximum diameter range of PTCs was 3.0-12.0 mm. All 10 patients underwent rigorous RFA procedure involving a four-step approach, and had received surgical management. Intraoperatively, no patients had muscle and nerve injuries, and mild adhesion of the post-ablation lesions with the anterior cervical muscle was observed in two cases. Histopathologically, no residual PTCs were observed in the ablated areas in all patients. Central lymph node metastasis (LNM) was found in three (30.0%, pN1a). Occult PTCs were observed in three cases (30.0%).

CONCLUSIONS

Our findings suggest that low-risk small PTCs can be completely treated with rigorous RFA, which does not affect subsequent surgical management, if necessary. RFA may be a treatment option, but occult PTCs and clinically negative LNMs may be overlooked. Long-term follow-up data are necessary to further identify its efficacy.

KEY POINTS

• RFA can completely treat low-risk small PTC. • RFA does not affect the subsequent surgical management if necessary. • Because occult PTCs and clinically negative LNMs may be overlooked by RFA, long-term follow-up data are necessary to further identify its efficacy.