The utility-and limitations-of the rodent synergist ablation model in examining mechanisms of skeletal muscle hypertrophy.

In this issue, Burke et al. discuss the utility of the rodent synergist ablation (SA) model for examining mechanisms associated with skeletal muscle hypertrophy. In this invited perspective, we aim to complement their original perspective by discussing limitations to the model along with alternative mechanical overload models that have strengths and limitations.

Endovascular Ablation of the Right Greater Splanchnic Nerve in Heart Failure With Preserved Ejection Fraction: Rationale, Design and Lead-in Phase Results of the REBALANCE-HF Trial.

OBJECTIVE: Splanchnic vasoconstriction augments transfer of blood volume from the abdomen into the thorax, which may increase filling pressures and hemodynamic congestion in patients with noncompliant hearts. Therapeutic interruption of splanchnic nerve activity holds promise to reduce hemodynamic congestion in patients with heart failure with preserved ejection fraction (HFpEF). Here we describe (1) the rationale and design of the first sham-controlled, randomized clinical trial of splanchnic nerve ablation for HFpEF and (2) the 12-month results of the lead-in (open-label) trial's participants. METHODS: REBALANCE-HF is a prospective, multicenter, randomized, double-blinded, sham-controlled clinical trial of endovascular, transcatheter, right-sided greater splanchnic nerve ablation for volume management (SAVM) in patients with HFpEF. The primary objectives are to evaluate the safety and efficacy of SAVM and identify responder characteristics to inform future studies. The trial consists of an open-label lead-in phase followed by the randomized, sham-controlled phase. The primary efficacy endpoint is the reduction in pulmonary capillary wedge pressure (PCWP) at 1-month follow-up compared to baseline during passive leg raise and 20W exercise. Secondary and exploratory endpoints include health status (Kansas City Cardiomyopathy Questionnaire), 6-minute walk test distance, New York Heart Association class, and NTproBNP levels at 3, 6 and 12 months. The primary safety endpoint is device- or procedure-related serious adverse events at the 1-month follow-up. RESULTS: The lead-in phase of the study, which enrolled 26 patients with HFpEF who underwent SAVM, demonstrated favorable safety outcomes and reduction in exercise PCWP at 1 month post-procedure and improvements in all secondary endpoints at 6 and 12 months of follow-up. The randomized phase of the trial (n = 44 SAVM; n = 46 sham) has completed enrollment, and follow-up is ongoing. CONCLUSION: REBALANCE-HF is the first sham-controlled randomized clinical trial of greater splanchnic nerve ablation in HFpEF. Initial 12-month open-label results are promising, and the results of the randomized portion of the trial will inform the design of a future pivotal clinical trial. SAVM may offer a promising therapeutic option for patients with HFpEF. TRIAL REGISTRATION: NCT04592445.

Early versus Late Recurrence of Hepatocellular Carcinoma after Microwave Ablation: Patterns, Treatments, and Post-Recurrence Survival.

INTRODUCTION: Recurrence after microwave ablation (MWA) has not been extensively studied. We aimed to investigate the patterns, treatments, and survival of patients with hepatocellular carcinoma (HCC) who experienced early and late recurrence after MWA. METHODS: This retrospective study included patients with HCC recurrence after MWA as the initial treatment from January 2008 to December 2021. Recurrence patterns, treatments, and outcomes between patients with early and late HCC recurrence were compared. Prognostic factors of post-recurrence survival (PRS) were identified by multivariable Cox regression analyses. RESULTS: Among 222 patients, 128 developed early recurrence (≤2 years after MWA) and 94 had late recurrence (>2 years). Majority of the recurrent HCC were intrahepatic-only recurrence, within the Milan criteria, and received potentially curative treatment. No significant differences in the recurrence patterns, vascular invasion, tumor staging, post-recurrence treatments, or median PRS (35.0 vs. 33.0 months, p = 0.523) were identified between patients with early and late recurrence. Multivariable analyses suggested that multiple tumor number (hazard ratio [HR]: 1.54; 95% CI: 1.03-2.30, p = 0.038), extrahepatic recurrence (HR: 2.14, 95% CI: 1.16-3.92, p = 0.015), vascular invasion (HR: 2.37, 95% CI: 1.18-4.76, p = 0.038), and higher ALBI grade (HR: 2.18, 95% CI: 1.54-3.08, p < 0.001) were independent risk factors of worse PRS, while curative treatment after recurrence (HR: 0.59, 95% CI: 0.38-0.92, p = 0.020) was associated with better PRS. CONCLUSIONS: No differences in recurrence patterns, post-recurrence treatments, or PRS were found between HCC patients with early and late recurrence following MWA. Tumor burden and patients' liver function reserve should be considered to decide the optimal post-recurrence treatment after MWA.

Targeted microwave ablation for prostate cancer (FOSTINE1b): a prospective 'ablate-and-resect' study.

OBJECTIVE: To assess histopathological outcomes, as well as feasibility and safety of targeted microwave ablation (TMA) via the Trinity® system (KOELIS, La Tronche, France). PATIENTS AND METHODS: Prospective, single-institution, interventional Phase IIa study with an 'ablate-and-resect' design. In all, 11 patients diagnosed with localised prostate cancer (PCa) underwent TMA via the Trinity system under conscious sedation in an outpatient setting using a single transrectal TATO® 18-G antenna with different treatment regimens. Magnetic resonance imaging (MRI) and robot-assisted radical prostatectomy (RARP) were conducted at 7 days and 1 month after TMA, respectively. Nine patients received RARP, and two patients chose to withdraw their consent following TMA. These men chose an active surveillance protocol upon confirmation of a low-risk prostate cancer diagnosis. Functional outcomes and adverse events were evaluated at baseline and follow-up visits using validated questionnaires. Prostate volumetry and confirmation of necrosis were carried out through MRI and whole-mount histopathological examination. RESULTS: The TMA was successfully executed, and all patients were discharged on the same day. No severe adverse events (Common Terminology Criteria for Adverse Events Grade ≥3) were reported at the 7-day and 1-month follow-up visits. Additionally, no declines were observed in urinary, sexual and ejaculation functional outcomes. T1-weighted MRI revealed clear and well-defined ablation zones. The RARP was executed without difficulty, particularly during the dissection of the posterior plane. As a result, no intraoperative complications were encountered. Histopathological assessment on surgical specimens confirmed the absence of viable cells, indicating complete necrosis of the ablative zone if a power intensity >10 W was used during TMA. Ablation zone volumetry revealed no notable distinctions between the three-dimensional segmentation of the virtual ablation zone at TMA (median volume: 2 mL) and MRI (median volume: 1.923 mL). Conversely, a significant reduction was noted in the surgical specimen (median volume: 0.221 mL). CONCLUSIONS: Targeted microwave ablation via the Trinity system for localised PCa treatment proves to be a secure and feasible procedure, with complete necrosis evidence within the ablation zone on surgical specimens.

Aquablation versus HoLEP in patients with benign prostatic hyperplasia: a comparative prospective non-randomized study.

PURPOSE: The question of best surgical treatment for lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH) remains controversial. We compared the outcomes of aquablation and holmium laser enucleation of the prostate ("HoLEP") in a prospective cohort. METHODS: Patients with BPH underwent aquablation or HoLEP according to their preference between June 2020 and April 2022. Prostate volume ("PV"), laboratory results, postvoid residual volume, uroflowmetry, IPSS, ICIQ-SF, MSHQ-EjD, EES and IIEF were evaluated preoperatively and at three, six and 12 months postoperatively. We also analyzed perioperative characteristics and complications via the Clavien Dindo ("CD") classification. RESULTS: We included 40 patients, 16 of whom underwent aquablation and 24 HoLEP. Mean age was 67 years (SD 7.4). Baseline characteristics were balanced across groups, except the HoLEP patients' larger PV. IPSS fell from 20.3 (SD 7.1) at baseline to 6.3 (SD 4.2) at 12 months (p < 0.001) without differences between aquablation and HoLEP. HoLEP was associated with shorter operation time (59.5 (SD 18.6) vs. 87.2 (SD 14.8) minutes, p < 0.001) and led to better PV reduction over all timepoints. At three months, aquablation's results were better regarding ejaculatory (p = 0.02, MSHQ-EjD) and continence function (p < 0.001, ICIQ-SF). Beyond three months, erectile, ejaculatory, continence function and LUTS reduction did not differ significantly between aquablation and HoLEP. CD ≥ grade 3b complications were noted in six patients in aquablation group while only one in HoLEP group (p = < 0.01). CONCLUSIONS: While aquablation revealed temporary benefits regarding ejaculation and continence at three months, HoLEP was superior concerning operation time, the safety profile and volumetric results.

Recurrences after nephron-sparing treatments of renal cell carcinoma: a competing risk analysis.

PURPOSE: To examine associations between ablative therapy (AT) and partial nephrectomy (PN) and the occurrence of local recurrence (LR), distant metastatic recurrence (DMR) and all-cause mortality in a nation-wide real-world population-based cohort of patients with nonmetastatic renal cell carcinoma (nmRCC). METHODS: Data on 2751 AT- or PN-treated nmRCC tumours diagnosed during 2005-2018, representing 2701 unique patients, were obtained from the National Swedish Kidney Cancer Register. Time to LR/DMR or death with/without LR/DMR was analysed using Cox regression models. RESULTS: During a mean of 4.8 years follow-up, LR was observed for 111 (4.0%) tumours, DMR for 108 (3.9%) tumours, and death without LR/DMR for 206 (7.5%) tumours. AT-treated tumours had a 4.31 times higher risk of LR (P < 0.001) and a 1.91 times higher risk of DMR (P = 0.018) than PN-treated, with no significant differences in risk of death without LR/DMR. During a mean of 3.2 and 2.5 years of follow-up after LR/DMR, respectively, 24 (21.6%) of the LR cases and 56 (51.9%) of the DMR cases died, compared to 7.5% in patients without LR/DMR. There were no significant differences between AT- and PN-treated regarding risks of early death after occurrence of LR or DMR. CONCLUSION: AT treatment of patients with nmRCC implied significantly higher risks of LR and DMR compared with PN treatment. To minimize the risks of LR and DMR, these results suggest that PN is preferred over AT as primary treatment, supporting the EAU guidelines to recommended AT mainly to frail and/or comorbid patients.

Surgical Ablative Therapies in Patients With Radiorecurrent Prostate Cancer.

Management of recurrent prostate cancer following radiotherapy and subsequent radical prostatectomy poses considerable challenges due to potential complications for patients. Focal therapies have emerged as a burgeoning approach in prostate cancer treatment. Research indicates that ablative therapies exhibit encouraging oncological efficacy while maintaining acceptable functional outcomes in salvage interventions. Here, we present a contemporary review of focal therapy treatment modalities as well as oncologic and functional outcomes.

Pre-operative lung ablation prediction using deep learning.

OBJECTIVE: Microwave lung ablation (MWA) is a minimally invasive and inexpensive alternative cancer treatment for patients who are not candidates for surgery/radiotherapy. However, a major challenge for MWA is its relatively high tumor recurrence rates, due to incomplete treatment as a result of inaccurate planning. We introduce a patient-specific, deep-learning model to accurately predict post-treatment ablation zones to aid planning and enable effective treatments. MATERIALS AND METHODS: Our IRB-approved retrospective study consisted of ablations with a single applicator/burn/vendor between 01/2015 and 01/2019. The input data included pre-procedure computerized tomography (CT), ablation power/time, and applicator position. The ground truth ablation zone was segmented from follow-up CT post-treatment. Novel deformable image registration optimized for ablation scans and an applicator-centric co-ordinate system for data analysis were applied. Our prediction model was based on the U-net architecture. The registrations were evaluated using target registration error (TRE) and predictions using Bland-Altman plots, Dice co-efficient, precision, and recall, compared against the applicator vendor's estimates. RESULTS: The data included 113 unique ablations from 72 patients (median age 57, interquartile range (IQR) (49-67); 41 women). We obtained a TRE ≤ 2 mm on 52 ablations. Our prediction had no bias from ground truth ablation volumes (p = 0.169) unlike the vendor's estimate (p < 0.001) and had smaller limits of agreement (p < 0.001). An 11% improvement was achieved in the Dice score. The ability to account for patient-specific in-vivo anatomical effects due to vessels, chest wall, heart, lung boundaries, and fissures was shown. CONCLUSIONS: We demonstrated a patient-specific deep-learning model to predict the ablation treatment effect prior to the procedure, with the potential for improved planning, achieving complete treatments, and reduce tumor recurrence. CLINICAL RELEVANCE STATEMENT: Our method addresses the current lack of reliable tools to estimate ablation extents, required for ensuring successful ablation treatments. The potential clinical implications include improved treatment planning, ensuring complete treatments, and reducing tumor recurrence.

The relationship between ablation range and ablation energy in papillary thyroid microcarcinoma: a comparison between microwave ablation and laser ablation.

OBJECTIVES: To study the relationship between the ablation range and applied energy of laser ablation (LA) and microwave ablation (MWA) in papillary thyroid microcarcinoma (PTMC). METHODS: A total of 201 PTMC patients were treated with LA (n = 102) or MWA (n = 99) with single-applicator fixed ablation. The ablation range was determined by contrast-enhanced ultrasound. The ratios of ablation volume, longitudinal diameter, and orthogonal diameter to ablation energy (RAV/E, RAL/E, RAO/E) were analyzed and compared between MWA and LA. The effects of PTMC characteristics and Hashimoto's thyroiditis (HT) on ablation efficiency were evaluated by linear regression. RESULTS: The RAV/E was 0.72 (0.65-0.84) mm3/J for MWA and 0.48 (0.39-0.54) mm3/J for LA. HT was significantly correlated with RAV/E of LA (coefficient = - 0.367, p < 0.0001). RAL/E did not differ significantly between MWA and LA (MWA 0.026 mm/J, LA 0.025 mm/J; p = 0.957). However, MWA had a greater RAO/E than LA (MWA 0.014 mm/J, LA 0.012 mm/J; p < 0.0001). The plateau values of MWA and LA on the ablation orthogonal diameter were 10.7 mm and 8.69 mm, respectively. CONCLUSIONS: MWA showed a higher RAV/E than LA. More intuitively, MWA had a better ablation performance than LA on the orthogonal axis rather than the longitudinal axis. Theoretically, MWA and LA could achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin. HT had a negative effect on LA but not on MWA. CLINICAL RELEVANCE STATEMENT: This study establishes strong connections between ablation energy and ablation range in papillary thyroid microcarcinoma (PTMC) in vivo, possibly contributing to the supplementation of the PTMC Ablation Consensus or Guidelines and providing a scientific basis for choosing clinical ablation parameters in PTMC. KEY POINTS: • Both microwave ablation (MWA) and laser ablation (LA) have excellent performance on the ablation longitudinal axis (easily exceeding 10 mm) for papillary thyroid microcarcinoma (PTMC). • MWA performed much better than LA on the ablation orthogonal axis. • MWA and LA are expected to achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin.

A comparison of three different microwave systems for laparoscopic liver tumor ablation.

BACKGROUND: Our aim was to perform a comparison of three current microwave ablation (MWA) systems widely used for laparoscopic liver ablations in terms of ablation kinetics and geometry of ablation zones. METHODS: This was a retrospective, institutional review board-approved study comparing Emprint, Emprint HP, and NeuWave systems for laparoscopic liver ablation. Analyses were performed via Mann-Whitney U and χ2 tests. Continuous data are presented as median (interquartile range). RESULTS: For Emprint, Emprint HP, and NeuWave groups, tumor size was 1.16 (0.8), 1.21 (0.7), and 1.27 (0.9) cm (p = 0.54). Ablation time per lesion was 7 (6), 4 (2.8), and 4 (3.3) min (p < 0.0001), yielding similar ablation zone volumes and margins. The time to first ablation bubble was 1 (0.13), 1.5 (0.85), and 0.75 (0.5) min, and total ablation times were 7 (4.4), 4 (2), and 3.5 (2.8) min (p < 0.0001). The roundness index A, B, and transverse were 0.94, 0.98, and 0.79; 0.95, 0.95, and 0.78; and 1.02, 0.95, and 0.96. CONCLUSIONS: Although a saline-cooling system with Emprint system allowed for larger diameter spherical ablation zones to be created, it led to decreased efficiency compared to the CO2-cooled NeuWave system, which exposes the active antenna directly to tissue. Increased power delivered by Emprint HP improved the efficiency of saline-cooled design, as demonstrated by faster ablation times.

Image-Guided Energy Ablation for Palliation of Painful Bony Metastases-A Systematic Review.

PURPOSE: To analyze the effectiveness of image-guided energy ablation techniques with and without concurrent therapies in providing palliative pain relief in patients with bone metastases. MATERIALS AND METHODS: Ovid Embase, Ovid Medline, and Pubmed were searched from inception to April 14, 2023, using search terms related to bone lesions and MeSH terms regarding ablation therapy. English peer-reviewed primary articles were included that reported pain scores following image-guided energy-based ablation of bone metastases. Exclusion criteria included nonpalliative treatment, pain scores associated with specific treatment modalities not reported, and nonmetastatic bone lesions. Mean percentage reduction in pain score was calculated. RESULTS: Of the 1,396 studies screened, 54 were included. All but 1 study demonstrated decreased pain scores at final follow-up. Mean reductions in pain scores at final follow-up were 49% for radiofrequency (RF) ablation, 58% for RF ablation and adjunct, 54% for cryoablation (CA), 72% for cryoablation and adjunct (CA-A), 48% for microwave ablation (MWA), 81% for microwave ablation and adjunct (MWA-A), and 64% for high-intensity focused ultrasound (US). Postprocedural adverse event rates were 4.9% for RF ablation, 34.8% for RF ablation and adjunct, 9.6% for CA, 12.0% for CA-A, 48.9% for MWA, 33.5% for MWA-A, and 17.0% for high-intensity focused US. CONCLUSIONS: Image-guided energy ablation demonstrated consistently strong reduction in pain across all modalities, with variable postprocedural adverse event rates. Owing to heterogeneity of included studies, quantitative analysis was not appropriate. Future primary research should focus on creating consistent prospective studies with established statistical power, explicit documentation, and comparison with other techniques.

Update on Percutaneous Ablation for Sarcoma.

PURPOSE OF REVIEW: To provide an update on the current state of percutaneous thermal ablation in the treatment of sarcoma. RECENT FINDINGS: Data continue to accrue in support of ablation for local control and palliation of specific sarcoma subtypes such as extra-abdominal desmoid fibromatosis and for broader indications such as the treatment of oligometastatic disease. The synergistic possibilities of various combination therapies such as cryoablation and immunotherapy represent intriguing areas of active investigation. Histotripsy is an emerging non-invasive, non-thermal ablative modality that may further expand the therapeutic arsenal for sarcoma treatment. Percutaneous thermal ablation is a valuable tool in the multidisciplinary management of sarcoma, offering a minimally invasive adjunct to surgery and radiation therapy. Although there remains a paucity of high-level evidence specific to sarcomas, ablation techniques are demonstrably safe and effective for achieving local tumor control and providing pain relief in select patients and are of particular benefit in those with metastatic disease or requiring palliative care.

Ablation of Kidney Tumors in Patients with Substantial Kidney Impairment: Current Status.

PURPOSE OF REVIEW: To review the current status of kidney tumor ablation in patients with substantial kidney impairment. RECENT FINDINGS: Few reports of kidney tumor ablation in such patients have recently been published. The reported prevalence of patients with stage 4 or 5 chronic kidney disease (CKD) among patients undergoing ablation is 2.0%-10%. In patients with stage 4 or 5 CKD, local tumor control rates were 88%-100%. The effect of ablation on CKD stage is unclear, and the observed deteriorations in kidney function are consistent with both the effect of cryoablation and the natural course of advanced CKD. According to guidelines, active surveillance may be selected. The goals of treatment are complete tumor removal and maintenance of kidney function, both of which can be met by ablation. Given the limited treatment options, ablation may play a pivotal role in the management of patients with advanced CKD.

Incomplete ablation of thyroid cancer: Achilles' Heel?

BACKGROUND: In recent years, the incidence of thyroid nodules has increased significantly. There are various ways to treat thyroid nodules, and ablation therapy is one of the important ways to treat thyroid nodules. However, there are many complications and deficiencies in the current ablation treatment of thyroid nodules, especially the incomplete ablation of thyroid cancer nodules, which limits the further application of ablation technology. In this paper, we report two cases of incomplete ablation of thyroid nodules, one of which underwent surgical treatment due to anxiety after ablation, and the postoperative pathology confirmed that there was still residual papillary thyroid carcinoma, and the other patient underwent an operation after ablation, but visited our medical institution again due to cervical lymph node metastasis in a short period of time, and after radical cervical lymph node dissection, pathology confirmed multiple cervical lymph node metastasis. Radionuclide therapy was performed after surgery, and two patients are currently receiving endocrine suppression therapy, and their condition is stable with no signs of recurrence. CONCLUSION: The incomplete ablation of thyroid cancer nodules limits the development of ablation therapy, making ablation treatment a double-edged sword. Guidelines and expert consensus can guide their development, but they need to evolve with the times, and a multidisciplinary diagnostic team can help screen the most suitable patients. Only by using this technology more standardly, using the most appropriate technology, and treating the most suitable patients, can benefit more and more patients.

Identifying symptom clusters and temporal interconnections in patients with lung tumors after CT-guided microwave ablation: A network analysis.

PURPOSE: To explore symptom clusters and interrelationships using a network analysis approach among symptoms in patients with lung tumors who underwent computed tomography (CT)-guided microwave ablation (MWA). METHODS: A longitudinal study was conducted, and 196 lung tumor patients undergoing MWA were recruited and were measured at 24 h, 48 h, and 72 h after MWA. The Chinese version of the MD Anderson Symptom Inventory and the Revised Lung Cancer Module were used to evaluate symptoms. Network analyses were performed to explore the symptom clusters and interrelationships among symptoms. RESULTS: Four stable symptom communities were identified within the networks. Distress, weight loss, and chest tightness were the central symptoms. Distress, and weight loss were also the most key bridge symptoms, followed by cough. Three symptom networks were temporally stable in terms of symptom centrality, global connectivity, and network structure. CONCLUSION: Our findings identified the central symptoms, bridge symptoms, and the stability of symptom networks of patients with lung tumors after MWA. These network results will have important implications for future targeted symptom management intervention development. Future research should focus on developing precise interventions for targeting central symptoms and bridge symptoms to promote patients' health.

Thermal ablation for the treatment of malignant thyroid nodules: present and future.

As the utilization of high-resolution imaging modalities, such as ultrasound, becomes increasingly prevalent, there has been a swift rise in the detection rates of malignant thyroid nodules (MTC). Surgery remains the cornerstone of standard treatment for these nodules. However, the advent and evolution of thermal ablation (TA) techniques, encompassing radiofrequency ablation, laser ablation, and microwave ablation, have emerged as a novel therapeutic avenue for patients with MTC, particularly for those deemed unsuitable for surgery due to high risks or for those who refuse surgery. Presently, TA has been validated as an efficacious and safe intervention for both benign thyroid nodules and a subset of MTC. An expanding body of research has been dedicated to broadening the applicability of TA, initially from recurrent thyroid cancer and lymph nodes to now encompass isolated papillary thyroid microcarcinomas (PTMC) alongside a comprehensive exploration into the expanded parameters such as size, number, and location of PTMC, and its applicability in other types of thyroid cancer. This review provides a detailed synthesis of the clinical evidence about the use of TA in the management of MTC, as endorsed by current guidelines. It further delves into the ongoing research efforts aimed at extending its indications and discusses the prospective implications and challenges of integrating TA into the clinical management paradigms for MTC.

Investigating the optimal maximum diameter of benign thyroid nodules for thermal ablation on the basis of complete disappearance rate.

OBJECTIVE: Thermal ablation (TA) is a safe and effective treatment for benign thyroid nodules (BTNs). However, there has been no consensus on the optimal maximum diameter (MD) of BTNs for TA. This study aimed to identify the optimal MD of BTNs for TA based on complete disappearance rate after TA. MATERIALS AND METHODS: This retrospective study included 639 BTNs treated with TA from June 2014 to January 2022. The complete disappearance rate of BTNs after TA was summarized, related influencing factors were explored, and the optimal MD of BTNs for TA was identified. RESULTS: At the final follow-up (median: 40 months, range: 24-95 months), the overall volume reduction rate was 95.4 ± 9.0%, and 50.5% of the BTNs (323/639) completely disappeared. The MD was significantly negatively correlated with complete disappearance (odds ratio 0.89, 95% confidence interval 0.87-0.92; p < 0.001). Calcification, comet-tail artifacts, multilocular cysts, and composition of BTNs, as well as diabetes were negatively correlated with complete disappearance. Restricted cubic spline indicated that an MD of 25.0 mm was the optimal threshold of BTNs for TA, which was confirmed by subgroup logistic regression analysis. Compared with BTNs with MD ≤ 25.0 mm, those with MD > 25.0 mm had a greater complication rate (6.5% vs. 2.4%, p = 0.012). CONCLUSIONS: The MD of BTNs was negatively correlated with complete disappearance after TA; an MD > 25.0 mm indicated a reduced likelihood of complete disappearance compared with an MD ≤ 25.0 mm. An MD of 25.0 mm is an appropriate threshold of BTNs for TA on the basis of complete disappearance rate.

Directional microwave ablation in spine: experimental assessment of computational modeling.

BACKGROUND: Despite the theoretical advantages of treating metastatic bone disease with microwave ablation (MWA), there are few reports characterizing microwave absorption and bioheat transfer in bone. This report describes a computational modeling-based approach to simulate directional microwave ablation (dMWA) in spine, supported by ex vivo and pilot in vivo experiments in porcine vertebral bodies. MATERIALS AND METHODS: A 3D computational model of microwave ablation within porcine vertebral bodies was developed. Ex vivo porcine vertebra experiments using a dMWA applicator measured temperatures approximately 10.1 mm radially from the applicator in the direction of MW radiation (T1) and approximately 2.4 mm in the contra-lateral direction (T2). Histologic assessment of ablated ex vivo tissue was conducted and experimental results compared to simulations. Pilot in vivo experiments in porcine vertebral bodies assessed ablation zones histologically and with CT and MRI. RESULTS: Experimental T1 and T2 temperatures were within 3-7% and 11-33% of simulated temperature values. Visible ablation zones, as indicated by grayed tissue, were smaller than those typical in other soft tissues. Posthumous MRI images of in vivo ablations showed hyperintensity. In vivo experiments illustrated the technical feasibility of creating directional microwave ablation zones in porcine vertebral body. CONCLUSION: Computational models and experimental studies illustrate the feasibility of controlled dMWA in bone tissue.

Efficacy and safety of microwave ablation for treatment of follicular thyroid neoplasms: a preliminary study.

OBJECTIVE: To assess the feasibility, efficacy, and safety of microwave ablation in treating follicular thyroid neoplasms and suspicious follicular thyroid neoplasms. METHODS: In this retrospective study, the data of patients treated with microwave ablation for follicular neoplasms from December 2016 to January 2024 were summarized. The changes in nodule size, volume, technical success rate, disease progression, complete tumor resolution, thyroid function, and complications post-ablation were evaluated. RESULTS: Seventy-four patients (15 men, 59 women; mean age 46.3 ± 15.2 years) with follicular neoplasms were included. Over a median follow-up of 13 months, complete ablation was achieved, giving a 100% technical success rate. At the first month post-ablation, the maximum diameter of nodules showed no significant change (p = 0.287). From the third month, both maximum diameter and volume significantly decreased (p < 0.005 for all). Volume reduction rates remained stable at one and three months (p = 0.389 and 0.06, respectively) but increased significantly thereafter (p < 0.005 for all). By 24 months, the median maximum diameter had reduced from 2.3 cm to 0 cm, achieving a median volume reduction rate of 100%. Nodules disappeared completely in 20.3% (15/74). Local recurrence was noted in 2.7% of cases (2/74), with no metastasis or neoplasm-related deaths reported. Thyroid function remained unchanged post-treatment (p > 0.05). The complication and side effect rates were 8.1% and 4.1%, respectively. CONCLUSIONS: Initial findings suggest microwave ablation is an effective and safe treatment for follicular neoplasms, with low incidences of disease progression and complications, while maintaining thyroid function.

Percutaneous microwave ablation, perfusion, and reconstruction combined with a synthetic bone substitute in symptomatic bone cysts: a minimum of 26 months follow-up.

PURPOSE: The objective was to describe the technique and clinical outcome of microwave thermal ablation (MWA) and perfusion combined with synthetic bone substitutes in treating unicameral bone cysts (UBCs) in adolescents. MATERIALS AND METHODS: A total of 14 consecutive patients were enrolled by percutaneous MWA and saline irrigation combined with synthetic bone substitutes. Clinical follow-up included the assessment of pain, swelling, and functional mobility. Radiological parameters included tumor volume, physis-cyst distance, cortical thickness of the thinnest cortical bone, and the Modified Neer classification system. RESULTS: The mean follow-up was 28.9 months (26-52 months). All UBCs were primary, and all patients underwent the MWA, saline perfusion, and reconstruction combined with a synthetic bone substitute session, except for one patient (7.1%) who required a second session. All patients had good clinical results at the final follow-up. Satisfactory cyst healing was achieved in 13 cases according to radiological parameters. Tumor volume decreased from a mean of 49.7 cm3 before surgery treatment to 13.9 cm3 at the final follow-up (p < 0.01). The physis-cyst distance increased from a mean of 3.17-4.83 cm at the final follow-up (p < 0.01). Cortical thickness improved from a mean of 1.1 mm to 2.0 mm at the final follow-up (p < 0.01). According to the proposed radiological criteria, our results were considered successful (Grading I and II) in 13 patients (92.9%) at the final follow-up. CONCLUSION: Percutaneous microwave ablation combined with a bone graft substitute is a minimally invasive, effective, safe, and cost-effective approach to treating primary bone cysts in the limbs of adolescents.