Safety and efficacy of microwave ablation for the treatment of low-risk papillary thyroid microcarcinoma: a prospective multicenter study

Risk factors for recurrent laryngeal nerve injury in microwave ablation of thyroid nodules: A multicenter study

BACKGROUND AND PURPOSE

This study aimed to investigate the risk factors for recurrent laryngeal nerve (RLN) injury after microwave ablation (MWA) of thyroid nodules and to identify factors influencing the recovery time of post-procedure hoarseness.

MATERIALS AND METHODS

We retrospectively analyzed data from patients who underwent MWA for thyroid nodules at five hospitals between November 2018 and July 2022. Patients were divided into malignant and benign nodule groups. Variables analyzed included nodule size and location, the shortest distance from nodules to the thyroid capsule and tracheoesophageal groove (TEG-D), and ablation parameters. Univariate and multivariate analyses were performed to identify risk factors. Kaplan-Meier and Cox analyses were used to evaluate the recovery time of hoarseness after MWA.

RESULTS

The study included 1,216 patients (mean age 44 ± 12 [SD] years; 901 women) with 602 malignant nodules and 614 benign nodules. The posterior capsule distance (PCD) and TEG-D were identified as independent influencing factors for hoarseness in all patients (P = 0.014, OR = 0.068; P < 0.001, OR = 0.005; AUC = 0.869). TEG-D was a significant risk factor for hoarseness, with safe thresholds identified at 4.9 mm for malignant nodules and 2.2 mm for benign nodules. Among patients who developed hoarseness, those in the close-distance group (TEG-D≤2 mm) had a longer recovery time compared to the distant-distance group. TEG-D was an independent factor influencing recovery time (P = 0.008, HR = 11.204).

CONCLUSION

Clinicians should consider several factors, particularly TEG-D and PCD, when assessing the risk of RLN injury before MWA. TEG-D was a vital independent factor influencing recovery time.

SUMMARY

Clinicians should pay attention to several influencing factors for RLN injury before MWA and TEG-D was an independent influencing factor for recovery time of hoarseness after MWA.

Thyroid cancer epidemiology in Ireland from 1994 to 2019 - Rising diagnoses without mortality benefit

BACKGROUND

The epidemiology and management of thyroid cancer has changed radically in the recent past, with rising international incidence of early-stage papillary thyroid cancer (PTC) in particular. In this paper, we review the epidemiology of thyroid cancer in Ireland.

METHODS

A retrospective cohort study of National Cancer Registry of Ireland data, 1994-2019.

RESULTS

Records from 4158 patients were analysed. 73 % (n = 3040) were female. The average age was 50.4 years. Patient sex did not change over time (p = 0.662), while age decreased significantly (p < 0.0001). The most common diagnoses were PTC (n = 2,905, 70 %) and follicular thyroid carcinoma (n = 549, 13 %). Incidence rose over threefold (1.8-6.2 cases/100000 person-years). The incidence of T1 PTC rose over twelvefold (0.169-2.1 cases/100000 person-years), while the incidence of stage III and IV disease did not change significantly. Five-year disease-specific survival (DSS) was 85 % and varied significantly by diagnosis - 97 % for PTC versus 5 % for anaplastic thyroid carcinoma. Survival did not change significantly over time. Male sex was a risk factor for more advanced disease (p < 0.0001) but did not independently predict overall survival except in PTC (HR 1.6, p = 0.03). The use of radioactive iodine declined markedly from 49 % to 12.5 %. RAI improved DSS for PTC patients aged over 55 years (p = 0.02) without a notable effect on survival for those under 55 years (p = 0.99).

CONCLUSION

The epidemiology and management of thyroid cancer in Ireland has changed dramatically in a manner reflective of international trends.

Microwave ablation for lymph node metastasis in thyroid cancer: the impact of lymph node diameter

Objectives

To explore the impact of lymph node diameter on the efficacy and safety of ultrasound-guided microwave ablation (MWA) in the treatment of cervical metastatic lymph nodes (CMLNs) from thyroid cancer.

Methods

A total of 32 patients with 58 CMLNs from thyroid cancer underwent ultrasound-guided MWA and were included in the retrospective study. Patients were divided into three groups based on the mean largest diameter of the CMLNs: Group A (diameter ≤10mm), Group B (10mm < diameter ≤20mm), and Group C (diameter >20mm). The research involved comparing changes in cervical metastatic lymph nodes and serum thyroglobulin (sTg) levels, as well as the incidence of complications, before and after microwave ablation across three groups of patients.

Results

The technical success rate of this study was 100% (32/32), and they showed no major complications. Compared with measurements taken before MWA, the mean largest diameter and volume of CMLNs, as well as the sTg level, showed significant reductions (p <0.05) at the last follow-up in all three patient groups. Group A and B exhibited higher lymph node volume reduction rates and complete disappearance rates compared to Group C. However, the recurrence rate in the three groups were in the following order: Group C > Group B > Group A. The occurrence rate of mild complications was Group A > Group C > Group B.

Conclusion

MWA is a safe and effective method for treating CMLNs, with advantages for localized nodes but limitations for larger ones. Careful consideration and personalized plans are advised, based on comprehensive evidence assessment.

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.

Ablation of Primary and Recurrent Thyroid Cancer: Current and Future Perspectives

Thyroid cancer is the most common endocrine malignancy, and its incidence is increasing, driven in part by the advent of ultrasound, and subsequent increased detection of small, early thyroid cancers. Yet even for small tumors, thyroidectomy with lymph node dissection remains standard of care. Specific to well-differentiated thyroid cancer, surgery has come under scrutiny as a possible overtreatment, in light of stable and favorable survival rates even as guidelines have allowed fewer radical resections and lymph node dissections over time. Moreover, thyroid cancer unfortunately has a known recurrence rate regardless of therapy, and surgical re-intervention for local structural recurrence is eventually limited by scar. Radioactive iodine therapy, another accepted treatment, is minimally invasive but can only treat patients with iodine-avid tumors. For all of these reasons, image-guided thermal ablation has emerged as a valuable complementary tool as a thyroid-sparing, parathyroid-sparing, voice-sparing, repeatable, minimally invasive outpatient focal therapy for both primary and recurrent well-differentiated thyroid cancers. However, the data are still evolving, and this represents a new patient cohort for some interventional radiologists. Therefore, the goal of this review is to discuss the technique and evidence for ablation of patients with thyroid cancer.

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.

Sonographic Evolution and Pathologic Findings of Papillary Thyroid Cancer After Radiofrequency Ablation: A Five-Year Retrospective Cohort Study

Background: The criteria for determining technical efficacy of thermal ablation for papillary thyroid carcinoma (PTC) are not clearly defined. We analyzed the involution process of the ablation zone with clear pathologic results on core-needle biopsy (CNB) to clarify the relationship between sonographic changes and pathologic findings. Methods: This retrospective cohort study included 382 patients with unifocal T1N0M0 PTC who underwent radiofrequency ablation (RFA) between May 2014 and August 2021. Patients with a single ablation zone biopsy (recommended at 3 or 6 months for T1a and 6 or 12 months for T1b) and regular neck ultrasound (US)/contrast-enhanced ultrasound imaging follow-up at 1, 3, 6, and 12 months and every 6-12 months thereafter after RFA were included. Patients also underwent yearly chest computed tomography. CNB was performed in the target lesion ablation zone's central, peripheral, and surrounding thyroid parenchyma to detect the presence of tumor cells. If the thyrotropin (TSH) was >2 mU/L, levothyroxine was prescribed with the intention of keeping the TSH 0.5-2 mU/L. Technical efficacy was defined as tumor disappearance by imaging follow-up together with the pathologically confirmed absence of tumor cells in the ablation zone. Results: During the mean follow-up period of 67.8 ± 18.2 months (22-110 months), the overall incidence of persistent disease and the technical efficacy rate were 3.9% (15/382; 2.9% of T1a, and 12.2% of T1b) and 96.1%, respectively. Tumor size (p = 0.03) and subcapsular location (p = 0.04) were risk factors associated with persistent disease. The technical success rate was 100%. Of the 367 ablation zones with benign CNB results, 336 (91.6%) showed tumor disappearance on US and no re-emergence of imaging-visible tumors during follow-up. Male sex (p = 0.006), age <40 years (p = 0.003), T1a tumor (p < 0.01), and energy per milliliter (p < 0.03) were significantly associated with tumor disappearance. Conclusions: US-guided RFA is an effective treatment for small low-risk PTC. Tumor disappearance on US after RFA may suggest an excellent prognosis and confirm complete ablation of the macroscopic tumor, but this sonographic finding is generally late and requires histological confirmation.

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.