Single-session Radiofrequency Ablation Research Articles

Outcomes of Radiofrequency Ablation for Autonomously Functioning Thyroid Adenomas-Mayo Clinic Experience.

Autonomously functioning thyroid nodules (AFTNs) constitute 5% to 7% of thyroid nodules and represent the second most common cause of hyperthyroidism following Graves' disease. Currently, radioactive iodine (RAI) and surgery are the standard treatment options, and both incur a risk of postprocedural hypothyroidism and other surgery and radiation-related complications. This work aimed at assessing the efficacy of radiofrequency ablation (RFA) as an alternative treatment option for resolving hyperthyroidism and the nodule volume rate reduction (VRR) and its associated adverse events. A total of 22 patients underwent RFA for a solitary AFTN. Seventy-two percent (n = 16) had subclinical hyperthyroidism, 9% (n = 2) had overt hyperthyroidism, and 18% (n = 4) were biochemically euthyroid on antithyroid medication. Average pretreatment TSH was 0.41 mIU/L (SD = 0.98) and free T4 1.29 ng/dL (SD = 0.33). Following a single RFA session, hyperthyroidism resolved in 90.9% (n = 20) and average VRR (61.13%) was achieved within 3 to 6 months following the ablation. Except for 1 nodule, none of the nodules grew during the follow-up period (16.5 months). Two patients (9%) developed transient tachycardia requiring short-term beta-blocker therapy, and 2 developed mild hypothyroidism requiring levothyroxine therapy. Two patients developed recurrent hyperthyroidism and elected to undergo lobectomy and repeat RFA respectively. No serious adverse effects were noted in this cohort. RAI and/or surgery represent the standard of care for toxic adenomas, but RFA shows excellent efficacy and safety profile. Therefore, at centers with RFA expertise, it should be considered an alternative treatment strategy, avoiding radiation and surgery-related complications.

8751 Radiofrequency Thermal Ablation in 32 Patients with Toxic Adenomas with Resolution of Hyperthyroidism in All Cases

Abstract Disclosure: L.G. Amato: None. E.M. Volpi: None. L.D. Volpi: None. P.M. Carani: None. A. Rahal: None. Introduction: In the general population, thyroid nodules are found in 3-7% of individuals on physical examination and in 20-76% on ultrasound. Around 8-10% of benign nodules may present autonomous behavior, being called hot nodules, causing symptoms of hyperthyroidism and being called toxic adenomas (TA). In TAs, autonomous hormone production can be caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis. Classically, the proposed treatment for autonomous nodules was surgical resection or radioiodine ablation (RAI). In this context, the prevalence of hypothyroidism after the procedure varies from 2% to 3% following lobectomy, and lower after isthmusectomy in the unique circumstance in which the TA is confined to the thyroid isthmus. A study following 684 patients with TA treated with RAI reported a progressive increase in overt and sub-clinical hypothyroidism. Potential complications following near-total/total thyroidectomy include the risk of permanent hypoparathyroidism (< 2.0%) or recurrent laryngeal nerve injury (RLN) (< 2.0%). A small risk of permanent RLN injury exists with surgery for TA. Following RAI therapy, there have been reports of new-onset Graves Disease (up to 4% prevalence) as well as concern for thyroid malignancy and a very minimal increase in late non thyroid malignancy. Radiofrequency ablation (RFA) has been a precise and effective alternative for the treatment of many benign thyroid nodules over the past ten years, including hot nodules. RFA could preserves normal thyroid function compared to surgery or RAI. Clinical case: We evaluated the effectiveness of a single session of RFA in 32 patients with TA, through hormonal status, achieving normalization of thyroid and volumetric reduction of the nodule. Among the 32 patients included in this study, aged between 25 and 88 years, of these, 31 were women and 1 was a man, all of whom underwent a single RFA procedure (“moving shot” technique associated with hydrodissection). We had a single case of a reversible complication: a patient who had transient vocal cord paralysis, with total reversal. There was a reduction in the volume of all nodules as well as all patients progressed to a state of euthyroidism within 60 days of follow-up. Conclusion: A single session of RFA was effective in treating autonomous nodules, restoring euthyroidism in all patients. Presentation: 6/3/2024

Long-term outcomes of radiofrequency ablation for intrathoracic goiter up to 5 years: evaluated by computed tomography/magnetic resonance imaging and ultrasound

Objectives This study evaluated the long-term efficacy and safety of radiofrequency ablation (RFA) for intrathoracic goiter (ITG) over a follow-up period exceeding six months. Methods From 2017 to 2022, 22 patients (6 males, 16 females) with 24 ITGs treated with RFA at a single medical center were evaluated. All patients underwent ultrasonography (US), computed tomography (CT), or magnetic resonance imaging (MRI) before RFA. Follow-up CT/MRI was performed six months after the initial RFA and then every 6–12 months. The primary outcomes measured were the degree of extension, goiter volume, volume reduction rate (VRR), tracheal deviation, and tracheal lumen. Additionally, we assessed the outcomes of single-session RFA (n = 16) vs. multiple sessions (n = 8) on goiters and explored the correlation between ITG volume measurements obtained using ultrasonography and CT/MRI. Results The median follow-up period was 12 months (interquartile range: 6–36.8 months). At the last follow-up, the nodule volume measured by CT/MRI had significantly decreased (76.2 vs. 24.6 mL; p < 0.05), with a VRR of 64.6%. Patients who underwent multiple RFA sessions showed a significantly higher VRR than the single-session patients (63.8 vs. 80.1%, p < 0.05). The intraclass correlation between goiter volumes measured using US and CT/MRI was moderate. Conclusion This study affirms the long-term efficacy and safety of RFA for ITG, providing an alternative treatment for nonsurgical candidates. Multiple RFA sessions may be beneficial for achieving better volume reduction. Sole reliance on ultrasonography is inadequate; therefore, integrating CT/MRI is essential for accurate pre-RFA and follow-up assessments.

Radiofrequency ablation compared to surgery for thyroid nodules: A case for office based treatment.

We aim to evaluate the safety and effectiveness of radiofrequency ablation (RFA) for benign thyroid nodules by ENT surgeons and to compare it to conventional hemithyroidectomy in the public healthcare, operating theater contained setting. 50 patients who underwent a single session of RFA for symptomatic benign thyroid nodules in Prince of Wales Hospital and Tseung Kwan O Hospital in Hong Kong from 2020 to 2022 were evaluated. Objective outcomes including nodule volume, volume reduction rate (VRR) and complications were recorded. Subjective response in the form of a 0-10 point scale for patient symptoms including obstructive, cosmetic, pain and satisfaction scores were collected. Significant reduction in mean VRR was found at 3, 6 and 12 months post treatment, accompanied by a significant reduction in the mean obstructive and cosmetic symptom scores. Comparing with conventional hemithyroidectomy, the RFA group had a significantly shorter mean procedure time and lower rate of complications. Estimated cost to patient for RFA was found to be less than half of that of hemithyroidectomy. RFA is a safe and effective treatment modality for benign thyroid nodules by ENT surgeons with advantages of being a scarless local anesthetic procedure with shorter procedure time, lower complication rate and lower cost to patient compared to hemithyroidectomy. In Hong Kong, where most of the population is treated in the public sector, there are limited resources, often with high caseload burden and long operation waiting times. Therefore, RFA is an office-based treatment that serves as a valuable alternative to hemithyroidectomy for benign nodules, especially in lower resource settings. 3.

The two-year prognosis of multinodular goiter following radiofrequency ablation: based on all nodule burdens.

Few studies used all nodule burdens to specify the prognosis of multinodular goiter (MNG) following radiofrequency ablation (RFA), so this study addresses this question for MNG after completely ablating dominant nodules. The RFA indications for MNG included a total of 2-5 benign nodules with over 50% normal tissue on ultrasound, 1-3 well-defined benign dominant nodules on cytology, largest diameter ≥20 mm and/or with clinical complaints, and patient refusal or unable of surgery. A retrospective study of 185 MNG patients with completely ablated dominant nodules in a single-session RFA was conducted. The efficacy and complications were evaluated at 1, 6, 12 months and yearly thereafter. Based on retreatment risks, progressive disease (PD), stable disease (SD) and complete relief (CR) were introduced to assess all nodule load changes. PD was clarified as having new/non-target nodules newly appeared to ACR TI-RADS≥4, or new/enlarged non-target nodules ≥1 cm. The initial ablation ratios of target nodules were 100% at one month. During a mean 22.38±13.75 months (range, 12-60 months), the VRR of ablated nodules was 98.25% at 24 months without regrowth. Cosmetic and symptomatic scores decreased to 1 and 0, respectively, after 48 months. 9.7% of patients (18/185) had PD and the retreatment rate was 2.2% (4/185). The complication rate was 2.7% (5/185). RFA provides cosmetic and symptomatic relief for an average of two years. RFA is an useful minimally invasive treatment modality for selected MNG patients.

SAT470 Outcomes Of Radiofrequency Ablation For Autonomously Functioning Thyroid Adenoma- Mayo Clinic Experience

Abstract Disclosure: M. Dhanasekaran: None. A.A. Rajwani: None. M.R. Castro: None. J.C. Morris: None. J. Schmitz: None. R.A. Lee: None. M. Callstrom: None. M. Stan: None. Context: Autonomously functioning thyroid nodules (AFTNs) constitutes 5% of thyroid nodules and is the second most common cause of hyperthyroidism following Graves’ Disease. Untreated hyperthyroidism is associated with adverse cardiovascular and skeletal complications. Currently, radioactive iodine (RAI) and surgery are the standard treatment options for AFTNs, and both incur a risk of post-procedural hypothyroidism. To overcome this and other surgery/radiation-related complications, radiofrequency ablation (RFA) has been utilized in multiple countries (for both toxic and non-toxic thyroid nodules). It has been shown to induce significant nodule volume reduction along with restoration of normal thyroid function in many AFTNs. Methods: We present a single-center experience using RFA as an alternative treatment modality for AFTNs. The study's primary aim was to assess the efficacy of RFA in normalizing thyroid hormone concentration and restoring the euthyroid state. In addition, we analyzed the efficacy of RFA in nodule volume rate reduction (VRR) and its associated adverse events. Results: A total of 22 consecutive patients (17 F and 5 M) underwent RFA for a solitary AFTN (hot nodule in thyroid uptake and scan) under variable degrees of general anesthesia. 72% (n=16) had subclinical hyperthyroidism, 9% (n=2) had overt hyperthyroidism, and 18% (n=4) were biochemically euthyroid on anti-thyroid drugs (ATD). The mean age at the time of ablation was 52.09 years (SD= 14.6), with a mean BMI of 27.36 kg/m2 (SD= 4.67). Average pre-treatment TSH was 0.41 mIU/L (SD= 0.980) and free T4 1.29 ng/dl (SD= 0.33). The thyroid function was assessed after a single RFA session. TSH normalized in all patients within 3-6 months following the ablation. All four patients on ATD pre-treatment discontinued therapy within three months following the procedure. The average VRR (62.54%) was achieved within 3-6 months following the RFA, and importantly, none of the nodules grew back during the follow-up period (up to 24 months). Two patients (9%) developed transient tachycardia requiring short-term beta-blocker therapy, and two (9%) developed mild hypothyroidism requiring levothyroxine therapy. One patient, euthyroid post RFA, developed recurrent hyperthyroidism 45 months later and elected to undergo lobectomy. No serious adverse effects were noted in this cohort. Conclusions - RAI and/or surgery represent the standard of care for toxic adenomas but RFA shows excellent efficacy along with an excellent safety profile. Therefore at centers with RFA expertise it should be considered an alternative treatment strategy, avoiding radiation and surgery-related complications. Presentation Date: Saturday, June 17, 2023

Efficacy of single-session radiofrequency ablation (RFA) in rendering euthyroidism for persistent/relapsed Graves' disease, a pilot study.

Graves' disease (GD) is the most common cause of hyperthyroidism. Antithyroid drug (ATD) is often the first-line treatment but > 50% patients suffer a relapse when ATD is discontinued. Surgery or radioiodine remains the current options of definitive treatment in these patients. This pilot study examined the short-term efficacy of single-session thyroid radiofrequency ablation (RFA) as a novel definitive treatment for persistent/relapsed GD. Consecutive patients with persistent/relapsed GD requiring ATD were considered. Those with a clear surgical indication, either thyroid lobe volume ≥ 20mL; those who were pregnant or lactating; and those who had any severe medical conditions that would pose extra treatment risks were excluded. Eligible patients received ultrasound-guided RFA of the entire bulk of thyroid gland. Thyroid function tests were monitored bi-monthly. The primary outcome was disease remission rate, defined as a state of biochemical euthyroidism or hypothyroidism without ATD. Secondary outcomes were complication rates. Of the 68 patients considered, 15 (22.1%) patients were eligible. Most were females (93.3%). The median age was 37 (IQR 31-48) years old. The disease remission rates were 79.0% at 6months and 73.3% at 12months. Among the 4 patients who relapsed after RFA, three required less ATD dose than before RFA. RFA was well-tolerated in the ambulatory setting. There were no vocal cord palsy, skin burn, hematoma, or thyroid storm after RFA. In well-selected patients, single-session RFA of the thyroid gland may be a potential treatment for patients with persistent/relapsed GD. It is a safe and well-tolerated ambulatory procedure. • Radiofrequency ablation of the thyroid gland is an efficacious treatment for persistent/relapsed Graves' disease in well-selected patients. • Radiofrequency ablation of the thyroid gland for the treatment of persistent/relapsed Graves' disease is a safe and well-tolerated ambulatory procedure. • Radiofrequency ablation of the thyroid gland may be a potential alternative treatment for well-selected patients with persistent/relapsed GD who do not wish to undergo either thyroidectomy or radioactive iodine or continue antithyroid drugs.

A novel parallel overlapping mode for complete ablation of large benign thyroid nodules in a single-session radiofrequency ablation.

BackgroundRadiofrequency ablation (RFA) has been widely applied in patients with benign thyroid nodules (BTNs), and complete ablation in a single-session treatment brings great benefits to patients. While how the ablation should be planned and performed to achieve complete ablation in a single-session treatment in large BTNs remains unknown.PurposeTo determine a more suitable ablation strategy for sufficient treatment in a single-session treatment.Materials and MethodsThis retrospective study included 108 BTNs receiving RFA treatment. These patients were divided into two groups: group A using one insertion point with a fan-shaped overlapping mode and group B using multiple insertion points with a novel parallel overlapping mode. All the treatments used a hydrodissection approach and moving-shot technique. Contrast-enhanced ultrasonography (CEUS) was used to guide the supplementary ablation. Follow-ups were performed at 1, 3, 6 and 12 months. The rates of supplementary ablation, initial ablation ratio (IAR), the rates of complete ablation (CAR), treatment effects and complications between the two groups were compared.ResultsThe group B had larger treated nodules (10.2ml vs 6.4ml, P<0.001) than group A, while group B had a lower rate of supplementary ablation (21.6% vs 75.4%, P<0.001), especially in the BTNs with craniocaudal diameters ≥30mm (22.0% vs 100%, P<0.001). With the assistance of supplementary ablation, both groups achieved similar IAR (100% vs 100%, P=0.372) and CAR (94.7% vs 94.1%, P=1.000). Two groups showed similar VRRs at 12-month follow-up (77.9% vs 77.5%, P=0.894) and similar rates of complications (3.5% vs 2.0%, P=1.000).ConclusionsNeedle placement using the multiple insertion points with a novel parallel overlapping mode would be easier to achieve complete ablation with less supplementary ablation, especially in large nodules.

Safety and Efficacy of Single-Session Radiofrequency Ablation Treatment for Benign Non-toxic Multinodular Goiter.

Radiofrequency ablation (RFA) is an effective treatment for benign thyroid nodules. However, it remains unclear if ablating multiple nodules in single-session offers comparable safety and efficacy to ablating single nodule. Our study compared early complication rate and 6-month nodule shrinkage between multiple-nodules ablation and single-nodule ablation by RFA. Among the 174 eligible patients undergoing RFA of one or more benign thyroid nodules, 85 (48.8%) had single-nodule ablation (group I) while 89 (51.1%) had two or three nodules ablation (group II). The 6-month nodule shrinkage of each nodule (by volume reduction ratio) (VRR) was calculated by (Baseline volume-volume at 6-month)/(Baseline volume)*100 and compared between two groups. To determine independent predictors for VRR, a multivariate analysis was done by logistic regression analysis. Patients in group II reported significantly higher pain scores during and 2-h after treatment than group I (42.31 vs. 29.66, p = 0.029 and 38.21 vs. 26.18, p = 0.037, respectively). Two vocal cord paresis occurred in each group. 3- and 6-month VRR of the largest nodule were comparable between two groups (67.39% vs. 63.89%, p = 0.248 and 77.29% vs. 73.38%, p = 0.182). Similar 3- and 6-month VRR were observed for 2 and 3 largest nodules in group II. In multivariate analysis, total energy given per nodule volume (OR = 1.007, 95% CI = 1.001-1.012, p = 0.036) was the only independent predictor for 6-month VRR. In the presence of multinodular goiter, ablating two or more nodules by RFA within one session appears to offer a comparable level of safety and efficacy to ablating single nodule.

Evaluation of Ethanol Injection, Radiofrequency Ablation, and Levothyroxine Therapy in the Management of Benign Thyroid Nodules

Background: Thyroid nodules are common clinical findings. Although there are various accepted treatments for benign thyroid nodules, such as surgery and thermal treatment, there are some alternative methods for the management of these patients at lower costs with minimal complications. Objectives: This study aimed to compare volume reduction in radiofrequency (RF) ablation and single-session ethanol ablation (EA) and to investigate the effects of levothyroxine therapy (LT4) on benign thyroid nodules. Patients and Methods: In this clinical trial, 91 patients with benign thyroid nodules, presenting to different medical centers in Tehran, Iran, from December 6, 2018, to December 6, 2019, were included. Patients who met the inclusion criteria were selected and randomly allocated into three groups: group 1, a single session of RF ablation (n = 31); group 2, a single session of ethanol injection (n = 30); and group 3, a six-month LT4 treatment (n = 30). Thyroid tests, including thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), anti-thyroid peroxidase (anti-TPO), T3 resin uptake (T3RU), and serum calcitonin level, were recorded at baseline and within one-, three-, and six-month intervals. The nodule volume was also assessed using sonography at baseline and in the follow-ups. Results: The mean volume reduction was 73.6%, 80.1%, and 8.7% at six months after the intervention in the ethanol injection, RF ablation, and LT4 treatment groups, respectively (P &lt; 0.001). There was a significant relationship between the mean volume reduction and the follow-up period (one, three, and six months) (P &lt; 0.001). Conclusion: The RF ablation therapy was found to be the optimal modality for the management of benign thyroid nodules, as it was associated with the greatest mean volume reduction. Conversely, the lowest mean volume reduction was observed in the LT4 treatment group during six months of follow-up.

Differences in the ultrasonographic appearance of thyroid nodules after radiofrequency ablation.

Radiofrequency ablation (RFA) is a well-tolerated approach to treating benign thyroid nodules (TNs), but no index can predict its success. Other than size decrease, little is known about TN appearance on ultrasonography (US) after RFA. This study aimed to (a) assess the effectiveness of single-session RFA treatment, (b) determine whether pre-ablation US characteristics correlate with its effectiveness, and (c) demonstrate TN characteristics on baseline and follow-up US. Retrospective cohort study among the patients who underwent single-session RFA for the treatment of benign TNs at a referral medical center between January 2018 and April 2019. A total of 116 patients (137 nodules) were included in the study. Characteristics were quantified using commercial software. TNs were classified into 2015 American Thyroid Association (ATA) sonographic patterns and American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TI-RADS) categories. The average volume reduction ratio (VRR) was 74.51% in 1year (95% confidence interval, 70.63%-78.39%). The only pre-ablation US feature significantly different between nodules with VRR <50% and VRR >50% was the cyst composition (0.05 vs. 0.02, p-value=.02). The VRR and margin change in the first 3months after ablation were found to be leading indicators significantly correlated to the VRR in 6months with correlation coefficients (r)=.72 and -.28 (p-value<.0001 and=.0008) and VRR in 1year with r=.65 and -.17 (p-value<.0001 and=.046), respectively. After RFA, more TNs became ATA high suspicion (2.9% vs. 19.7%, p<.0001) and more appeared to be the non-ATA patterns (12.4% vs. 23.4%, p<.0001). Also, a greater number of post-RFA TNs were classified as ACR-TI-RADS categories 4 and 5 (40.1% vs. 70.1%, p<.0001). Radiofrequency ablation therapy is effective for treating TNs. Pre-ablation cyst components, 3-month post-ablation volume reduction and margin change of TNs were related to the 6-month and 1-year response. Clinicians should consider that TNs would appear peculiar on US after RFA, mistakenly suggesting malignant potential.

Laser Ablation Versus Radiofrequency Ablation for Thyroid Nodules: 12-Month Results of a Randomized Trial (LARA II Study).

Radiofrequency ablation (RFA) seems to achieve a significantly larger nodule volume reduction rate (VRR) than laser ablation (LA) in benign nonfunctioning thyroid nodules (BNTNs). To compare the efficacy and safety of both treatments at 12-month follow-up in patients with solid or predominantly solid BNTN. This was a single-center, 12-month, randomized, superiority, open-label, parallel-group trial conducted in an outpatient clinic. Sixty patients with a solitary BNTN or dominant nodule characterized by pressure symptoms/cosmetic problems were randomly assigned (1:1 ratio) to receive either a single session of RFA or LA. Twenty-9 patients per group completed the study. The main outcome measures were VRR and proportion of nodules with more than 50% reduction (technical success rate). At 12 months, VRR was 70.9 ± 16.9% and 60.0 ± 19.0% in the RFA and LA groups, respectively (P = .024). This effect was confirmed in the linear regression model that was adjusted for age, sex, nodule baseline volume, and proportion of cellular components (RFA treatment: β = .390; P = .009). No significant between-group difference was observed in the technical success rate at 12 months after treatment. A statistically significant improvement was observed from the baseline to the 12-month follow-up for compression (RFA: 4.6 ± 2.6 and 1.3 ± 0.8, P < .001; and LA: 4.6 ± 2.1 and 1.6 ± 0.8, respectively, P < .001) and cosmetic (RFA: 3.4 ± 0.6 and 1.3 ± 0.5, P < .001; and LA: 3.4 ± 0.5 and 1.4 ± 0.6, P < .001) scores although the between-group differences were not significant. RFA achieved a significantly larger nodule volume reduction at 12 months; however, the technical success rate was similar in the RFA and LA groups.

The Ablation of Thyroid Nodule's Afferent Arteries Before Radiofrequency Ablation: Preliminary Data.

Induced radiofrequency thermal ablation is the cytoreductive treatment of symptomatic benign thyroid nodules, metastatic and recurrent thyroid tumors and papillary thyroid microcarcinomas. It is a safe and effective alternative to surgery and it allows to obtain satisfactory results in terms of volumetric reduction of the nodule with significant improvement in the quality of life. The trans-isthmic approach and the moving shot technique are the two basic techniques; however, an advanced technique, artery-first feeding radiofrequency ablation, has been developed and validated. We have prospectively included 29 consecutive patients who have undergone radiofrequency ablation (Group A) or artery- first vRFA (Group B). All included patients had a diagnosis of benign nodular goiter and they underwent a single session of radiofrequency ablation. All patients followed a follow-up program at 1 month, 3 months, and 6 months. Continuous variables (age, TSH value, basal volume of nodule, used Joule, time in second of the procedure, nodules’ volume at 1-, 3-, and 6- months of follow-up and percentage of volume reduction at 1-, 3-, and 6- months of follow-up) were described as mean, standard deviation and range, while categorical variables (gender, nodule structure and nodule vascularization) were described as number of cases and percentage. Independent samples t-test were performed to compare the continuous variables. A Test of Proportions was applied to the categorical variables. The Fisher’s exact test was used to analyze the gender. Statistical significance was considered in case of p-value <0.05. Solid structure and spongiform structure showed statistic differences with p-values of 0.022 and 0.023 respectively between two groups. The percentage of reduction at 1 month did not show a significant difference between two groups; instead, the percentage of volume reduction was decreased mostly in the Group B at 3 months and 6 months of follow-up with a p-value of 0.003 and 0.013, respectively. The Joules/energy used showed a statistically significant difference (p-value=0.05), more energy must be used in vascular radiofrequency ablation. These data allow us to hypothesize that vRFA may improve the effectiveness of the procedure, allowing for a reduction in volume more quickly. They were preliminary but promising results, clearly a larger series of cases and prolonged follow-up are needed to clarify and confirm our observations.

Radiofrequency Ablation of Papillary Thyroid Microcarcinoma: A 10-Year Follow-Up Study

PurposeTo investigate the efficacy and safety of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) after > 10 years of follow-up.Materials and MethodsThis study included five patients who underwent RFA to treat PTMCs (five lesions, mean diameter 0.5 cm, range 0.4–0.7 cm) between November 2006 and December 2009. The inclusion criteria were histopathologically confirmed PTMCs, a single PTMC lesion without extrathyroidal extension, no metastasis, and ineligibility or refusal to undergo surgery. RFA was performed by a single radiologist using a radiofrequency generator and an internally cooled electrode. We retrospectively analyzed the procedure-induced complications, serial changes in ablated tumors, recurrence, and local as well as lymph node metastasis based on data obtained from medical records and radiological images.ResultsThe mean follow-up period was 130.6 months (range 121–159 months). Three patients underwent a single RFA session, and two patients underwent two RFA sessions. We observed no procedure-induced complications. Three tumors completely disappeared after ablation, and ablation of the other two tumors resulted in the formation of a small scar that showed long-term stability (mean duration 16.8 months, range 12–27 months). At the last follow-up, no patient showed recurrence or lymph node metastasis, and serum thyroglobulin levels were within normal limits in all patients.ConclusionRFA may be effective and safe to treat low-risk PTMC in patients who refuse or are ineligible for surgery.

Efficacy of Ultrasound-guided Radiofrequency Ablation of Parathyroid Hyperplasia: Single Session vs. Two-Session for Effect on Hypocalcemia

To evaluate safety and efficacy of one- vs. two-session radiofrequency ablation (RFA) of parathyroid hyperplasia for patients with secondary hyperparathyroidism (SHPT) and to compare the outcome of both methods on hypocalcemia. Patients with secondary hyperparathyroidism underwent ultrasound guided RFA of parathyroid hyperplasia. Patients were alternately assigned to either group 1 (n = 28) with RFA of all 4 glands in one session or group 2 (n = 28) with RFA of 2 glands in a first session and other 2 glands in a second session. Serum parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) values were measured at a series of time points after RFA. RFA parameters, including operation duration and ablation time and hospitalization length and cost, were compared between the two groups. Mean PTH decreased in group 1 from 1865.18 ± 828.93 pg/ml to 145.72 ± 119.27 pg/ml at 1 day after RFA and in group 2 from 2256.64 ± 1021.72 pg/ml to 1388.13 ± 890.15 pg/ml at 1 day after first RFA and to 137.26 ± 107.12 pg/ml at 1 day after second RFA. Group 1’s calcium level decreased to 1.79 ± 0.31 mmol/L at day 1 after RFA and group 2 decreased to 1.89 ± 0.26 mmol/L at day 1 after second session RFA (P < 0.05). Multivariate analysis showed that hypocalcemia was related to serum ALP. Patients with ALP ≥ 566 U/L had lower calcium compared to patients with ALP < 566 U/L up to a month after RFA (P < 0.05). Group 1’s RFA time and hospitalization were shorter and had lower cost compared with Group 2. US-guided RFA of parathyroid hyperplasia is a safe and effective method for treating secondary hyperparathyroidism. Single-session RFA was more cost-effective and resulted in a shorter hospital stay compared to two sessions. However, patients with two-session RFA had less hypocalcemia, especially those with high ALP.

Single-session treatment of benign thyroid nodules with radiofrequency ablation: Results at 6 months in 24 patients

ObjectiveTo evaluate the efficacy and safety of one single-session of radiofrequency ablation (RFA) performed in thyroid benign and predominantly solid nodules. Patients and methodsUnicentric retrospective study in usual clinical setting that included patients with solid and benign thyroid nodules treated with one single session of RFA and with follow-up of at at least 6 months after the procedure. RFA was performed as an alternative to surgery in cases of pressure symptoms or nodular growth evidence. Patients were evaluated basally and at one, 3 and 6 months after RFA and also at twelve months if the follow-up was available. In each evaluation efficacy variables were recorded (percentual change from basal volume, percentage of nodules reaching a volume reduction above 50% from baseline, patients with disappearance of pressure symptoms and the possibility of antithyroid drug withdrawal) and safety variables were also registered including minor complications (pain needing analgesic drugs, hematoma) and major complications (voice changes, braquial plexus injury, nodule rupture and thyroid dysfunction). Results24 patients with a follow-up of at least 6 months after RFA were included, 16 of them with more than 12 months of follow-up. Mean nodule volume changed from 25.4 ± 15.5 ml basally to 10.7 ± 9.9 ml at month 6 (p < 0,05) and to 9.9 ± 10,4 ml at month 12 in 16 nodules. 6 months after RFA mean volumetric reduction was 57.5 ± 24% and 65% of the nodules reached a volume reduction above 50% from baseline. Median percentage of reduction at month 6 was 50.4 ± 25.7% for nodules with a basal volume above 20 ml (n = 13) and 65.3 ± 20.1% for nodules with a lower basal volume (n = 11). Pressure symptoms reported in 12 patients disappeared in all cases. Antithyroid drugs could be stopped in 3 of 4 cases treated before RFA. A mild and transient pain responsive to conventional analgesic drugs was recorded in 9 patients during the 24 h after the procedure and in 7 a small perithyroid and transient hematoma was observed in the 48 following hours. One major complication was described as a nodule rupture that recovered spontaneously. There were no changes in hormonal values in euthyroid cases. ConclusionA single session of RFA seems to be an effective and safe procedure in patients with solid thyroid nodules with pressure symptoms or relevant growth evidence. As an outpatient and scarless procedure with no need of general anaesthesia it could become an useful alternative to lobectomy when surgery is refused or in patients at high surgical risk.

3:09 PM Abstract No. 128 Development of real-time optical image-assessed thermal ablation of hepatic tumor

To investigate the feasibility of using indocyanine green (ICG)-based optical imaging to instantly assess the effective radiofrequency ablation (RFA) on VX2 tumor cells, towards the development of intratumoral real-time optical imaging-guided RFA of larger tumors. We first optimized the uptake characteristics of a clinically applicable optical contrast, indocyanine green (ICG), by VX2 tumor cells. 1×104 VX2 cells in each of different cell groups were treated with various ICG concentrations from 0 to 125 μg/mL, over incubation times from 0 min to 48 hours. Then, in comparison to ICG solution-only, ICG-labeled VX2 cells were treated by thermal ablation at 80 °C for 30 minutes. ICG in cells were subsequently qualitatively and quantitatively evaluated by fluorescence microscopy and optical imaging. The optimization of the ICG concentration demonstrated a linear increase of fluorescent signal intensities (SI), with the peak SI at 100 μg/mL of ICG, starting at the time point of 24 hours post-ICG labeling. Both the fluorescent SIs of ICG-only and ICG-labeled VX2 cell groups were significantly decreased after the thermal ablation treatment (For ICG solution: average SI pretreatment vs. SI posttreatment = 11075.2 ± 1060.9 count vs. 4681.1 ± 442.1 count, P <0.001; and for ICG-labeled VX2 cells: 926.2 ± 197.1 count vs. 301.4 ± 53.9 count, P <0.001). This study demonstrated the feasibility of using indocyanine green (ICG)-based optical imaging to evaluate the instant treatment effect of thermal ablation on VX2 tumor cells, which has encouraged the further on-going studies for developing the new interventional molecular imaging technique to ensure the complete removal of larger tumors during a single RFA session.

Resultados de una sesión única de ablación por radiofrecuencia en nódulos tiroideos benignos: Resultados a 6 meses en 24 pacientes

ObjectiveTo evaluate the efficacy and safety of one single-session of radiofrequency ablation (RFA) performed in thyroid benign and predominantly solid nodules. Patients and methodUnicentric retrospective study in usual clinical setting that included patients with solid and benign thyroid nodules treated with one single session of RFA and with folllow-up of at at least 6 months after the procedure. RFA was performed as an alternative to surgery in cases of pressure symptoms or nodular growth evidence. Patients were evaluated basally and at one, 3 and 6 months after RFA and also at 12 months if the follow-up was available. In each evaluation efficacy variables were recorded (percentual change from basal volume, percentage of nodules reaching a volume reduction above 50% from baseline, patients with disappearance of pressure symptoms and the possibility of antithyroid drug withdrawal) and safety variables were also registered including minor complications (pain needing analgesic drugs, hematoma) and major complications (voice changes, braquial plexus injury, nodule rupture and thyroid dysfunction). ResultsTwenty-four patients with a follow-up of at least 6 months after RFA were included, 16 of them with more than 12 months of follow-up. Mean nodule volume changed from 25.4±15.5ml basally to 10.7±9.9ml at month 6 (P<.05) and to 9.9±10,4ml at month 12 in 16 nodules. Six months after RFA mean volumetric reduction was 57.5±24% and 65% of the nodules reached a volume reduction above 50% from baseline. Median percentage of reduction at month 6 was 50.4±25.8% for nodules with a basal volume above 20ml (n=13) and 65.3±20.1% for nodules with a lower basal volume (n=11). Pressure symptoms reported in 12 patients disappeared in all cases. Antithyroid drugs could be stopped in 3 of 4 cases treated before RFA. A mild and transient pain responsive to conventional analgesic drugs was recorded in 9 patients during the 24h after the procedure and in 7 a small perithyroid and transient hematoma was observed in the 48 following hours. One major complication was described as a nodule rupture that recovered spontaneously. There were no changes in hormonal values in euthyroid cases. ConclusionA single session of RFA seems to be an effective and safe procedure in patients with solid thyroid nodules with pressure symptoms or relevant growth evidence. As an outpatient and scarless procedure with no need of general anaesthesia it could become an useful alternative to lobectomy when surgery is refused or in patients at high surgical risk.

Clinical assessment of magnetic resonance imaging-guided radiofrequency ablation for breast cancer.

The aim of the present study was to investigate the efficacy of magnetic resonance imaging (MRI)-guided radiofrequency ablation (RFA) for breast cancer patients who cannot undergo traditional surgery. A total of 10 patients were treated by MRI-guided RFA, of whom 6 had stage IV disease (lung metastasis n=3, bone metastasis n=1, liver metastasis n=1 and mediastinal metastasis n=1) and the remaining 4 patients, who refused surgery, had stage III disease accompanied by severe underlying conditions. The changes in feasibility, tumor volume, bleeding, local recurrence, metastasis and complications were evaluated after RFA. The patients were followed up at 1, 3, 6 and 12 months, and annually thereafter. A total of 14 RFA sessions were successfully performed (100%) in the 10 patients, among whom 7 patients underwent a single RFA session, 2 patients underwent two sessions, and 1 patient underwent three sessions. Compared with pre-RFA, the volume of the tumors at 6 months after RFA was markedly decreased. There was no local tumor recurrence or metastasis detected during a mean follow-up period of 19.5±3.46 months, and no major complications were reported. Therefore, RFA was found to be a minimally invasive and feasible treatment method in the present study, and MRI-guided RFA may be a promising alternative option for breast cancer patients who are unable to tolerate surgery. However, more prospective studies on the applicability of RFA in breast cancer are required.

Endoscopic radiofrequency biliary ablation treatment: A comprehensive review.

Radiofrequency ablation (RFA) functions by delivering thermal energy within tissue, the result of a high-frequency alternating current released from an active electrode, leading to coagulative necrosis and cellular death. Recently, a biliary catheter working on a guidewire has been developed and a number of studies have so far been carried out. The present article provides a comprehensive review of the literature on the results of the use of RFA for the clinical management of patients with unresectable malignant biliary strictures, benign biliary strictures, and residual adenomatous tissue in the bile duct after endoscopic papillectomy. Available data show that biliary RFA treatment is a promising adjuvant therapy in patients with unresectable malignant biliary obstruction. The procedure is safe, well tolerated and improves stent patency and survival, even though more studies are warranted. In patients with residual endobiliary adenomatous tissue after endoscopic papillectomy, a significant rate of neoplasia eradication after a single RFA session has been reported, thus favoring this treatment over surgical intervention. In these patients, as well as in those with benign biliary strictures, dedicated probes with a short electrode able to focus the RF current on the short stenosis are needed to expand RFA treatment for these indications.