Thyroid Tissue: US-guided Percutaneous Laser Thermal Ablation

Clinical Outcomes of Thermal Ablation Re-Treatment of Benign Thyroid Nodules: A Multicenter Study from the Italian Minimally Invasive Treatments of the Thyroid Group

Background: Thermal ablation (TA) is an established therapeutic option alternative to surgery in patients with solid benign thyroid nodules causing local symptoms. However, a variable part of thyroid nodules remain viable after these nonsurgical treatments, and as many as 15% of nodules treated with TA may require a second treatment over time. This study aimed to evaluate the outcomes of TA re-treatment on symptomatic benign thyroid nodules where the volume decreased by <50% after the first procedure ( = technique inefficacy). Methods: We performed a multicenter retrospective cohort study including patients who underwent re-treatment with TA for benign thyroid nodules, whose volume decreased by <50% after initial treatment. The primary aim was to evaluate volume and volume reduction ratio (VRR) over time and compare the 6- and 12-month VRR after first versus second treatment. The secondary aim was to identify protective or risk factors for technique inefficacy, regrowth, and further treatments, expressed as adjusted hazard ratios (HRs) and confidence interval [CI], after adjustment for sex, age, nodule volume, structure and function, nodule regrowth or symptom relapse, technique used and if the same technique was used for the first and second TA and time between them. Results: We included 135 patients. Re-treatment led to VRR of 50% and 52.2% after 6 and 12 months. VRR after re-treatment was greater than after first treatment in small and medium size nodules (<30 mL), while there were no differences for large nodules (>30 mL). After re-treatment technique inefficacy rate was 51.9%, regrowth rate was 12.6%, and further treatment rate was 15.6%. Radiofrequency ablation (RFA) was protective toward technique inefficacy (HR = 0.40 [CI 0.24-0.65]) and need of further treatments (HR = 0.30 [CI 0.12-0.76]). Large nodule volume (>30 mL) was associated with increased risk of re-treatment (HR = 4.52 [CI 1.38-14.82]). Conclusions: This is the first study evaluating the outcomes of re-treatment on symptomatic benign thyroid nodules with a VRR <50% after the initial TA treatment. Best results were seen in small and medium nodules (<30 mL) and after RFA. Prospective confirmatory studies are needed.

[Application of Radiofrequency Ablation to Thyroid Cancer: Past, Present, and Future]

Thyroid cancer, characterized by high incidence rates, good prognosis, and frequent recurrence, is typically treated surgically. However, since the early 2000s, radiofrequency ablation, which is commonly utilized in liver, lung, and kidney cancers, is being performed for management of primary and recurrent thyroid cancers. Many studies have focused on inoperable cases of low-risk papillary microcarcinoma (≤ 1 cm) and some have investigated its role in larger lesions (up to 4 cm). Overall, these studies have reported positive results. Radiofrequency ablation for recurrent cancer has primarily been performed for locally recurrent cervical cancer, and this therapeutic approach has been attempted for treatment of distant metastases in lungs and bones, with encouraging outcomes. A growing global trend, particularly in South Korea, the United States, and Europe supports radiofrequency ablation for thyroid cancer. However, this therapy is currently not recognized as a treatment option recommended by universally accepted clinical guidelines such as those established by the National Comprehensive Cancer Network. Based on past efforts and future research, radiofrequency ablation is expected to play a key role in thyroid cancer treatment in the near future.

Outcomes of laser-induced thermotherapy for thyroid nodules at the West Vascular Center, Ukraine

Thyroid nodules are common, occurring in 50-60% of healthy patients. Currently, there are no effective conservative treatment options for nodular goiter, and surgery can have limitations and potential complications. The purpose of this study was to evaluate the efficacy, tolerability, and long-term results of using sclerotherapy and laser-induced interstitial thermotherapy (LITT) to treat benign thyroid nodules. A retrospective analysis was conducted on 456 patients with benign nodular goiter who received LITT. The volume of the nodular goiter was measured at 1, 3, 6, and 12 months post-treatment, and a repeated fine needle aspiration (FNA) with the cytological examination was performed to verify the structure of the nodular goiter in the long term. The results showed that LITT was an effective method for treating nodular mass (nodules), as evidenced by a decrease in the volume of NG by 51-85% after 6-12 months. FNA results 2-3 years after LITT showed no thyrocytes, only connective tissue, indicating the efficacy of LITT for benign thyroid nodules. LITT is highly effective in most cases, often resulting in the disappearance or significant decrease in nodular formations.

Efficacy and Safety of Radiofrequency Ablation for the Treatment of Autonomously Functioning Thyroid Nodules: A Long-Term Prospective Study

Objective

This study aims to evaluate the efficacy and safety of RFA in the AFTN treatment after 2 years of follow-up and to find the factors related to treatment responses through TSH level and VRR.

Materials and Methods

This long-term prospective study was conducted from September 2017 to April 2021 on 17 AFTNs treated with RFA. Clinical evaluations, thyroid function tests, thyroid scintigraphy, and ultrasonography examinations were performed at 1 month, 3 months, 6 months, and 24 months after ablation. The primary endpoint was the success rate of RFA in restoring the euthyroidism stage after 24 months of follow-ups; secondary outcomes were VRR and improvements of US parameters, clinical examinations, and complications. The Spearman rank correlation test was used to determine related factors with treatment response variables.

Results

At the 24 months after the procedure, symptom score, cosmetic score, vascularity grade, and nodule volume significantly decreased. The VRR reduced approximately 42.77%, 63.13%, 78.3%, and 95.65% after 1 month, 3 months, 6 months, and 24 months follow-up. All 17 patients were restored euthyroid state without taking ATDs. No major complications were collected. The last TSH level was significantly correlated with the age of patients (Spearman rho = −0.637, p = 0.008). The VRR was significantly correlated with age of patients (Spearman rho = 0.566, p = 0.018) and initial TSH (Spearman rho = 0.485, p = 0.048).

Conclusion

RFA was demonstrated as a safe and effective option for AFTN treatment in long-term follow-up. It can be used as an alternative treatment with encouraging results.

A New Perspective for Predicting the Therapeutic Success of RFA in Solid BTNs: Quantitative Initial RFA Ratio by Contrast-Enhanced Ultrasound

OBJECTIVE

The short-term therapeutic success of radiofrequency ablation (RFA) in solid benign thyroid nodules is of great concern. The aim of this study was to investigate a new method, initial radiofrequency ablative ratio (IRAR) using contrast-enhanced ultrasound (CEUS), for predicting therapeutic success of RFA in solid benign thyroid nodules (BTNs) immediately and effectively after RFA.

METHODS

A total of 813 nodules in 776 patients with benign thyroid nodules were treated with RFA from January 2014 to August 2018, among which 120 patients (M:F=41:79) with 120 solid BTNs (small: ≤10ml, n=57; medium: 10-30ml, n=42; large: >30ml, n=21) were enrolled in our study according to the inclusion criteria. The IRAR was defined as the ablative volume ratio immediately after RFA displayed by CEUS. The therapeutic success was evaluated at the 6-month follow-up. The relationship between the IRAR and volume reduction ratio (VRR) at 6-month was analyzed. The marginal regrowth of solid BTNs was also examined by CEUS at the 6 and 12 months of follow-up.

RESULTS

In medium and large nodules, the IRAR was significantly and positively correlated with VRR (r= 0.69, P < 0.001) at 6 months after RFA. There was a tendency to achieve therapeutic success (50% VRR: 55/63, 87.3%) when the IRAR exceeded 75%, and marginal regrowth was also relatively slow within 12 months after a single session treatment. No significant correlation between IRAR and VRR of small nodules was found. In conclusion, IRAR is significantly and positively correlated with VRR, which may indicate therapeutic success when it exceeds 75%.

CONCLUSIONS

CEUS can be used to accurately quantify the IRAR, which is positively correlated with the VRR. Moreover, the IRAR may be used as a parameter to predict the short-term therapeutic success of RFA in solid BTNs.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A comprehensive review of interventional ablation techniques for the management of thyroid nodules and metastatic lymph nodes

Thyroidectomy remains the gold standard treatment for benign, symptomatic, or enlarging thyroid nodules, malignant nodules, and metastatic lymph node disease. However, in the past 2 decades, image-guided interventional techniques have emerged as promising alternative treatments for these conditions. Percutaneous ethanol ablation is now an accepted first-line treatment for recurring cystic thyroid nodules. Thermal ablation techniques such as high-intensity focused ultrasound, laser ablation, radiofrequency ablation, and microwave ablation have shown efficacy in producing a nodular volume reduction of greater than 50% that is maintained for several years with resolution of local compressive symptoms. There is also increasing evidence that these techniques can effectively treat papillary thyroid microcarcinomas and recurrent metastatic lymph node disease. Because these interventional ablation techniques are performed safely in an outpatient setting, are well tolerated, and the risk for needing thyroid hormone supplementation is negligible, they are becoming a popular alternative treatment to surgical resection. In this comprehensive review, we discuss each of these percutaneous interventions: the devices and techniques, the advantages and disadvantages of each energy, and summarize the outcomes published in the literature.

Radiofrequency Ablation and Autonomous Functioning Thyroid Nodules: Review of the Current Literature

OBJECTIVE

Autonomously functioning thyroid nodules (AFTNs) have long been treated with either surgery or radioactive iodine (RAI). Being an invasive procedure, even thyroid lobectomy for this condition is associated with complications such as anesthesia side effects, scarring, iatrogenic hypothyroidism, and injury to other structures. Similarly, RAI is associated with hypothyroidism and may require multiple courses. Therefore, minimally invasive techniques such as radiofrequency ablation (RFA) are being advocated as an alternative treatment for AFTNs. To date, only few studies have been published on this topic and are largely on European and Asian populations. The aim of this review is to assess the efficacy and safety of RFA as a potential alternative for treatment of AFTNs compared to conventional surgery and radioiodine.

METHODS/STUDY DESIGN

Comprehensive PubMed and Embase searches were performed using the following terms such as (autonomously functioning thyroid nodules and radiofrequency ablation), (radiofrequency ablation and hyperthyroidism), and (radiofrequency ablation and toxic thyroid nodule). Both prospective and retrospective studies were included based on the inclusion and exclusion criteria specified in the text.

RESULTS

Initially, 57 studies were identified and after excluding 47 studies, finally 10 studies were included in the review.

CONCLUSION

Although surgery remains the first line treatment for AFTN. However, RFA is a safe option compared to RAI or surgery, especially in patients who are high-risk surgical candidates or have absolute contraindications to RAI. Currently, trials with follow-up greater than or equal to 5 years are warranted. It will aid in formulating a standardized surveillance protocol and also generalize RFA's use for AFTN. Laryngoscope, 2021.

European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 Clinical Practice Guideline for the Use of Minimally Invasive Treatments in Malignant Thyroid Lesions

The growing detection of papillary thyroid microcarcinomas (PTMCs) is paralleled by an increase in surgical procedures. Due to the frequent indolent nature, cost, and risk of surgery, active surveillance (AS) and ultrasound-guided minimally invasive treatments (MITs) are in suitable cases of incidental PTMC proposed as alternatives to thyroidectomy. Surgery and radioiodine are the established treatments for relapsing cervical differentiated thyroid carcinoma (DTC) metastases. But radioiodine refractoriness, risk of surgical complications, adverse influence on quality of life, or declining repeat surgery have led to AS and MIT being considered as alternatives for slow-growing DTC nodal metastases. Also, for distant radioiodine-refractory metastases not amenable to surgery, MIT is proposed as part of a multimodality therapeutic approach. The European Thyroid Association and the Cardiovascular and Interventional Radiological Society of Europe commissioned these guidelines for the appropriate use of MIT. Based on a systematic PubMed search, an evidence-based approach was applied, and both knowledge and practical experience of the panelists were incorporated to develop the manuscript and the specific recommendations. We recommend that when weighing between surgery, radioiodine, AS, or MIT for DTC, a multidisciplinary team including members with expertise in interventional radiology assess the demographic, clinical, histological, and imaging characteristics for appropriate selection of patients eligible for MIT. Consider TA in low-risk PTMC patients who are at surgical risk, have short life expectancy, relevant comorbidities, or are unwilling to undergo surgery or AS. As laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective thermal ablation (TA) techniques, the choice should be based on the specific competences and resources of the centers. Use of ethanol ablation and high-intensity focused ultrasound is not recommended for PTMC treatment. Consider MIT as an alternative to surgical neck dissection in patients with radioiodine refractory cervical recurrences who are at surgical risk or decline further surgery. Factors that favor MIT are previous neck dissection, presence of surgical complications, small size metastases, and <4 involved latero-cervical lymph nodes. Consider TA among treatment options in patients with unresectable oligometastatic or oligoprogressive distant metastases to achieve local tumor control or pain palliation. Consider TA, in combination with bone consolidation and external beam radiation therapy, as a treatment option for painful bone metastases not amenable to other established treatments.

Predictor Analysis in Radiofrequency Ablation of Benign Thyroid Nodules: A Single Center Experience

Purpose

To confirm the efficacy of ultrasound (US) guided radiofrequency ablation (RFA) in the treatment of benign thyroid nodules, we evaluated as primary outcome the technical efficacy and clinical success in a single center dataset. The secondary outcome was to find a correlation between nodules' pre-treatment features and volume reduction rate (VRR) ≥75% at 12 months after RFA and during follow-up period.

Methods

This retrospective study included 119 consecutive patients (99 females, 20 males, 51.5 ± 14.4 years) with benign thyroid nodules treated in our hospital between October 2014 and December 2018 with a mean follow-up of 26.8 months (range 3-48). Clinical and US features before and after RFA were evaluated by a US examination at 1, 3, 6, 12 months and annually thereafter up to 48 months.

Results

The median pre-treatment volume was 22.4 ml; after RFA we observed a statistically significant volume reduction from the first month (11.7 ml) to the last follow-up (p < 0.001 for all follow-up times). The median VRR was 47.1, 55.3, 61.2, 67.6, 72.8, 71.3, and 62.9% at 1, 3, 6, 12, 24, 36, and 48 months of follow-up respectively, showing a progressive significant improvement up to 24 months (VRRs 1 vs 3 months, 3 vs 6 months and 6 vs 12 months p < 0.001, 12 vs 24 months p = 0.05) while no differences at 24 vs 36 and 36 vs 48 months were observed. Symptoms improved significantly (complete resolution 64.35%, partial resolution 35.65%), and neck circumference was reduced as compared to pre-treatment (p < 0.001). Lower pre-treatment neck circumference (37.5 vs 36.0 cm, p = 0.01) was a positive predictor of VRR ≥75% at 12 months. Macrocystic echostructure (HR 2.48, p 0.046) and pre-treatment volume >22.4 ml (HR 0.54, p 0.036) were found to be independent positive and negative predictors of VRR ≥75% respectively. One-month post RFA VRR ≥50% represented the best positive predictor of technical success.

Conclusions

This study confirmed the efficacy of RFA in the treatment of benign thyroid nodules. In particular we show that by selecting macrocystic nodules smaller than 22.4 ml better long-term response can be achieved, which is predicted by an early shrinkage of the nodule.

Percutaneous Ultrasound-Guided Laser Ablation of Benign Thyroid Nodules: Results of 10-Year Follow-Up in 171 Patients

Context

Percutaneous, ultrasound-guided laser ablation is effective in nodular thyroid disease.

Objective

The aim of this study was to evaluate the long-term (10-year) efficacy and safety of laser ablation in the treatment of benign thyroid nodules.

Methods

From 2009 to 2010, 171 patients received a single session of laser ablation. Evaluation of nodule volume was performed before treatment, at 6 months, and every year.

Results

Technique efficacy was achieved in 92% of patients at 1 year. Median nodule volume significantly decreased from 16.7 mL (range, 11.0-97.0 mL) at baseline to 5.0 mL (range, 4.1-32.0 mL) at 1 year, a volume reduction ratio (VRR) of 68%. The benefit of the treatment was durable (P < 0.001 vs baseline at all timepoints), with a VRR of 59% after 10 years. No cases of nodule regrowth > 50% were observed at 1 year, although such cases did occur after 4 years (n = 3; 1.7% of the overall cohort) and 7 years (n = 8; 4.7%). There were no further cases of regrowth beyond 7 years. When patients were stratified according to baseline nodule volume (< 15 mL, 15-25 mL, or > 25 mL), durable results were observed across all 3 categories, with the largest, most prolonged effect observed in patients with nodules < 15 mL. Treatment was well tolerated, with only minor, transient complications of fever and local pain, and 98% of patients willing to recommend the treatment.

Conclusion

Percutaneous, ultrasound-guided laser ablation of benign thyroid nodules provides long-term benefits and the treatment is well tolerated.

Percutaneous laser ablation of cervical metastatic lymph nodes in papillary thyroid carcinoma: clinical efficacy and anatomical considerations

Background: Papillary thyroid carcinoma is the most common type of thyroid cancer; despite its generally indolent course, patients often develop local post-operative recurrences. Re-operation, however, holds a high complication rate, while at the same time, not all patients benefit from radioiodine ablation. This systematic review investigates the application of laser ablation therapy (LAT) for cervical lymph node metastases as an additional treatment modality.Methods: This systematic review was conducted in accordance with the PRISMA Statement. Medline electronic database and Cochrane Library were searched for eligible articles.Results: Five studies were included in the systematic review. All studies included patients with metastatic lymph nodes from papillary thyroid carcinoma, that were unsuitable for further radioiodine or surgical treatment. Patients were treated with two different LAT devices. Regardless of the utilized assessment modalities, all researchers reported significant outcomes on local disease control. No permanent complications were observed.Conclusions: LAT is relatively safe and effective for the treatment of cervical metastatic lymph nodes in patients with papillary thyroid carcinoma.

Five-Year Results of Radiofrequency and Laser Ablation of Benign Thyroid Nodules: A Multicenter Study from the Italian Minimally Invasive Treatments of the Thyroid Group

Background: Radiofrequency ablation (RFA) and laser ablation (LA) are effective treatments for benign thyroid nodules. Due to their relatively recent introduction into clinical practice, there are limited long-term follow-up studies. This study aimed to evaluate technique efficacy, rate of regrowth, and retreatment over 5 years after RFA or LA and to identify predictive factors of outcome. Methods: In this multicenter retrospective study, the rates of technique efficacy, regrowth, and retreatment were evaluated in 406 patients treated with either RFA or LA, and followed for 5 years after initial treatment. Propensity score matching was used to compare treatments. Cumulative incidence studies with hazard models were used to describe regrowth and retreatment trends, and to identify prognostic factors. Logistic regression models and receiver operating characteristic analyses were used for risk factors and their cutoffs. Results: RFA and LA significantly reduced benign thyroid nodule volume, and this reduction was generally maintained for 5 years. Technique efficacy (defined as a reduction ≥50% after 1 year from the treatment) was achieved in 74% of patients (85% in the RFA and 63% in the LA group). Regrowth occurred in 28% of patients (20% in the RFA and 38% in the LA group). In the majority of cases, further treatment was not required as only 18% of patients were retreated (12% in the RFA and 24% in the LA group). These data were confirmed by propensity score matching. Cumulative incidence studies showed that RFA was associated with a lower risk of regrowth and a lower risk of requiring retreatment over time. Overall, technique inefficacy and regrowth were associated with low-energy delivery. Retreatments were more frequent in young patients, in large nodules, in patients with lower volume reduction at 1 year, and in cases of low-energy delivery (optimal cutoff was 918 J/mL for RFA). Conclusions: Both thermal ablation techniques result in a clinically significant and long-lasting volume reduction of benign thyroid nodules. The risk of regrowth and needing retreatment was lower after RFA. The need for retreatment was associated with young age, large baseline volume, and treatment with low-energy delivery.

Role of laser ablation in multimodal treatment of radioiodine- refractory bone metastases of thyroid cancer: a retrospective study

PURPOSE

To assess the efficacy, safety, and pain benefits of imaging-guided laser ablation (IGLA) in patients with radioiodine-refractory (RR) bone metastases from differentiated thyroid carcinoma (DTC).

PATIENTS AND METHODS

The institutional medical records of patients with bone metastases from DTC treated with laser ablation (LA) were reviewed retrospectively. Local response, complications, and effects on pain relief were investigated.

RESULTS

Six osteolytic lesions in five patients (one male, four females; mean age 65.4 ± 5.1 years, range 58-72) were treated with IGLA. All lesions were osteolytic and all have had previous treatments with high-dose radioiodine therapy followed by external radiotherapy (EBRT). All patients assumed opioid analgesics for severe pain. Overall, the lesions (mean size 5.8 ± 3.2 cm; median 5.0 cm, range 3.0-12.0 cm) underwent nine IGLA sessions (mean 1.8 ± 0.4 sessions; median 2.0 sessions, range 1-2). In four (80%) out five lesions, cross-sectional imaging showed a nearly complete response (CR) while the largest lesion was ablated by 80%. Pain changes were assessed with the Brief Pain Inventory-Short Form, that was administered before IGLA and during a 6-month follow-up. Patients experienced significant reduction in worst pain, average pain, and pain interference. Following IGLA, the average daily opioid requirement rapidly and progressively decreased. Treatments were well-tolerated and no major complications occurred.

CONCLUSIONS

IGLA is an effective and safe debulking procedure and provides significant pain relief in patients suffering from DTC bone metastases that are not responsive to standard treatments. So, IGLA could be considered as part of a multimodality management of advanced thyroid cancer with RR metastatic skeletal involvement.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

Thermal ablation for benign, non-functioning thyroid nodules: A clinical review focused on outcomes, technical remarks, and comparisons with surgery

Thermal ablation (TA) is a therapeutic option for benign, non-functioning thyroid nodules causing symptoms of compression and/or aesthetic concerns. TA was initially introduced as a treatment for patients who refused or were ineligible for surgery. In more recent years, the increase in the positive experiences of TA have paved the way for the idea that TA could be suggested as a first-line treatment. The present review was conceived to summarize the evidence achieved in this field, and to offer a clinical perspective on TA, with particular reference to the comparison between TA and surgery. We searched literature that was focused on two types of TA, laser (LA) and radiofrequency (RFA). The searched literature included short- mid-term prospective and retrospective studies, randomized trials, and meta-analyses that demonstrated a satisfactory volume reduction ratio (VRR), and benefits in cosmetic and symptoms scores. An important drawback of the use of TA, is the regrowth of a certain number of nodules, which necessitate further TA procedures or surgery. Long-term randomized controlled trials to evaluate the cost/effectiveness of TA vs surgery are not currently available. The selection of the nodule, the optimization of interventional techniques, and ultimately, a well-timed second treatment, are all factors that should be considered in a proactive strategy to prevent TA failure.

Laser and radiofrequency ablations for benign and malignant thyroid tumors

A growing body of evidence is being published regarding the safety and efficacy of minimally invasive image-guided ablation techniques. While clinical applications of these techniques are increasing, international societies have started to publish treatment guidelines and to make efforts to standardize both terminology and reporting criteria for image-guided thyroid ablations. Laser ablation and radiofrequency ablation (RFA) are among the most common ablation techniques either for benign and malignant thyroid nodules. Unlike laser ablation and RFA in the treatment of benign thyroid nodules, where safety and efficacy have been widely demonstrated, evidence regarding local tumor control of thyroid malignancies is still limited. However, preliminary results are encouraging and image-guided thermal ablation techniques can be considered a valid alternative to surgery for the treatment of benign thyroid nodules and recurrent thyroid cancers. This review evaluates the basic concept of RFA and laser ablations, their techniques, clinical outcomes, and complications based on the suggestions of several society guidelines. Multidisciplinary collaboration remains critical to identify patients which may benefit from minimally invasive image-guided thermal ablations, especially if surgery or radioiodine therapy are not feasible options.

Distinguishing Recurrent Thyroid Cancer from Residual Nonmalignant Thyroid Tissue Using Multiphasic Multidetector CT

BACKGROUND AND PURPOSE

During thyroidectomy incomplete resection of the thyroid gland may occur. This complicates the imaging surveillance of these patients as residual thyroid needs to be distinguished from local recurrence. Therefore, the purpose of this study was to determine if multiphasic multi-detector computed tomography (4D-MDCT) can differentiate residual nonmalignant thyroid tissue and recurrent thyroid carcinoma after thyroidectomy.

MATERIALS AND METHODS

In this retrospective study, Hounsfield unit values on multiphasic multidetector CT in precontrast, arterial (25 seconds), venous (55 seconds), and delayed (85 seconds) phases were compared in 29 lesions of recurrent thyroid cancer, 29 with normal thyroid, and 29 with diseased thyroid (thyroiditis/multinodular thyroid). The comparison of Hounsfield unit values among lesion types by phase was performed using ANOVA. The performance of Hounsfield unit values to predict recurrence was evaluated by logistic regression and receiver operating characteristic analysis.

RESULTS

All 3 tissue types had near-parallel enhancement characteristics, with a wash-in-washout pattern. Statistically different Hounsfield unit density was noted between the recurrence (lowest Hounsfield unit), diseased (intermediate Hounsfield unit), and normal (highest Hounsfield unit) thyroid groups throughout all 4 phases (P < .001 for each group and in each phase). Dichotomized recurrence-versus-diseased/normal thyroid tissue with univariate logistic regression analysis demonstrated that the area under the receiver operating characteristic curve for differentiating benign from malignant thyroid for the various phases of enhancement was greatest in the precontrast phase at 0.983 (95% CI, 0.954-1), with a cutoff value of ≤62 (sensitivity/specificity, 0.966/0.983) followed by the arterial phase.

CONCLUSIONS

Recurrent thyroid carcinoma can be distinguished from residual nonmalignant thyroid tissue using multiphasic multidetector CT with high accuracy. The maximum information for discrimination is in the precontrast images, then the arterial phase. An optimal clinical protocol could be built from any number of phases but should include a precontrast phase.

Ultrasound-Guided Laser Ablation Versus Microwave Ablation for Patients With Unifocal Papillary Thyroid Microcarcinoma: A Retrospective Study

BACKGROUND AND OBJECTIVES

The objective of this study is to compare the efficacy and the safety of ultrasound-guided microwave ablation (MWA) and laser ablation (LA) for the treatment of papillary thyroid microcarcinoma (PTMC).

STUDY DESIGN/MATERIALS AND METHODS

A total of 67 patients with unifocal PTMC were studied retrospectively, including 33 cases who underwent MWA (MWA group) and 34 cases who received LA (LA group). The follow-up consisted of thyroid function tests, ultrasonography, contrast-enhanced ultrasonography (CEUS), and chest X-ray or computed tomography scan. The treatment response and complications were compared between the two groups.

RESULTS

The follow-up time for the MWA and LA group was 23.3 ± 4.4 and 22.8 ± 4.1 months, respectively. All the ablations were successfully performed as planned without complementary ablations, and it was confirmed by CEUS after treatment in both groups. It was observed that, at the last follow-up, the mean largest diameter decreased from 5.0 ± 1.4 mm to 0.1 ± 0.4 mm (MWA group) and from 4.5 ± 1.6 mm to 0.6 ± 1.2 mm(LA group) (P < 0.05 for both). The average volume reduced from 51.9 ± 40.8 to 0.2 ± 1.0 mm³ (MWA group) and from 38.5 ± 43.0 to 1.3 ± 3.8 mm³ (LA group) (P < 0.05 for both). The complication rates did not differ between the MWA group (9.1%) and the LA group (2.9%) (P > 0.05). No local recurrence or distant metastasis occurred in either group.

CONCLUSIONS

During the short-term follow-up period, ultrasound-guided MWA and LA were both safe and effective methods in treating patients with unifocal PTMC. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Safety and efficacy of thermal ablation (radiofrequency and laser): should we treat all types of thyroid nodules? †

Background: Thermal ablation is a minimally invasive technique that is gradually acknowledged as an effective alternative to surgery to treat thyroid nodules. Two main techniques have been described: radiofrequency (RFA) and laser ablation. Objective: To evaluate the safety and efficacy of the two main techniques (RFA and laser ablation) for the treatment of benign thyroid nodules. Patients: This bicentric retrospective study included 166 consecutive patients, who received clinical, biological and ultrasound evaluations for thyroid nodules, from October 2013 to November 2017. Methods: One of the two techniques was proposed if a nodule was proven to be benign after fine needle aspiration cytology or micro-biopsy. Adverse events and outcomes (symptoms, nodule reduction) were assessed at 6 weeks and 6, 12, and 18 months after treatment. Results: One hundred and eighty-nine nodules (mean size 17.5 ± 16.9 mL, 86.1% palpable) were treated by RFA (n = 108 (57.1%)) or laser ablation (n = 81 (42.9%)) in 166 patients (80.1% women, mean age 51.7 years). Two cases of transient recurrent laryngeal nerve palsy, one hematoma, and two successfully drained abscesses (5/166 = 3%) were observed. Clinical symptoms improved significantly in the two groups (anterior cervical discomfort -83.6%, esthetic complaints -84.9% and dysphagia -86.4%). Nodule volume (mL) decreased significantly (baseline vs. 18 months) from 20.4 ± 18.6 to 5.8 ± 6.6 (-75%) in the RFA, and from 13.6 ± 13.3 to 3.4 ± 4.1 (-83.9%) in the laser ablation groups. Conclusions: Transient but potentially serious adverse events were reported in 3% of patients. A significant volumetric reduction was achieved with both techniques, regardless of nodule's characteristics, at 18 months.

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.

Single-Fiber Laser Ablation in Treating Selected Metastatic Lymph Nodes of Papillary Thyroid Carcinoma and Benign Cold Thyroid Nodules-Preliminary Results

Background and Objectives

To evaluate the feasibility and efficacy of single‐fiber laser ablation (LA) under ultrasound guidance and appropriate ablation modes in the treatment of selected metastatic lymph nodes of papillary thyroid carcinoma (PTC) and benign cold thyroid nodules

Study Design/Materials and Methods

A total of 18 patients (consisting of 8 patients with 18 metastatic lymph nodes of PTC and 10 patients with 10 benign cold thyroid nodules) each underwent one session of single‐fiber LA under ultrasound guidance. On the basis of the sizes of the nodules, the ablation modes were chosen accordingly. The single‐dot ablation mode was used in the nodules with three orthogonal diameters measuring no greater than 10 mm in diameter, with a dot, a level and an insertion. The double‐dots overlapping ablation mode was used in the nodules with the largest diameters measuring greater than 10 mm (in which the nodules measured no more than 15 mm in diameter and with the other two perpendicular diameters measuring no greater than 10 mm in diameter) with two dots, a level and two insertions. The multiple levels and dots overlapping ablation mode was used in the nodules with the three orthogonal diameters all measuring larger than 10 mm, with multiple dots, levels and insertions.

Results

After 12 months of follow‐up in the treated nodules of the metastatic lymph nodes of PTC and benign cold thyroid nodules, the mean baseline volumes decreased from 0.29 ± 0.12  to 0.03 ± 0.03 ml and 3.85 ± 0.64 to 1.1 ± 0.37 ml, respectively, and the mean volume reduction ratios (VRRs), which was calculated as {[(initial volume−final volume) × 100%]/initial volume}, were 90.3 ± 7.6% and 72 ± 5.8%, respectively. There were six ablative zones that completely disappeared, whereas the ablative zones that still existed presented as scar‐like areas or small hyperechoic areas that were compatible with scar tissue among the 18 malignant nodules at the last follow‐up.

Conclusions

Single‐fiber LA under ultrasound guidance, with the appropriate ablation modes, is feasible and effective for the treatment of selected metastatic lymph nodes of PTC and benign cold thyroid nodules. This study suggests that single‐fiber LA may be applied to selected cases with appropriate ablation modes. Lasers Surg. Med. 2019 © 2019 Wiley Periodicals, Inc.

Medullary thyroid carcinoma treated with percutaneous ultrasound-guided radiofrequency ablation

PURPOSE

Minimally invasive image-guided thermal ablation has been proposed as alternative to surgery for treatment of benign thyroid nodules and recurrent differentiated thyroid carcinoma. Here, we report for the first time the use of radiofrequency ablation (RFA) in a patient with non-metastatic medullary thyroid carcinoma (MTC) who did not undergo surgery due to high anesthesiological risk.

METHODS AND RESULTS

A 64-year-old woman was referred to our institution for a routine endocrinological visit. No thyroid-related symptoms were present. She had a history of metabolic, cardiovascular and neurological diseases. On clinical examination, a nodular lesion of about 10 mm was palpable in the right thyroid lobe; ultrasonography (US) confirmed the presence of a 13 mm thyroid nodule in the lower pole of the right lobe, that was hypoechoic and with regular margins. Serum calcitonin (Ctn) level was significantly high (647 pg/mL). Fine-needle aspiration (FNA) of the thyroid nodule was negative for malignant cells, but the marked increase of Ctn level in the FNA wash-out fluid confirmed the diagnostic suspicion of MTC. Since patient refused surgery due to high anesthesiological risk, percutaneous US-guided RFA in single session was performed. At 6-months follow-up the serum Ctn level decreased from the initial value of 647 pg/mL, reaching near-normal range (15 pg/mL), and neck ultrasound showed a complete necrosis of the tumour. Afterward, serum Ctn slowly increased to 49 pg/mL at 15-month follow-up. The US performed at 6 and 12 months of follow-up revealed fibrotic tissue in place of the thyroid nodule, without evidence of cervical lymph-node metastases.

CONCLUSIONS

This clinical case suggests that RFA may be effective and safe for treatment of MTC when surgery cannot be performed.

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.

Comparison between radioiodine therapy and single-session radiofrequency ablation of autonomously functioning thyroid nodules: A retrospective study

OBJECTIVE

To compare the efficacy of Radioiodine (RI) and Radiofrequency ablation (RFA) in the treatment of autonomously functioning thyroid nodules (AFTNs). End-points: nodule volume reduction (NVR) and thyroid function normalization.

DESIGN, PATIENTS AND MEASUREMENTS

Twenty-two patients (2:20 M:F; 51.9 ± 13.9 years) affected by 25 AFTNs, treated by RFA were retrospectively compared with 25 patients (8:17 M:F; 57.2 ± 12.8 years) affected by a single AFTN treated by RI. Both group showed analogous characteristics as to age, gender, toxic/pretoxic phase and pretreatment nodule volume (calculated by the ellipsoid formula). Thyroid hormone levels and autoimmune thyroid profile were assessed before treatment. A fixed RI activity of 555 MBq (15 mCi) was administered. RFA was performed with an 18G, single-tipped electrode, by the "modified moving shot technique." Thyroid hormones were assessed and the nodule post-treatment volume calculated 12 months after treatment.

RESULTS

No statistical difference was found between the post-treatment NVR by comparing RI and RFA (P = 0.69). The volume reduction rates were 68.4 ± 28.9% and 76.4 ± 16.9% after RI and RFA, respectively. As to the thyroid function, 5/25 patients developed clinical hypothyroidism after RI. After RFA, all the 22 patients silenced their AFTN and normalized the thyroid hormones. Subclinical hypothyroidism was recorded in two patients after both RI and RFA. Thus, the functional therapeutic success, defined as the restoration of euthyroidism, was achieved in 18/25 (72%) patients treated by RI and in 20/22 (90.9%) treated by RFA.

CONCLUSIONS

No statistical difference in NVR was found between RI and RFA. All patients responded to RI but 5/25 were "over-treated" developing hypothyroidism. RFA was effective in all patients with no case of post-treatment clinical hypothyroidism. No radiation exposure and lower risk of post-treatment hypothyroidism might make RFA the favourite option especially for young patients.

Strategies for Image-Guided Therapy, Surgery, and Drug Delivery Using Photoacoustic Imaging

Photoacoustic imaging is a rapidly maturing imaging modality in biological research and medicine. This modality uses the photoacoustic effect ("light in, sound out") to combine the contrast and specificity of optical imaging with the high temporal resolution of ultrasound. The primary goal of image-guided therapy, and theranostics in general, is to transition from conventional medicine to precision strategies that combine diagnosis with therapy. Photoacoustic imaging is well-suited for noninvasive guidance of many therapies and applications currently being pursued in three broad areas. These include the image-guided resection of diseased tissue, monitoring of disease states, and drug delivery. In this review, we examine the progress and strategies for development of photoacoustics in these three key areas with an emphasis on the value photoacoustics has for image-guided therapy.

Microwave Ablation Compared With Laser Ablation for Treating Benign Thyroid Nodules in a Propensity-Score Matching Study

Objective: The efficacy and safety of percutaneous ultrasound-guided microwave and laser ablation (MWA and LA, respectively), for treating benign thyroid nodules (BTNs), were retrospectively compared. Methods: Patients (n = 318) underwent ablation of 328 BTNs. Confounding bias was reduced by propensity-score matching, and finally the MWA and LA groups each comprised 160 nodules. At baseline (before ablation), 3, 6, and 12 months, and every 6 months thereafter, the following were recorded: nodule volume reduction rate (VRR), neck symptom scores, cosmetic scores, complications, and side effects. Results: The baseline characteristics of the MWA and LA groups were comparable. The volumes of all nodules were less at all follow-ups relative to the baseline, as were the symptom and cosmetic scores at postoperative 6 months and thereafter (P < 0.01). At each follow-up, the overall VRRs of the MWA and LA groups were comparable. However, for nodules ≥13 mL, the VRR associated with LA at ≥6 months was significantly greater than that of MWA. The average ablation time for MWA was less than that of LA (P < 0.01). The overall incidences of major complications, minor complications, and side effects were 1.6, 2.2, and 18.4%, respectively, and there were no significant differences between the MWA and LA groups. Conclusion: Percutaneous ultrasound-guided MWA and LA are both safe and effective for the treatment of BTNs. Each can significantly reduce the nodule volume and improve the neck symptoms and appearance of patients, with a low incidence of adverse side effects. The efficiency of MWA is higher than that of LA. For nodules ≥13 mL, MWA may be preferred, but at 6 months and subsequent follow-ups the reduction in volume was greater in patients receiving LA.

Percutaneous laser ablation of benign thyroid nodules: a one year follow-up study

Objective

To evaluate safety and effectiveness of nodule volume reduction and thyroid function after percutaneous laser ablation treatment in patients with benign nonfunctioning thyroid nodules.

Methods

Prospective single-center study, from January 2011 to October 2012, which evaluated 30 euthyroid and thyroid antibodies negative patients with benign solitary or dominant nodule with indication of treatment due to compressive symptoms and aesthetic disturbances. The clinical and laboratory (thyroid ultrasound, TSH, FT4, TG, TG-Ab, TPO-Ab and TRAb levels) evaluations were performed before the procedure, and periodically 1 week, 3 months and 6 months after. The ablation technique was performed under local anesthesia and sedation. In each treatment, one to three 21G spinal needle were inserted into the thyroid nodule. The laser fiber was positioned through the needle, which was then withdrawn 10mm to leave the tip in direct contact with the nodule tissue. Patients were treated with a ND: Yag-laser output power of 4W and 1,500 to 2,000J per fiber per treatment. The entire procedure was performed under US guidance.

Results

Thirty patients, with a total of 31 nodules submitted to laser ablation were evaluated. The median volumetric reduction of the nodule was approximately 60% after 12 months. No statistical significance was observed on thyroid function and antibodies levels. There was a peak on the level of thyroglobulin after the procedure due to tissue destruction (p<0.0001). No adverse effects were observed.

Conclusion

Percutaneous laser ablation is a promising outpatient minimally invasive treatment of benign thyroid nodule.

Initial Ablation Ratio: Quantitative Value Predicting the Therapeutic Success of Thyroid Radiofrequency Ablation

BACKGROUND

The aims of this study were to determine a quantitative index, the initial ablation ratio (IAR), representing the amount of ablation, to predict therapeutic success and to evaluate the correlation between the IAR and volume reduction ratio (VRR).

METHODS

Among the patients who underwent radiofrequency ablation (RFA) for the treatment of benign thyroid nodules at the Withsim Clinic between April 2008 and December 2016, 130 patients with 134 nodules were included. The relationship between the IAR and VRR was analyzed at six months, 12 months, and the final follow-up. The relationship between the IAR and final VRR was also analyzed according to the initial nodule volumes.

RESULTS

The mean VRR was 78.7 ± 17.5% (range 23.3-100%) at a mean follow-up period of 22.6 ± 20.1 months (range 3-93 months). The mean IAR was 90.0 ± 11.6% (range 39.1-100%). The correlation coefficient between the IAR and final VRR was 0.65, which indicates a positive correlation (p < 0.001). When the IAR exceeded 70%, it tended to achieve 50% VRR in most cases.

CONCLUSIONS

The IAR is a quantitative indicator of how well the RFA procedures are performed, and it is highly correlated with the VRR. If the IAR is >70%, VRR of >50% may be expected after RFA.

Summary of the 2017 thyroid radiofrequency ablation guideline and comparison with the 2012 guideline

Radiofrequency ablation (RFA) is a new, minimally invasive modality that serves as an alternative to surgery in patients with thyroid tumors. The Task Force Committee of the Korean Society of Thyroid Radiology developed recommendations for the optimal use of RFA for thyroid tumors in 2012 and revised them in 2017. Herein, we review and summarize the 2017 thyroid RFA guideline and compare it with the 2012 thyroid RFA guideline.

Percutaneous laser ablation for benign and malignant thyroid diseases

Minimally invasive image-guided thermal ablation is becoming increasingly common as an alternative to surgery for the treatment of benign thyroid nodules. Among the various techniques for thermal ablation, laser ablation (LA) is the least invasive, using the smallest applicators available on the market and enabling extremely precise energy deposition. However, in some cases, multiple laser fibers must be used simultaneously for the treatment of large nodules. In this review, the LA technique is described, and its main clinical applications and results are discussed and illustrated.

Ultrasound-guided laser ablation for local control of neck recurrences of medullary thyroid cancer. A feasibility study

BACKGROUND

Surgery is the standard treatment for cervical metastases of medullary thyroid cancer (MTC) diagnosed after initial surgical treatment. Repeated neck dissections, however, carry an elevated risk of complications, have an adverse impact on the quality of life, and sometimes do not achieve cure of the disease Clinical case: In a patient who had undergone two cervical neck dissections complicated by accessory nerve injury, an US-guided laser ablation (LA) of a lymph node metastasis of MTC was performed. LA was performed with two treatments during a five month period. The procedure was carried out with one optical fiber and an energy delivery of 3300 and 360 Joules. Treatments were well tolerated and resulted in complete structural and biochemical cure during a 12 month follow-up. No major complication was registered.

CONCLUSIONS

LA is a promising tool for the management of relapsing cervical metastases that are localized in non- critical areas and are characterized by low progression rate. Advantages of LA are the outpatient setting, the absence of general anesthesia, the tolerability and the safety of the procedure. Thus, LA may be considered as an alternative approach to surgery or active surveillance for the management of local recurrences of MTC in selected patients.

MR Thermography-Guided Head and Neck Lesion Laser Ablation

Interstitial laser ablation has been successfully used as a minimally invasive treatment option for tumors in many parts of the body, including the head and neck. In this article, we describe the use of MR imaging guidance and mapping sequences for accurate localization of the target lesion, percutaneous interstitial laser ablation methods, and the use of MR thermography for temperature monitoring during laser ablation, with a focus on applications in the head and neck region.

2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology

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 (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Image-guided chemical and thermal ablations for thyroid disease: Review of efficacy and complications

Image-guided ablation of thyroid disease is increasingly being commonly reported. Techniques including ethanol injection and thermal ablation using radio-frequency, laser, and microwave devices have been described. Minimally invasive approaches to the management of benign cystic, solid, and functional thyroid nodules as well as both primary and recurrent thyroid malignancy have been reported. The purpose of this article is to review the current evidence relating to image-guided ablation of thyroid disease with a focus on clinical outcomes and complication rates for patients treated with this minimally invasive approach.

Interventional radiology of the thyroid gland: critical review and state of the art

Thyroid nodules are a common incidental finding during a routinely ultrasound (US) exam unrelated to the thyroid gland in the healthy adult population with a prevalence of 20-76%. As treated before with surgery, in the last years new minimally invasive techniques have been developed as an alternative to surgery. The aim of this review, based on newly revised guidelines, is to provide some information regarding the basic principles, indications, materials, techniques, and results of mini-invasive procedures or treatments for thyroid nodules. We performed a narrative review including both newest and representative papers and guidelines based on the different procedures of ablation techniques developed in the last years for the diagnosis and the treatment of thyroid nodules. All examined papers referred very good results in term of volume nodule reduction, improvement in related symptoms and cosmetic problems, with a very low rate of complications and side effects for all the minimally invasive technique analyzed. Obviously, some differents between technique based on different kind of thyroid nodules and different indication were found. In conclusion, many thyroid nodules nowadays could be treated thanks to the advent of new mini-invasive technique that are less expensive and present a lower risk of major complications and side effects compared to surgery.

A single session of laser ablation for toxic thyroid nodules: three-year follow-up results

PURPOSE

To confirm the effectiveness of laser ablation on toxic nodules in a large population with three years of follow-up.

MATERIAL AND METHODS

Between 2009 and 2014, we treated 82 patients with hyperthyroidism related to the presence of a toxic nodular goitre. Patients were pre-treated pharmacologically with methimazole prior to single session of laser ablation (LA) and then followed up every 3 months with FT4 and TSH blood tests as well as ultrasound examination of the nodules treated.

RESULTS

All patients responded to the treatment. The median nodule volume decreased from 12 ml (range 5-118 ml) to 5 ml (range 1.2-40 ml) after three years (p < 0.001). The percentage of patients who discontinued methimazole therapy was reduced by increasing the initial volume of the toxic nodule. In nodules with a volume less than 5 ml, all patients were able to suspend methimazole; this percentage was reduced to 90.2% in nodules with a volume between 5 and 15 ml, 61.1% in those with volume 15-25 ml and only 28.5% in nodules larger than 25 ml. We had no major complications but only moderate pain and fever in the evening, a few hours after ablation therapy in 10% of treated patients.

CONCLUSIONS

Single session of LA of toxic thyroid nodules is effective and safe, especially in nodules with a volume under 15 ml.

Percutaneous Ethanol Injection in Combination with Laser Ablation for a 100 ml Partially Cystic Thyroid Nodule

Until nonsurgical techniques like laser ablation (LA) or radiofrequency became available, patients suffering from large nodules with compressive symptoms were addressed to surgery. We describe the case of a 59-year-old woman with a large, partially cystic thyroid nodule having a volume of about 100 ml. As the patient refused surgery, despite her constant local discomfort, such large partially cystic nodule underwent several percutaneous ethanol injections (PEI) and then was submitted to LA. The combination of these two procedures allowed firstly complete disappearance of the cystic component and secondly a significant reduction of thyroid nodule, which finally measured 17 ml in volume (82% reduction compared to baseline). This case demonstrates that even in very large partially cystic nodules LA preceded by PEI represents a valid alternative to surgery.

Nodule size as predictive factor of efficacy of radiofrequency ablation in treating autonomously functioning thyroid nodules

CONTEXT

No defined pre-treatment factors are able to predict the response to radiofrequency ablation (RFA) of an autonomously functioning thyroid nodule (AFTN).

OBJECTIVE

Primary endpoint was to evaluate the success rate of RFA to restore euthyroidism in a cohort of adult patients with small solitary AFTN compared with medium-sized nodules. Secondary endpoints included nodule volume reduction and rate of conversion from hot nodules to cold using scintiscan.

METHODS

This was a 24-month prospective monocentric open parallel-group trial. Twenty-nine patients with AFTN were divided into two groups based on thyroid volume: 15 patients with small nodules (<12 mL) in group A and 14 patients with medium nodules (>12 mL) in group B. All patients underwent a single session of RFA and were clinically, biochemically, and morphologically evaluated at baseline and at 1, 6, 12 and 24 months after treatment.

RESULTS

After RFA, there was greater nodule volume reduction in group A compared with group B (p < 0.001 for each follow-up point). In group A, there was a greater increase in TSH levels than in group B at 6 (p = 0.01), 12 (p = 0.005), and 24 months (p < 0.001). At 24 months, the rate of responders was greater in group A than in group B (86 vs. 45%; p < 0.001). In group A, 86% of nodules converted from hot to cold compared with 18% in group B (p < 0.001).

CONCLUSIONS

A single session of RFA was effective in restoring euthyroidism in patients with small AFTNs. Nodule volume seems to be a significant predictive factor of the efficacy of RFA in treating AFTN.

Radiofrequency ablation of primary thyroid carcinoma: efficacy according to the types of thyroid carcinoma

OBJECTIVE

To evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) according to the types of thyroid carcinoma, particularly in patients with a high-surgical risk.

MATERIALS AND METHODS

Eight patients with nine tumours of pathologically proven papillary and anaplastic carcinoma were treated by US-guided RFA. Patients with primary thyroid carcinoma were divided into three groups; group (1) Anaplastic carcinoma, group (2) papillary macrocarcinoma, and group (3) papillary microcarcinoma. We evaluated changes in clinical symptoms, tumour volume and local tumour recurrence/metastasis after RFA. Patients were followed up at 1, 6 and 12 months and annually thereafter.

RESULTS

Among nine tumours, one anaplastic carcinoma was treated three times and the other anaplastic carcinoma and one papillary macrocarcinoma were treated twice. Group 3 were treated once. The initial mean tumour volume was 107.9 ± 78.6 (with neck bulging), 126.9 (with neck bulging) and 0.16 ± 0.08 mL (without cosmetic or symptomatic problems) in groups 1-3, respectively. Group 1 showed no improvement in clinical symptoms or neck bulging after RFA, whereas group 2 demonstrated a decreased tumour volume measuring 0.7 mL with improved neck bulging. In group 3, mean volume decreased measuring 0.07 ± 0.12 mL. No local tumour recurrence or metastatic lesion was detected during the mean follow-up of 19.3 months in papillary carcinomas. No major complications were encountered.

CONCLUSIONS

In patients with primary thyroid carcinoma, RFA achieved excellent local tumour control for papillary macro- and microcarcinoma; however, its clinical effect on anaplastic carcinoma was questionable.

Laser ablation of the biliary tree: in vivo proof of concept as potential treatment of unresectable cholangiocarcinoma

OBJECTIVES

The palliative treatment of cholangiocarcinoma is based on stent placement with well-known procedure-related complications. Consequently, alternative energy-based techniques were put forward with controversial long-term results. This study aims to evaluate the safety and effectiveness of biliary tree laser ablation (LA) in terms of: (i) absence of perforation, (ii) temperature increase, (iii) induced thermal damage in in vivo models.

MATERIALS AND METHODS

The common bile duct and cystic ducts of two pigs were ablated with a diode laser (circumferential irradiation pattern) for 6 and 3 min at 7 W. Laser settings were chosen from previous ex vivo experiments. Local temperature was monitored through a fibre Bragg grating (FBG) sensor embedded into the laser delivery probe. Histopathological analysis of the ablated specimen was performed through in situ endomicroscopy, haematoxylin and eosin (H&E) and nicotinamide adenine dinucleotide (NADH) stains.

RESULTS

Temperature reached a plateau of 53 °C with consequent thermal damage on the application area, regardless of laser settings and application sites. No perforation was detected macroscopically or microscopically. At the H&E stain, wall integrity was always preserved. The NADH stain allowed to evaluate damage extension. It turned out that the ablation spreading width depended on application time and duct diameter. In situ endomicroscopy revealed a clear distinction between ablated and non-ablated areas.

CONCLUSIONS

The temperature distribution obtained through LA proved to induce a safe and effective intraductal coagulative necrosis of biliary ducts. These results represent the basis for further experiments on tumour-bearing models for the treatment of obstructive cholangiocarcinoma.

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

Safety and Efficacy of Low-Level Laser Therapy in Autoimmune Thyroiditis: Long-Term Follow-Up Study

INTRODUCTION

A randomized clinical trial (RCT) was performed to evaluate the efficacy of low-level laser therapy (LLLT) for hypothyroidism induced by chronic autoimmune thyroiditis (CAT).

OBJECTIVE

The objective was to assess the safety and actions of LLLT 6 years after completion of the RCT.

MATERIALS AND METHODS

Forty-three participants were invited to participate in this study 6 years after completion of the RCT. Twenty-five were subjected to LLLT (group L), and 18 were subjected to placebo (group P). Primary outcome measure: frequency of thyroid nodules, which were subjected to fine-needle aspiration biopsy. Secondary outcome measures: dose of levothyroxine required to treat hypothyroidism, thyroid peroxidase antibodies (anti-TPO), and anti-thyroglobulin antibodies (anti-Tg).

RESULTS

In group L, a nodule was observed in three patients, who all had a Bethesda II classification. In group P, a nodule was also observed in three patients, with two classified as Bethesda II and one as Bethesda III. The levothyroxine dose required by group L was significantly lower than that required by group P (P = 0.002). The anti-TPO and anti-Tg levels did not differ between the groups.

CONCLUSION

LLLT, by the methods described, has been shown to be safe for the treatment of hypothyroidism resulting from CAT. This trial is registered with ClinicalTrials.gov Identifier: NCT02240563.