Revisiting Rupture of Benign Thyroid Nodules after Radiofrequency Ablation: Various Types and Imaging Features

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.

The Comparison of Efficacy and Safety between Radiofrequency Ablation Alone and Ethanol Ablation Followed by Radiofrequency Ablation in the Treatment of Mixed Cystic and Solid Thyroid Nodule

Purpose

To compare the efficacy and safety of radiofrequency ablation (RFA) and ethanol ablation (EA) followed by RFA in treating mixed cystic and solid thyroid nodules.

Materials and Methods

We included 243 nodules from 243 patients who underwent RFA for mixed cystic and solid benign nodules. The nodules were divided into two groups (RFA alone and EA + RFA). We evaluated volume reduction rate (VRR), therapeutic success rate, improvement in symptomatic and cosmetic issues, complications, and adverse effects.

Results

The RFA group included 204 patients, and the EA + RFA group included 39 patients. The long-term success rates in the RFA only and EA + RFA groups were 90.2% and 97.4%, respectively. The mean VRR at the last follow-up in the RFA and EA + RFA groups were 81.6% and 87.2%, respectively. Therapeutic results were similar in both groups at the last follow-up. Cosmetic and symptomatic problems markedly improved in both groups. No major complications were observed.

Conclusion

Both RFA alone and EA + RA are safe and effective methods for treating mixed cystic and solid thyroid nodules, although EA + RFA is slightly more effective.

Thyroid nodule rupture after radiofrequency ablation: case report and literature review

Purpose

Radiofrequency ablation (RFA) is an effective and safe modality for the treatment of thyroid nodules. Nodule rupture is a major complication of RFA. There is little known on the natural history of nodule rupture due to a lack of clinical experience and no consensus on its management. A comprehensive review of nodule rupture presentation, diagnosis, and management is needed.

Methods

We report a case of nodule rupture and conduct a literature review. A total of 33 patients experiencing nodule rupture after RFA were included, and their clinical presentation, management, and outcomes were collected and analyzed.

Results

Nodule rupture presents with acute swelling (90.3%) and pain (77.4%) within 7 months of RFA procedure, most commonly due to disruption of the anterior thyroid capsule (87%), and can be diagnosed with ultrasonography. Most ruptures can be managed conservatively, exemplified by our reported case. There are no reported cases of long-term sequalae.

Conclusion

Nodule rupture is the second most common major complication of RFA. Based on the available evidence, we propose a treatment algorithm for nodule rupture and recommendations for future data collection to address gaps in our understanding of rupture etiology and effective management.

Cutaneous fistula formation after thyroid nodule rupture: A rare complication after radiofrequency ablation

BACKGROUND

With innovative treatment options such as radiofrequency ablation (RFA) for thyroid nodules, new complications are being identified. It is important to define and delineate complications in order to counsel patients appropriately about treatment options and their associated risks and benefits.

METHODS

A 46-year-old male presented with a left thyroid nodule (6.5 cm). Fine needle aspiration results were benign. He started to develop intermittent dyspnea and underwent one RFA procedure. Approximately 6 days post-RFA, the neck area was raised and red with blister. The skin overlying the blister underwent eventual dehiscence with fluid spillage. Several months later, MRI imaging showed substernal extension with tracheal deviation.

RESULTS

A left thyroid lobectomy was performed with cutaneous excision and successful closure of a fistula.

CONCLUSIONS

This is the first reported case of a thyroid nodule rupture following RFA which manifested into a thyro-cutaneous fistula and required surgical intervention.

Assessing the efficacy of thyroid nodule radiofrequency ablation using patient-reported outcome measures

BACKGROUND

Radiofrequency ablation has recently emerged as an alternative treatment for thyroid nodules. Most studies are centered on volume reduction, whereas a few have assessed symptom improvement mainly with nonstandardized metrics. As experience in the United States is growing, we aim to assess the efficacy of radiofrequency ablation in treating benign thyroid nodules using the validated Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease.

METHODS

This is a prospective study of a newly established radiofrequency ablation program at a single tertiary referral center in 2022. Patients who underwent radiofrequency ablation were evaluated using the Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease, a validated metric ranging from 0 to 100 at baseline, 2 weeks, 3 months, and 6 months. In addition, a thyroid ultrasound was done at those intervals to assess size and volume reduction. Procedure complications were evaluated as well.

RESULTS

A total of 25 patients underwent radiofrequency ablation during the study period for a total of 32 nodules treated; 84% were female with a mean age of 51 years. The baseline mean nodule volume and largest dimension were 13 ± 11 mL and 3.4 ± 1 cm, respectively. A significant change in the Patient-Reported Outcomes Measurement for Parathyroid and Thyroid Disease compressive score was seen at 3 months (38.9 ± 26.4 to 21.0 ± 21.4; P = .004) and 6 months (32.7 ± 19.9 to 17.5 ± 21.0; P = .02) but not at 2 weeks (41.0 ± 22.7 to 36.1 ± 21.9; P = .28). Significant volume and size reductions were seen at all 3-time points. Two complications occurred.

CONCLUSION

Our initial results of the thyroid radiofrequency ablation program find that it effectively alleviates symptoms by reducing nodule size in patients with symptomatic benign thyroid nodules.

Efficacy of radiofrequency ablation for treatment of toxic thyroid nodules-a narrative review

Background and Objective

Radiofrequency ablation (RFA) has been used in the treatment of benign thyroid nodules for the past 20 years. The adaptation of RFA to benign autonomously functioning thyroid nodules (AFTNs) has been introduced into clinical practice with variable efficacy and outcomes published in the literature. To better understand international practices, we performed a literature search to better elucidate the efficacy and outcomes in the treatment of AFTNs with RFA.

Methods

Comprehensive literature searches were independently conducted by two investigators on PubMed, EMBASE, and Scopus in October of 2022 to identify articles reporting AFTN treated by RFA using the terms "RFA", "radiofrequency ablation", "thyroid nodule", "toxic nodules", and "autonomous functioning thyroid nodule". Papers were selected by relevance of the title or abstract, and the date of publication.

Key Content and Findings

In patients with toxic nodules, studies have shown 50% remission rate one year after single session of RFA, up to 71% after second dose. Adverse events are generally limited to postoperative pain lasting less than one day, however there are reports of self-limited voice changes, and self-limited hypothyroidism. RFA has been shown to be safe with no reported instances of post-procedure hypothyroidism or hypocalcemia when compared to radioactive iodine (RAI) and surgery.

Conclusions

RFA is an acceptable alternative to surgical resection for the treatment of AFTNs in selective patients, however more studies on long-term hyperthyroidism remission rates and nodule regrowth are necessary for further applications.

Radiofrequency ablation of thyroid nodules: a clinical review of treatment complications

Radiofrequency ablation (RFA) is a minimally invasive ablative modality for the treatment of thyroid nodules. Reports of RFA use have demonstrated an impressive safety profile and excellent volume reduction rates between 60-90%. Given its increased popularity in the United States as well as globally, numerous recent works have been published and a discussant of relevant complications incorporating recent insight may assist practitioners in minimizing complications and optimizing patient outcomes. Herein, we provide a comprehensive and updated review of the reported complications and side effects following RFA, summarizing their frequency and clinical presentation. We also describe a means of minimizing such complications and/or side effects. Overall, the safety profile of RFA is impressive and superior to that of thyroid surgery. The overall risk of complication is reportedly 2-3%. The risk of permanent complication or severe injury is very unlikely, below 1%. Complications are infrequent, but may be nerve-related, endocrine-related, or iatrogenic-related, and consequences of localized heat delivery. The vast majority of complications related to RFA can be managed conservatively, without need for invasive measures. This review will assist surgeons and clinicians in recognizing and treating the various complications and side effects in clinical practice.

Radiofrequency Ablation for Benign Thyroid Nodules

CONTEXT

Thermal ablative techniques of the thyroid have recently gained clinical traction as a therapeutic alternative that provides symptomatic relief and confers potential advantages over surgery. A truly multidisciplinary technique, thyroid ablation is currently performed by endocrinologists, interventional radiologists, otolaryngologists, and endocrine surgeons. Radiofrequency ablation (RFA), specifically, has seen widespread adoption, particularly in the treatment of benign thyroid nodules. This review summarizes current evidence on the application of RFA in benign thyroid nodules, and provides a start to finish overview of procedural preparation, performance, and outcomes.

EVIDENCE ACQUISITION

A narrative review of literature focusing on RFA in the treatment of benign nodular disease was performed. Emphasis was placed on consensus statements, best practice guidelines, multi-institutional studies, and systematic reviews to summarize key concepts in candidacy, techniques, expectations, and outcomes.

FINDINGS

RFA is increasingly recognized as a first-line treatment strategy in the management of symptomatic nonfunctional benign thyroid nodules. It can also be considered in functional thyroid nodules with small volumes or in patients ineligible for surgery. A targeted and efficacious technique, RFA results in gradual volume reduction that preserves the function of the surrounding thyroid parenchyma. Proper procedural technique, proficiency in ultrasound, and experience in ultrasound-guided procedures are instrumental to maintaining low complication rates and achieving successful ablation outcomes.

CONCLUSIONS

In pursuit of a personalized approach, physicians across disciplines are increasingly incorporating RFA into their treatment algorithms, most commonly for benign nodules. As with any intervention, thoughtful selection and implementation ensure a safe procedure with optimal patient benefit.

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

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

Radiofrequency Ablation for Benign Thyroid Nodules: Radiology In Training

Two patients, one with benign nonfunctioning nodules and one with functioning thyroid nodules, both of whom underwent radiofrequency ablation, are presented. Preprocedural evaluation, procedural considerations, and follow-up care of thyroid radiofrequency ablation, as well as published evidence on the topic, are discussed.

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.

Microwave Ablation Vs Traditional Thyroidectomy for Benign Thyroid Nodules: A Prospective, Non-Randomized Cohort Study

RATIONALE AND OBJECTIVES

To evaluate the efficacy of microwave ablation (MWA) for benign thyroid nodules (BTNs) and compare trauma and complication rates between MWA and traditional thyroidectomy for BTNs.

MATERIALS AND METHODS

84 patients with BTNs were recruited and followed up at 1, 3, 6, and 12months. 56 and 28 patients chose to undergo MWA (group A) and traditional thyroidectomy (group B), respectively. Efficacy was assessed by volume reduction rate (VRR) and therapeutic success rate (TSR) at each follow-up. Trauma was compared using inflammation response parameters, visual analog scale (VAS) scores, quality of life (QOL) and thyroid function measures at 1, 3, and 6 months. Complications rates were also compared.

RESULTS

The VRR was 80.70 ± 18.60%, and TSR was 91.70% at 6-months. Furthermore, the VRR increased to 90.45 ± 11.51%, and TSR increased to 100% at 12-months. C-reactive protein levels were significantly higher in group B on the first postoperative day (POD) (3.89 ± 0.86 mg/mL vs 3.39 ± 0.56 mg/mL, p = 0.002). Visual analog scale scores were significantly lower in group A on the first and second POD. Thyroid stimulating hormone levels were significantly lower in group A at three (1.71 ± 1.12uIU/mL vs 2.37 ± 1.24uIU/mL, p = 0.013) and 6-months (1.34 ± 0.70uIU/mL vs 1.97 ± 0.94uIU/mL, p = 0.002). There were no significant between-group differences in QOL and complication rates.

CONCLUSION

Microwave ablation shows acceptable and promising efficacy. Compared with thyroidectomy, MWA was associated with less trauma and comparable complication rates.

American Association of Clinical Endocrinology Disease State Clinical Review: The Clinical Utility of Minimally Invasive Interventional Procedures in the Management of Benign and Malignant Thyroid Lesions

OBJECTIVE

The objective of this disease state clinical review is to provide clinicians with a summary of the nonsurgical, minimally invasive approaches to managing thyroid nodules/malignancy, including their indications, efficacy, side effects, and outcomes.

METHODS

A literature search was conducted using PubMed and appropriate key words. Relevant publications on minimally invasive thyroid techniques were used to create this clinical review.

RESULTS

Minimally invasive thyroid techniques are effective and safe when performed by experienced centers. To date, percutaneous ethanol injection therapy is recommended for recurrent benign thyroid cysts. Both ultrasound-guided laser and radiofrequency ablation can be safely used for symptomatic solid nodules, both toxic and nontoxic. Microwave ablation and high-intensity focused ultrasound are newer approaches that need further clinical evaluation. Despite limited data, encouraging results suggest that minimally invasive techniques can also be used in small-size primary and locally recurrent thyroid cancer.

CONCLUSION

Surgery and radioiodine treatment remain the conventional and established treatments for nodular goiters. However, the new image-guided minimally invasive approaches appear safe and effective alternatives when used appropriately and by trained professionals to treat symptomatic or enlarging thyroid masses.

Minimally-invasive treatments for benign thyroid nodules: recommendations for information to patients and referring physicians by the Italian Minimally-Invasive Treatments of the Thyroid group

PURPOSE

In this paper, the members of the Italian Working Group on Minimally-Invasive Treatments of the Thyroid (MITT group) aim to summarize the most relevant information that could be of help to referring physicians and that should be provided to patients when considering the use of MITT for the treatment of benign thyroid nodules.

METHODS

An interdisciplinary board of physicians with specific expertise in the management of thyroid nodules was appointed by the Italian MITT Group. A systematic literature search was performed, and an evidence-based approach was used, including also the knowledge and the practical experience of the panelists to develop the paper.

RESULTS

The paper provides a list of questions that are frequently asked by patients to operators performing MITT, each with a brief and detailed answer and more relevant literature references to be consulted.

CONCLUSIONS

This paper summarizes the most relevant information to be provided to patients and general practitioners/referring physicians about the use of MITT for the treatment of benign thyroid nodules.

Radiofrequency ablation and thyroid cancer: review of the current literature

BACKGROUND

Thyroid nodules are commonly being diagnosed in general population and have a potential for malignant transformation. Historically, surgery has been considered as the first line treatment for these tumors. However, with passage of time newer minimally invasive techniques such as RFA (radiofrequency ablation) has been adapted. Though, RFA for thyroid tumors has been performed more commonly in Asian and European countries, it is a fairly new technique in North America. The aim of the review is to assess the current data and conclude that whether RFA is likely a valuable option when compared to surgery for treatment of thyroid tumors.

MATERIALS AND METHODS

A Comprehensive PubMed/MEDLINE, Embase and Web of Science search was performed. To expand our search, references of the retrieved articles were also screened for additional data. After selecting the studies that fulfilled the initial screening, authors independently reviewed the selected studies and screened the full texts to identify those that met the inclusion criteria.

RESULTS

The comprehensive literature search from PubMed/MEDLINE, Web of Science, and EMBASE databases revealed 1094 studies (Embase 870, PubMed 200, and Web of Science 24). References were imported for screening. Amongst 1094 studies, 138 duplicates removed, and 956 studies were screened against title and abstract. After these 777 studies were excluded the remaining 179 studies were assessed for full-text eligibility. Amongst them 127 studies excluded due to wrong design or setting. Finally, 18 studies were included in the review.

CONCLUSION

RFA appears to be a safe alternative to surgery in selected cases. However, it is not widely used and there are few randomized controlled trials. Furthermore, it is associated with a low risk profile and has shown promising results in patients who are difficult surgery candidates. Currently large-scale prospective studies are needed in North America to establish the efficacy of RFA and its use as an alternative to surgery for thyroid tumors.

Long-Term Follow-Up of Single-Fiber Multiple Low-Intensity Energy Laser Ablation Technique of Benign Thyroid Nodules

Aim

The short-term and long-term efficacy of different thermal percutaneous ablation techniques remains a topical issue. Our group implemented percutaneous laser ablation (LA), a moving-shot technique to increase efficiency and reduce costs and variability of LA by applying multiple lower-intensity energy illuminations (MLIEI) covering the nodular volume (V) through changes in position of a single laser fiber within the thyroid nodule. The aim of the present study was to evaluate the efficacy of the single-fiber LA-MLIEI during a 5-year follow-up and to identify possible predictors of the final outcome.

Methods

Prospective study: Thirty outpatients (23 women and seven men) with benign symptomatic thyroid nodules were assigned to single-fiber LA-MLIEI, between 2012 and 2015. A single LA session was performed under real-time ultrasound (US) guidance using a 1,064-nm continuous-wave laser at 3 W. A 400-µm optical fiber was inserted through a 21-gauge needle, and 3–10 illuminations were performed per nodule, administering between 400 and 850 J/illumination. The total administered energy was calculated on the initial V of the nodule and the estimated ablation area. US evaluation was performed after LA-MLIEI at 1 week and 1, 3, 6, and 12 months and after that annually up to 5 years. Clinical symptoms, laboratory thyroid function during follow-up, and acute and chronic complications of treatment were registered.

Results

On follow-up, 67% (n: 20) were responders to single-fiber LA-MLIEI, while 33% (n: 10) were non-responders. The responder group initiated V reduction (ΔV) at 1 month, with remission of symptoms, and presented a 50% ΔV at 3 months of treatment; the maximum response was achieved at 24 months and remained stable until the end of the study. The non-responder group presented a ΔV of less than 50% at 12 months; though a tendency to >50% ΔV was observed at 24–36 months, there was subsequent regrowth, and 40% of this group required surgery. ΔV was positively correlated with the total administered energy/V (J/V) and inversely with nodule V. No severe adverse effects were observed. Thyroid function remained normal in all patients. Remission of symptoms occurred rapidly after 1 month.

Conclusions

LA with multiple fractional discharges employing a single fiber in a unique session is a safe and inexpensive technique that allows rapid reduction of thyroid nodules, with a stable response up to 5 years, similarly to what has been reported with the conventional LA. Total nodule volume appears as a predictive factor of the reduction.

Radiofrequency ablation and related ultrasound-guided ablation technologies for treatment of benign and malignant thyroid disease: An international multidisciplinary consensus statement of the American Head and Neck Society Endocrine Surgery Section with the Asia Pacific Society of Thyroid Surgery, Associazione Medici Endocrinologi, British Association of Endocrine and Thyroid Surgeons, European Thyroid Association, Italian Society of Endocrine Surgery Units, Korean Society of Thyroid Radiology, Latin American Thyroid Society, and Thyroid Nodules Therapies Association

BACKGROUND

The use of ultrasound-guided ablation procedures to treat both benign and malignant thyroid conditions is gaining increasing interest. This document has been developed as an international interdisciplinary evidence-based statement with a primary focus on radiofrequency ablation and is intended to serve as a manual for best practice application of ablation technologies.

METHODS

A comprehensive literature review was conducted to guide statement development and generation of best practice recommendations. Modified Delphi method was applied to assess whether statements met consensus among the entire author panel.

RESULTS

A review of the current state of ultrasound-guided ablation procedures for the treatment of benign and malignant thyroid conditions is presented. Eighteen best practice recommendations in topic areas of preprocedural evaluation, technique, postprocedural management, efficacy, potential complications, and implementation are provided.

CONCLUSIONS

As ultrasound-guided ablation procedures are increasingly utilized in benign and malignant thyroid disease, evidence-based and thoughtful application of best practices is warranted.

Symptomatic aseptic necrosis of benign thyroid lesions after microwave ablation: risk factors and clinical significance

BACKGROUND

Symptomatic aseptic necrosis (SAN) followed by nodule rupture is a kind of severe complications after thermal ablation for benign thyroid nodules (BTN). No studies are available to evaluate its pathologic process, clinical manifestations, risk factors and effectiveness of therapies after microwave ablation (MWA).

METHODS

From 2012 to 2019, 398 patients who received MWA for BTN were retrospectively reviewed. Clinical data included baseline patient characteristics, imaging features (internal vascularity and the proportion of the solid component), ablation power and time, complications and prognosis were collected and documented.

RESULTS

Ten patients (2.51%) experienced post-MWA SAN, eight patients with nodule rupture and the other two without. The mean time from MWA to SAN symptom was 8.6 days and to rupture was 16.3 days. The initial symptoms of SAN patients were neck bulging, swelling and discomfort. Patients would go through nodule rupture once the nodule contents extended into the extrathyroidal area with the discontinuity of the anterior thyroid capsule, and fistula formed unavoidably in this condition. Incision drainage was effective for rupture and early treatment of non-steroidal anti-inflammatory drug might cure the early-stage SAN. Multivariate analysis showed sex (OR = 0.13; 95% CI: 0.03, 0.61; p=.03) was the risk factor leading to SAN and males were more vulnerable to SAN.

CONCLUSION

SAN after MWA came earlier and initially illustrated as neck bulging, swelling and discomfort. Early detection and early treatment might prevent the rupture of nodules. Once the breakdown of thyroid capsule occurred, rupture of ablated nodules out of skin was unavoidable and invasive procedures might be the most effective treatment.

Ultrasonographic characteristics of thyroid nodule rupture after microwave ablation: Three case reports

RATIONALE

Thyroid nodule rupture is a rare complication after microwave ablation (MWA). The ultrasonographic characteristics, clinical course, treatment, or prognosis of thyroid nodule rupture after ablation have not been systematically summarized. Three cases with thyroid nodule rupture after MWA were reported in this study, including the characteristic ultrasound images before ablation and after rupture. Meanwhile, we investigated the etiology, diagnosis, treatment and prevention of the rupture. These findings can provide references for the future clinical practice.

PATIENTS CONCERNS

All 3 patients were pathologically diagnosed as benign thyroid nodules by core needle biopsy and then received 1 session of MWA.

DIAGNOSES

Fourteen days to 1 month after MWA later, all 3 patients presented with abrupt neck pain and swelling, and 1 of them had a fever. Ultrasound examinations shared common features that the rupture of thyroid capsule and a soft-tissue mass with unclear margin in front of the thyroid gland, which connected with the post-ablation nodule. Three patients were diagnosed as thyroid nodule ruptures.

INTERVENTIONS

All 3 patients received conservative management after the ruptures. With the treatment of intravenous antibiotics for 1 week, the neck swelling of patients 1 and 2 both disappeared. The aggravation of neck swelling was found in patient 3. Ultrasonography of the neck revealed irregular fluid echo in the soft-tissue mass, suggesting abscess formation. Aspiration and irrigation were performed. The neck swelling regressed gradually over another 2 weeks with the treatment of antibiotics. Two months after ablation, ultrasound examination showed that the mass had completely disappeared.

OUTCOMES

None of the 3 patients underwent open surgery due to thyroid nodule rupture. At 1-year follow-up, the volume reduction rate of thyroid nodules in 3 patients were as follows: 100%, 98.1% and 90.7%.

LESSONS

Nodule rupture is a rare but severe complication after MWA of the thyroid nodules. The diagnosis can be confirmed by clinical symptoms and ultrasound examination, and most nodule ruptures could be cured with conservative treatment. Grasping the characteristics of ultrasound imaging during the course of disease, and dynamically assessing course of disease progression by ultrasonography could avoid unnecessary imaging examinations or invasive procedures.

The Importance of Nodule Size in the Management of Ruptured Thyroid Nodule After Radiofrequency Ablation: A Retrospective Study and Literature Review

BACKGROUND

Nodule rupture is a relatively uncommon yet severe complication of radiofrequency ablation (RFA). When nodule rupture occurs, determining suitable therapeutic management is a critical issue. A study herein aimed to identify the predictive factors affecting the management of post-RFA nodule rupture.

METHODS

Post-RFA nodule rupture data of 9 patients were enrolled from 2 medical centers. A literature investigation was performed, uncovering nodule rupture data of 17 patients. A total of 26 patients were analyzed and divided into two groups, categorized as patients requiring either invasive or conservative therapeutic management. Data including initial symptoms, imaging, therapeutic management, and prognosis were reviewed and compared between the two groups.

RESULTS

Significant differences in nodule diameter, and the ablation time of the course prior to rupture (RUP time) were noted between the two groups (p = 0.045 and 0.008, respectively). Logistic regression analysis indicated the initial nodule diameter and RUP time significantly affected the requirement of invasive treatment (OR 1.99 and 1.11, respectively). Considering practicality, when a nodule with an initial maximum diameter of >4.5cm ruptured, invasive management was suggested (sensitivity 69% and specificity 79%).

CONCLUSION

Though nodule ruptures can be managed conservatively, a ruptured nodule with an initial maximum diameter of >4.5cm may require invasive management. Understanding the significant clinical and imaging features will help physicians make an appropriate risk assessment to determine the correct treatment in a timely manner.

Effectiveness of Injecting Cold 5% Dextrose into Patients with Nerve Damage Symptoms during Thyroid Radiofrequency Ablation

BACKGROUND

Although radiofrequency ablation (RFA) is a safe treatment for thyroid tumors, nerve damage is a frequent complication. A previous retrospective study suggested that an injection of cold 5% dextrose in water (5% DW) can reduce nerve damage during RFA. This study validated the efficacy of injecting cold 5% DW for management of nerve damage during RFA.

METHODS

Between November 2017 and December 2018, 242 patients underwent 291 RFA sessions for treatment of benign thyroid nodules or recurrent thyroid cancers. Using a standardized technique, cold (0°C to 4°C) 5% DW was immediately injected around the damaged nerve into patients with any symptoms suggesting nerve damage. The incidence of nerve damage, the volume of 5% DW injected, symptom recovery time and the incidence of permanent nerve damage were evaluated.

RESULTS

Nineteen patients experienced nerve damage symptoms related to 21 RFA sessions, including 17 patients during 19 sessions and two patients on the day after two sessions. Patients with nerve damage symptoms detected during RFA were treated by injection of a mean 41 mL (range, 3 to 260) cold 5% DW, but the two patients who experienced symptoms the next day did not receive cold 5% DW injections. Immediate recovery was observed after 15 RFA sessions in 14 patients. No patient experienced permanent nerve damage.

CONCLUSION

Injection of cold 5% DW is effective in managing nerve damage during RFA of thyroid lesions.