Ablation Of Nodules Research Articles

3D ultrasound guidance for radiofrequency ablation in an anthropomorphic thyroid nodule phantom

BackgroundThe use of two-dimensional (2D) ultrasound for guiding radiofrequency ablation (RFA) of benign thyroid nodules presents limitations, including the inability to monitor the entire treatment volume and operator dependency in electrode positioning. We compared three-dimensional (3D)-guided RFA using a matrix ultrasound transducer with conventional 2D-ultrasound guidance in an anthropomorphic thyroid nodule phantom incorporated additionally with temperature-sensitive albumin.MethodsTwenty-four phantoms with 48 nodules were constructed and ablated by an experienced radiologist using either 2D- or 3D-ultrasound guidance. Postablation T2-weighted magnetic resonance imaging scans were acquired to determine the final ablation temperature distribution in the phantoms. These were used to analyze ablation parameters, such as the nodule ablation percentage. Further, additional procedure parameters, such as dominant/non-dominant hand use, were recorded.ResultsNonsignificant trends towards lower ablated volumes for both within (74.4 ± 9.1% (median ± interquartile range) versus 78.8 ± 11.8%) and outside of the nodule (0.35 ± 0.18 mL versus 0.45 ± 0.46 mL), along with lower variances in performance, were noted for the 3D-guided ablation. For the total ablation percentage, 2D-guided dominant hand ablation performed better than 2D-guided non-dominant hand ablation (81.0% versus 73.2%, p = 0.045), while there was no significant effect in the hand comparison for 3D-guided ablation.Conclusion3D-ultrasound-guided RFA showed no significantly different results compared to 2D guidance, while 3D ultrasound showed a reduced variance in RFA. A significant reduction in operator-ablating hand dependence was observed when using 3D guidance. Further research into the use of 3D ultrasound for RFA is warranted.Relevance statementUsing 3D ultrasound for thyroid nodule RFA could improve the clinical outcome. A platform that creates 3D data could be used for thyroid diagnosis, therapy planning, and navigational tools.Key PointsTwenty-four in-house-developed thyroid nodule phantoms with 48 nodules were constructed.RFA was performed under 2D- or 3D-ultrasound guidance.3D- and 2D ultrasound-guided RFAs showed comparable performance.Real-time dual-plane imaging may offer an improved overview of the ablation zone and aid electrode positioning.Dominant and non-dominant hand 3D-ultrasound-guided RFA outcomes were comparable.Graphical

US-guided percutaneous ablation of thyroid nodules with 177LU-MAA (LUTMA) - Feasibility study

PurposeThe main purpose is to evaluate the safety, and efficacy of 177Lutetium labeled macroaggregated albumin (LUTMA) ablation of thyroid nodules. Materials and methodsPatients with confirmed benign nodules who were not candidate or did not accept surgery were enrolled. Under ultrasonography (USG) guidance, LUTMA which was produced in our department, was administered into the nodules. Nodule volumes were assessed via USG before the injection and at 1-week, 1-month, and 3-months post-treatment. We calculated the volume reduction rates (VRRs) for these intervals. To detect extranodular activity leakage, patients underwent SPECT/CT imaging at one hour, 24 h, and one week post-injection. ResultsFifteen patients (male: 12, female: 3) with benign thyroid nodules were eligible to join this study. These nodules were categorized as cystic (n = 9), solid (n = 3), or mixed (n = 3). Median nodules volume was 6.59 ml (range: 0.56–55 ml). Predicted absorbed dosee to the nodules varied between 10–1036 Gy. The VRRs at 3 months was 85% for all nodule types with gradual increases over time: 0%–92%, 20%–97%, and 28%–98% at 1 week, 1 month, and 3-months, respectively. The median VRR of cystic nodules was 89% (range: 81%–98%) at 3-months. It is significantly higher than solid ones (P = .009). None of the patients experienced adverse reactions or discomfort during the injection or follow-up. ConclusionLUTMA treatment significantly reduces the volume of benign thyroid nodules, offering relief from disease-associated symptoms and cosmetic concerns. It emerges as a promising alternative to surgical and other local treatments for benign thyroid nodule ablation. Clinical significationLUTMA is a novel theranostic radiopharmaceutical which is promising in local ablative treatment of benign thyroid nodules.

Analysis of trends in radiofrequency ablation in a tertiary care center practice.

Radiofrequency ablation (RFA) for thyroid nodules has recently been introduced into the United States healthcare system landscape. Little is known about the process of incorporating this procedure into existing clinical practice. A retrospective chart review of a single institution was conducted to examine referral patterns and decision-making after the introduction of RFA into an endocrine surgery-focused practice. Patient demographics and thyroid-specific data were recorded. Two reviewers abstracted and coded reasons for the noncompletion of RFA. Two-sample t tests were used to compare groups; linear regression was used to assess trends and practice patterns. Chart review identified 451 patients referred for consideration of RFA from January 2020 to December 2022. Only 255 (56.5%) went on to receive the treatment. There was no significant difference in nodule volume between treated and nontreated groups (18.5 vs. 14.9 cm3, p = 0.07). Concern for malignancy on genetic testing, size (too large/too small), recommendation for Ethanol ablation, and multinodular disease without target nodules were the most common reasons for physician deferral. Of patients who declined to proceed, 46% opted to undergo surgical excision. Linear regression showed that referral numbers significantly increased with time; however, the proportion of patients receiving treatment decreased yearly, primarily because of higher rates of physician deferral. This study reflects the complex decision-making in offering minimally invasive thyroid nodule ablation. Despite a greater number of referrals over time, physician criteria became increasingly selective. Optimal candidacy in RFA is an evolving determination requiring patient and physician input to guide ideal practice patterns.

Safety and feasibility of transbronchial microwave ablation for subpleural lung nodules.

Transbronchial microwave ablation in treating lung nodules is gaining popularity. However, microwave ablation in subpleural lung nodules raised concerns about pleural-based complications due to the proximity between the pleura and the ablation zone. Patients who underwent transbronchial microwave ablation between March 2019 and November 2022 were included in this analysis. The lung nodules were categorized into the subpleural group-less than 5 mm distance to the nearest pleural surface; the deep nodule group-larger or equal to 5 mm distance to the nearest pleural surface. A review of the safety profile of subpleural lung nodule ablation was conducted. Eighty-two lung nodules (n = 82) from 77 patients were treated. The mean nodule size was 14.2 ± 5.50 mm. The technical success rate was 100%. The mean procedural time was 133 min. No statistically significant differences were detected in the complication rate and the length of stay between the subpleural and deep nodule groups. Complications occured in 21 nodules (25.6%). No minor pneumothorax was reported. Total five cases of pneumothorax required drainage were observed (6.06% in subpleural nodules [n = 2] vs. 6.12% in deep nodules [n = 3], p = 0.991). Total seven cases of pleuritic chest pain were observed (12.1% in subpleural nodules [n = 4] vs. 6.12% in deep nodules [n = 3], p = 0.340). This single-center retrospective analysis found no significant difference in the safety outcomes between subpleural and nonsubpleural lung nodule ablation. The overall rate of complications was low in the cohort. This demonstrated that transbronchial microwave was feasible and safe for most lung nodules.

Progress in research on ablation of thyroid nodules.

The incidence of thyroid nodules is rising annually. Surgical treatment is effective, but often results in significant trauma, recurrent laryngeal nerve injury, hypoparathyroidism, and other complications. Recent years have seen significant breakthroughs in thyroid nodule ablation for treating thyroid diseases, although its application remains controversial. The objective was to review the development history and current research status of thyroid nodule ablation to provide a reference for future studies. The literature on thyroid nodule ablation was reviewed, analysing its advantages and disadvantages. The therapeutic effect of thyroid nodule ablation in treating benign thyroid lesions is noteworthy, but issues such as lax treatment indications and excessive medical treatment persist. Initial success has been achieved in treating thyroid malignant lesions, particularly papillary thyroid microcarcinoma (PTMC). However, the curative effect requires further follow-up verification.

An anthropomorphic thyroid phantom for ultrasound-guided radiofrequency ablation of nodules.

Needle-based procedures, such as fine needle aspiration and thermal ablation, are often applied for thyroid nodule diagnosis and therapeutic purposes, respectively. With blood vessels and nerves nearby, these procedures can pose risks in damaging surrounding critical structures. The development and validation of innovative strategies to manage these risks require a test object with well-characterized physical properties. For this work, we focus on the application of ultrasound-guided thermal radiofrequency ablation. We have developed a single-use anthropomorphic phantom mimicking the thyroid and surrounding anatomical and physiological structures that are relevant to ultrasound-guided thermal ablation. The phantom was composed of a mixture of polyacrylamide, water, and egg white extract and was cast using molds in multiple steps. The thermal, acoustical, and electrical characteristics were experimentally validated. The ablation zones were analyzed via non-destructive T2 -weighted magnetic resonance imaging scans utilizing the relaxometry changes of coagulated egg albumen, and the temperature distribution was monitored using an array of fiber Bragg grating sensors. The physical properties of the phantom were verified both on ultrasound as well as in terms of the phantom response to thermal ablation. The final temperature achieved (92°C), the median percentage of the nodule ablated (82.1%), the median volume ablated outside the nodule (0.8mL), and the median number of critical structures affected (0) were quantified. An anthropomorphic phantom that can provide a realistic model for development and training in ultrasound-guided needle-based thermal interventions for thyroid nodules has been presented.

General principles for the safe performance, training and adoption of ablation techniques for benign thyroid nodules: An American Thyroid Association Statement.

The primary goal of this interdisciplinary consensus statement is to provide a framework for the safe adoption and implementation of ablation technologies for benign thyroid nodules. This consensus statement is organized around three key themes: i. safety of ablation techniques and their implementation, ii. optimal skillset criteria for proceduralists performing ablative procedures, and iii. defining expectations of success for this treatment option given its unique risks and benefits. Ablation safety considerations in pre-procedural, peri-procedural and post-procedural settings are discussed including clinical factors related to patient selection and counselling, anesthetic and technical considerations to optimize patient safety, peri-procedural risk mitigation strategies, post-procedural complication management and safe follow-up practices. Prior training, knowledge and steps that should be considered by any physician who desires to incorporate thyroid nodule ablation into their practice are defined and discussed. Examples of successful clinical practice implementation models of this emerging technology are provided. Thyroid ablative procedures provide valid alternative treatment strategies to conventional surgical management for a subset of patients with symptomatic benign thyroid nodules. Careful patient and nodule selection are critical to the success of these procedures as is extensive pre-procedural patient counselling. Although these emerging technologies hold great promise, they are not without risk and require development of a unique skillset and environment for optimal, safe performance and consistent outcomes.

Vocal Cord Monitoring by Flexible Fiberoptic Laryngoscopy During Thyroid Radiofrequency Ablation.

Introduction: Thermal injury to recurrent laryngeal nerve (RLN) during radiofrequency ablation (RFA) can produce temporary or permanent vocal cord paralysis.1 Hydrodissection with cold 5% glucose of "danger triangle" protects RLN during RFA.2 When RFA is performed under local anesthesia, RLN function is monitored by patients producing vocal sounds.3 Large lesions requiring longer RFAs warrant general sedation where voice cannot be assessed, therefore, an additional technique for RLN protection is advisable. Observation of passive symmetrical vocal cord movements during breathing by laryngeal ultrasonography is useful in assessing vocal cord function4; however, flexible-fiberoptic fibrolaringoscopy (FFL) is gold standard for assessing vocal cord movements,5 anticipating potential RLN damage. We report FFL monitoring during RFA under general sedation on a large thyroid nodule. FFL during RFA may detect RLN irritation and dysfunction if asymmetry in passive vocal cord movements is noted. Should asymmetry appear, RFA operator stops delivering energy and repositions electrode needle. Materials and Methods: Thyroid function tests, blood glucose, creatinine, transaminase, International-Normalized-Ratio, and electrocardiogram were performed. Operating room (OR) layout created sufficient space for ear-nose-throat (ENT) and RFA operators. An examination with a fiberscope camera demonstrated normal vocal cord adduction during phonation and abduction during breathing. The procedure was assisted by an anesthetist administering fentanyl 50 mcg, midazolam 1.5 to 5.0 mg, and propofol infusion 2 mg/(kg·h). General sedation was conducted so that reflexes were attenuated but still observable. Incorporating in OR by an anesthetist who performs general sedation reduces side effects and complications.6 Ultrasonography showed a 34-mL right lobe nodule abutting on the RLN area. After sedation with propofol, the ENT specialist inserted an endoscope until the glottic plane. During calm breathing, vocal cords moved symmetrically. After obtaining anterior nodule hydrodissection from strap and sternocleidomastoid muscles with 10 mL of 2% lidocaine, posterior hydrodissection was achieved by ultrasound-guided administration of 30 mL of 5% cold glucose. Anterior and posterior hydrodissections merged, separating nodule from neck structures. The radiofrequency electrode needle was then inserted into the nodule, initially positioned in inferior nodule portion adjacent to danger triangle previously isolated by hydrodissection. Initial power was 30 watts. Moving-shot technique was used. Results: FFL was performed throughout thyroid RFA. Symmetric vocal cord movements during breathing demonstrated no RLN irritation. FFL monitoring allowed observation of natural reflexive phenomena, including swallowing. Complete nodule ablation was achieved. FFL performed post-RFA confirmed normal vocal cord motility. Conclusions: We report the first-time use of FFL for vocal cord monitoring during RFA. FFL was easily performed by the ENT specialist and well tolerated by the patient. Avoiding danger triangle and precise RFA needle positioning is key in preventing RLN injury. Benign nodules regrow if total ablation is not achieved7 and some authors propose additional procedures to complete ablation8 that obviously incurs costs. Total RFA nodule ablation-assisted FFL monitoring eliminates the need for repetitive RFAs, thus reducing overall treatment costs. Finally, FFL monitoring does not prolong procedure, as it is performed simultaneously with RFA. FFL is a valid technique when used in conjunction with hydrodissection to further prevent RLN thermal injury during RFA, especially indicated for large thyroid nodule ablation and professional voice users. Patient Consent and Permission: The patient provided written consent for FFL monitoring and permission to use his portrayals and ultrasonographic images during RFA. The study was completed in accordance with the Declaration of Helsinki as revised in 2013. Adherence to institutional review board protocols was granted. Disclaimer: Representation of any instrumentation within the video does not indicate any endorsement of the product and/or company by the publisher, the American Thyroid Association, or the authors. No competing financial interests exist. Runtime of video: 9 mins 39 secs.

Concomitant electromagnetic navigation transbronchial microwave ablation of multiple lung nodules is safe, time-saving, and cost-effective

ObjectivesTransbronchial microwave ablation of lung nodules using electromagnetic navigation bronchoscopy is an emerging local therapy for lung oligometastases and multifocal lung cancers as part of a lung-preserving strategy. Concomitant ablation of multiple lung nodules in a single operating session may provide a one-stop solution. MethodsBetween April 2019 and April 2023, 25 patients had 2 or more lung nodules ablated concomitantly in our hybrid operating room. Nodules were proven or highly suspicious of malignancies or metastases. Feasibility and safety were retrospectively reviewed. ResultsA total of 56 nodules in 25 patients received concomitant multi-nodular ablation. The mean age of patients was 60 years, and the reasons for the lung-preserving strategy were multifocal lung cancers (80%) and lung oligometastases (20%). Among those with multifocal disease, 65% had previous major lung resection for lung cancer. Two to 4 nodules were ablated in each session. The mean nodule size was 9.9 mm (range, 5-20 mm), and the mean minimal margin was 5.9 mm. When comparing concomitant nodule ablation with the 103 single-nodule ablations performed in our institute, a mean of 86 minutes of operative time and 131 minutes of anesthetic time were saved. There were no increased complications despite overlapping ablation zones, and the mean hospital stay was 1.23 days. The rate of pneumothorax was 8%, and that of pleural effusion, pain, and fever was 4% respectively. ConclusionsConcomitant transbronchial microwave ablation of multiple lung nodules is feasible, safe, and associated with reduction in overall anesthetic and operative time. It is an important armamentarium in the contemporary lung-preserving strategy for battling multifocal lung cancers or lung oligometastases.

Comparison of microwave alone and combined with ethanol ablation for different types of benign mixed thyroid nodules.

To evaluate the efficacy and safety of microwave ablation (MWA) plus ethanol ablation (EA) for different types of benign mixed thyroid nodules. A total of 81 patients with 81 benign mixed thyroid nodules were enrolled into the study; 39 were divided to the MWA group and 42 to the combined group (MWA combined with EA). Nodule ablation rate, volume reduction rate (VRR) and surgical complications of all patients were analyzed before and after treatment. The mean ablation rate were 86.49 ± 6.68% and 90.09 ± 5.79% in the microwave and combined groups respectively, and the ablation rate of nodule decreased as the nodule volume increased. For nodules ≥15 ml in volume, the mean ablation rate of the combined group was higher than that of the microwave group (all P < 0.05). The mean VRR at 12 months postoperatively was 89.58 ± 4.32% in the microwave group and 92.92 ± 3.49% in the combined group, showing statistical significantly different between both arms (P = 0.001). The combined group decreased in volume more significantly than the microwave group for nodules with 20-50% or 50-80% cystic proportions or >15 ml in volume (all P < 0.05). The complication rate was 23.08% and 2.38% respectively. MWA combined with EA is more effective than MWA for treating mixed thyroid nodules. MWA combined with EA may be the first approach for nodules with >20% cystic proportions or volume >15 ml.

The iceberg technique: an innovative approach for radiofrequency ablation of diving thyroid nodules.

Diving thyroid nodules are a limitation of radiofrequency ablation because the mediastinal component cannot be adequately identified by ultrasound (US). We aim to describe a new technique, the iceberg technique, to overcome this issue and explain our three-year experience of using this novel method. The iceberg technique consists of a two-stage treatment. First, the ablation of the cervical portion of the nodules (easily visualized during the initial US exam) using trans-isthmic access is performed using the moving-shot technique. After three to six months, there is a volumetric reduction of the treated portion, leading to retraction of the thyroid parenchyma. This brings the mediastinal component to the cervical region, thereby enabling a perfect visualization by US. Then, the second stage of treatment is carried out with complete nodule ablation, and the region that was treated first is looked at a second time. From April 2018 to April 2021, nine patients with nine benign nodules were submitted for the iceberg technique. No complications occurred during the entire follow-up period. The patients displayed normal hormonal levels after the procedures, and there was a significant volume reduction of the nodules until three months post-ablation. The iceberg technique is an effective and safe option for the radiofrequency treatment of diving goiters.

Local ablation of pulmonary malignancies abutting pleura: Evaluation of midterm local efficacy and safety.

ObjectiveTo retrospectively evaluate the efficacy and safety of local ablation treatment for adjacent pleural lung tumors.Materials and methodsSixty-two patients who underwent pulmonary nodule ablation at the Affiliated Cancer Hospital of Zhengzhou University were enrolled between January 2016 and December 2020. All patients were followed up with enhanced computed tomography or magnetic resonance imaging within 48 h after treatment and 2, 4, 6, 9, and 12 months after treatment. All patients were followed for at least 12 months.ResultsA total of 84 targeted tumors (62 patients) underwent 94 ablations. In the 12-month follow-up images, 69 of the 84 targeted tumors were completely ablated, 15 had incomplete ablation, and the 12-month incomplete ablation rate was 17.8% (15/84). Of the 15 incompletely ablated tumors, six had partial responses, five had stable disease, and four had progressive disease. The most common adverse event was pneumothorax, with an incidence of 54.8% (34/62). The second most common complication was pleural effusion, with an incidence rate of 41.9% (26/62). The incidence of needle-tract bleeding was 21% (13/62) and all patients were cured using hemostatic drugs. Serious complications were bronchopleural fistula in four patients (6.5%, 4/62) and needle tract metastasis in one patient. Four cases of bronchopleural fistula were found in the early stages and were cured after symptomatic treatment.ConclusionLocal ablation is effective for the treatment of adjacent pleural lung tumors, and its operation is safe and controllable.

Recurrent Laryngeal Nerve Injury in Thermal Ablation of Thyroid Nodules-Risk Factors and Cause Analysis.

Recurrent laryngeal nerve (RLN) injury is a complication of thermal thyroid nodule treatment. We investigated the influencing factors of RLN injury in patients who underwent thermal ablation of thyroid nodules. The data of 1004 patients (252 male, 752 female; median age 44 years) who underwent thermal thyroid nodule ablation were retrospectively reviewed. Patients were divided into benign cystic, benign solid, and papillary thyroid cancer (PTC) groups. The parameters related to RLN injury were analyzed, including the largest diameter, location of the nodules, and shortest distance of the nodule to thyroid capsule and tracheoesophageal groove (TEG). Univariate and multivariate analyses were performed to select risk factors for RLN injury. The RLN injury rate was higher in PTC (6.3%) than in benign cystic (1.2%, P = 0.019) and solid nodules (2.9%, P = 0.018). PTC subgroup analysis showed that the RLN injury rate was higher in T1b (10.7%) and T2 (28.6%) PTC than in T1a PTC (5.0%, P < 0.05). In the PTC group, TEG distance, anterior capsule distance, median capsule distance, posterior capsule distance, and maximum nodule diameter were risk factors for RLN injury. The logistic regression fitting of the nomogram showed high prediction efficiency (C-Index 0.876). The main cause of RLN injury was insufficient medial isolating fluid (MIF). The safety thicknesses of MIF for benign cystic, benign solid, and PTC nodules were 3.1 mm, 3.7 mm, and 3.9 mm, respectively. Several risk factors for RLN injury should be considered before thermal ablation of thyroid nodules. The RLN injury rate could be predicted with the nomogram.

Radiofrequency Ablation of Solid Benign Thyroid Nodules

Symptomatic solid benign thyroid nodules may present either as nonfunctioning nodules causing compressive symptoms or as hyperfunctioning nodules causing symptoms of hyperthyroidism. While surgical resection or radioiodine ablation of these nodules can be performed, percutaneous radiofrequency ablation (RFA) of benign solid thyroid nodules has been shown to be a safe and effective alternative in select patients. Preprocedural evaluation should include a history focusing on signs and symptoms of thyroid dysfunction, a physical exam, thyroid ultrasound, thyroid function tests, and discussion of key intraprocedural details with the patient such as the anesthesia plan and risks. Thyroid RFA can be safely performed as an outpatient procedure with less than 2% major and minor complication rates. This report will focus on the basic technique of performing RFA for symptomatic thyroid nodules.

Continuous, Large-Volume Hydrodissection to Protect Delicate Structures around the Thyroid throughout the Radiofrequency Ablation Procedure

Introduction: Small-volume hydrodissection liquid dissipates rapidly and confers only short-term protection during radiofrequency ablation (RFA) of benign thyroid nodules. The aim of this study was to establish a safe method for continuous, large-volume hydrodissection. Methods: A long needle was inserted and positioned outside the thyroid capsule; 5% glucose was injected to maintain a 3- to 5-mm continuous safety buffer. From October 2015 to July 2020, 166 patients underwent hydrodissection with different volumes, and ablation efficacy and complications associated with different liquid volumes (≤40 mL vs. >40 mL) were compared at 1-month postprocedure. Moreover, 20 mL liquid (equivalent to 250 mL in the human body) was injected around the thyroid of a rhesus monkey, after which CT scans were used to visualize the liquid’s fate and verify its safety. Results: The 51 patients with 10–40 mL injections and 116 patients with larger injections (45–450 mL) showed similar complete ablation rates (88.46% vs. 90.44%, p = 0.582), comparable 6-month VRR (82.79% vs. 76.62%, p = 0.079), and complication incidences, although the latter group had larger nodules (9.11 mL vs. 13.79 mL, p = 0.003), more energy delivered (3.44 kcal vs. 6.04 kcal, p < 0.001), and longer operation times (51.37 min vs. 69.2 min, p < 0.001). In the animal experiment, the 20 mL of liquid diffused quickly (within 10 min) from the vicinity of the thyroid to the mediastinum and retropharyngeal space. It was observed in the kidneys at 10 min and disappeared from the neck and chest space by 24 h. Conclusions: Continuous, large-volume hydrodissection can protect the delicate structures around the thyroid throughout the RFA procedure and might be beneficial in large thyroid nodule ablation.

Matrix 3D ultrasound-assisted thyroid nodule volume estimation and radiofrequency ablation: a phantom study

BackgroundTwo-dimensional (2D) ultrasound is well established for thyroid nodule assessment and treatment guidance. However, it is hampered by a limited field of view and observer variability that may lead to inaccurate nodule classification and treatment. To cope with these limitations, we investigated the use of real-time three-dimensional (3D) ultrasound to improve the accuracy of volume estimation and needle placement during radiofrequency ablation. We assess a new 3D matrix transducer for nodule volume estimation and image-guided radiofrequency ablation.MethodsThirty thyroid nodule phantoms with thermochromic dye underwent volume estimation and ablation guided by a 2D linear and 3D mechanically-swept array and a 3D matrix transducer.ResultsThe 3D matrix nodule volume estimations had a lower median difference with the ground truth (0.4 mL) compared to the standard 2D approach (2.2 mL, p < 0.001) and mechanically swept 3D transducer (2.0 mL, p = 0.016). The 3D matrix-guided ablation resulted in a similar nodule ablation coverage when compared to 2D-guidance (76.7% versus 80.8%, p = 0.542). The 3D mechanically swept transducer performed worse (60.1%, p = 0.015). However, 3D matrix and 2D guidance ablations lead to a larger ablated volume outside the nodule than 3D mechanically swept (5.1 mL, 4.2 mL (p = 0.274), 0.5 mL (p < 0.001), respectively). The 3D matrix and mechanically swept approaches were faster with 80 and 72.5 s/mL ablated than 2D with 105.5 s/mL ablated.ConclusionsThe 3D matrix transducer estimates volumes more accurately and can facilitate accurate needle placement while reducing procedure time.

Effect of combined acupuncture-medicine anesthesia in thyroid nodule ablation and its effect on serum β-endorphin

To investigate the anesthetic effect of combined acupuncture-medicine anesthesia in microwave ablation of benign thyroid nodules and its effect on serum β-endorphin. A total of 60 patients who met the inclusion criteria and received microwave ablation of benign thyroid nodules were randomly divided into the treatment group and the control group, with 30 patients in each. The patients in the treatment group were given combined acupuncture-medicine anesthesia, and those in the control group were given intravenous anesthesia. The two groups were compared in terms of the sedative and analgesic effects of anesthesia, amount of anesthetics used, incidence rate of intraoperative snore and respiratory depression, and change in serum β-endorphin level before anesthesia, before surgery, and after the surgery. Both groups obtained satisfactory anesthetic effects. Compared with the control group, the sedation score, the amounts of fentanyl and propofol used, the incidence rates of intraoperative snore and respiratory depression in the treatment group were obviously lower (P<0.05, P<0.01). The treatment group had an increase in serum β-endorphin level before surgery and at the end of surgery (P<0.05), while the control group showed no significant change in serum β-endorphin level at each time point. In microwave ablation of benign thyroid nodules, combined acupuncture-medicine anesthesia has good sedative and analgesic effects and can reduce the amounts of anesthetics used as well as the incidence rates of intraoperative snore and respiratory depression. The analgesic effect of acupuncture anesthesia is associated with increased β-endorphin secretion.

Long-Term Results of Thermal Ablation of Benign Thyroid Nodules: A Systematic Review and Meta-Analysis.

BackgroundUltrasound-guided thermal ablations have become one of the main options for treating benign thyroid nodules. To determine efficacy of thermal ablation of benign thyroid nodules, we performed a meta-analysis of studies with long-term follow-up of more than 3 years.MethodsDatabases were searched for studies published up to August 25, 2019, reporting patients with benign thyroid nodules treated with thermal ablation and with follow-up data of more than 3 years. Data extraction and quality assessment were performed according to PRISMA guidelines. The analysis yielded serial volume reduction rates (VRRs) of ablated nodules for up to 3 years or more, and adverse effect of ablation during follow-up. Radiofrequency ablation (RFA) and laser ablation (LA) were compared in a subgroup analysis.ResultsThe pooled VRRs for ablated nodules showed rapid volume reduction before 12 months, a plateau from 12 to 36 months, and more volume reduction appearing after 36 months, demonstrating long-term maintenance of treatment efficacy. Thermal ablation had an acceptable complication rate of 3.8%. Moreover, patients undergoing nodule ablation showed no unexpected delayed complications during the follow-up period. In the subgroup analysis, RFA was shown to be superior to LA in terms of the pooled VRR and the number of patients who underwent delayed surgery.ConclusionThermal ablations are safe and effective methods for treating benign thyroid nodules, as shown by a long follow-up analysis of more than 3 years. In addition, RFA showed superior VRRs compared with LA for the treatment of benign thyroid nodules, with less regrowth and less delayed surgery.

Clinical Outcomes after Pulmonary Cryoablation with the Use of a Triple Freeze Protocol

PurposeTo elucidate clinical variables associated with safety and efficacy in patients after cryoablation of pulmonary tumors with the use of a triple freeze protocol. Materials and MethodsPercutaneous cryoablation of pulmonary tumors was performed using Galil Medical cryoprobes (Arden Hills, Minnesota) with a triple freeze protocol: 67 nodules in 42 patients were treated at a single institution from 2012 to 2016. Average nodule diameter was 1.6 cm (range 0.4–5.9); 13 nodules (19.4%) were pathologically determined to be a primary lung malignancy, whereas 54 (80.6%) were metastatic nodules of extrapulmonary origin. Average patient age was 68.1 years (range 39.6–89.6), and the male-female ratio was 1.3:1. Ipsilateral thoracic surgery, intervention, or radiotherapy had been performed before the first cryoablation in 18 patients (42.9%). Mean imaging follow-up was 326 days (range 9–1,152). ResultsPneumothorax occurred in 19 cases (33.9%), 7 (12.5%) requiring chest tube, the likelihood of which was significantly greater in patients with 3 or more cryoprobes (P < .01). Local tumor recurrence/residual disease occurred in 6 cases (9.0%). Local tumor recurrence was not seen after ablation of nodules measuring <1.0 cm at the time of procedure, a significant difference from the recurrence ratee of 14.3% for nodules measuring ≥1.0 cm (P < .05). Likelihood of tumor recurrence/residual disease did not correlate with tumor pathology, tumor location, or procedural factors. The estimated marginal probabilities of local recurrence were 11.4%, 11.4%, and 38.1% at 1, 2, and 3 years after ablation, respectively. ConclusionsCryoablation of pulmonary tumors with the use of a triple freeze protocol is a viable modality with low recurrence and complication rates.

Further Investigation on High-intensity Focused Ultrasound (HIFU) Treatment for Thyroid Nodules: Effectiveness Related to Baseline Volumes

Several minimally invasive thermal techniques have been developed for the treatment of benign thyroid nodules. A new technique for this indication is high-intensity focused ultrasound (HIFU). The aim of this study was to assess effectiveness in varying preablative nodule volumes and whether outcome patterns that were reported during studies with other thermal ablative procedures for thyroid nodule ablation would also apply to HIFU. Over the last 2 years, 19 nodules in 15 patients (12 women) whose average age was 58.7 years (36-80) were treated with HIFU in an ambulatory setting. Patients with more than one nodule were treated in multiple sessions on the same day. The mean nodule volume was 2.56 mL (range 0.13-7.67 mL). The therapeutic ultrasound probe (Echopulse THC900888-H) used in this series functions with a frequency of 3 MHz, reaching temperatures of approximately 80°C-90°C and delivering an energy ranging from 87.6 to 320.3 J per sonication. To assess the effectiveness of thermal ablation, nodular volume was measured at baseline and at 3-month follow-up. The end point of the study was the volume reduction assessment after 3 months' follow-up. Therapeutic success was defined as volume reduction of more than 50% compared to baseline. This study was retrospectively analyzed using the Wilcoxon signed rank test and Kendall tau. The median percentage volume reduction of all 19 nodules after 3 months was 58%. An inverse correlation between preablative nodular volume and percentage volume shrinking was found (tau = -0.46, P < .05). Therapeutic success was achieved in 10 out of 19 patients (53%). HIFU of benign thyroid nodules can be carried out as an alternative therapy for nodules ≤3 mL if patients are refusing surgery or radioiodine therapy.