Ultrasound-Guided Radiofrequency Ablation Versus Surgery for Low-Risk Papillary Thyroid Microcarcinoma: Results of Over 5 Years' Follow-Up

Exploring Radiofrequency Ablation for T1 Papillary Thyroid Cancer in the United States: Mayo Clinic Experience

OBJECTIVE

To report the efficacy, safety, and feasibility of radiofrequency ablation (RFA) for T1 papillary thyroid carcinoma (PTC) in a large referral center in the United States.

PATIENTS AND METHODS

We conducted a retrospective study of 8 patients who underwent RFA for T1 PTC at Mayo Clinic in Rochester Minnesota, between July 1, 2020, and February 28, 2023. The RFA technique and the type of anesthesia are described. Thyroid function, changes in ablated zone, and adverse events were analyzed for up to 24 months after the procedure.

RESULTS

Of the 8 patients included in the study, 7 were female and 1 was male with a mean ± SD age of 53±16.4 years. Thyroid status was unaffected in 7 of the 8 patients. The median duration of RFA was 6 minutes (range, 2 to 14.5 minutes) with energy delivered at between 25 and 45 W. The mean ± SD volume of small PTCs was 0.3±0.2 mL, and the mean largest diameter was 9.5±3.3 mm (range, 6 to 15 mm). The mean ± SD ablated volume at 3 to 6 months was larger than the target lesion (0.8±0.7 mL), with a reduction in mean ± SD ablated volume of 0.4±0.4 mL at 7 to 12 months and 0.1±0.06 mL at 13 to 18 months. The ablated zone almost disappeared at 19 to 24 months (0.04±0.04 mL). There were no major adverse events during or after the RFA procedure.

CONCLUSION

This is the first reported series of T1 PTC treated with RFA in the United States. Early postablation imaging revealed that the ablated region was larger than the target lesions, followed by a serial decrease in size. Therefore, RFA at centers with such expertise appears to be a safe and effective treatment for small PTCs. Further studies are needed to evaluate its long-term efficacy and the risk of recurrence.

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.

Thyroid nodulectomy: A promising approach to the management of solitary thyroid nodules

The choice between nodulectomy and lobectomy for managing thyroid nodules is a subject of debate in the field of thyroid surgery. The present study aims to share the experience of a single center in managing solitary thyroid nodules through nodulectomy from January 2023 to October 2023. The inclusion criteria encompassed symptomatic or suspicious solitary nodules and medically necessitated cases. The extracted data included patient demographics, medical history, symptoms, diagnostic details, surgery indication, procedure outcome and histopathological findings. The follow-up included clinic visits and phone calls. The mean age of the patients was 36.64±11.63 years, with 85.0% females and 15.0% males. Predominantly, patients were housewives (58.5%). Neck swelling (62.3%) was the most common presentation. Ultrasound examination revealed mixed nodules in more than half of the cases (54.7%). Right nodulectomy was performed in 26 cases (49.1%) and left nodulectomy in 23 (43.4%), and four cases (7.5%) underwent isthmusectomy. The mean operation time was 36.04±9.37 min and no drainage tube was used in any of the cases. One case (1.9%) of seroma was the only observed complication during the observational period. Nodulectomy may be a suitable choice for managing benign, large, solitary thyroid nodules, small suspicious nodules or microcarcinomas.

The Role of Radiofrequency Ablation in Benign and Malignant Thyroid Nodules

Radiofrequency ablation (RFA) offers a minimally invasive solution for benign, autonomously functioning (AFTN), and malignant thyroid nodules. The technique utilizes high-frequency alternating current to induce coagulative necrosis, effectively destroying target tissue. RFA is performed in the outpatient setting with local anesthesia and sonographic guidance. RFA is effective in producing substantial volume reduction rates in benign nodules and is emerging as a favorable option in AFTN and papillary thyroid microcarcinoma. RFA's advantages include lower complication rates, minimal scarring, and improved quality-of-life outcomes compared to surgery. However, its efficacy in larger and recurrent malignancies requires further investigation.

Comparison of radiofrequency ablation and surgery for thyroid papillary microcarcinoma: efficacy, safety and life quality

Objective

To compare the efficacy, safety and patients' quality of life of radiofrequency ablation (RFA) and surgery in the treatment of papillary thyroid microcarcinoma (PTMC).

Methods

MEDLINE, EMBASE, Cochrane, CNKI and other databases were searched for studies on radiofrequency ablation versus traditional surgery for PTMC up to October 2022. RevMan5.4 software was used for Meta-analysis.

Results

10 articles were selected from 392 articles, including 873 cases of radiofrequency ablation and 781 cases of open surgery. After meta-analysis, the incidence of postoperative complications in the radiofrequency ablation group was lower than that in the surgery group, and the difference was statistically significant [OR=0.24, 95%CI (0.14,0.41), P<0.001]. There were no significant differences in lymph node metastasis rate, local recurrence rate, and new tumor rate between the two groups [OR=1.6, 95%CI (0.21, 12.41), P>0.05; OR=0.85, 95%CI (0.05, 13.8), P>0.05; OR=0.12, 95%CI (0.01, 0.98), P>0.05]. The treatment time and hospital stay in the radiofrequency ablation group were shorter than those in the open surgery group [MD=-49.99, 95%CI (-62.02, -37.97), P<0.001; MD=-5.21, 95%CI(-7.19,-3.23),P<0.001], and the cost was significantly lower than that of the traditional surgery group [SMD=-14.97, 95%CI (-19.14, -10.81), P<0.001]. The quality of life of patients in the radiofrequency ablation group was higher than that in the surgery group [MD=-1.61, 95%CI (-2.06, -1.17), P<0.001].

Conclusion

Compared with traditional open surgery, radiofrequency ablation for papillary thyroid microcarcinoma has the advantages of less trauma, fewer complications, faster recovery and higher quality of life. The indications need to be strictly controlled in the treatment.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022374987).

Development and validation of a clinical predictive model for high-volume lymph node metastasis of papillary thyroid carcinoma

The central lymph node metastasis (CLNM) status in the cervical region serves as a pivotal determinant for the extent of surgical intervention and prognosis in papillary thyroid carcinoma (PTC). This paper seeks to devise and validate a predictive model based on clinical parameters for the early anticipation of high-volume CLNM (hv-CLNM, > 5 nodes) in high-risk patients. A retrospective analysis of the pathological and clinical data of patients with PTC who underwent surgical treatment at Medical Centers A and B was conducted. The data from Center A was randomly divided into training and validation sets in an 8:2 ratio, with those from Center B serving as the test set. Multifactor logistic regression was harnessed in the training set to select variables and construct a predictive model. The generalization ability of the model was assessed in the validation and test sets. The model was evaluated through the receiver operating characteristic area under the curve (AUC) to predict the efficiency of hv-CLNM. The goodness of fit of the model was examined via the Brier verification technique. The incidence of hv-CLNM in 5897 PTC patients attained 4.8%. The occurrence rates in males and females were 9.4% (128/1365) and 3.4% (156/4532), respectively. Multifactor logistic regression unraveled male gender (OR = 2.17, p < .001), multifocality (OR = 4.06, p < .001), and lesion size (OR = 1.08 per increase of 1 mm, p < .001) as risk factors, while age emerged as a protective factor (OR = 0.95 per an increase of 1 year, p < .001). The model constructed with four predictive variables within the training set exhibited an AUC of 0.847 ([95%CI] 0.815-0.878). In the validation and test sets, the AUCs were 0.831 (0.783-0.879) and 0.845 (0.789-0.901), respectively, with Brier scores of 0.037, 0.041, and 0.056. Subgroup analysis unveiled AUCs for the prediction model in PTC lesion size groups (≤ 10 mm and > 10 mm) as 0.803 (0.757-0.85) and 0.747 (0.709-0.785), age groups (≤ 31 years and > 31 years) as 0.778 (0.720-0.881) and 0.837 (0.806-0.867), multifocal and solitary cases as 0.803 (0.767-0.838) and 0.809 (0.769-0.849), and Hashimoto's thyroiditis (HT) and non-HT cases as 0.845 (0.793-0.897) and 0.845 (0.819-0.871). Male gender, multifocality, and larger lesion size are risk factors for hv-CLNM in PTC patients, whereas age serves as a protective factor. The clinical predictive model developed in this research facilitates the early identification of high-risk patients for hv-CLNM, thereby assisting physicians in more efficacious risk stratification management for PTC patients.

Advances in clinical research on ultrasound-guided radiofrequency ablation for papillary thyroid microcarcinoma

Ultrasound-guided radiofrequency ablation (RFA) emerges as a minimally invasive strategy for papillary thyroid microcarcinoma (PTMC), offering advantages over traditional surgical approaches. RFA employs high-frequency electric currents under precise ultrasound guidance to ablate cancerous tissue. Clinical trials consistently demonstrate RFA's efficacy in tumor control and patient-reported outcomes. However, long-term studies are essential to validate its durability and monitor for potential complications. Collaborative efforts among various medical disciplines ensure procedural accuracy and comprehensive postoperative care. Technological innovations, such as enhanced ultrasound imaging and temperature control, promise to refine RFA's precision and effectiveness. Nevertheless, challenges persist, including the need for standardized protocols and comparative studies with traditional treatments. Future research should focus on long-term outcomes, patient selection criteria, and optimization of procedural techniques to solidify RFA's role in PTMC management. RFA presents a promising avenue for PTMC treatment, warranting further investigation and refinement in clinical practice.

Thyroid Nodule Rupture Following Radiofrequency Ablation for Benign Thyroid Nodules

Importance

Nodule rupture is a rare but serious complication of thyroid radiofrequency ablation (RFA). With growing adoption of thyroid RFA across the US, an understanding of thyroid nodule rupture (TNR) is crucial for recognition, management, and, ultimately, prevention.

Objective

To determine procedural and patient factors that may contribute to TNR and describe experiences in managing TNR while synthesizing existing literature.

Design, Setting, and Participants

This retrospective case series examined all RFA procedures for benign thyroid nodules performed by 2 attending physicians at a single academic referral center between December 2019 and January 2024. A total of 298 consecutive patients underwent RFA for benign thyroid nodules. Criteria for offering RFA included nodules with 2 benign fine-needle aspirations, no suspicious ultrasonography features, a greatest dimension of 2 cm or greater, compressive or cosmetic concerns, and accessibility to a straight needle.

Exposures

All RFAs were performed using ultrasonography guidance using the moving-shot technique and a 7-mm or 10-mm active tip.

Main Outcomes and Measures

The primary outcome was TNR, and measures were procedure, nodule, and patient characteristics that may have contributed to its pathogenesis. Secondary outcomes were nodule volume reduction, thyroid function, and management and sequelae of TNR. The hypothesis on the pathogenesis of TNR was formed before data collection.

Results

Six of 298 patients (2%; 4 women [67%]) with a mean age of 48.5 years (range, 34-65 years) experienced TNR for a mean of 36 days postprocedure (range, 19-54 days). The mean (SD) initial nodule volume among patients with TNR was 31.45 (16.52) mL, and 3 of 6 patients (50%) underwent prior lobectomy. All ruptures were anterior. All patients were treated conservatively, and none required surgery. Five patients recovered completely; the sixth and most recent patient was healing as of last follow-up.

Conclusions and Relevance

There are limited data on the etiology and optimal management of TNR. These 6 cases of anterior rupture suggest that a potential contributor to TNR is thermal and mechanical trauma exerted at the fulcrum point during the moving-shot technique. The use of a smaller active tip (eg, 7 mm) and cessation of energy delivery before this point may help avoid TNR. More robust reporting of this complication may clarify risk factors for and enhance prevention of TNR.

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.

Thermal Ablation of Thyroid Nodules, From the AJR "How We Do It" Special Series

Ablation has been shown to be an effective option for treatment of well-selected patients with thyroid nodules, particularly benign nodules, and thermal ablation is being increasingly used for this purpose. The general approach to thermal ablation of the thyroid will be familiar to interventional radiologists who perform ablation in other tissues; however, thermal ablation of the thyroid has additional unique considerations. In this review, we provide evidence-based and real-world guidance on the performance of thermal ablation for the treatment of patients with thyroid nodules, drawing on our collective experience and clinical practice. We describe patient selection, ablation modalities, equipment, general procedural approach, additional technical considerations, and postprocedural follow-up. We discuss various clinical scenarios; give tips on performing specific portions of the procedure and highlight a range of relevant anatomic, biochemical, and clinical factors, as a guide for interventional radiologists in establishing a successful thyroid ablation practice.

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.

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.

Efficacy and safety of thermal ablation modalities for the treatment of papillary thyroid microcarcinoma: Systematic Review and network meta-analysis

Background

Thermal ablation (TA) modalities such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) have been widely used in the treatment of papillary thyroid microcarcinoma (PTMC) patients. Based on previous small-sample meta-analyses, this network meta was designed to further compare the efficacy and safety of these thermal ablation methods in PTMC patients.

Methods

China National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Embase, and the Cochrane Library databases were searched to retrieve relevant studies published before May 2022. The efficacy outcomes was recurrence and lymph node metastasis (LNM), the safety outcome included operation time, intra-operative blood loss, hospital stays and complications. The Newcastle-Ottawa Scale (NOS) was selected for the risk of bias assessment. Stata 14.0 was used for statistical analysis.

Results

Twenty-nine articles were included. Based on as least 6 months follow up, our analysis discovered no significant statistical differences in all efficacy and safety outcomes between MWA, RFA, and LA groups. Moreover, three TA treatments all produced significant least operation time, hospital stays, and complications than surgery group. Additionally, our study found that RFA showed relatively less complications, LNM, operation time and intra-operative blood loss, compared with other TA treatments. MWA indicated the lowest probability of recurrence, LA showed the longest hospital stays.

Conclusions

MWA, RFA, and LA are all effective treatment strategies for patients with PTMC, but could not completely replace conventional surgical treatment.

The relationship between ablation range and ablation energy in papillary thyroid microcarcinoma: a comparison between microwave ablation and laser ablation

OBJECTIVES

To study the relationship between the ablation range and applied energy of laser ablation (LA) and microwave ablation (MWA) in papillary thyroid microcarcinoma (PTMC).

METHODS

A total of 201 PTMC patients were treated with LA (n = 102) or MWA (n = 99) with single-applicator fixed ablation. The ablation range was determined by contrast-enhanced ultrasound. The ratios of ablation volume, longitudinal diameter, and orthogonal diameter to ablation energy (RAV/E, RAL/E, RAO/E) were analyzed and compared between MWA and LA. The effects of PTMC characteristics and Hashimoto's thyroiditis (HT) on ablation efficiency were evaluated by linear regression.

RESULTS

The RAV/E was 0.72 (0.65-0.84) mm3/J for MWA and 0.48 (0.39-0.54) mm3/J for LA. HT was significantly correlated with RAV/E of LA (coefficient =  - 0.367, p < 0.0001). RAL/E did not differ significantly between MWA and LA (MWA 0.026 mm/J, LA 0.025 mm/J; p = 0.957). However, MWA had a greater RAO/E than LA (MWA 0.014 mm/J, LA 0.012 mm/J; p < 0.0001). The plateau values of MWA and LA on the ablation orthogonal diameter were 10.7 mm and 8.69 mm, respectively.

CONCLUSIONS

MWA showed a higher RAV/E than LA. More intuitively, MWA had a better ablation performance than LA on the orthogonal axis rather than the longitudinal axis. Theoretically, MWA and LA could achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin. HT had a negative effect on LA but not on MWA.

CLINICAL RELEVANCE STATEMENT

This study establishes strong connections between ablation energy and ablation range in papillary thyroid microcarcinoma (PTMC) in vivo, possibly contributing to the supplementation of the PTMC Ablation Consensus or Guidelines and providing a scientific basis for choosing clinical ablation parameters in PTMC.

KEY POINTS

• Both microwave ablation (MWA) and laser ablation (LA) have excellent performance on the ablation longitudinal axis (easily exceeding 10 mm) for papillary thyroid microcarcinoma (PTMC). • MWA performed much better than LA on the ablation orthogonal axis. • MWA and LA are expected to achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin.

Ablation techniques or active surveillance compared to surgical resection in patients with low-risk papillary thyroid cancer: a systematic review and meta-analysis

BACKGROUND

The global prevalence of thyroid cancer is on the rise. About one-third of newly diagnosed thyroid cancer cases comprise low-risk papillary thyroid cancer (1.5 cm or more minor). While surgical removal remains the prevailing approach for managing low-risk papillary thyroid cancer (LPTC) in patients, other options such as active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) are also being considered as viable alternatives. This study evaluated and compared surgical thyroid resection (TSR) versus non-surgical (NS) methods for treating patients with LPTC.

METHODS

The study encompassed an analysis of comparisons between surgical thyroid resection (TSR) and alternative approaches, including active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), or laser ablation (LA). The focus was on patients with biopsy-confirmed low-risk papillary thyroid cancer (LPTC) of less than 1.5 cm without preoperative indications of local or distant metastasis. The primary outcomes assessed were recurrence rates, disease-specific mortality, and quality of life (QoL). Data were collected from prominent databases, including Cochrane Database, Embase, MEDLINE, and Scopus, from inception to June 3rd, 2020. The CLARITY tool was utilized to evaluate bias risk. The analysis involved odds ratios (OR) with 95% confidence intervals (CI) for dichotomous outcomes, as well as mean differences (MD) and standardized mean differences (SMD) for continuous outcomes. The study is registered on PROSPERO under the identifier CRD42021235657.

RESULTS

The study incorporated 13 retrospective cohort studies involving 4034 patients. Surgical thyroid resection (TSR), active surveillance (AS), and minimally invasive techniques like radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) were performed in varying proportions of cases. The analysis indicated that specific disease mortality rates were comparable among AS, MWA, and TSR groups. The risk of recurrence, evaluated over different follow-up periods, showed no significant differences when comparing AS, RFA, MWA, or LA against TSR. Patients undergoing AS demonstrated better physical health-related quality of life (QoL) than those undergoing TSR. However, no substantial differences were observed in the overall mental health domain of QoL when comparing AS or RFA with TSR. The risk of bias was moderate in nine studies and high in four.

CONCLUSION

Low-quality evidence indicates comparable recurrence and disease-specific mortality risks among patients with LPTC who underwent ablation techniques or active surveillance (AS) compared to surgery. Nevertheless, individuals who opted for AS exhibited enhanced physical quality of life (QoL). Subsequent investigations are warranted to validate these findings.

Follow-up strategy of radiofrequency ablation for papillary thyroid microcarcinoma: defining a response-to-ablation system

OBJECTIVE

To define a response-to-ablation system based on dynamic risk stratification proposed by the 2015 American Thyroid Association guidelines for predicting clinical outcomes and guiding follow-up strategies for patients with low-risk papillary thyroid microcarcinoma (PTMC) who underwent radiofrequency ablation (RFA).

METHODS

This retrospective study reviewed patients with low-risk PTMC who underwent RFA between 2014 and 2018. We classified patients into three groups based on their response to therapy at the 1-year follow-up: complete, indeterminate, and incomplete. The primary endpoints were local tumor progression (LTP) and disease-free survival (DFS).

RESULTS

Among the 748 patients (mean age, 43.7 years ± 9.8; 586 women), 4.0% (30/748) had LTP during a median follow-up of 5 years. The response was complete in 80.2% (600/748) of the patients, indeterminate in 18.1% (135/748), and incomplete in 1.7% (13/748). The LTP rate in the final follow-up was 1% (6/600), 8.1% (11/135), and 100% (13/13), respectively. The risk of LTP was significantly different in the incomplete response group (HR, 1825.82; 95% CI: 458.27, 7274.36; p < 0.001) and indeterminate response group (HR, 8.12; 95% CI: 2.99, 22.09; p < 0.001) than in the complete response group. There were significant differences in DFS among groups (p < 0.001). The proportion of variation explained and C-index of the system was high (27.66% and 0.79, respectively).

CONCLUSIONS

We defined a response-to-ablation system that provides a new paradigm for the management of patients with PTMC who underwent RFA. Our data confirm that the system can effectively predict the risk of LTP and guide ongoing follow-up recommendations.

KEY POINTS

• The response-to-ablation system can classify patients with low-risk PTMC who underwent RFA into complete, indeterminate, or incomplete response categories. • Results suggest that, in this population, this system can identify three separate cohorts of patients who have significantly different clinical outcomes. • The response-to-ablation system will help better tailor the ongoing follow-up recommendations.

Radiofrequency Ablation for Benign Nodules and for Cancer, Too?

Radiofrequency ablation (RFA) is a minimally invasive procedure performed under ultrasound guidance that offers the ability to significantly reduce the size of benign thyroid nodules. Although application for benign nodules has only emerged during the past 5 to 10 years in North America, RFA has an impressive track record of nodule reduction, compressive and cosmetic symptom improvement, and excellent safety profile without the morbidity of open surgery. The role of RFA in autonomous functioning nodules, thyroid cancer, and indeterminate nodules is controversial and remains an area of investigation.

Radiofrequency ablation for papillary thyroid microcarcinoma with a trachea-adjacent versus trachea-distant location

OBJECTIVE

To evaluate the outcomes of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) adjacent to the trachea and compare them with those of PTMC distant from the trachea.

METHODS

Patients who received RFA for solitary low-risk PTMC between June 2014 and July 2020 were reviewed and classified into adjacent and distant groups. To balance between-group confounders, the propensity score matching approach was employed. Volume, volume reduction ratio (VRR), tumor disappearance, complications, and disease progression were assessed and compared between the groups. Furthermore, factors affecting disease progression were evaluated.

RESULTS

A total of 122 and 470 patients were included in the adjacent and distant groups, respectively. Overall VRR was 99.5% ± 3.1 and cumulative tumor disappearance rate was 99.4% after a mean follow-up time of 40.1 months ± 16.2. Overall disease progression and complications incidence were 3.7% and 1.0%, respectively. No substantial differences were observed between the two groups in the latest volume (0.8 mm3 ± 4.1 vs. 0.9 mm3 ± 4.2, p = .77), VRR (99.7% ± 1.6 vs. 99.5% ± 2.7, p = .75), cumulative tumor disappearance rate (92.6% vs. 94.2%, p = .58), and incidence of disease progression (4.1% vs. 4.5%, p = .70) and complication (1.7% vs. 0.8%, p = .86) after 1:2 matching. Additionally, tracheal adjacency exhibited no association with disease progression in multivariate Cox regression analysis (p = .73).

CONCLUSION

For eligible patients with PTMC located adjacent to or distant from the trachea, RFA may offer a safe and effective alternative treatment method.

Health-Related Quality of Life in Patients with Low-Risk Differentiated Thyroid Cancer: A Systematic Review Examining the Extent of Thyroidectomy

Background: Total thyroidectomy (TT) and hemithyroidectomy (HT) are acceptable surgical options for the treatment of low-risk differentiated thyroid cancer (DTC). While previous data suggest similar disease-free and disease-specific survival regardless of initial surgical treatment, the effect of the extent of surgery on health-related quality of life (HRQOL) is less clear. This systematic review aimed to examine HRQOL in low-risk DTC survivors after TT compared with HT. Methods: A search of PubMed, CINAHL, Cochrane, PsycINFO, and Scopus databases was conducted to identify studies published between January 1, 2011, and December 31, 2022, that assessed HRQOL predominantly in patients with low-risk DTC who underwent open thyroid surgery. Covidence™ software was used to apply the inclusion criteria, and a validated instrument was used to assess study quality. Results: Sixteen of the 1402 identified studies were included: 5 prospective and 11 retrospective cohort studies. The majority of included studies were of good quality (n = 14) and were from Asia and the Middle East (n = 11). Overall, six studies concluded that HT led to a better HRQOL than TT, two concluded that HT only resulted in better HRQOL compared with TT with central neck dissection (CND), and two concluded HT resulted in better short-term HRQOL that dissipated by 6 months postoperatively. The HRQOL domains found across all studies to be most consistently improved after HT included physical health, psychological/emotional, and social function. Factors found to be associated with HRQOL in more than one study included age, stage, and marital status. Conclusion: Differences in HRQOL after HT and TT tended to favor HT particularly when measured <6 months after surgery or when compared with TT with CND. Additional prospective and ideally randomized data are needed to fully determine the impact of the extent of surgery on HRQOL in patients with low-risk thyroid cancer.

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.

Constructing a nomogram based on the distribution of thyroid nodules and suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies to predict metastasis in papillary thyroid carcinoma

Purpose

Elevated concentrations of thyroglobulin eluent is a risk factor for lateral cervical lymph node metastasis (LLNM) in patients with papillary thyroid cancer (PTC). We aimed to develop a practical nomogram based on the distribution of thyroid nodules and the presence of suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies (LN-FNABs), including the cytopathology and the suspicious lateral cervical lymph node (LLN) thyroglobulin eluent (Tg), to predict the possibility of LLNM preoperatively in patients with PTC.

Methods

The clinical data of PTC patients who were admitted to the Third Affiliated Hospital of Soochow University from January 2022 to May 2023 to undergo fine-needle aspiration biopsy (FNAB) were included in this study. A total of 208 patients in 2022 served as the training set (70%), and 89 patients in 2023 served as the validation set (30%). The clinical characteristics and LN-FNAB results were collected to determine the risk factors of LLNM. A preoperative nomogram was developed for predicting LLNM based on the results of the univariate and multivariate analyses. Internal calibration, external calibration, and decision curve analysis (DCA) were performed for these models.

Results

The multivariate logistic regression analysis showed that the maximum thyroid nodule diameter (Odds Ratio (OR) 2.323, 95% CI 1.383 to 3.904; p = 0.001), Tg level (OR 1.007, 95% CI 1.005 to 1.009; p = 0.000), Tg divided by serum thyroglobulin, (Tg/sTg) [odds ratio (OR) 1.005, 95% CI 1.001 to 1.008; p = 0.009], and cytopathology (OR 9.738, 95% CI 3.678 to 25.783; p = 0.000) (all p <  0.05) had a significant impact on the LLNM of patients with suspicious LLNs. The nomogram showed a better predictive value in both the training cohort [area under the curve, (AUC) 0.937, 95% CI 0.895 to 0.966] and the validation cohort (AUC 0.957, 95% CI 0.892 to 0.989). The nomogram also showed excellent internal and external calibration in predicting LLNM. According to the DCA, the diagnostic performance of this model was dependent on the following variables: maximum thyroid nodule diameter, Tg level, Tg/sTg, and cytopathology.

Conclusion

Based on the aforementioned risk factors, we believe that it is necessary to establish a personalized LLNM model for patients with PTC. Using this practical nomogram, which combines clinical and Tg risk factors, surgeons could accurately predict the possibility of LLNM preoperatively. The nomogram will also help surgeons to establish personalized treatment plans before surgery.

Five-year Outcome Between Radiofrequency Ablation vs Surgery for Unilateral Multifocal Papillary Thyroid Microcarcinoma

CONTEXT

Ultrasound (US)-guided radiofrequency ablation (RFA) has been considered as an alternative to surgery or active surveillance for papillary thyroid microcarcinoma (PTMC). However, little is known about the long-term outcomes of RFA in comparison with surgery for unilateral multifocal PTMC.

OBJECTIVE

This work aims to report the comparison between RFA vs surgery for unilateral multifocal PTMC over a more than 5-year follow-up period.

METHODS

This was a retrospective study at a primary care center with a median follow-up period of 72.9 months. A total of 97 patients with unilateral multifocal PTMC were treated with RFA (RFA group, n = 44) or surgery (surgery group, n = 53). In the RFA group, patients were treated by a bipolar RFA generator and an 18-gauge bipolar RF electrode with a 0.9-cm active tip. In the surgery group, patients underwent thyroid lobectomy with prophylactic central neck dissection.

RESULTS

During the follow-up, no statistically significant differences were found in disease progression (4.5% vs 3.8%; P = ≥.999), lymph node metastasis (2.3% vs 3.8%; P = ≥.999), persistent lesion (2.3% vs 0%; P = .272), and RFS rates (97.7% vs 96.2%; P = .673) in the RFA and surgery groups. Patients undergoing RFA had a shorter hospitalization (0 vs 8.0 [3.0] d; P < .001), shorter procedure time (3.5 [2.4] vs 80.0 [35.0] min; P < .001), lower estimated blood loss (0 vs 20.0 [15.0] mL; P < .001), and lower costs ($1768.3 [0.1] vs $2084.4 [1173.8]; P = .001) than those in the surgery group. The complication rate in the surgery group was 7.5%, whereas none of the RFA-treated patients experienced any complications (P = .111).

CONCLUSION

This study revealed 6-year comparable outcomes between RFA and surgery for unilateral multifocal PTMC. RFA may be a safe and effective alternative to surgery in selected patients with unilateral multifocal PTMC.

Radiofrequency ablation for papillary thyroid cancer located in isthmus: comparison with that originated in thyroid lobe

PURPOSE

To analyze the outcomes of radiofrequency ablation (RFA) for isthmus papillary thyroid cancer (PTC) versus PTC originating from the lobes.

METHODS

Patients with solitary low-risk PTC treated with RFA between July 2014 and December 2019 were retrospectively reviewed. This study was approved by our institutional review board. Of the 562 patients, 104 and 458 had PTCs located in the thyroid isthmus and thyroid lobes, respectively. Local tumor progression (LTP), LTP-free survival (LTPFS), changes in tumor volume, and complications were compared between the two groups using propensity-score matching (PSM).

RESULTS

The isthmic and lobar groups showed no significant differences in LTP (2.9% vs. 3.8%), new PTC (2.9% vs. 2.9%), persistent lesions (0.0% vs. 0.2%), or LTPFS after PSM. Before PSM, the two groups showed significant differences in the volume reduction ratio (VRR) of the ablated tumors at 1, 3, 24, 30, and 48 months after RFA, but no differences between the two groups were observed in tumor volume, VRR, or disappearance rate after PSM (p > .05). One patient in the isthmic group presented with coughing, while another complained of hoarseness. Complications did not differ significantly between the two groups (p > .05).

CONCLUSIONS

The outcomes of RFA for patients with low-risk PTC in the thyroid isthmus and thyroid lobes were similar. Therefore, RFA may serve as an alternative treatment option for patients with low-risk isthmic PTC.

Recommend with caution: A meta-analysis investigating papillary thyroid carcinoma tumor progression under active surveillance

BACKGROUND

Papillary thyroid carcinoma (PTC) is an indolent disease with favorable outcomes. The non-surgical treatment approach known as active surveillance (AS) has been introduced as an alternative treatment instead of the traditional thyroidectomy. However, 10-15 % of PTC tend to progress. We sought to determine factors predicting the progression of PTC under AS.

METHODS

A systematic search was performed in January 2022 using PubMed, Embase, Google Scholar, Web of Science, and ScienceDirect. PRISMA guidelines were used by multiple reviewers to extract study characteristics (author name, publication date, journal name, country, institution, and study design), as well as main outcomes and measures. A combination of utilization of thyroid replacement therapy, baseline tumor size and volume, follow-up tumor size and volume, and the presence of lymph node metastasis and its distribution, as well as surveillance duration, were the main measures of this study.

RESULTS

Nine studies with 4166 patients were included, of which 354 showed tumor progression during AS (15 %; 95%CI = 7 % - 23 %). The average follow-up period was 41.58 months. The mean tumor maximum diameter was 8.54 mm (95%CI = 7.04-10.03). Tumor progression was most commonly secondary to an increase in volume by ≥50 % (75 %; 95%CI = 68 % - 80 %), then increase in diameter by ≥3 mm (41 %; 95%CI = 13 % - 76 %), and finally the development of lymph node metastasis (13 %; 95%CI = 9 % - 19 %). Approximately only 2 % of all patients thus developed new lymph node metastasis. Patient age, sex, and tumor size were not associated with higher risks of tumor progression. 12 % of AS patients eventually underwent surgery, though only 40 % (95%CI = 27 % - 53 %) of these patients displayed tumor progression.

CONCLUSIONS

Our meta-analysis determined a tumor progression rate of 15 % in patients who underwent AS management, 13 % of which (2 % of all patients) developed lymph node metastasis. We found no protective or risk factors for tumor progression, and that almost half of all patients who underwent delayed surgery did so for reasons other than tumor progression. While not biopsying small (<1 cm) or very low suspicious nodules is already recommended, AS may be an appropriate treatment option in patients appropriately counseled, considering the low risk of advanced tumor progression but also the considerable patient population who fail to adhere to treatment. Alternatively, in aim of preventing overtreatment in patients who would rather take proactive measures against their low-risk carcinoma, minimally-invasive ablation techniques may be an attractive option.

Publications on ultrasound-guided thermal ablation for thyroid nodules from 2000 to 2022: a bibliometric analysis

BACKGROUND

Thyroid nodules are increasingly treated with minimally invasive surgery. Thermal ablation could efficiently treat patients with benign thyroid nodules, recurrent thyroid cancer, and low-risk papillary thyroid carcinoma. This research aims to explore the research field of thermal ablation for thyroid nodules using bibliometric analysis.

METHODS

The web of science core collection (WoSCC) database was utilized from its inception to 1 October 2022, to collect research articles and reviews on ultrasound-guided thermal ablation for thyroid nodules. We applied the R package 'bibliometrix' to summarize the main findings, calculate the occurrences of the top keywords and visualize the international collaboration networks. The co-authorship and co-occurrence analyses were conducted with VOSviewer software. CiteSpace was used to identify the top references and keywords with the highest citation bursts.

RESULTS

A total of 820 publications from 32 countries were retrieved. The annual number of related publications showed an increasing trend. China, Italy, and Korea were the most contributing countries. The University of Ulsan College of Medicine in Korea was the most productive institution, and Jung Hwan Baek published the maximum number of articles. The International Journal of Hyperthermia was the most productive journal. 'Papillary thyroid micro-carcinoma (PTMC)' and 'association guideline' were the most frequently used keywords in the field of thermal ablation for thyroid nodules, which indicated the potential hot research topics and frontiers in the future.

CONCLUSION

This bibliometric study conducts a comprehensive analysis of publications on thermal ablation for thyroid nodules, which aids investigators in discovering potential research directions.

Effectiveness and Safety of Percutaneous Treatment in Lesions Suggestive of Thyroid Cancer (Bethesda V and VI-T1aN0M0) Compared to Surgical Treatment: Systematic Review and Meta-Analysis

INTRODUCTION

Thyroid nodules are common entities, with 5% malignancy. Differentiated thyroid cancer represents 90% of thyroid malignancies, with papillary carcinoma being the most common. Management is generally surgical; among its complications are injury to the recurrent laryngeal and superior laryngeal nerve, causing hoarseness, postsurgical hypoparathyroidism, hypothyroidism, and pain. Other noninvasive percutaneous interventions of thermal ablation such as microwave, radiofrequency, or laser incur lower costs and could be an option for treatment.

OBJECTIVE

To determine the effectiveness and safety of thermal ablation in lesions suspected of thyroid cancer (Bethesda V and VI/T1aN0M0) compared to surgical treatment.

METHODS

Systematic review/meta-analysis of observational studies and clinical trials. Database search includes MEDLINE/PUBMED, Embase, Scopus, Scielo, and BVS/LILACS. Studies on patients over 18 years of age with lesions suspicious of thyroid cancer were included.

RESULTS

A total of 10 studies were obtained, with 2939 patients: 1468 subjected to thermal ablation and 1471 to surgery. Regarding effectiveness, no differences were found in local recurrence [relative risk (RR) 1.17 (95% CI 0.69-1.99)] and cervical lymph node metastasis [RR 0.76 (95% CI 0.43-1.36)]. Regarding safety, infection [RR 0.29 (95% CI 0.05-1.74)], hematoma [RR 0.57 (95% CI 0.17-1.94)], and transient hoarseness [RR 0.77 (95% CI 0.39-1.51)] were evaluated, without difference. However, permanent hoarseness had significant differences in favor of thermal ablation [RR 0.29 (95% CI 0.11-0.75)].

CONCLUSIONS

Thermal ablation for the treatment of T1aN0M0 papillary thyroid carcinoma is equally effective when compared to surgical techniques and offers a better safety profile, particularly in permanent hoarseness.

Important parameters should be paid attention in PTMC radiofrequency ablation

In order to provide clinical references for the RFA procedure and to study the pivotal factors affecting the recovery time of radiofrequency ablation (RFA) in patients with papillary thyroid microcarcinoma (PTMC), 176 patients with low-risk intrathyroidal PTMC were included in this research. We randomly divided the whole cohort into training and test groups at a ratio of 7:3. The two-sample t-test was used to detect differences between the two groups. Least absolute shrinkage and selection operator (LASSO) regression was used to select the best predictor variables for predicting the status of RFA zone. Multiple test methods were used to ensure the scientific nature and accuracy of the Cox proportional hazards model. We tested the performance for the parameters and revealed the best cut-off value of each variable by the ROC curve and log-rank tests. The results showed patients aged above 49 years old, with RFA energy above 2800 J, the average diameter of the original tumour above 0.6 cm, or the average diameter of ablation zone at 1 month after RFA above 1.1 cm are risk factors for RFA zone delayed healing.

Choice in Ablative Therapies for Thyroid Nodules

Ultrasound-guided ablation procedures have been growing in popularity and offer many advantages compared with traditional surgery for thyroid nodules. Many technologies are available, with thermal ablative techniques being the most popular currently though other nonthermal techniques, such as cryoablation and electroporation, are gaining interest. The objective of the present review is to provide an overview of each of the currently available ablative therapies and their applications in various clinical indications.

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.

Long-term Outcomes of Ultrasound-guided Thermal Ablation for the Treatment of Solitary Low-risk Papillary Thyroid Microcarcinoma: A Multicenter Retrospective Study

OBJECTIVE

To report more than 5-year outcomes of ultrasound-guided thermal ablation (TA) for patients with solitary low-risk papillary thyroid microcarcinoma (PTMC) in a large multicenter cohort.

BACKGROUND

TA, including radiofrequency ablation (RFA) and microwave ablation (MWA) have been used in patients with low-risk PTMC who refuse surgery or active surveillance. However, its clinical value remains controversial.

MATERIALS AND METHODS

This retrospective multicenter study included 474 patients with solitary low-risk PTMC treated with TA (357 for RFA; 117 for MWA) from 4 centers and followed up for at least 5 years. Disease progression including lymph node metastasis and recurrent tumors, volume reduction rate (VRR), tumor disappearance rate, complications, and delayed surgery were assessed. RFA and MWA outcomes were compared using propensity score matching.

RESULTS

During the median follow-up period of 77.2 months, disease progression incidence, lymph node metastasis, and recurrent tumors rates were 3.6%, 1.1%, and 2.5%, respectively. Age below 40 years old, male sex, Hashimoto thyroiditis, and tumor size were not independent factors associated with disease progression by Cox analysis. The median VRR was 100% and 471 tumors disappeared radiographically. Eight patients experienced transient voice change (1.7%) which recovered within 3 months. None of the patients underwent delayed surgery because of anxiety. After 1:1 matching, no significant differences were found in the disease progression, VRR, tumor disappearance rate, or complications between RFA and MWA subgroups.

CONCLUSION

This multicenter study revealed that TA was an effective and safe treatment for patients with solitary low-risk PTMC, which could be offered as a treatment option for the management for low-risk PTMC.

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.

Age-Dependent Clinicopathological Characteristics of Patients with T1b Papillary Thyroid Carcinoma: Implications for the Possibility of Active Surveillance

BACKGROUND

Active surveillance (AS) of low-risk T1a papillary thyroid carcinoma (PTC) is generally accepted as an alternative to immediate surgery. The cut-off in the size criterion for AS has recently been extended in select individuals, especially older patients. We evaluated the clinicopathological differences of T1b PTC according to age to investigate the possibility of AS in older patients.

PATIENTS AND METHODS

From a cohort study of 1269 patients undergoing lobectomy for PTC, 1223 PTC patients with T1 stage disease (tumor ≤ 2 cm) were enrolled. The clinicopathological characteristics between T1a and T1b patients according to age were analyzed.

RESULTS

Among the 1223 T1 cases, 918 (75.1%) were T1a (≤ 1 cm) and 305 (34.9%) T1b (> 1 and ≤ 2 cm). T1b PTC was associated with male sex, minimal extrathyroidal extension, lymphovascular invasion, occult central lymph node (LN) metastasis, and a higher number of metastatic LNs than T1a. However, in patients over 55 years of age, the clinicopathological features of the patients with T1a and T1b PTC were not significantly different except for minimal extrathyroidal extension, although many clinicopathological differences were observed in patients under 55 years of age.

CONCLUSION

The clinicopathological features of patients with T1b PTC over 55 years of age are similar to those with T1a PTC and less aggressive than those with T1b PTC under 55 years of age. These findings suggest that AS may be possible in patients with T1b PTC over 55 years of age without high-risk features on preoperative examinations.

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.

Analysis of Therapeutic Effect and Influencing Factors of Ultrasound-Guided Radiofrequency Ablation in the Treatment of Papillary Thyroid Microcarcinoma

OBJECTIVES

The current study sought to explore the effects of ultrasound (US)-guided radiofrequency ablation (RFA) on papillary thyroid microcarcinoma (PTMC) and influencing factors.

METHODS

PTMC patients were assigned to observation (US-guided RFA) and control (surgical operation) groups. A series of operation-related indexes (operation time, intraoperative bleeding, wound closure time, hospital stay, and expenses), visual analogue scale score, lesion size, and thyroid function-related indexes (thyroid-stimulating hormone [TSH], free triiodothyronine*** [FT3], free thyroxine [FT4]), inflammatory factors, and thyroglobulin antibody (TgAb) were assessed and compared. After a 6-month follow-up period, the complications and recurrence were recorded, in addition to analyses of postoperative recurrence cumulative incidence and evaluation of recurrence risk factors.

RESULTS

Operation-related indexes of the observation group were relatively decreased compared with the control group. In addition, the lesion volume in the observation group was lower compared to that in the control group at the 6th month after operation, whereas the volume reduction rate was higher. There were no significant differences in regard to thyroid function-related indexes in the observation group before/after operation. After operation, serum TSH levels and inflammatory factors, and TgAb levels were all diminished, while the FT3 and FT4 levels were both elevated in the observation group relative to the control group, and postoperative recurrence cumulative incidence was lower in the observation group. TSH and TgAb were established as the independent risk factors for recurrence after RFA in PTMC patients.

CONCLUSIONS

Our findings highlighted that US-guided RFA exhibits better efficacy, safety, and postoperative recovery and lower recurrence risk for PTMC.

Risk factors and prediction models of lymph node metastasis in papillary thyroid carcinoma based on clinical and imaging characteristics

BACKGROUND

Papillary thyroid carcinoma (PTC) commonly presents with lymph node metastasis, which may be associated with worsened prognosis. This study aimed to comprehensively evaluate the risk factors of lymph node metastasis in PTC based on preoperative clinical and imaging data and to construct a nomogram model to predict the risk of lymph node metastasis.

METHODS

A total of 989 patients with PTC were enrolled and randomly divided into training and validation cohorts in an 8:2 ratio. Independent risk factors for lymph node metastasis in PTC were analyzed using univariate and stepwise multivariate logistic regression. An importance analysis of independent risk factors affecting lymph node metastasis was performed according to the random forest method. Subsequently, a nomogram to predict lymph node metastasis was constructed, and the predictive effect of the nomogram was evaluated using receiver operating characteristic analysis and calibration curves.

RESULTS

Univariate regression analysis revealed that age, sex, body weight, systolic blood pressure, free triiodothyronine, nodule location, nodule number, Thyroid Imaging Reporting and Data System (TI-RADS) grade on color Doppler ultrasound, enlarged lymph node present on imaging, and nodule diameter could affect lymph node metastasis in PTC. Stepwise multivariate regression analysis showed that sex, age, enlarged lymph node present on imaging, nodule diameter, and color Doppler TI-RADS grade were independent risk factors for lymph node metastasis in PTC. Combining these five independent risk factors, a nomogram prediction model was constructed. The area under the curve (AUC) of the nomogram in the training and validation cohorts was 0.742 and 0.765, respectively, with a well-fitted calibration curve.

CONCLUSION

Our study showed that independent risk factors for lymph node metastasis in PTC were sex, age, enlarged lymph node present on imaging, nodule diameter, and color Doppler TI-RADS grade. The nomogram constructed based on these independent risk factors can better predict the risk of lymph node metastasis.

Latest evidence of microwave ablation for papillary thyroid microcarcinoma compared with surgery: A systematic review and meta-analysis

Background

The most typical thyroid gland malignant lesion is papillary thyroid cancer (PTC). In many nations, the prevalence of thyroid cancer (TC) is rising, particularly papillary thyroid microcarcinoma (PTMC). Microwave ablation (MWA) has been gradually carried out in some patients with benign thyroid nodules, some low-risk PTMC, and metastatic lymph nodes in the neck. The role and safety of MWA remain controversial topics. So we conducted this study to provide the latest evidence of MWA for PTMC compared with surgery.

Methods

Patients' postoperative outcomes (duration of hospital stay and hospitalization expenditures), intraoperative outcomes (surgery time, blood loss, and incision size), and follow-up outcomes were all examined (complication rate, recurrence rate, and lymph node metastasis). The effectiveness and safety of MWA versus surgery for PTMC patients were compared using the weighted mean difference (WMD) and odds ratio (OR).

Results

In total, we included 7 articles (7 trial comparisons) which contained 1, 567 PTMC patients. The results showed that MWA had significant advantages in operative time (WMD = -53.47, 95% CI: -67.62 to -39.32), postoperative hospital stay (WMD =-4.59, 95% CI: -6.40 to -2.77), hospitalization costs (WMD= -70.06, 95% CI: -90.93 to -49.19), blood loss (WMD =-28.07, 95% CI: -33.77 to -22.38), incisions size (WMD =-59.69, 95% CI: -67.79 to -51.59), and complication rates (OR = 0.28; 95% CI: 0.18 to 0.42) compared with surgery. It also showed that recurrence rates and risk of lymph node metastasis are similar to surgery.

Conclusions

For PTMC patients, MWA could be an efficient, safe, and affordable therapy.

Optimal thyrotropin level for low-risk papillary thyroid carcinoma after ultrasound-guided radiofrequency ablation

PURPOSE

Maintaining an optimal thyroid stimulating hormone (TSH) level is important in the postoperative management of papillary thyroid carcinoma (PTC). However, there is little evidence for TSH target levels in patients undergoing radiofrequency ablation (RFA). This study aimed to determine the optimal TSH level for management in low-risk patients who underwent RFA.

METHODS

This retrospective propensity score-matched cohort study included patients with low-risk PTC who underwent RFA from January 2014 to December 2018. The patients were categorized into two groups based on the range of TSH levels: low (≤2 mU/L) and high (>2 mU/L) TSH levels. Local tumor progression and disease-free survival (DFS) were compared between the low TSH and high TSH groups, using propensity score analyses based on patient- and tumor-level characteristics. Univariate analyses were performed to select risk factors for tumor progression.

RESULTS

Overall, our study included 516 patients with low-risk PTC who underwent RFA with a long-term follow-up of 5-years. During follow-up, the overall incidence rate of local tumor progression was 4.8% (25/516), with no significant difference between the matched groups (7/106 [6.6%] vs. 5/53 [9.4%], p = 0.524). DFS did not differ between the two groups (p = 0.5). Moreover, TSH level was not regarded as a significant predictor of tumor progression after Cox analysis; primary tumor size was the only relevant risk factor.

CONCLUSION

This large propensity-matched study revealed no association between TSH levels and tumor progression. Thus, for patients with low-risk PTC who underwent RFA, the optimalTSH level is recommended at the euthyroid range.

Surgical treatment of thyroid cancer: Established and novel approaches

Thyroid surgery is one of the most common head and neck procedures. The thyroid can be accessed through an anterior cervical incision, or by remote access techniques such as the transoral endoscopic thyroidectomy vestibular approach (TOETVA) which is favored for its ease, safety and direct plane to the thyroid gland. Other novel approaches for targeting small-localized well-differentiated thyroid cancer are by thermal ablation, namely ultrasound guided radiofrequency ablation. These innovative techniques for minimizing a cutaneous scar or for targeting small cancers directly without removal of the gland have developed alongside our realization that low risk well-differentiated thyroid cancer tends to be slow growing and indolent. Up to date, the most robust data supports offering these therapies primarily to patients who would be eligible for active surveillance protocols. In this paper, we review the traditional surgical approaches for removing well-differentiated thyroid cancer, as well as innovative remote access techniques (namely TOETVA), and minimally invasive thermal ablation (namely RFA).

Position paper from the Endocrine Task Force of the European Organisation for Research and Treatment of Cancer (EORTC) on the management and shared decision making in patients with low-risk micro papillary thyroid carcinoma

The incidence of differentiated thyroid cancer (DTC) has been increasing worldwide, mostly, as an increase in the incidental detection of micro papillary thyroid carcinomas (microPTCs), many of which are potentially overtreated, as suggested by the unchanged mortality. Several international guidelines have suggested a less aggressive approach. More recently, it has been shown that active surveillance or minimally invasive treatments (MIT) are good alternatives for the management of these patients. In this context, patient participation in the decision-making process is paramount. The Endocrine Task Force of the European Organisation for Research and Treatment of Cancer (EORTC) has undertaken the task to establish consensus and define its position based on the scientific evidence concerning, 1) the current state of diagnostic and management options in microPTCs, including the current opinion of physicians about shared decision making (SDM), 2) the available evidence concerning patients' needs and the available decision instruments, and 3) to provide practical suggestions for implementation of SDM in this context. To improve SDM and patients' participation, knowledge gaps and research directions were highlighted.

A comparative study of quality of life in patients with papillary thyroid carcinoma undergoing microwave ablation vs. Total thyroidectomy

OBJECTIVE

To compare the health-related quality of life (HRQoL) of patients with T1N0M0 papillary thyroid carcinoma (PTC) who underwent microwave ablation (MWA) and those who underwent total thyroidectomy (TT).

MATERIALS AND METHODS

From February 2018 to February 2022, 180 T1N0M0 PTC patients were enrolled in present study, including 90 in the MWA group and 90 in the TT group, respectively. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and Thyroid Cancer-Specific Quality of Life Questionnaire (THYCA-QoL) were completed by patients to evaluate their HRQoL scores.

RESULTS

According to the results of the EORTC-QLQ-C30, there was a significant difference in the scores of global health, physical, emotional, etc. between the two groups, which indicated that the quality of life in these items in the MWA group was better than those in the TT group (all p < 0.05). According to the results of the THYCA-QoL, all items had significant differences between the two groups except for headache, which demonstrated the thyroid-specific quality of life was higher in the MWA group than in the TT group (all p < 0.05).

CONCLUSION

Ultrasound (US)-guided MWA offers a significant advantage in HRQoL over TT in T1N0M0 PTC patients, which provides an important reference for MWA as an alternative strategy to TT.

Nomogram for predicting central lymph node metastasis in T1-T2 papillary thyroid cancer with no lateral lymph node metastasis

OBJECTIVE

Whether routine central lymph node dissection (CLND) is necessary for T1-T2 papillary thyroid carcinoma (PTC) patients without certain lateral lymph node metastases (LLNM) remains controversial. This study aims to construct a nomogram that predicts central lymph node metastasis (CLNM) for T1-T2 PTC patients without LLNM.

METHODS

We retrospectively reviewed adult T1-T2 PTC patients with no LLNM retrieved from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. We also collected data from patients treated at the First Hospital of China Medical University between February and April 2021 for external validation. Logistic regression model was used to construct a risk prediction model nomogram. The receiver-operating characteristic (ROC) curve, calibration plot, and decision curve analyses (DCA) were used for assessing the nomogram.

RESULTS

5,094 patients from the SEER database and 300 patients from our department were finally included in this study. Variables such as age, gender, race, tumor size, multifocality, and minimal extrathyroidal extension (mETE) were found to be associated with CLNM and were subsequently incorporated into our nomogram. The C-index of our constructed model was 0.704, while the internal and external validation C-indexes were 0.693 and 0.745, respectively. The nomogram was then evaluated using calibration and decision curve analyses.

CONCLUSION

A visualized nomogram was successfully developed to predict CLNM in T1-T2 PTC patients without LLNM and assist clinicians in making personalized clinical decisions.

Cost comparison between open thyroid lobectomy and radiofrequency ablation for management of thyroid nodules

BACKGROUND

There is an increasing array of treatment options for addressing clinically significant thyroid nodules, including radiofrequency ablation (RFA). While effective, the cost compared to alternative approaches has not been well elucidated.

METHODS

This study involved a retrospective chart review, focusing on variable direct cost (VDC) of each procedure, from April 2016 to January 2020. We analyzed costs for 53 open lobectomies and 16 RFA procedures.

RESULTS

Cost effectiveness depended on the simulated cost of the RFA probe. In comparison to open lobectomy, the VDC to perform RFA was $597 (19%) cheaper when the simulated probe cost was $1500 and $403 (13%) more expensive for a probe cost of $2500. Statistical significance was achieved for both these differences.

CONCLUSIONS

If cost per RFA probe can be less than $2100-the break-even dollar amount between open lobectomy and RFA-there would be considerable cost savings for treating thyroid nodules.

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.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Thermal ablation

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with thermal ablation, which may constitute an alternative to thyroid surgery in selected patients.

A systematic review and meta-analysis comparing tumor progression and complications between radiofrequency ablation and thyroidectomy for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid cancers worldwide. The efficacy and acceptability of radiofrequency ablation (RFA) in the treatment of PTC have been intensively studied. The aim of this study is to focus on extra detailed that may influent for PTC or papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

We identified a total of 1,987 records of a primary literature searched in PubMed, Embase, Cochrane Library, and Google Scholar by key words, from 2000 to 2022. The outcome of studies included complication, costs, and local tumor progression. After scrutiny screening and full-text assessment, six studies were included in the systematic review. Heterogeneity was estimated using I2, and the quality of evidence was assessed for each outcome using the GRADE guidelines.

RESULTS

Our review enrolled 1,708 patients reported in six articles in the final analysis. There were 397 men and 1,311 women in the analysis. Two of these studies involved PTC and four focused on PTMC. There were 859 patients in the RFA group and 849 patients in the thyroidectomy group. By contrast, the tumor progression of RFA group was as same as that surgical groups [odds ratio, 1.31; 95% CI, 0.52-3.29; heterogeneity (I2 statistic), 0%, p = 0.85]. The risk of complication rates was significantly lower in the RFA group than that in the surgical group [odds ratio, 0.18; 95% CI, 0.09-0.35; heterogeneity (I2 statistic), 40%, p = 0.14].

CONCLUSIONS

RFA is a safe procedure with a certain outcome for PTC. RFA can achieve a good efficacy and has a lower risk of major complications.

Microwave Ablation versus Surgical Resection for Solitary T1N0M0 Papillary Thyroid Carcinoma

Background Microwave ablation (MWA) has attracted interest as a minimally invasive treatment for papillary thyroid carcinoma (PTC). However, comparisons between MWA and surgical resection (SR) in the management of T1N0M0 PTC are rare. Purpose To compare the technical effectiveness, disease progression, and complications of MWA and SR for solitary T1N0M0 PTC. Materials and Methods This retrospective study was conducted in a single center. A total of 1029 patients with T1N0M0 PTC treated with either MWA or SR from January 2015 to May 2021 were studied and divided into two groups according to treatment modality. Propensity score matching and inverse probability of treatment weighting were used to control for confounding factors. Disease progression was analyzed in T1N0M0 PTCs as well as T1a and T1b subgroups by using Kaplan-Meier curves and Cox proportional hazards regression models. Results A total of 404 patients (mean age, 43 years ± 12 [SD]; 289 women; 337 with T1a PTC) underwent MWA, and 625 (mean age, 46 years ± 12; 495 women; 521 with T1a PTC) underwent SR. During the follow-up (median, 25 months; IQR, 7-61 months), there was no evidence of differences regarding disease progression in T1N0M0 (4.0% vs 4.0%; P = .97), T1a (3.4% vs 3.8%; P = .89), or T1b PTCs (6.8% vs 5.0%; P = .72). Compared with SR, MWA resulted in less blood loss (2 mL vs 10 mL) and a shorter procedure time (23 minutes vs 72 minutes) (both P < .001). The rate of major complications was 5.4% (19 of 350 patients) in the MWA group and 6.3% (22 of 350 patients) in the SR group (P = .75). Permanent hoarseness only occurred in the SR group (1.7%; P = .03). Conclusion For T1a and T1b solitary T1N0M0 papillary thyroid carcinomas, there was no evidence of differences regarding disease progression and major complications between microwave ablation and surgical resection. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by vanSonnenberg and Simeone in this issue.

Comparison of ultrasound-guided radiofrequency ablation versus thyroid lobectomy for T1bN0M0 papillary thyroid carcinoma

OBJECTIVE

To investigate and compare the clinical outcomes between radiofrequency ablation (RFA) and thyroid lobectomy (TL) for T1bN0M0 papillary thyroid carcinoma (PTC).

METHODS

This retrospective study evaluated 283 patients with solitary T1bN0M0 PTC treated with RFA (RFA group, 91 patients) or TL (TL group, 192 patients) from May 2014 to November 2018. The patients were regularly followed up after treatment. Local tumor progression, lymph node metastasis (LNM), recurrent tumor, persistent tumor, recurrence-free survival (RFS), treatment variables (hospitalization, procedure time, estimated blood loss, and cost), complication, and delayed surgery were compared.

RESULTS

During the follow-up (median [interquartile ranges], 50.4 [18.0] months), no significant differences were found in the local tumor progression (4.4% vs 3.6%, p = 1.000), LNM (1.1% vs 2.1%, p = 0.917), recurrent tumor (2.2% vs 1.6%, p = 1.000), persistent tumor (1.1% vs 0%, p = 0.146), and RFS rate (95.6% vs 96.4%, p = 0.816) in the RFA and TL groups. Distant metastasis was not detected. Patients in the RFA group had a shorter hospitalization (0 vs 7.0 [3.0] days, p < 0.001), shorter procedure time (5.6 [2.9] vs 90.0 [38.5] min, p < 0.001), lower estimated blood loss (0 vs 20 [20] mL, p < 0.001), lower cost ($1972.5 [0.1] vs $2362.4 [1009.3], p < 0.001), and lower complication rate (0 vs 12/192 [6.3%], p = 0.015) than those in the TL group. No patients in the RFA group underwent delayed surgery.

CONCLUSIONS

This study revealed comparable 4-year clinical outcomes between RFA and TL for T1bN0M0 PTC in terms of local tumor progression and RFS. As a minimally invasive modality, RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

KEY POINTS

• No significant difference in local tumor progression and RFS was found between RFA and TL for T1bN0M0 PTC during a median follow-up period of 50.4 months. • Compared with TL, RFA led to a shorter hospitalization, lower estimated blood loss, lower cost, and lower complication rate. • RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

Ultrasound gray scale ratio for differential diagnosis of papillary thyroid microcarcinoma from benign micronodule in patients with Hashimoto's thyroiditis

BACKGROUND

To investigate the diagnostic value of ultrasound gray scale ratio (UGSR) in differentiating papillary thyroid microcarcinomas (PTMCs) from benign micronodules (BMNs) in patients with Hashimoto's thyroiditis (HT).

METHODS

The ultrasound images of 285 PTMCs (from 247 patients) and 173 BMNs (from 140 patients) in the HT group, as well as 461 PTMCs (from 417 patients) and 234 BMNs (from 197 patients) in the non-HT group were retrospectively analyzed. The diagnosis of all cases was confirmed by histopathological examinations. The gray scale values of the nodules and surrounding thyroid tissues were measured and subsequently the UGSRs were calculated. Receiver operating characteristic curve analysis was used to determine the area under the curve (AUC), optimal UGSR threshold, sensitivity and specificity in differentiating PTMCs and BMNs in the two groups.

RESULTS

The UGSR of PTMC and BMN was 0.52 ± 0.12 and 0.85 ± 0.24 in the HT group (P < 0.001), and 0.57 ± 0.13 and 0.87 ± 0.20 in the non-HT group (P < 0.001), respectively. The difference in PTMC-UGSR was significant between the two groups (P < 0.001), whereas BMN-UGSR did not differ between the two groups (P = 0.416). The AUC, optimal UGSR threshold, sensitivity and specificity of UGSR for differentiating PTMC and BMN in the HT and non-HT group were 0.890 versus 0.901, 0.68 versus 0.72, 91.23% versus 90.67%, and 77.46% versus 82.05%, respectively.

CONCLUSIONS

The USGR of the HT group was lower than that of the non-HT group. Moreover, UGSR exhibited important diagnostic value in differentiating PTMC from BMN in both HT and non-HT groups.