Therapy: a new nonsurgical therapy option for benign thyroid nodules?

Assessing the relative effectiveness of various ultrasound-guided ablation techniques for treating benign thyroid nodules: A systematic review and network meta-analysis

BACKGROUND

Benign thyroid nodules (BTNs) represent a prevalent clinical challenge globally, with various ultrasound-guided ablation techniques developed for their management. Despite the availability of these methods, a comprehensive evaluation to identify the most effective technique remains absent. This study endeavors to bridge this knowledge gap through a network meta-analysis (NMA), aiming to enhance the understanding of the comparative effectiveness of different ultrasound-guided ablation methods in treating BTNs.

METHODS

We comprehensively searched PubMed, Embase, Cochrane, Web of Science, Ovid, SCOPUS, and ProQuest for studies involving 16 ablation methods, control groups, and head-to-head trials. NMA was utilized to evaluate methods based on the percentage change in nodule volume, symptom score, and cosmetic score. This study is registered in INPLASY (registration number 202260061).

RESULTS

Among 35 eligible studies involving 5655 patients, NMA indicated that RFA2 (radiofrequency ablation, 2 sessions) exhibited the best outcomes at 6 months for percentage change in BTN volume (SUCRA value 74.6), closely followed by RFA (SUCRA value 73.7). At 12 months, RFA was identified as the most effective (SUCRA value 81.3). Subgroup analysis showed RFA2 as the most effective for solid nodule volume reduction at 6 months (SUCRA value 75.6), and polidocanol ablation for cystic nodules (SUCRA value 66.5).

CONCLUSION

Various ablation methods are effective in treating BTNs, with RFA showing notable advantages. RFA with 2 sessions is particularly optimal for solid BTNs, while polidocanol ablation stands out for cystic nodules.

Recurrent multinodular goitre and primary hyperparathyroidism due to adenoma arising in a parathyroid autotransplant more than 20 years after near-total thyroidectomy

The patient is a female in her 60s with a remote history of a near-total thyroidectomy in 1997 for multinodular goitre. At the initial operation, she sustained a left recurrent laryngeal nerve injury. A devascularised parathyroid gland was autotransplanted into the right sternocleidomastoid muscle. She had been off of thyroid hormone for long periods, and her most recent levothyroxine requirement had fallen to only 25 mcg daily. The patient presented more than 20 years after her thyroidectomy with hoarseness, fatigue and dyspnoea. Laboratory studies suggested primary hyperparathyroidism. Imaging demonstrated bilateral pulmonary emboli and bulky thyroid tissue extending into her mediastinum. She underwent a completion thyroidectomy with the removal of a parathyroid adenoma arising in the autotransplanted parathyroid. This case illustrates the possibility of regrowth of benign thyroid tissue after thyroidectomy. In addition, to our knowledge, this is the first case report of a parathyroid adenoma arising from autotransplantation of a normal parathyroid.

Meta-analysis of the efficacy and safety of thermal ablation for treating large benign thyroid nodules

OBJECTIVE

Many large benign thyroid nodules have symptoms and cosmetic problems. This study consisted of a meta-analysis to accurately assess the effect of thermal ablation on these nodules.

METHODS

The PubMed, Embase, Web of Science, and Scopus databases were systematically searched for retrospective or prospective studies of thermal ablation since June 1, 2021. The weighted mean differences of the measures were analysed before and after treatment.

RESULTS

A total of 10 eligible studies were included. By comparing the initial nodule volume with the nodular volume after thermal ablation, we found that the volume reduction rate was increased significantly after 1 month (SMD = 0.453, 95% CI: 0.323-0.583, p < .001), 3 months (SMD = 0.655, 95% CI: 0.563-0.747, p < .001), 6 months (SMD = 0.691, 95% CI: 0.607-0.774, p < .001), and 12 months (SMD = 0.694, 95% CI: 0.583-0.803), p < .001). The nodular volume was also found to decrease significantly, after 1 month (SMD = 2.381, 95% CI: 1.278-3.485, p < .001), 3 months (SMD = 5.071, 95% CI: 2.386-7.756, p < .001), 6 months (SMD = 5.363, 95% CI: 2.765-7.962, p < .001), and 12 months (SMD = 8.194, 95% CI: 2.113-14.274), p < .001). Symptom score (SMD = 4.419, 95% CI: 2.573-6.265, p < .001)and cosmetic score (SMD = 4.245, 95% CI: 2.566-5.359, p < .001) were reduced after thermal ablation.

CONCLUSIONS

Thermal ablation could become an alternative to manage large benign thyroid nodules.

Safety and Efficacy of Ultrasound-Guided Radiofrequency Ablation for Benign Nonfunctional Thyroid Nodules in Children: A Retrospective Study of 62 Patients with Over Four Years of Follow-Up

Background: Image-guided radiofrequency ablation (RFA) for benign nonfunctional thyroid nodules in adults has been shown to be effective and safe, but few trials address the use of RFA in children. Therefore, this study was designed to assess the efficacy and safety of RFA application to benign nonfunctional thyroid nodules in children. Methods: A retrospective study of RFA for 70 benign nonfunctional thyroid nodules in 62 children with four-year follow-up was conducted. Volume reduction ratio (VRR), technique efficacy, regrowth rate, symptom score, and cosmetic score were calculated to evaluate the efficacy. Complications and side effects were recorded. Logistic regression analysis was performed to identify risk factors, and subgroup analyses were performed. Results: Patients were followed up for at least four years (59.1 ± 10.5 months, range 48-85 months). After RFA treatment, the VRR and technique efficacy rates were highest at the first year^* (77.5% and 91.4%, respectively) but decreased by four years (55.1% and 81.4%, respectively). The symptom score decreased from 4.0 ± 2.1^* to 0.8 ± 1.6 (Z = -6.82, p < 0.001), and the cosmetic score decreased from 3.3 ± 0.7 to 1.3 ± 0.9 (Z = -7.0, p < 0.001).^* The nodule regrowth rate was 22.9%, of which 56.3% of cases represented loss of efficacy. In the cases of loss of efficacy, 66.7% had greater volume than their initial presentation. Patients who received a second RFA treatment due to loss of efficacy lost efficacy again. Bilateral nodules, low vascularity, and low cystic components were independent risk factors correlating with technique efficacy. Bilateral nodules correlated with low VRR, low efficacy rate, and high regrowth rate. Nodules with a higher proportion of cystic components had higher VRR. The overall complication rate was 4.8%. Conclusions: RFA was effective in reducing the volume of benign nonfunctional thyroid nodules in children, providing significant symptomatic relief with a good safety profile during short- and long-term follow-up. RFA is a good minimally invasive treatment modality for selected pediatric patients, and it may not be appropriate for the treatment of bilateral thyroid nodules in children.

Efficacy in size and symptom reduction of radiofrequency ablation of benign non-functioning thyroid nodules

INTRODUCTION

Radiofrequency ablation (RFA) plays an increasing role in the management of thyroid nodules. The purpose of this study was to evaluate the safety and efficacy of RFA of benign thyroid nodules in terms of volume reduction and symptom relief.

METHODS

We reviewed the medical records of patients with a solitary thyroid nodule who received RFA at our centre from April 2016 to January 2020. Ultrasound-guided RFA was performed by the moving-shot technique. Patients were followed up with ultrasound examinations and thyroid function tests. We evaluated changes in volume and in compressive (0-10 scale) and cosmetic (4-point scale) symptoms to analyse efficacy and complications, and in thyroid function to evaluate safety.

RESULTS

A total of 72 patients were included in the study. The mean follow-up was 11.1±0.7 months. There was a statistically significant reduction in size of the nodules at Month 1, 3, 6 and 12 after RFA (expressed as volume reduction rate: 34%±2.1, 50.8%±2.2, 60.3%±2.6, 58.87%±3.5, p<0.0001). We found statistically significant improvement in compressive symptoms (from 7.1±0.26 to 1.76±0.33, p<0.0001) and in cosmetic alteration (from 3.66±0.09 to 2.14±0.14, p<0.0001). No major complications were observed.

DISCUSSION

RFA achieved significant volume reduction and improved compressive symptoms as well as cosmetic complaints, with minimum side effects. Our results are in line with recent available evidence and further support the use of RFA as a safe and effective therapeutic option in the management 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.

Significance of radiofrequency ablation in large solid benign thyroid nodules

OBJECTIVE

The aim of this study is to explore efficacy and safety for radiofrequency ablation (RFA) among cases attacked by large benign solid thyroid nodules, mainly focusing on volume reduction, complication rate, and thyroid function.

METHODS AND MATERIALS

From June 2015 to November 2019, 24 patients with 25 large benign solid thyroid nodules (more than 25 ml) underwent single or sequential RFA in our institution. Eleven nodules achieved complete ablation after single RFA, whereas the other 14 nodules received sequential RFA. Volume reduction in large nodules was evaluated. Following single or sequential RFA, all patients received clinical and ultrasound evaluations, and the median follow-up duration among them was 23.5 months. Technical success, complication rate, and recurrence rate were assessed as well.

RESULTS

In single RFA group, volume reduction ranged from 62.6% to 99.4% (mean ± SD, 93.6 ± 9.9%) 6 months after RFA. In sequential RFA group, volume reduction ranged from 30.6% to 92.9% (mean ± SD, 67.4 ± 17.8%) after the first RFA and was between 83.4% and 98.4% (mean ± SD, 94.8± 3.8%) 6 months after the second RFA. The concentrations of FT3 and FT4 increased slightly 1 day after RFA and returned to normal level 1 month after.

CONCLUSIONS

Single or sequential RFA is safe and effective in treating large benign solid thyroid nodules (more than 25 ml) that cause obvious compressive symptoms. Hence, compression symptoms and cosmetic conditions could be effectively improved through single or sequential RFA without marginal recurrence.

Effects of energy-based ablation on thyroid function in treating benign thyroid nodules: a systematic review and meta-analysis

BACKGROUND

Whether thyroid function would be affected by ablation remains controversial. This systematic review and meta-analysis aimed to investigate the effects of energy-based ablation on thyroid function in treating benign thyroid nodules.

METHODS

EMBASE, PubMed, Cochrane Library, and Web of Science databases were searched. The mean difference (MD) or standard MD (SMD) was applied to assess changes in thyroid function, thyroglobulin (Tg), and antibodies after ablation. RevMan version 5.3 was used for data synthesis.

RESULTS

Forty-two studies involving 6380 patients were eligible. The pooled results revealed significant decrease of 1-day thyroid-stimulating hormone (95% CI, -0.67 to -0.14), significant increase of 1-day, 1-week, and 1-month free thyroxine (95% CI, 1.57 to 5.28; 95% CI, 0.61 to 2.42; 95% CI, -0.76 to -0.15), 1-day and 1-week Tg level (95% CI, 0.40 to 0.81; 95% CI, 0.21 to 1.29), 6-month anti-thyroglobulin antibodies (95% CI, 0.02 to 0.26), 1- and 3-month thyroperoxidase antibody (95% CI, 0.02 to 0.22; 95% CI, 0.17 to 0.43), and 1-day, 1-, and 3-month thyrotrophin receptor antibody (95% CI, 0.10 to 0.43; 95% CI, 0.00 to 0.30; 95% CI, 0.13 to 0.36) after ablation. No statistically significant differences were found in these six indicators in the longer term. The results of subgroup analysis were similar to the pooled results. No significant publication bias was found.

CONCLUSIONS

Energy-based ablation was more likely to have negative effects on thyroid function and antibodies and led to transient increase in Tg level in the short term. However, most of the patients would not develop any thyroid dysfunction in the long-term follow-up.

Radiofrequency ablation and thyroid nodules: updated systematic review

PURPOSE

In the thyroid gland, radiofrequency ablation (RFA) is being applied to both benign nodules and cancers internationally, while interest is also growing in the West. Benign thyroid nodules (BTNs) may be candidates for intervention when symptoms develop. For differentiated thyroid cancers (DTC), surgery is currently the first-line treatment. However, for candidates with high surgical risk or those who refuse to undergo repeated surgery, newer techniques such as RFA are an option. Surgery is associated with complications including hypothyroidism, voice change, hypocalcemia, and a scar. RFA has been used in Asian and European institutions as an alternative to surgery, but is relatively new in North America. Although RFA is not associated with significant complications, few randomized control trials have assessed its efficacy. The studies to date suggest a low rate of severe complications and a small need for thyroid hormone replacement following RFA. Further large-scale studies focusing on a Western population are needed. The aim of this review is to evaluate the evidence with respect to the current studies and data about the safety and efficacy of radiofrequency ablation for the management of BTNs and DTC.

METHODS

We systematically searched the PubMed/MEDLINE, EMBASE, Clinical Queries, and Web of Science databases, for articles published up to April 30th, 2020.

RESULTS

Total of 75 studies that met the inclusion criteria were included in the review. Thirty-five studies focused on RFA use for solid nodules, 12 studies on predominantly cystic nodules, 10 for autonomously functioning thyroid nodules, and 18 studied were published on differentiated thyroid cancer.

CONCLUSIONS

RFA seems to be an effective and safe alternative to surgery in high-risk surgical patients with thyroid cancers and for selected BTNs. Additional trials with longer follow-up in North American patients are needed to validate its full role in the armamentarium of thyroid ologists.

A Novel Strategy for Single-Session Ultrasound-Guided Radiofrequency Ablation of Large Benign Thyroid Nodules: A Pilot Cohort Study

Background: Ultrasound-guided radiofrequency ablation (RFA) of thyroid nodules (TNs) is a minimally invasive procedure that has been widely used to induce volume reduction in symptomatic solid benign TNs. The goal of this study was to investigate a novel therapeutic approach for single-session ablation of large thyroid nodules (LTNs, vol > 20 ml). Methods: We performed a pilot cohort study of 21 patients with symptomatic solid benign LTNs (vol > 20 ml), who accepted ultrasound-guided RFA treatment between September 2018 and November 2019. RFA was performed using an 18-gauge internally cooled electrode with ultrasonographic guidance in a single session combined with intraoperative hydrodissection and immediate contrast-enhanced ultrasound (CEUS) to optimize safety and efficacy. Nodule volume was evaluated before ablation and at 1, 3, and 6 months after initial ablation, and all patients were asked to assess the cosmetic score (from 1 to 4) and symptom score (from 0 to 10) before ablation and at every follow-up after ablation. Results: At the 6 month follow-up, there was significant nodule volume reduction, from 27.49 ml ± 7.9 (standard deviation) to 3.82 ml ± 5.02 (p = 0.001). Cosmetic signs (p = 0.001) and pressure symptoms (p = 0.001) were significantly improved. All patients underwent RFA without any major complications, and very few patients developed a change in voice (2/21). However, the changes subsided within 1 month. Almost half of the patients received an additional RFA (11/21) treatment to achieve complete ablation on the intraoperative immediate CEUS evaluation. Conclusion: RFA is effective for treating LTNs (vol > 20 ml) and controlling clinical symptoms with a low complication rate. Patients were satisfied with cosmetic sign and pressure symptom improvement. The intraoperative hydrodissection and immediate CEUS represent a novel therapeutic approach for single-session ablation of LTNs.

Long-Term Efficacy of a Single Session of RFA for Benign Thyroid Nodules: A Longitudinal 5-Year Observational Study

CONTEXT

Radiofrequency ablation (RFA) of benign thyroid nodules has been gaining consensus. However, no solid information on its long-term efficacy is available.

OBJECTIVE

To analyze the long-term results of single-session RFA.

DESIGN

Retrospective longitudinal observational study.

SETTING

Primary care center.

PATIENTS OR OTHER PARTICIPANTS

Adult outpatients who underwent a single-session RFA and posttreatment follow-up of least 3 years.

INTERVENTION

Ultrasound-guided RFA was performed after local anesthesia by "moving-shot" technique. RFA was performed with a median power of 55W and a median time of 14 minutes with an internally cooled 18-gauge electrode with an active 10-mm tip.

MAIN OUTCOME MEASURES

Objective (trend of nodule volume) and subjective (compressive and cosmetic concerns) response to RFA were evaluated. Continuous variables were analyzed by the Wilcoxon and ANOVA test and their correlations by using the Spearman test. Categorical variables were compared by Pearson χ2 test.

RESULTS

Two hundred and fifteen patients were included. An early significant reduction of nodule volume was found at 1 year, lasting up to 5 years. A 67% nodule shrinkage was observed at the end of the observation period. The best response was recorded in nodules below 10 mL (79% reduction early and 81% at 5 years). Patients' symptoms were significantly reduced.

CONCLUSIONS

This study, by demonstrating a durable shrinkage of benign thyroid nodules treated by RFA with an improvement of subjective symptoms, establishes the reliability of RFA as alternative to surgery in the management of thyroid nodules, thus representing a remarkable novelty for clinical practice.

High-intensity focused ultrasound (HIFU) for benign thyroid nodules: 2-year follow-up results

BACKGROUND

High-intensity focused ultrasound (HIFU) is the last introduced thermal treatment of thyroid nodules. Here we evaluated the results at 24 months after HIFU.

METHODS

Since 2016, HIFU was considered as a therapeutic option at our institute in patients with benign thyroid nodules presenting local symptoms. We searched in our database all patients who had undergone thyroid HIFU and selected for the study only cases followed-up for at least 24 months after the treatment. Volume reduction rate (VRR) was evaluated. A reduction above 50% defined the success of HIFU.

RESULTS

Thirty-one nodules of 31 patients (24 females and 7 males, median age 67 years) with median major diameter from 17 to 34 mm and estimated nodule volume of 5.48 mL were included. HIFU was performed with median power of 42 W/site (interquartile range 25-45) and median energy of 263 J/site (interquartile range 225-273). Median duration of the procedure was 6 min (interquartile range 5-7). At 2 years after HIFU, nodule volume was significantly (p < 0.0001) lower (i.e., 3.40 mL) with VRR of 43.3%, and 26 (83.9%) lesions were reduced. A reduction by at least 50% was observed at 6, 12, and 24 months in 2 (6.4%), 5 (16.1%), and 7 (22.5%) nodules, respectively. Visual analog score showed a significant improvement (p < 0.0001). No complications were recorded.

CONCLUSIONS

A reduction of benign thyroid nodule by more than 40% could be reached within 1 year by HIFU. Given the non-significant size increase of some lesions later, a larger study with a longer follow-up is necessary.

Long-term outcome following laser therapy of benign cystic-solid thyroid nodules

OBJECTIVE

Laser therapy (LT) is considered a safe and effective procedure for inducing thyroid nodule necrosis, fibrosis and shrinkage. Little is known about long-term efficacy of LT in benign complex thyroid nodules, which we report here.

DESIGN AND METHODS

One hundred and ten euthyroid outpatients (28 men and 82 women; median age 48 years (range 17-82)) with a recurrent cytologically benign cystic (≥2 mL cyst volume) thyroid nodule causing local discomfort were assigned to LT. LT was performed after complete cyst aspiration and under continuous ultrasound (US) guidance. Nineteen patients (17 within 6 months) had surgery after LT. The median follow-up for the remaining 91 patients was 45 months (range: 12-134).

RESULTS

The overall median nodule volume in the 110 patients decreased from 9.0 mL (range: 2.0-158.0) to 1.2 mL (range: 0.0-85.0) (P < 0.001) at the final evaluation, corresponding to a median reduction of 85% (range: -49 to 100%). Remission of the cystic part (volume ≤1 mL) was obtained in 82 of 110 (75%) patients after LT. The median cyst volume decreased from 6.3 mL (range: 2.0-158.0) to 0.0 mL (range: 0.0-85.0) (P < 000.1), corresponding to a median reduction of 100% (range: -49 to 100%). These results correlated with a significant decrease in pressure as well as cosmetic complaints. Side effects were restricted to mild local pain.

CONCLUSION

US-guided aspiration and subsequent LT of benign recurrent cystic thyroid nodules results in a satisfactory long-term clinical response in the majority of patients. LT constitutes a clinically relevant alternative to surgery in such patients.

Successful radiofrequency ablation strategies for benign thyroid nodules

PURPOSE

This study aimed to evaluate the effectiveness of ultrasound (US)-guided radiofrequency ablation (RFA) treatment of benign thyroid nodules in consecutive large number series. To find out whether there is any difference according to the nature of the nodules, nodules were subdivided into two groups of predominantly solid vs. predominantly cystic lesions.

METHODS

We retrospectively analyzed clinical data of thyroid nodules receiving percutaneous RFA treatment in our institution. We subdivided data into two groups according to the nodule's sonographic characteristics. We defined therapeutic success as a volume reduction rate >50% at 6 months post-RFA. The second ablation was performed in case where <50% VRR was achieved at 6 months. The primary endpoint was to identify factors prognosticating response to RFA treatment.

RESULTS

A total of 1000 patients with 1619 thyroid nodules received US-guided RFA treatment. A volume reduction of >50% (therapeutic success) after the first ablation was 78.9% vs. 78.2% (p = 0.439) and 91.4% vs. 93.4% (p = 0.148) after the final ablation for predominantly cystic vs. predominantly solid lesions, respectively, with comparable post-interventional morbidity. RFA sessions were more frequent in the solid group than in the cystic group. Small volume of thyroid nodule (<4 mL) was the only factor significantly associated with therapeutic success in the multivariate analysis (OR 1.848; 95% CI 1.537-2.789, p = 0.030).

CONCLUSION

RFA was effective in reducing the volume of benign thyroid nodules volume with non-inferior result in PS group comparing to PC group and can be considered a principal treatment method for treating benign thyroid nodules, including cystic nodules.

Patient satisfaction of radiofrequency ablation for symptomatic benign solid thyroid nodules: our experience for 2-year follow up

Background

The patient satisfaction of symptoms improvement and disease factors that may affect long-term treatment efficacy of radiofrequency ablation (RFA) for non-functioning solid benign thyroid nodules (TNs) over a 2-year follow up study was investigated.

Methods

This retrospective study evaluated 194 non-functioning solid benign TNs of 103 patients. The TNs were categorized as small (≤5 ml), medium (5.1 to 13 ml), intermediate (13.1 to 30 ml) and large (over 30 ml) according to the initial volume of TNs before ablation. Clinical evaluation and contrast-enhanced ultrasound (CEUS) were carried out before ablation and the follow up at 1, 3, 6 months and every 6 months after ablation. All patients were asked to assess the cosmetic score (1–4 scores) and symptom score (0–10 scores) before ablation and every follow up after ablation.

Results

All patients underwent RFA without any major complications. The mean treatment sessions were 1.5 ± 0.6. 98 nodules required a single session (98/194, 50.5%), 87 required two sessions (87/194, 44.9%), 9 required three sessions (9/194, 4.6%). The average follow up months were 16.3 ± 5.6 (range, 6–24 months) and no nodule regrew in our study. After RFA treatment, the TNs volume significantly decreased (P < 0.001). The small group of nodules shrunk larger compared to the medium, intermediate and large groups (P < 0.001). Cosmetic signs and pressure symptoms were significantly improved, particularly in the intermediate and large groups (P < 0.05).

Conclusions

RFA is effective for treating non-functioning solid benign TNs and controlling clinical symptoms with a low complication rate during 2 years follow up. The reduction rate was related to the initial volume of nodules. Patients were satisfied with cosmetic signs and pressure symptoms improvement, particularly in the intermediate and large groups. However, multiple RFA treatments should be used in larger nodules to achieve the desired clinical outcomes.

Surgical Confirmation of Incomplete Treatment for Primary Papillary Thyroid Carcinoma by Percutaneous Thermal Ablation: A Retrospective Case Review and Literature Review

BACKGROUND

Recently, thermal ablation has been proposed for treating primary papillary thyroid carcinoma (PTC), triggering an extensive debate. This study aimed to analyze surgical outcomes of post-ablation cases to investigate the effectiveness and safety of thermal ablation in primary PTC.

METHODS

Primary PTC patients treated with thermal ablation were retrospectively searched for from the authors' medical record database prior to August 2017. The surgical patients met the following criteria: (i) primary PTC treated with thermal ablation, (ii) findings suspicious for malignancy of the post-ablation lesions on ultrasound or malignancy confirmed by cytology, or with clinical evidence of cervical lymph node metastasis (LNM), (iii) written informed consent for surgery, (iv) preference for definite diagnosis of the post-ablation lesions for the patients without evidence for malignant findings, and (v) tolerance of a thyroidectomy and without severe illness. Moreover, a systematic review of the literature was made to analyze relevant cases.

RESULTS

Twelve patients with an average age of 41.0 ± 13.6 years constituted the Fudan University Shanghai Cancer Center cohort in this study. Twenty-two foci with a mean size of 1.3 ± 0.7 cm were ablated percutaneously under ultrasound guidance. Residual PTCs were confirmed in all cases by histopathology, and LNM was present in 66.7% (8/12) of the patients. Intraoperatively, adhesion of the post-ablation lesions with the strap muscles was observed in six cases. Strap muscles were found to be cauterized in five cases, and notably the recurrent laryngeal nerve was involved in one case. Furthermore, seven relevant studies from Korea, Italy, and China were retrospectively reviewed, and incomplete ablation of primary PTC and omission of LNM by thermal ablation were observed frequently.

CONCLUSIONS

Surgical therapy demonstrated incomplete ablation of primary PTC and omission of LNM by thermal ablation in this cohort of patients. Thermal ablation should be recommended with caution as treatment of operable patients with primary PTC.

Bortezomib sensitizes thyroid cancer to BRAF inhibitor in vitro and in vivo

Although overall survival rate for patients with thyroid cancer (TC) is high, there is an alarming 10-year recurrence rate of up to 30% conferring a ~50% survival among these high-risk patients. The BRAF^V600E mutation is estimated to be present in over 50% of papillary thyroid cancer (PTC) cases besides being associated with carcinogenesis and poor prognosis. We assessed the status of NF-κB, Ki-67, cyclin D1 and BRAF^V600E in TC tissues and TC cell lines using immunohistochemistry and Western blot analysis. Concurrently, we evaluated the outcomes of combined targeting of the proteasome pathway in addition to selective BRAF inhibitors in cases of PTC. In this study, BRAF^V600E-bearing TC cells were treated with BRAF^V600E inhibitor, Vemurafenib alone or in combination with the proteasome inhibitor, Bortezomib. The combination of both drugs showed synergistic effects as evidenced by cell growth inhibition (P < 0.05), increased G2-phase cell cycle arrest and induced apoptosis (P < 0.05). In our TC xenograft model, the combination of Vemurafenib and Bortezomib significantly reduced tumor size (P < 0.05) and expression of the markers of cell growth and proliferation, Ki-67 and cyclin D1 (P < 0.001), when compared to monotherapy. Further analysis demonstrated that treatment with Bortezomib sensitized TC cells to Vemurafenib via mitochondrial dysregulation and apoptosis of TC cells, as evidenced by the increase in the expression of p53, Noxa protein, the loss of mitochondrial membrane potential, cytochrome c release and Poly (ADP-ribose) polymerase cleavage. Our results demonstrate a strong clinical potential for the combination of the Bortezomib and the BRAF inhibitor Vemurafenib as an efficient therapeutic approach for the treatment of TC.

Radiofrequency ablation for the management of thyroid nodules: A critical appraisal of the literature

The majority of benign thyroid nodules are asymptomatic, remain stable in size and do not require treatment. However, a minority of patients with growing nodules may have local symptoms or cosmetic concerns, and thus demand surgical therapy. The timely use of ultrasound-guided, minimally invasive thermal therapies has changed the natural history of benign, enlarging thyroid nodules (TNs). These procedures produce persistent shrinkage of TNs and an improvement of local symptoms. Among the various procedures, percutaneous ethanol injection represents the first-line treatment for thyroid cysts, while in solid cold nodules, laser and radiofrequency ablation (RFA) have proven to be very effective and safe techniques in producing significant volume reduction that remains stable over several years. In particular, RFA seems to be suited for the management of small and medium nodules, while larger nodules may require repeated RFA treatments, and could be difficult to treat if they extend into the chest. RFA is performed in outpatient clinics and has a lower risk of complications compared to surgery. However, to date, there is still no unanimous consensus on the percutaneous treatment of benign nodules using such minimally invasive thermal techniques. In this review, we critically revise the literature to identify patients who are more likely to benefit from RFA treatment as an alternative to surgery.

Minimally invasive local ablative therapies in combination with radioiodine therapy in benign thyroid disease: preparation, feasibility and efficiency - preliminary results

PURPOSE

Initial studies of combinations of radioiodine therapy (RIT) and local ablative procedures for the treatment of thyroid nodules have shown promising results. The goal of this study was to evaluate the effectiveness of RIT combined with radiofrequency ablation (RFA) in patients with goitres and to determine which ablative procedure is the most suitable for a combined therapy.

METHODS

Thirty patients with goitres were divided into two subgroups. A test group of 15 patients received combined therapy (RIT + RFA) and a control group of 15 patients received RIT mono therapy. All patients underwent assessments including ultrasound, laboratory evaluation (T3, T4, TSH, TG, TPOAb, TgAbTRAb) and scintigraphic imaging with Tc-99m-Pertechnetate. The 3-month volume reduction was used to evaluate therapy effectiveness.

RESULTS

Combined therapy (subgroup 1) resulted in a significant (p < 0.05) thyroid volume reduction (22.3 ± 54 ml/32.2 ± 58.2%) with better performance (p > 0.05) than the control group (20.2 ± 32.2 ml/29.6 ± 42.1%). All patients became euthyroid after treatment. No major discomfort or complications occurred. A review of the literature investigating combinations of other local ablative procedures with RIT was performed to determine the most promising combination.

CONCLUSIONS

The present study confirms the positive experiences with the combined therapy of RIT and local ablative procedures shown in the current literature and approves this approach for the treatment of goitres with RFA + RIT. These findings, when confirmed by further studies, should expand the indication of combined therapy as a minimally invasive alternative to surgery.

Efficacy and safety of a single radiofrequency ablation of solid benign non-functioning thyroid nodules

Objective

The objective of our study is to evaluate the clinical outcomes and safety of radiofrequency thermal ablation (RFA) for benign thyroid nodules (BTNs) over a 1-year follow-up.

Subjects and methods

This is a monocentric retrospective study. Forty-eight patients with solid, non-functioning BTNs were treated by RFA using a 17G internally cooled electrode. We categorized thyroid nodules as small (≤ 12 mL), medium (12 to 30 mL), or large (over 30 mL). BTNs volume reduction, thyroid function, cosmetic and compressive score changes and side effect evaluation at 6 and 12 months were evaluated.

Results

BTN volume decreased significantly from baseline to 6 (mean percentage decrease of BTN volume was 66.8 ± 13.6%, p < 0.001). At 12 months, the mean percentage reduction of BTN volume compared to six months was 13.7 ± 17.1% (p < 0.001). At 6-month, symptom score had improved significantly (p < 0.001) while it does not change significantly between 6 and 12 months. In particular, symptom score improved significantly in the medium (p < 0.001) and large (p < 0.01) subgroups. Cosmetic score improved significantly between baseline and 6 months (p < 0.001) and between 6 and 12 months (p < 0.01). In all the subgroups, cosmetic score improved significantly between baseline and 6 months, while between 6 and 12 months it improved significantly only in the large group (p < 0.05). RFA was well tolerated. Only one patient experienced permanent right paramedian vocal cord palsy.

Conclusions

A single RFA treatment was effective in reducing BTNs volume, in particular small and medium nodules. Cosmetic score improved in all treated BTNs while symptom score only got better in the medium and large BTNs.

Laser, radiofrequency, and ethanol ablation for the management of thyroid nodules

PURPOSE OF REVIEW

The majority of benign thyroid nodules are nearly asymptomatic, remain stable in size, and do not require treatment. However, a minority of patients with growing nodules may complain of local symptoms or have cosmetic concerns, and thus seek surgical consultation.

RECENT FINDINGS

The timely use of ultrasound-guided minimally invasive procedures can change the natural history of benign enlarging thyroid nodules. The procedures produce persistent shrinkage of thyroid nodules and are associated with improvement of local symptoms. Among the various procedures, percutaneous ethanol injection represents the first-line treatment for relapsing thyroid cysts. In solid nonfunctioning nodules, laser and radiofrequency ablation produces a more than 50% reduction in nodular volume that remains persistent over several years. For hyperfunctioning nodules, thermal ablation techniques are not appropriate unless radioactive iodine is contraindicated or not accessible.

SUMMARY

MITs are best suited for the management of medium or large-sized nodules that are sonographically well visualized. Conversely, large nodules or nodular goiters that extend into the chest are difficult to treat. MITs are performed in outpatient clinics, are less expensive, and have a lower risk of complications, compared to surgery, and usually do not induce thyroid dysfunction. However, malignancy should be ruled out with a dedicated ultrasound neck assessment and repeat fine needle aspiration of the lesion before treatment.

Efficacy and Safety of Radiofrequency Ablation Versus Observation for Nonfunctioning Benign Thyroid Nodules: A Randomized Controlled International Collaborative Trial

BACKGROUND

Percutaneous radiofrequency thermal ablation (RFA) has been reported as an effective tool for the management of benign thyroid nodules (BTN). However, large, randomized controlled trials (RCTs) are lacking.

OBJECTIVE

The aims of this study were to assess the volume reduction of BTN after a single RFA performed using the moving-shot technique and to compare the volume reduction obtained in patients treated in two centers with different experience of the moving-shot technique.

METHOD

This study was an international prospective RCT. It was carried out at the Mauriziano Hospital (Turin, Italy) and the Asan Medical Center (Seoul, Korea). Eighty patients harboring solid, compressive, nonfunctioning BTN (volume 10-20 mL) were enrolled. Twenty patients in each country were treated by RFA using a 18-Gauge internally cooled electrode (group A); 20 nontreated patients in each country were followed as controls (group B).

RESULTS

At six months, BTN volume significantly decreased in group A (15.1±3.1 mL vs. 4.2±2.7 mL; p<0.0001), whereas it remained unchanged in group B (14.4±3.3 mL vs. 15.2±3.5 mL). The baseline volume was larger in the Italian series (16.4±2.5 mL vs. 13.9±3.3 mL, p=0.009). However, at six months, there was no significant difference between the Korean group and the Italian group (3.7±2.9 mL vs. 5.5±2.2 mL). Both cosmetic and compressive symptoms significantly improved (3.6±0.5 vs. 1.7±0.4 and 3.6±1.9 vs. 0.4±0.7, respectively; p<0.001). No side effects occurred.

CONCLUSIONS

RFA was effective in reducing the volume of BTN. The outcome was similar in centers with different experience in the moving-shot technique.

Radiofrequency ablation is a thyroid function-preserving treatment for patients with bilateral benign thyroid nodules

PURPOSE

To evaluate the efficacy and safety of radiofrequency (RF) ablation for treatment of bilateral thyroid nodules as well as preservation of thyroid function.

MATERIALS AND METHODS

Between January 2007 and October 2012, 18 patients (16 women and 2 men; mean age, 49.9 y; median age, 44 y; age range, 27-81 y) with bilateral thyroid nodules treated by RF ablation were included in this study. The inclusion criteria included bilateral thyroid nodules, pressure symptoms or cosmetic problems, cytologic confirmation of benignancy without atypical cells, and patient refusal of surgery. We used an RF generator (Cool-tip RF system [Covidien, Boulder, Colorado] or SSP-2000, Taewoong Medical Co, Ltd [Gyeonggi-do, Republic of Korea]) and an 18-gauge internally cooled electrode with 1-cm active tips (Cool-tip [Covidien] or Well-Point RF electrode [Taewoong Medical Co, Ltd]). RF ablation was conducted using the moving shot technique and a trans-isthmic approach. RF ablation was performed in separate sessions for nodules in each lobe. Follow-up ultrasound examinations were performed at 1-6 months, 6-12 months, and during the last month of follow-up. The diameter and volume of the nodule and clinical problems including cosmetic and symptom scores were evaluated before and after the procedure.

RESULTS

The mean initial nodule size was 4.1 cm ± 1.9, although there was a significant decrease by the time of the last follow-up examination (range, 1-48 mo; mean, 18.1 mo ± 12.8; P < .001, 2.5 cm ± 1.4). The initial nodule volume was 24.4 mL ± 32.2 and was decreased at the last follow-up (6.3 mL ± 19.0, P < .001), with a mean volume reduction of 75.9% ± 19.0. The symptom (P < .001) and cosmetic (P < .001) scores were decreased. Serum hormone levels did not differ significantly before treatment and at the last follow-up (P > .05).

CONCLUSIONS

RF ablation improves cosmetic problems and symptoms and preserves thyroid function in patients with bilateral thyroid nodules.

Microwave ablation of benign thyroid nodules

ABSTRACT: 

Microwave ablation (MWA) has become increasingly popular as a minimally invasive treatment for benign and malignant tumors of the liver, lung and kidney. Recently, two studies have attempted to apply the technique to debulk benign thyroid nodules and gained positive results. MWA of benign nodules demonstrated significant volume reductions, while solving nodule-related clinical problems. This article reviews the basic physics, therapeutic indications, patient preparation, devices, procedures, clinical results and complications of thyroid MWA.

Diagnosis of endocrine disease: thyroid ultrasound (US) and US-assisted procedures: from the shadows into an array of applications

In patients with thyroid nodules, ultrasound (US) imaging represents an indispensable tool for assessment of the risk of malignancy. Over approximately four decades, innovative technology and successive improvements have facilitated its entry into the routine management and greatly improved its predictive value. When US features cannot reliably rule out thyroid cancer, US guidance allows a correct and safe sampling also of small or deeply located thyroid lesions. Obtained in this way, cytological or microhistological specimens may reliably define the nature of most thyroid nodules, and the information from histochemical or molecular markers shows promise in the classification of the remaining indeterminate cases. While a prompt surgical treatment can be offered in the minority of suspicious or definitely malignant cases, most individuals warrant only a follow-up. However, at initial evaluation, or over the years, a fraction of these benign lesions may grow and/or become symptomatic. Such cases may benefit from US-guided minimally invasive procedures as an alternative to surgery. Image-guided percutaneous treatments most often achieve relief of neck complaints, are inexpensive, and can be performed on an outpatient basis. The risk of major complications, after adequate training, is very low. Importantly, thyroid function is preserved. Currently, percutaneous ethanol injection for cystic lesions and thermal ablation, with laser or radiofrequency, for solid nodules are increasingly used and disseminated beyond the initial core facilities. In centres with expertise and high patient volume, their use should be considered as first-line treatment alternatives to surgery for selected patients with benign enlarging or symptomatic thyroid lesions.

Interstitial laser photocoagulation (ILP) of benign cystic thyroid nodules--a prospective randomized trial

CONTEXT

Recurrence rate, after aspiration, in cystic thyroid nodules is very high. Interstitial laser photocoagulation (ILP) is a minimally invasive procedure that reduces the need for surgery in patients with a benign solid thyroid nodule.

OBJECTIVE

The aim of the study was to evaluate the efficacy of ILP on remission rates in recurrent, predominantly cystic thyroid nodules.

DESIGN AND METHODS

Forty-four consecutive outpatients with a symptomatic, recurrent, and cytologically benign cystic (cyst volume ≥ 2 mL) thyroid nodule were randomized to a single aspiration with (n = 22) or without (n = 22) subsequent ILP and followed up after 1, 3, and 6 months.

RESULTS

Successful outcome (cyst volume ≤ 1 mL) was obtained in 15 of 22 (68%) patients in the ILP group, compared to 4 of 22 (18%) in the aspiration group (P = .002). In the ILP group, the solid part of the nodule was reduced from a median of 1.8 to 1.0 mL (P = .02). In the aspiration-alone group, neither the cyst volume nor the solid nodule volume was significantly reduced. The reduction in median visual analog score (0-10 cm) for pressure symptoms was significantly higher in the ILP group (from 3.0 to 0.0 cm) than in the aspiration-alone group (from 4.0 to 3.5 cm) (P = .006, between groups). No major side effects occurred, and thyroid function was unaffected throughout.

CONCLUSIONS

US-guided aspiration and subsequent ILP of benign recurrent predominantly cystic thyroid nodules is safe. It significantly reduces recurrence rate, the volume of the solid nodule component, and pressure symptoms. ILP constitutes an important alternative to surgery in such patients.

Thyroid nodules treated with percutaneous radiofrequency thermal ablation: a comparative study

PURPOSE

Percutaneous radiofrequency thermal ablation (RTA) was reported as an effective tool for the management of thyroid nodules (TNs). The aim of this study was to investigate the effects of RTA and to establish whether they were treatment-related by comparison with a matched, untreated control group.

PATIENTS AND METHODS

The study population included 40 patients with compressive TNs: 22 had nontoxic TNs, and 18 had toxic TNs and were treated with methimazole. In all patients, a fine-needle aspiration cytology was performed to exclude a thyroid malignancy.

STUDY DESIGN

Twenty patients were treated with RTA (group A), and 20 others did not receive any treatment (group B). At baseline, age, gender, and TN features did not differ significantly between groups. All patients were clinically, biochemically, and morphologically evaluated at baseline and after 1, 3, 6, and 12 months.

RESULTS

TN volume significantly decreased in group A (1.8 ± 0.3 ml at 12 months vs. 13.3 ± 1.8 ml at baseline; P < 0.0001) and remained stable in group B [11.7 ± 1.5 ml at 12 months vs. 11.2 ± 1.5 ml at baseline; P = not significant (NS)]. At 3-, 6-, and 12-month evaluations, TN volume was significantly lower in group A than in group B (P < 0.005). At the end of the follow-up, pressure symptoms were improved in all patients in group A but persisted unchanged in group B. In group A, hyperthyroidism completely recovered in 40% and improved in 40% of patients with toxic TNs, whereas it persisted in all patients with toxic TNs in group B. RTA was safe and well tolerated in all patients.

CONCLUSIONS

RTA induced a marked TN volume shrinkage resulting in parallel improvement of pressure symptoms. In most patients with toxic TNs, hyperthyroidism significantly improved as well. RTA may represent a valid therapeutic approach in patients with TNs not receiving conventional treatments.

Radiofrequency ablation of benign non-functioning thyroid nodules: 4-year follow-up results for 111 patients

OBJECTIVES

To evaluate the clinical outcomes and safety of radiofrequency (RF) ablation for benign non-functioning thyroid nodules over a 4-year follow-up.

METHODS

We evaluated 126 benign non-functioning thyroid nodules of 111 patients treated with RF ablation and followed-up more than 3 years. RF ablation was performed using the Cool-Tip RF system and an internally cooled electrode. Nodule volume and cosmetic and symptom scores were evaluated before treatment and during follow-up. Complications and factors related to efficacy were evaluated.

RESULTS

The mean follow-up duration was 49.4 ± 13.6 months. Thyroid nodule volume decreased significantly, from 9.8 ± 8.5 ml before ablation to 0.9 ± 3.3 ml (P < 0.001) at final evaluation: a mean volume reduction of 93.4 ± 11.7 %. The mean cosmetic (P < 0.001) and symptom scores (P < 0.001) improved significantly. Factors related to efficacy were initial solidity and volume. The overall recurrence rate was 5.6 % (7/126). The overall complication rate was 3.6 % (4/111).

CONCLUSIONS

RF ablation was effective in shrinking benign thyroid nodules and in controlling nodule-related problems over a 4-year follow-up. There were no life-threatening complications or sequelae. Therefore, RF ablation can be used as a non-surgical treatment for patients with benign non-functioning thyroid nodules.

Symptomatic benign thyroid nodules: efficacy of additional radiofrequency ablation treatment session--prospective randomized study

PURPOSE

To prospectively evaluate the efficacy of additional radiofrequency (RF) ablation by comparing the results of one and two sessions.

MATERIALS AND METHODS

All patients gave written informed consent to participate in this institutional review board-approved prospective study. From September 2007 to February 2008, 30 patients with benign predominantly solid thyroid nodules causing pressure symptoms and/or cosmetic problems were randomly assigned to undergo single-session (group 1, n = 15) or two-session (group 2, n = 15) RF ablation. RF ablation was performed by using an 18-gauge internally cooled electrode with ultrasonographic guidance. Nodule volume and cosmetic and symptom scores were evaluated before ablation and at 1, 3, and 6 months after initial ablation, and quantitative comparisons of these were performed by using the Mann-Whitney and Wilcoxon signed rank tests; the Spearman rank test was used for correlation between nodule volume reduction and applied energy.

RESULTS

At 6-month follow-up, there was significant nodule volume reduction, from 13.3 mL ± 12.9 (standard deviation) to 3.8 mL ± 4.4 in group 1 (P = .001), and from 13.0 mL ± 6.8 to 3.0 mL ± 2.2 in group 2 (P = .001). Each group showed significant improvement in cosmetic (P < .0001) and symptom (P = .001) scores. However, there was no significant difference in volume reduction, cosmetic score, and symptom score between two groups (P = .078, P > .99, and P = .259, respectively). In group 1, three of four patients who had a pretreatment nodule volume larger than 20 mL underwent additional RF ablation because of unresolved clinical problems after the first session.

CONCLUSION

Single-session RF ablation showed significant volume reduction and satisfactory clinical response in most patients. Therefore, additional RF ablation should be limited to patients with a large nodule (>20 mL) or unresolved clinical problems.

Radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: consensus statement and recommendations

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus.

Approach to and treatment of goiters

The main causes of simple diffuse goiter (SDG) and multinodular goiter (MNG) are iodine deficiency, increase in serum thyroid-stimulating hormone (TSH) level, natural goitrogens, smoking, chronic malnutrition, and lack of selenium, iron, and zinc. Increasing evidence suggests that heredity is equally important. Treatment of SDG and MNG still focuses on L-thyroxine-suppressive therapy surgery. Radioiodine alone or preceded by recombinant human TSH stimulation is widely used in Europe and other countries. Each of these therapeutic options has advantages and disadvantages, with acute and long-term side effects.

Severe Graves' ophthalmopathy after percutaneous ethanol injection in a nontoxic thyroid nodule

BACKGROUND

Percutaneous ethanol injection (PEI) is used to treat cystic or mixed benign thyroid nodules. This treatment can result in rare complications, and three cases of Graves' disease (GD) without Graves' ophthalmopathy (GO) have been reported after PEI treatment of toxic thyroid adenomas. Here we present a 55-year-old male patient who developed GD and severe GO after PEI treatment of a mixed cystic-solid, nontoxic thyroid nodule.

PATIENT FINDINGS

Six months after PEI, the nodule volume had decreased from 8.9 to 3.0 mL, but we observed severe hyperthyroidism with elevated serum free triiodothyronine, free thyroxine, and thyrotropin receptor antibody levels. We also observed ophthalmopathy with symmetrical orbit and soft tissue involvement (grade b/c) and a clinical activity score of 4/7. The diagnosis of GO was confirmed by bilateral corneal damage, increased intraocular pressure on upgaze, and inconstant diplopia. A computed tomography scan showed that the inferior, medial, and superior extraocular muscles were bilaterally enlarged, the perineural space at the orbital cone was slightly reduced and the ophthalmic vein was congested.

SUMMARY

A cause-effect relationship between PEI and GD/GO was likely in this patient because of the temporal sequence. Although the mechanism was unknown, we speculated that the thyroid tissue damage caused by PEI released a large amount of antigenic materials from follicular thyroid cells, including thyrotropin receptor protein, which triggered the autoimmune inflammatory response against the thyroid itself and the orbital soft tissues. The patient did not have any risk factors for either GD or GO.

CONCLUSIONS

This observation raises the concern, therefore, that unpredictable and severe complications, such as GD and GO, may occur in a few patients treated with PEI.

Radiofrequency ablation of thyroid nodules: basic principles and clinical application

Radiofrequency (RF) ablation has been gaining popularity as a minimally invasive treatment for benign thyroid nodules regardless of the extent of the solid component. RF ablation of benign nodules demonstrated volume reductions of 33-58% after one month and 51-85% after six months, while solving nodule-related clinical problems. RF ablation has recently shown positive short-term results for locoregional control as well as symptom improvement in patients with recurrent thyroid cancers. This paper reviews the basic physics, indications, patient preparation, devices, procedures, clinical results, and complications of RF ablation.

High-intensity focused ultrasound ablation of thyroid nodules: first human feasibility study

BACKGROUND

Thyroid surgery is common, but complications may occur. High-intensity focused ultrasound (HIFU) is a minimally invasive alternative to surgery. We hypothesized that an optimized HIFU device could be safe and effective for ablating benign thyroid nodules without affecting neighboring structures.

METHODS

In this open, single-center feasibility study, 25 patients were treated with HIFU with real-time ultrasound imaging 2 weeks before a scheduled thyroidectomy for multinodular goiter. Thyroid ultrasonography imaging, thyroid function, were evaluated before and after treatment. Adverse events were carefully recorded. Each patient received HIFU for one thyroid nodule, solid or mixed, with mean diameter ≥8 mm, and no suspicion of malignancy. The HIFU device was progressively adjusted with stepwise testing. The energy level for ablation ranged from 35 to 94 J/pulse for different groups of patients. One pathologist examined all removed thyroids.

RESULTS

Three patients discontinued treatment due to pain or skin microblister. Among the remaining 22 patients, 16 showed significant changes by ultrasound. Macroscopic and histological examinations showed that all lesions were confined to the targeted nodule without affecting neighboring structures. At pathological analysis, the extent of nodule destruction ranged from 2% to 80%. Five out of 22 patients had over 20% pathological lesions unmistakably attributed to HIFU. Seventeen cases had putative lesions including nonspecific necrosis, hemorrhage, nodule detachment, cavitations, and cysts. Among these 17 cases, 12 had both ultrasound changes and cavitation at histology that may be expected for an HIFU effect. In the last three patients ablated at the highest energy level, significant ultrasound changes and complete coagulative necrosis were observed in 80%, 78%, and 58% of the targeted area, respectively. There were no major complications of ablation.

CONCLUSION

This study showed the potential efficacy of HIFU for human thyroid nodule ablation. Lesions were clearly visible by histology and ultrasound after high energy treatments, and safety and tolerability were good. We identified a power threshold for optimal necrosis of the target thyroid tissue. Further studies are ongoing to assess nodule changes at longer follow-up times.

Thermal ablation for benign thyroid nodules: radiofrequency and laser

Although ethanol ablation has been successfully used to treat cystic thyroid nodules, this procedure is less effective when the thyroid nodules are solid. Radiofrequency (RF) ablation, a newer procedure used to treat malignant liver tumors, has been valuable in the treatment of benign thyroid nodules regardless of the extent of the solid component. This article reviews the basic physics, techniques, applications, results, and complications of thyroid RF ablation, in comparison to laser ablation.

Ultrasound-guided laser ablation of incidental papillary thyroid microcarcinoma: a potential therapeutic approach in patients at surgical risk

BACKGROUND

Incidental papillary thyroid microcarcinoma (PTMC), a frequent clinical problem, is usually associated with a favorable outcome. During long-term follow-up, only a minority of cases show aggressive behavior with either lymph node or distant metastases. Recently, we had an opportunity to evaluate the efficacy of nonsurgical, ultrasound (US)-guided percutaneous laser ablation (PLA) for local treatment of PTMC in an otherwise inoperable patient.

PATIENT AND METHODS

Neck US examination revealed an incidental, solitary, 8 × 7 × 7 mm hypoechoic nodule with microcalcifications of the right thyroid lobe. The patient suffered from decompensated liver cirrhosis, renal failure, and recent surgery followed by external beam radiation therapy for breast cancer. Cytologic diagnosis showed papillary thyroid carcinoma, but the patient declined surgery because of high risk of thyroid surgery. After local anesthesia with 2% xylocaine, PLA was performed according to the previously reported procedure with an Nd:YAG laser.

SUMMARY

The procedure was well tolerated, without side effects, and the patient required no analgesics. US-guided fine-needle aspiration biopsy and core-needle biopsy were performed at 1 and 12 months after PLA, which demonstrated necrotic material and inflammatory cells with no viable neoplastic cell. At the 24 months US follow-up examination, the area of necrosis further decreased, demonstrating a 4 × 4 mm hypoechoic zone and a small hyperechoic area due to fibrotic changes. A fine-needle aspiration biopsy confirmed the absence of malignant cells.

CONCLUSIONS

Laser-induced thermal ablation was a safe and effective ablative treatment for a patient with PTMC confined to the thyroid gland who was at high surgical risk. This approach should be considered only in elderly patients and/or in those with comorbidities that might expose the patients to an undue high surgical risk and only after the evaluation by neck US, computed tomography, magnetic resonance imaging, or positron emission tomography/computed tomography rules out lymph-node involvement or metastatic disease.

Percutaneous laser ablation of cold benign thyroid nodules: a 3-year follow-up study in 122 patients

BACKGROUND

Percutaneous laser ablation (PLA) is a proposed therapeutic procedure for the management of benign thyroid nodules. However, long-term results are unknown. The aim of this study was to evaluate retrospectively the safety and effects of PLA treatment in patients with benign nonfunctioning thyroid nodules in a 3-year follow-up.

METHODS

One hundred twenty-two patients (95 women and 27 men; age 52.2 ± 12.3 years) with benign cold thyroid solitary nodules or a dominant nodule within a normo-functioning multinodular goiter (volume range: 2.6-86.4 mL) underwent thermal Nd:YAG laser ablation of thyroid nodular tissue by 1-4 optical fibers positioned into the tissue by 21-gauge needles under ultrasound real-time assistance. The setting was an interventional suite and outpatient endocrine clinics in a community hospital in Italy. Nodule volume, ablation volume, side effects, serum thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine (fT4), thyroglobulin (Tg), anti-Tg, anti-thyroperoxidase antibodies, symptoms, and cosmetic signs were recorded.

RESULTS

Data are mean ± standard deviation. Energy delivered was 8522  ± 5365 J with an output power of 3.1 ± 0.5 W. Three years after PLA, nodule volume decreased from 23.1 ± 21.3 to 12.5 ± 18.8 mL (-47.8%  ± 33.1% of initial volume, p ≤ 0.001). At day 1, TSH and fT4 values significantly changed (time 0 vs. day 1: TSH = 1.16  ± 1.06 vs. 0.62 ± 0.81 μU/mL, p ≤ 0.001; fT4 = 11.68 ± 1.88 vs. 13.20 ± 3.32 pg/mL, p ≤ 0.01) and normalized within 1 month. No change in free triiodothyronine, thyroperoxidase antibodies, and Tg antibodies values was observed. Symptoms improved in 89 patients (73.0%), were unchanged in 28 (22.9%), and worsened in 5 (4.1%). Cosmetic signs improved in 87 patients (71.3%), were unchanged in 29 (23.8%), and worsened in 6 (4.9%). In 11 patients (9%), nodules regrew above baseline. Two patients (1.6%) experienced delayed (12-24 hours) laryngeal dysfunction with vocal cord motility recovery after 6-10 weeks. Two patients (1.6%) became hypothyroid and two patients (1.6%) hyperthyroid after PLA.

CONCLUSIONS

After 3 years, the PLA technique achieved shrinkage of about 50% of the initial volume in a wide size range of benign cold thyroid nodules, with an improvement in local symptoms and signs. Side effects and failures were few although not negligible. PLA may be a new option for the management of benign cold thyroid nodules. Long-term controlled studies are required to establish the eligibility of patients for routine PLA.