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This paper presents the findings of a comprehensive study exploring the synergistic effects arising from the combination of microwave ablation and pulsed electromagnetic field (PEMF) therapy on prostate cancer cells. The research encompassed five distinct experimental groups, with continuous electric field measurements conducted during the entire treatment process. Group 1 and Group 2, subjected to microwave power below 350 W, exhibited specific electric field values of 72,800 V/m and 56,600 V/m, respectively. In contrast, Group 3 and Group 4, exposed to 80 W microwave power, displayed electric field levels of approximately 1450 V/m, while remaining free from any observable electrical discharges. The migratory and invasive capacities of PC3 cells were assessed through a scratch test in all groups. Notably, cells in Group 3 and Group 4, subjected to the combined treatment of microwave ablation and PEMF, demonstrated significantly accelerated migration in comparison to those in Groups 1 and 2. Additionally, Group 5 cells, receiving PEMF treatment in isolation, exhibited decreased migratory ability. These results strongly suggest that the combined approach of microwave ablation and PEMF holds promise as a potential therapeutic intervention for prostate cancer, as it effectively reduced cell viability, induced apoptosis, and impeded migration ability in PC3 cells. Moreover, the isolated use of PEMF demonstrated potential in limiting migratory capacity, which could hold critical implications in the fight against cancer metastasis. In this study, a new approach to treat prostate cancer by combining microwave ablation (MWA) and pulsed electromagnetic field (PEMF) therapy is explored. We used specific devices like rectangular waveguides for MWA and circular coils for PEMF. The energy sources utilized in the study comprised a magnetron tube system, similar to the microwave source found in a microwave oven, for generating microwaves, and a signal generator for producing PEMF. We used specialized equipment for MWA and PEMF to maintain controlled conditions, ensuring precise and reliable results. The research included testing various groups of prostate cancer cells exposed to different intensities of microwave power and magnetic flux density. The movement of cancer cells in different groups was examined through a wound healing assay, where cancer cells were placed on a flat surface, and we observed whether they filled the gap created by their movement. Interestingly, cells treated with both MWA and PEMF demonstrated faster movement compared to cells treated with MWA alone or PEMF alone. This combined treatment not only effectively decreased cell movement but also showed the potential cell death. The results showed that the combination of MWA and PEMF suggest a promising therapeutic strategy. The findings contribute to the development of precise and effective therapies that could enhance patient outcomes and quality of life. However, further research and validation are essential before translating these findings into clinical applications. [ABSTRACT FROM AUTHOR]

The present study analyzed the microwave ablation of cancerous tumors located in six major cancer-prone organs and estimated the significance of input power and treatment time parameters in the apt positioning of the trocar into the tissue during microwave ablation. The present study has considered a three-dimensional two-compartment tumour-embedded tissue model. FEA based COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids, and laminar flow physics has been used to obtain the numerical results. Based on the mortality rates caused by cancer, the present study has considered six major organs affected by cancer, viz. lung, breast, stomach/gastric, liver, liver (with colon metastasis), and kidney for MWA analysis. The input power (100 W) and ablation times (4 minutes) with apt and inapt positioning of the trocar have been considered to compare the ablation volume of various cancerous tissues. The present study addresses one of the major problems clinicians face, i.e. the proper placement of the trocar due to poor imaging techniques and human error, resulting in incomplete tumor ablation and increased surgical procedures. The highest values of the ablation region have been observed for the liver, colon metastatic liver and breast cancerous tissues compared with other organs at the same operating conditions. The present study has investigated the application of microwave ablation for cancer treatment in six major organs, specifically emphasizing the evaluation of ablation volume during the procedure. Using COMSOL-Multiphysics software, the study has investigated MWA of tumor embedded organs in the lung, breast, stomach, liver, and kidney. The positioning of the trocar, a crucial element in the treatment process, has been examined to address challenges in effectively ablating tumors. From the results, it has been revealed that liver, colon metastatic liver, and breast cancer tissues exhibited the largest areas of ablation volume compared with other organs.Organs like the breast and hepatic glands, characterized by lower heat capacity and density, have shown larger ablation zones. Trocar positioning significantly influenced the stomach, liver, and kidney, where improper placement led to notable increases in ablation volume, posing a risk of unintended damage to healthy tissue. Further, the study has concluded that precise trocar positioning plays a crucial role in optimizing microwave ablation. This precision has the potential to enhance the effectiveness of cancer treatments while minimizing harm to healthy tissue. The insights gained from this research offer valuable information for clinicians looking to enhance the precision of cancer therapies, ultimately aiming for improved outcomes for patients. [ABSTRACT FROM AUTHOR]

Lung tumor is the first malignant tumor with the highest mortality, but only no more than one-third of patients can be treated by surgical resection. Microwave ablation (MWA) has become a new adjuvant therapeutic mean for lung tumors because of its low trauma, short treatment time, large ablation volume and wide application range. However, the treatment parameters of MWA, such as input power and ablation time, still depend on the doctors' experience, which leads to the ineffectiveness of MWA. Therefore, the accurate modeling of temperature distribution of lung tumor MWA has become a significant technical problem to be solved. Recent research was devoted to personalized characterization of lung tumor parameters, finite element analysis of temperature distribution in MWA and accurate ablation effect evaluation. In this paper, a review of the recently obtained results and data will be presented and discussed. [ABSTRACT FROM AUTHOR]

In this study, using radiofrequency and bioheat transfer modules, heat transfer in tumor treatment was simulated easily and realistically with a low error rate. The modeling aimed to effectively suppress or destroy the growth of cancerous tissue. Bioheat transfer equations of Maxwell and Penne were used in the electromagnetic application. A 2-D microwave antenna model was designed to be used in the treatment of hyperthermia using the finite element method. Parameters related to antenna geometry, chemical and biological parameters to be used in temperature equations were used from previous studies in this field. The distribution of the total power density applied by the microwave power source in the brain tissue, the specific absorption rates (SAR), the temperature of the antenna and its surroundings, and the distribution of the damaged area at the end of the application were controlled. The safe power, frequency, time interval, and geometric properties of the microwave antenna catheter applied to the brain tissue in the treatment of glioblastoma multiforme (GBM) were determined. The application time is about 10 minutes, the power range is 5-10 W, the frequency is between 0.915 GHz − 2.45 GHz and the antenna geometry should be 70 mm long. Its length should be suitable for the tissue and its width should be 30 mm. [ABSTRACT FROM AUTHOR]

The study was designed to evaluate the efficiency of microwave ablation (MWA) in combination with anti-programmed death receptor 1 (anti-PD-1)/cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) in renal cell carcinoma (RCC) treatment. After tumors were established on C57/BL6 mice, MWA treatment and/or immune checkpoint inhibitor (ICI) treatment to the mice were performed. Tumor volume was recorded every 7 days. A rechallenge test was conducted on mice with tumors in the left kidney to explore the systemic establishment of antitumor immunity on day 7. In this study, during the 21-day observation period, tumors were continued to grow in all groups. However, compared with the tumor growth rate in MWA or control group, the rate in the ICI or MWA+ICI groups was decreased. Moreover, the population of CD8+T-cells was increased only in the MWA+ICI group, while that of regulatory T cells was decreased in the MWA, ICI, and MWA+ICI groups. Additionally, the MWA+ICI group had the highest interferon-γ level among all groups. Furthermore, histopathological examination revealed that CTLA-4 expression in distant tumors was reduced in the ICI and MWA + ICI groups. MWA treatment increased PD-L1/PD-1 expression; however, after the combination treatment with ICI, PD-L1/PD-1 expression was decreased. According to the rechallenge test, mice (16.7%) in the MWA group, ICI group (50%), and MWA+ICI group (66.7%) exhibited successful tumor rejection, whereas no mice in the control group exhibited the capability of tumor rejection. Overall, the systemic antitumor immunity induced by MWA was boosted when combined with anti-PD-1/CTLA-4 treatment in an RCC murine model. [ABSTRACT FROM AUTHOR]

This study aimed to retrospectively evaluate the safety and feasibility of computed tomography (CT)-guided synchronous percutaneous core-needle biopsy (CNB) and microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) in patients with idiopathic pulmonary fibrosis (IPF). From January 2019 to January 2023, nineteen stage I NSCLC patients with IPF underwent CT-guided synchronous percutaneous CNB and MWA in this study. The technical success rate, complications, local tumor progression (LTP) and overall survival (OS) were observed, and the effect of synchronous percutaneous CNB and MWA were evaluated. The technical success rate of synchronous percutaneous CNB and MWA was 100%. With a median follow-up time of 20.36 months, the median OS was 25 months (95% CI: 21.79, 28.20). The six-, twelve- and eighteen-month OS rates were 94.73%, 89.47% and 57.89%, respectively. The six-, twelve- and eighteen-month LTP rates were 0%, 10.52% and 31.57%, respectively. Major complications including pneumothorax, bronchopleural fistula and pneumonia occurred in 26.32% (5/19) patients. None of the patients died during the procedure. According to the results of the current study, CT-guided synchronous percutaneous CNB and MWA appears to be a safe and effective for stage I NSCLC in patients with IPF and providing an alternative therapeutic option for local control of pulmonary malignancy in high-risk patients. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the effect of intratumoral perfusion on microwave ablation (MWA) area in hepatocellular carcinoma (HCC). Patients who underwent curative MWA for HCC between October 2013 and May 2015 were enrolled. Three days before MWA, contrast-enhanced ultrasound (CEUS) was performed to illustrate the perfusion characteristics of the target lesion. Using the Sonoliver quantification software, time-intensity curves of dynamic CEUS were obtained, and quantitative parameters were extracted. Two microwave antennae were inserted into the center of the tumor and MWA was performed with a continuous power output of 50 W for 5 min. A second CEUS was performed to measure the size of the ablated region. Thereafter, an additional MWA procedure was performed until complete ablation with a 5–10-mm safety margin was achieved. A total of 38 patients who underwent curative MWA for 39 HCC nodules were enrolled. The mean age was 57 years (34–80 years), and the median maximum diameter of the HCC was 3.4 cm (interquartile range, 2–6.8 cm). Time-intensity curves were obtained and the area under the curve (AUC) was selected as a parameter for intratumoral perfusion. The AUC was inversely and linearly correlated with the size of the MWA area, including long- and short-axis diameters and ablation volume. A 1,000-dB·s change in the AUC produced an average change of 1.17 ± 0.44 mm, 0.725 ± 0.355 mm, and 2.4995 ± 0.6575 cm³ in the long- and short-axis diameters and ablation volume, respectively. The intratumoral perfusion of HCC was inversely correlated with MWA area size. [ABSTRACT FROM AUTHOR]

To analyze the efficacy and safety of radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LA) in T1N0M0 papillary thyroid carcinoma (PTC) patients by evaluating data on several outcomes on a large scale. Literature searches were conducted in PUBMED, EMBASE and the Cochrane Library for studies of thermal ablation (TA) for treating T1N0M0 PTC. Data on the volume reduction rate (VRR) at the 12-month follow-up and final follow-up, complete disappearance rate, local recurrence rate, lymph node metastasis rate, and complication rate of RFA, MWA and LA were evaluated separately. RFA effects were compared between T1aN0M0 and T1bN0M0 patients. A total of 36 eligible studies were included. RFA presented superior efficacy than MWA in 12-month VRR. At the final follow-up, the difference was slight in subgroups, showing a significant reduction. The complete disappearance rate of LA (93.00%) was higher than that of RFA (81.00%) and MWA (71.00%). Additionally, the local recurrence rate pooled proportions of MWA and RFA were both 2.00%, lower than that of the LA group (3.00%). There was no event of distant metastasis. The lymph node metastasis rates were similar, as RFA (1.00%) had the lowest. For minor complication rates, the pooled proportions of RFA (3.00%) were smaller than those of LA (6.00%) and MWA (13.00%). T1aN0M0 lesions presented with better outcomes than T1bN0M0 lesions. RFA, MWA and LA were reliable in curing PTC, and RFA presented advantages in most outcomes. T1aN0M0 patients may experience fewer side effects than T1bN0M0 patients. [ABSTRACT FROM AUTHOR]

To explore the safety and efficacy of ultrasound-guided microwave ablation (MWA) for tertiary hyperparathyroidism (THPT) in patients with renal transplantation (RT). In total, fifteen patients with THPT after renal transplantation who underwent MWA were enrolled in the study. The pre- and post-MWA intact parathyroid hormone (iPTH), serum calcium, phosphorus, creatinine, urea nitrogen and estimated glomerular filtration rate (eGFR) values were compared. A total of 38 parathyroid hyperplastic nodules in 15 RT patients were treated with ultrasound-guided MWA. The mean (median, range) size of the hyperplastic parathyroid nodules was 11.5 mm (11 mm, 5–25 mm), and the average (median, range) ablation time was 163.5s (121 s, 44–406 s). The average levels of serum iPTH and calcium at 1 d, 7 d, 1 month, 3 months, 6 months, 1 year post-MWA and at the end of follow-up were significantly lower than those pre-MWA (all p < 0.05). Compared with the pre-MWA value (0.76 mmol/L), the serum phosphorus levels at 1 d post-MWA (0.63 mmol/L) were significantly decreased, and those at 7 d, 1 month, 3 months, 6 months, 1 year post-MWA and at the end of follow-up were significantly increased, but all were within the normal range. There was no significant difference in serum creatinine and eGFR pre-MWA and post-MWA. No major MWA-related complications occurred. Ultrasound-guided MWA shows potential as a viable treatment for THPT in RT patients. However, further studies are required to confirm its safety and effectiveness in larger cohorts of longer duration. [ABSTRACT FROM AUTHOR]

To develop a computational model of microwave ablation (MWA) with a thermal accelerant gel and apply the model toward interpreting experimental observations in ex vivo bovine and in vivo porcine liver. A 3D coupled electromagnetic-heat transfer model was implemented to characterize thermal profiles within ex vivo bovine and in vivo porcine liver tissue during MWA with the HeatSYNC thermal accelerant. Measured temperature dependent dielectric and thermal properties of the HeatSYNC gel were applied within the model. Simulated extents of MWA zones and transient temperature profiles were compared against experimental measurements in ex vivo bovine liver. Model predictions of thermal profiles under in vivo conditions in porcine liver were used to analyze thermal ablations observed in prior experiments in porcine liver in vivo. Measured electrical conductivity of the HeatSYNC gel was ∼83% higher compared to liver at room temperature, with positive linear temperature dependency, indicating increased microwave absorption within HeatSYNC gel compared to tissue. In ex vivo bovine liver, model predicted ablation zone extents of (31.5 × 36) mm with the HeatSYNC, compared to (32.9 ± 2.6 × 40.2 ± 2.3) mm in experiments (volume differences 4 ± 4.1 cm3). Computational models under in vivo conditions in porcine liver suggest approximating the HeatSYNC gel spreading within liver tissue during ablations as a plausible explanation for larger ablation zones observed in prior in vivo studies. Computational models of MWA with thermal accelerants provide insight into the impact of accelerant on MWA, and with further development, could predict ablations with a variety of gel injection sites. [ABSTRACT FROM AUTHOR]

To compare the health-related quality of life (HRQoL) of patients with T1N0M0 papillary thyroid carcinoma (PTC) who underwent microwave ablation (MWA) and those who underwent total thyroidectomy (TT). From February 2018 to February 2022, 180 T1N0M0 PTC patients were enrolled in present study, including 90 in the MWA group and 90 in the TT group, respectively. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and Thyroid Cancer-Specific Quality of Life Questionnaire (THYCA-QoL) were completed by patients to evaluate their HRQoL scores According to the results of the EORTC-QLQ-C30, there was a significant difference in the scores of global health, physical, emotional, etc. between the two groups, which indicated that the quality of life in these items in the MWA group was better than those in the TT group (all p < 0.05). According to the results of the THYCA-QoL, all items had significant differences between the two groups except for headache, which demonstrated the thyroid-specific quality of life was higher in the MWA group than in the TT group (all p < 0.05). Ultrasound (US)-guided MWA offers a significant advantage in HRQoL over TT in T1N0M0 PTC patients, which provides an important reference for MWA as an alternative strategy to TT. [ABSTRACT FROM AUTHOR]

To compare the long-term efficacy and safety of microwave ablation (MWA) as first-line therapy for hepatocellular carcinoma (HCC) adjacent versus nonadjacent to the gallbladder. From 2006 to 2018, 657 patients with ≤5 cm HCC who underwent percutaneous ultrasound-guided MWA as first-line therapy from 5 hospitals were enrolled in this retrospective study. Patients were grouped into the adjacent group (n = 49) and the nonadjacent group (n = 608) according to whether the tumor was adjacent to the gallbladder. Propensity score matching (PSM) was used to balance baseline variables between the two groups. Forty-eight patient pairs were matched after PSM. For the PSM cohort, during a median follow-up time of 60 months, there were no differences in PFS (hazard ratio [HR], 1.011; 95% confidence interval [CI], 0.647-1.578; p = 0.963) or OS (HR 0.925; 95% CI 0.522-1.639; p = 0.789) between the adjacent and nonadjacent groups. Univariate and multivariate analyses revealed that the tumor adjacent to the gallbladder was not an independent risk factor for PFS or OS (all p > 0.05). Subgroup analysis showed comparable PFS and OS between the two groups in the <3 cm subgroup and the 3-5 cm subgroups (all p > 0.05). In addition to more use of assistive technology (p < 0.05), the adjacent group shared comparable local tumor progression, complications, technical success rate, and hospital stay (all p > 0.05) to the nonadjacent group. There were comparable long-term efficacy and complications between patients with HCC adjacent and nonadjacent to the gallbladder treated with MWA. The application of MWA to HCC adjacent and nonadjacent to the gallbladder resulted in comparable PFS and OS and complications. For both cohorts, MWA shared comparable complications (immediate and delayed), LTP, hospitalization, and operative time. MWA might be a first-line alternative for ≤5 cm HCC adjacent to the gallbladder with the use of assistive technologies and advances in technology. [ABSTRACT FROM AUTHOR]

To study the safety of improved hydrodissection based on the periparathyroidal fascial space during microwave ablation (MWA) for secondary hyperparathyroidism (SHPT). Data from 337 patients (162 males and 175 females; mean age, 50.8 ± 12.8 [range, 16-84] years) who underwent MWA for SHPT were retrospectively reviewed. Among them, 177 patients underwent traditional hydrodissection (traditional group) and 160 patients underwent improved hydrodissection based on periparathyroidal fascial spaces (improved group). Safety enhancement was analyzed by comparing the complications between the two groups. The characteristics of the hydrodissected fascial spaces, complications, and the follow-up results were recorded. The baseline data, clinical parameters, laboratory indices and characteristics of SHPT lesions were analyzed to assess the risk factors associated with hoarseness. Hydrodissection was successfully performed in all the enrolled patients according to the protocol. Six periparathyroid fascial spaces were hydrodissected, depending on the location of the SHPT lesions. The incidence of hoarseness due to recurrent laryngeal nerve injury, the most common complication of thermal ablation for SHPT lesions, was lower in the improved group than in the traditional group (6.9% vs. 13.0%, p = 0.044). The median hoarseness recovery time in the improved group was shorter than that in the traditional group (2 vs. 6 months, p < 0.001). There was no difference in technical efficiency between the two groups (improved group vs. traditional group: 75.0% vs. 70.6%; p > 0.05). Compared with traditional hydrodissection, improved hydrodissection based on periparathyroidal fascial spaces could enhance safety during MWA for SHPT. [ABSTRACT FROM AUTHOR]

To compare the clinical efficacy of percutaneous vertebroplasty (PVP) alone and microwave ablation (MWA) combined with PVP for the treatment of painful spinal metastases from non-small cell lung cancer (NSCLC). From October 2014 to October 2021, the data of 58 NSCLC patients with refractory painful spinal metastases (visual analog scale score ≥ 5) were retrospectively collected and analyzed. Patients in Group A (n = 30) and Group B (n = 28) received PVP alone and MWA combined with PVP, respectively. The primary endpoint was pain relief. The secondary endpoints were quality of life (QoL), local tumor progression (LTP), and complications. The technical success rate was 100% in both groups. Patients in both groups showed similar pain relief at 1–12 weeks, but patients in Group B still showed sustained pain relief at 24 weeks compared to those in Group A (p = 0.03). The assessment of QoL showed similar changes. LTP (33.00% vs. 7.14%, p = 0.02) and cement leakage rates (40.00% vs. 7.14%, p = 0.03) were lower in Group B. The multivariate analysis demonstrated spinal metastases with a maximum diameter ≤ 3.0 cm (p = 0.027) and MWA combined with PVP (p = 0.028) were two independent protective factors for LTP. For cement leakage, spinal metastases with vertebral body compression (p = 0.019) was an independent risk factor, while MWA combined with PVP (p = 0.042) was an independent protective factor. MWA combined with PVP for painful spinal metastases from NSCLC performed more sustained pain relief (>6 months) and ultimately improved QoL with lower LTP and cement leakage rates, compared to PVP alone. [ABSTRACT FROM AUTHOR]

Transvaginal ultrasound- and laparoscopy-guided percutaneous microwave ablation (TLPMA) is a minimally invasive alternative technique with low risk, fast recovery and few side effects. We aimed to evaluate the safety and long-term efficacy of TLPMA for treating adenomyosis. We included 79 patients with symptomatic adenomyosis who underwent TLPMA and 44 patients with adenomyosis who received the levonorgestrel-releasing intrauterine system (LNG-IUS). We evaluated the role of laparoscopy in TLPMA as well as the short- and long-term effects of TLPMA. The mean age of the 79 patients who underwent TLPMA was 41.8 years. There was no difference in the mean age between the TLPMA and LNG-IUS groups. Laparoscopy could help to separate pelvic adhesions, provide a wide antenna path, and observe the uterine surface and bowel movement. No major complications were found in patients who underwent TLPMA. There was a significant post-treatment reduction in both the uterine and lesion volumes (p < 0.001). After a median follow-up duration of 36 months (range: 1–60 months), the uterine and lesion volumes remained stable. Additionally, most patients remained without dysmenorrhea, which confirms the long-term efficacy of TLPMA. TLPMA is a feasible, minimally invasive technique for the treatment of adenomyosis, which significantly decreases the uterine and lesion volumes and has a good long-term effect. [ABSTRACT FROM AUTHOR]

To investigate the feasibility and efficacy of real-time 3.0 T magnetic resonance imaging (MRI) guided percutaneous microwave ablation (MWA) in the treatment of multifocal liver cancer. A total of 76 lesions in 26 patients with multifocal liver cancer who underwent 3.0 T MRI-guided microwave ablation in our hospital from April 2020 to April 2022 were retrospectively analyzed. The technical success rate, average operation time, average ablation time, and complications were evaluated. The upper abdomen was reviewed by pre- and post-contrast enhanced MRI scan every 1 months after the operation. The short-term curative effect was evaluated according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria (2020 version), and the local control rate was calculated. All 76 lesions were successfully operated. The technical success rate was 100%, the average operation time was 103.58 ± 18.57 min, the average ablation time of a single lesion was 11.00 ± 4.05 min, and the average ablation power was 43.03 ± 4.45 W. There were no serious complications such as massive bleeding, liver failure, and infection after the operation, except in one case with a small amount of pleural effusion and one case with right upper abdominal pain. The average follow-up time was 13.88 ± 6.62 months. One patient died due to liver failure, and one lesion developed a local recurrence. The local control rate was 98.7%. MWA of multifocal liver cancer guided by real-time 3.0 T MRI is a safe and feasible technique and has excellent short-term efficacy. [ABSTRACT FROM AUTHOR]

To investigate the feasibility of percutaneous intrauterine instillation of chilled saline to protect the endometrium during microwave ablation (MWA) treating types 1–3 uterine fibroids. Twenty-six patients with types 1–3 uterine fibroids were prospectively enrolled in an intrauterine saline instillation group (study group). The same number of patients with types 1–3 uterine fibroids who previously received MWA without endometrial protection were retrospectively included in a control group. Endometrial impairment was evaluated by hysteroscopy and magnetic resonance imaging (MRI). In the study group, hysteroscopy revealed an intact endometrium in 17 patients, congestion and reddening of the endometrium due to heat in 8 patients, and a burnt necrosis with a size < 1 cm on the functional layer of the endometrium in 1 patient. On MRI, in the study group, there were 17 (65.4%), 6 (23.1%), and 3 (11.5%) patients with grades 0, 1, and 2 endometrial impairment, respectively, but no grade 3 endometrial impairment. In the control group, there were 8 (30.8%), 8 (30.8%), 7 (26.9%), and 3 (11.5%) patients with grades 0, 1, 2, and 3 endometrial impairment, respectively. Endometrial impairment in the study group was significantly better than that in the control group (p = 0.006). One patient had puncture tunnel bleeding and no other complications occurred in the study group. Intraoperative percutaneous intrauterine instillation of chilled saline may be effective and safe in reducing the thermal damage to the endometrium caused by MWA for treating types 1–3 uterine fibroids. [ABSTRACT FROM AUTHOR]

Microwave ablation (MWA) is a promising modality that needs to be further investigated for cystic lesions. The present study aimed to determine the effects of MWA on cysts and cystic neoplasms with a tissue-mimicking model. Twenty New Zealand White rabbits were randomly divided into Group A (cyst mimic models, n = 10, φ = 5 cm) and Group B (cystic neoplasm mimicking models, n = 10, φ = 5 cm). For each group, ex vivo rabbit healthy bladder and VX2-implanted tumor bladder were fixed and embedded in agarose gel to mimic cyst and cystic neoplasm. In the MWA experimental subgroups, microwave antennas guided by computed tomography (CT) were introduced into these models. A system thermometer was placed at the outer edge of the bladder wall to monitor temperature changes. Immediately after MWA, ex vivo rabbit healthy bladders and VX2-implanted tumor bladders were harvested for gross anatomy and prepared for pathological evaluation. A total of twenty cyst and cystic neoplasm mimicking models were successfully developed. Ninety percent of the MWA procedures were successful, and no peri-procedural complications were encountered. The temperature of the cystic wall increased with duration in both MWA experimental subgroups and an effective ablation temperature (>60 °C) was achieved. Pathological examination of the cyst and cystic neoplasm mimic models revealed degenerative necrosis of the bladder wall mucosal epithelial cells, loss of bladder wall tissue structure and coagulative necrosis of VX2 tumor cells. Our data indicate that MWA could cause thermal damage to the tissue structure of cyst and cystic neoplasm, and it is an effective technique for treating cystic diseases. ex vivo rabbit healthy bladder and VX2-implanted tumor bladder were fixed and embedded in agarose gel to mimic cyst and cystic neoplasm. The temperature of the cystic wall increased with MWA duration and an effective ablation temperature (> 60 °C) was achieved. MWA could cause thermal damage to the tissue structure of the cyst and cystic neoplasm and it is effective in treating cystic diseases, as assessed by histopathology. [ABSTRACT FROM AUTHOR]

This retrospective study assessed the incidence rate, risk factors, and clinical course of early enlarging cavitation after percutaneous microwave ablation (MWA) of primary lung cancer (PLC). This study included 557 lesions of 514 patients with PLC who underwent CT-guided percutaneous MWA between 1 January 2018 and 31 December 2021. Of these patients, 29 developed early enlarging cavitation and were enrolled in the cavity group, and 173 were randomly enrolled in the control group. Early enlarging cavitation of the lung was defined as the development of a cavity ≥30 mm within 7 days after MWA. Overall, 31 (5.57%, 31/557 tumors) early enlarging cavitations occurred at an average of 5.83 ± 1.55 d after MWA. The risk factors were lesion contact with a large vessel (diameter ≥3 mm), lesion contact with the bronchus (diameter ≥2 mm), and a large ablated parenchymal volume. The cavity group had a higher incidence rate of delayed hydropneumothorax (12.9%) and bronchopleural fistula (9.68%) than the control group, resulting in a longer hospitalization (9.09 ± 5.26 days). Until Dec 31, 2022, 27 cavities disappeared after a mean of 217.88 ± 78.57 d (range, 111–510 d), two persisted, and two were lost to follow-up. Early enlarging cavitation occurred in 5.57% PLC cases that underwent MWA, causing serve complications and longer hospitalization. The risk factors were ablated lesion contact with large vessels and bronchi, as well as a larger ablated parenchymal volume. [ABSTRACT FROM AUTHOR]

To compare metal artifacts and evaluation of metal artifact reduction algorithms during probe positioning in computed tomography (CT)-guided microwave ablation (MWA), cryoablation (CRYO), and radiofrequency ablation (RFA). Using CT guidance, individual MWA, CRYO, and RFA ablation probes were placed into the livers of 15 pigs. CT imaging was then performed to determine the probe's position within the test subject's liver. Filtered back projection (B30f) and iterative reconstructions (I30-1) were both used with and without dedicated iterative metal artifact reduction (iMAR) to generate images from the initial data sets. Semi-automatic segmentation-based quantitative evaluation was conducted to estimate artifact percentage within the liver, while qualitative evaluation of metal artifact extent and overall image quality was performed by two observers using a 5-point Likert scale: 1-none, 2-mild, 3-moderate, 4-severe, 5-non-diagnostic. Among MWA, RFA, and CRYO, compared with non-iMAR in B30f reconstruction, the largest extent of artifact volume percentages were observed for CRYO (11.5–17.9%), followed by MWA (4.7–6.6%) and lastly in RFA (5.5–6.2%). iMAR significantly reduces metal artifacts for CRYO and MWA quantitatively (p = 0.0020; p = 0.0036, respectively) and qualitatively (p = 0.0001, p = 0.0005), but not for RFA. No significant reduction in metal artifact percentage was seen after applying iterative reconstructions (p > 0.05). Noise, contrast-to-noise-ratio, or overall image quality did not differ between probe types, irrespective of the application of iterative reconstruction and iMAR. A dedicated metal artifact algorithm may decrease metal artifacts and improves image quality significantly for MWA and CRYO probes. Their application alongside with dedicated metal artifact algorithm should be considered during CT-guided positioning. [ABSTRACT FROM AUTHOR]

To study the efficacy and safety of an improved hydrodissection protocol based on the perithyroidal fascial space during microwave ablation for papillary thyroid carcinoma (PTC). The data of 341 patients (94 men and 247 women, median age 41 years old, 25%–75% interquartile range 34–53 years old, nodule maximum diameter 0.2–1.9 cm) who underwent microwave ablation for PTC were retrospectively reviewed. Among them, 185 patients underwent traditional hydrodissection and served as a control group, and 156 patients underwent improved hydrodissection based on perithyroidal fascial spaces, constituting the improved group. Improvements in safety were analyzed by comparing complications between the two groups. The characteristics of hydrodissected spaces, complications, and follow-up results were recorded. Hydrodissection was successfully performed in all enrolled patients according to the protocol. The incidence of hoarseness caused by recurrent laryngeal nerve injury, the most common complication in thermal ablation of thyroid nodules, was significantly lower in the improved group than in the control group (1.9% vs. 8.1%, p = 0.021). The median hoarseness recovery time in the improved group was shorter than that in the control group (2 months vs. 3 months, p = 0.032). During follow-up, no local recurrence was encountered in either group. The tumor disappearance rate was not significantly different between the two groups (69.9% vs. 75.7%, p = 0.228). Improved hydrodissection based on perithyroidal fascial spaces had better protective effects than traditional hydrodissection. [ABSTRACT FROM AUTHOR]

The purpose of the study is to retrospectively evaluate the development and technological progress in local oncological treatments of patients with breast cancer liver metastasis (BCLM) using LITT (laser interstitial thermotherapy), MWA (microwave ablation) and TACE (transarterial chemoembolization) ablation techniques in a multimodal application. The study uses data generated between 1993 and 2020. Therapy results were evaluated using the Kaplan–Meier survival estimate, Cox proportional hazard regression and log-rank test. Cox regression analysis showed that the different treatment methods are statistically significant predictors of survival of patients. Median survival times for groups treated with LITT (212 patients) and LITT + TACE (215 patients) were 2.2 years and 2.1 years respectively; median survival times for groups treated with MWA (17 patients) and MWA + TACE (143 patients) were 5.6 and 2.4 years respectively. For LITT only treatments, the 1-, 3- and 5-year survival probability scored 80%, 37%, 22%. Results for combined LITT + TACE treatments were 76%, 34% and 15%. In group MWA, the 1-/3-/5-year survival probability rates were calculated as 89%, 89%, 89% (however, they should be interpreted carefully due to a relatively small sample size of n = 17 patients). Group MWA + TACE offered values of 77%, 38% and 22%. A separate group of 549 patients was analyzed with TACE monotherapy treatment. The estimated median survival time in this group was 0.8 years. The 1-/3-/5-year survival probability rates were 37%, 8% and 4%. Treatments with combined MWA and MWA + TACE resulted in the best median survival time estimations in this study. [ABSTRACT FROM AUTHOR]

This retrospective study aimed to assess the safety and efficacy of synchronous biopsy and microwave ablation (MWA) for highly suspected malignant lung ground-glass opacities (GGOs) adjacent to the mediastinum (distance ≤10 mm). Ninety patients with 98 GGOs (diameter range, 6–30 mm), located within 10 mm of the mediastinum, underwent synchronous biopsy and MWA at a single institution from 1 May 2020, to 31 October 2021 and were enrolled in this study. Synchronous biopsy and MWA involving the completion of the biopsy and MWA in a single procedure was performed. Safety, technical success rate, and local progression-free survival (LPFS) were evaluated. The risk factors for local progression were calculated using the Mann–Whitney U test. The technical success rate was 97.96% (96/98 patients). The LPFS rates at 3, 6, and 12 months were 95.0%, 90.0%, and 82.0%, respectively. The diagnostic rate of biopsy-proven malignancy was 72.45% (n = 71/98). Invasion of lesions into the mediastinum was a risk factor for local progression (p = 0.0077). The 30-day mortality rate was 0. The major complications were pneumothorax (13.27%), ventricular arrhythmias (3.06%), pleural effusion (1.02%), hemoptysis (1.02%), and infection (1.02%). Minor complications included pneumothorax (30.61%), pleural effusion (24.49%), hemoptysis (18.37%), ventricular arrhythmias (11.22%), structural changes in adjacent organs (3.06%), and infection (3.06%). Synchronous biopsy and MWA was effective for treating GGOs adjacent to the mediastinum without severe complications (Society of Interventional Radiology classification E or F). Invasion of lesions into the mediastinum was identified as a risk factor for local progression. [ABSTRACT FROM AUTHOR]

Exosomal miRNAs play key roles in various biological processes such as cell proliferation, angiogenesis, migration and invasion. We explored whether exosomal miRNAs can promote local recurrence (LR) of lung tumors following incomplete microwave ablation (MWA) therapy. Exosomal miRNA profiles before and after incomplete MWA in lung cancer (LC) patients with LR (n = 3) were sequenced and compared. The differentially expressed miRNAs of interest were validated in clinical samples (n = 10) and MWA-treated cells using RT-qPCR analysis. Target genes of the miRNAs were predicted and validated. The biological functions of miRNAs in proliferation, angiogenesis and metastasis of A549 cells were evaluated in vitro and in vivo. A total of 270 miRNAs (243 upregulated and 27 downregulated) were differentially expressed after incomplete MWA in patients with local recurrence. Upregulation of miR-133a-3p after MWA was validated in the cells and clinical samples. Cell functional experiments suggested that miR-133a-3p overexpression derived from serum exosomes increased cell viability, migration and invasion ability, tube formation activity and proliferation of A549 cells. Sirtuin 1 (SIRT1) was identified as a target gene for miR-133a-3p. Moreover, miR-133a-3p delivered by exosomes significantly promoted tumor growth, paralleled by reduced SIRT1 expression in a subcutaneous tumorigenesis animal model and increased the number of lung nodules by tail vein metastasis in vivo. Exosomal miR-133a-3p overexpression promoted tumor growth and metastasis following MWA and could be a promising biomarker for LC recurrence after incomplete MWA. [ABSTRACT FROM AUTHOR]

Benign breast lesions are often associated with hard nodule formation after microwave ablation (MWA), which persists for a long time and causes problems in patients. The aim of this study was to evaluate the efficacy of decorin in the treatment of hard nodule formation and its potential mechanism of action. Using a Bama miniature pig model of mammary gland hyperplasia, immunohistochemistry, Masson's trichrome and western blotting were firstly applied to compare the extent of fibrosis and activation of key members of the TGF-β1/SMAD and MAPK signaling pathways of hard nodule in the control and MWA groups, and then the extent of fibrosis and expression of signaling pathways in hard nodule were examined after application of decorin. The results showed that the MWA group had increased levels of TGF-β1, p-SMAD2/3, p-ERK1/2, and collagen I proteins and increased fibrosis at 2 weeks, 4 weeks, and 3 months after MWA. After decorin treatment, the expression levels of each protein were significantly downregulated, and the degree of fibrosis was reduced at 2 weeks, 4 weeks, and 3 months after MWA compared with the MWA group. In conclusion, these results suggest that activation of TGF-β1 may play an important role in hard nodule formation and that decorin may reduce hard nodule formation after MWA in a model of mammary gland hyperplasia by inhibiting the TGF-β1/SMAD and MAPK signaling pathways. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the safety of bronchoscopic microwave ablation (MWA) of peripheral lung parenchyma using the NEUWAVE™ FLEX Microwave Ablation System, and robotic-assisted bronchoscopy (RAB) using the MONARCH™ Platform in a swine model. Computed tomography (CT)-guided RAB MWA was performed in the peripheral lung parenchyma of 17 Yorkshire swine (40–50 kg) and procedural adverse events (AEs) documented. The acute group (day 0, n = 5) received 4 MWAs at 100 W for 1, 3, 5, and 10 min in 4 different lung lobes. Subacute and chronic groups (days 3 and 30, n = 6 each) received one MWA (100 W, 10 min) per animal. The study was completed without major procedural complications. No postprocedural AEs including death, pneumothorax, bronchopleural fistula, hemothorax, or pleural effusions were observed. No gross or histological findings suggestive of thromboembolism were found in any organ. One 3-Day and one 30-Day swine exhibited coughing that required no medication (minor AEs), and one 30-Day animal required antibiotic medication (major AE) for a suspected lower respiratory tract infection that subsided after two weeks. CT-based volumetric estimates of ablation zones in the acute group increased in an ablation time-dependent (1–10 min) manner, whereas macroscopy-based estimates showed an increasing trend in ablation zone size. The NEUWAVE FLEX and MONARCH devices were safely used to perform single or multiple RAB MWAs. The preclinical procedural safety profile of RAB MWA supports clinical research of both devices to investigate efficacy in select patients with oligometastatic disease or primary NSCLC. [ABSTRACT FROM AUTHOR]

The range of an ablation zone (AZ) plays a crucial role in the treatment effect of microwave ablation (MWA). The aim of this study was to analyze the factors influencing the AZ range. Fourteen factors in four areas were included: patient-related factors (sex, age), disease-related factors (tumor location, liver cirrhosis), serological factors (ALT, AST, total protein, albumin, total bilirubin, direct bilirubin, and platelets), and MWA parameters (ablation time, power, and needle type). Multiple sequence MRI was used to delineate AZ by three radiologists using 3D Slicer. MATLAB was used to calculate the AZ length, width, and area of the largest section. Linear regression analysis was used to analyze influencing factors. Moreover, a subgroup analysis was conducted for patients with viral hepatitis. 220 patients with 290 tumors were included between 2010–2021. In addition to MWA parameters, cirrhosis and tumor location were significant factors that influenced AZ (p < 0.001). The standardized coefficient (beta) of cirrhosis (cirrhosis vs. non-cirrhosis) was positive, which meant cirrhosis would lead to a decrease in AZ range. The beta of tumor location (near the hepatic hilar zone, intermediate zone, and periphery zone) was negative, indicating that AZ range decreased as the tumor location approached the hepatic hilum. For viral hepatitis patients, Fibrosis 4 (FIB4) score was a significant factor influencing AZ (p < 0.001), and the beta was negative, indicating that AZ range decreased as FIB4 increased. Liver cirrhosis, tumor location, and FIB4 affect the AZ range and should be considered when planning MWA parameters. [ABSTRACT FROM AUTHOR]

The treatment of hepatic hemangioma includes surgical resection, radiofrequency ablation and Transarterial embolization. However, complications, mortality and compromised effectiveness limit their applications. Microwaves with effective heating generation and short ablation time become a promising treatment. The aim of this study is to conduct systematic review and meta-analyses to evaluate the effectiveness of Microwave Ablation (MWA) for the treatment of hepatic hemangioma. A systematic literature review was conducted in PubMed. Main outcomes were defined as hemangioma decreases in diameters and volume changes post-MWA. Conventional random-effect meta-analysis technique was applied to analyze the pooled data, and meta-regression model was established to explore the association among factors. There were nine studies with a total of 501 patients retrieved. The pooled estimate of mean differences and 95% CI of hemangioma decreases after MWA treatment in diameter and in volume change (%) were 3.009 cm and (1.856, 4.161), and 53.169% and (51.274, 55.065), respectively. The pooled estimates of liver enzyme, ALT and AST, elevation were 219.905 with 95%CI (160.860, 278.949) and 315.679 with 95%CI (226.961, 404.397), respectively. Major complications were defined as acute kidney injury (AKI), pleural effusion, diaphragmatic hernia, and jaundice that needed to be treated, and the pooled incidence was 0.017 with 95% CI of (0.006, 0.029). No mortality related to MWA was reported. Meta-regression showed ablation time was associated with pre-operative lesion size (p =.001). MWA is effective and safe in treatment of hepatic hemangioma, and our study suggests that hemangioma size should be investigated in the future MWA pretreatment difficulty scoring system study. [ABSTRACT FROM AUTHOR]

To determine the effects of tract embolization with gelatin sponge particles on the prevention of pneumothorax after percutaneous microwave ablation (MWA) in rabbit lungs. Twenty-four New Zealand white rabbits were randomly divided into Group A (MWA followed by tract embolization with gelatin sponge particles, n = 12) and Group B (MWA without tract embolization, n = 12). For each group, CT images were reviewed for the occurrence of pneumothorax within 30 min after MWA. The rate of pneumothorax was compared by Chi-square Test. Lung tissue around the needle tract was harvested after the rabbits were euthanized, and histopathological examinations were performed and studied with hematoxylin and eosin stains. Twenty-four animals underwent 47 sessions of MWA (24 sessions in Group A and 23 sessions in Group B). Group A had a statistically lower rate of pneumothorax than Group B (25.0 vs. 56.5%; p = 0.028). The pathological examinations of both groups demonstrated thermal injury of the needle tract characterized by a rim of the coagulated lung parenchyma, which might be responsible for pneumothorax after MWA. Gelatin sponge particles could be arranged in irregular flakes densely to effectively seal the needle tract, thus reducing the occurrence of pneumothorax. The gelatin sponge particles could be almost completely absorbed about 14 days later. Results of the present study showed needle tract embolization with gelatin sponge particles after CT-guided pulmonary MWA can significantly reduce the incidence of pneumothorax. Gelatin sponge particles can effectively seal the needle tract after ablation and can be completely absorbed in the body with good safety. [ABSTRACT FROM AUTHOR]

Clinically, the management of cystic renal masses is tricky. The study aims to evaluate the safety and efficacy of laparoscopic microwave ablation-assisted partial nephrectomy (LMAPN) for cystic renal tumors. Between November 2017 and January 2022, LMAPN was performed on 43 patients (29 men and 14 women; age range: 22–80 years; median age 54 years) with Bosniak category III (n = 15) or IV (n = 28) cystic renal tumors (size range: 1.2–5.0 cm; mean size 2.8 cm). The median follow-up period was 26 months (range: 7–56 months). Baseline and perioperative data, pathological features, renal function, postoperative complications and oncologic outcomes were collected and evaluated. Forty-three cystic renal tumors were successfully managed by LMAPN. The mean operating time was 79 min (range: 40–130 min). The mean time of renal pedicle clamping was 19 min (range: 12–25 min). Mean intraoperative blood loss was 28.4 mL (range: 10–80 mL). The mean postoperative hospitalization duration was 4 days (range: 2–6 days). Negative surgical margins were diagnosed in all cases. During the follow-up, no patient appeared with distant metastasis, wound or peritoneal cavity implantation. No major but minor complications of Clavien–Dindo grade I were encountered after the operation. The 1-, 3- and 4-year overall survival rate was 100%, 96.6% and 88.5%, respectively. This is the first study focusing on LMAPN for cystic renal tumors, demonstrating its favorable feasibility, safety and disease control. Long-term follow-up is necessary to draw conclusions on the preference and advantages of the new therapeutic approach. [ABSTRACT FROM AUTHOR]

Background: In order to study the effect of bifurcation vessels parameters on the temperature field and coagulation zone of microwave ablation on lung tissue. Methods: The finite element method was used to establish the simulation model. The angle of bifurcation vessel model was 60°. The position of the antenna and the main blood vessel are parallel, and the distance between them was 5, 10 and 15 mm, respectively. Temperature field distribution was obtained at 2450 MHz, 50 W and 300 s. The blood flow velocity was set to 0.1 and 0.2 m/s. Results: The results showed when the antenna was 5 mm away from the bifurcation vessel and the velocity was 0.1 m/s, the position of x = 8.4 mm achieved the complete necrosis at 220 s, while the fraction of necrotic tissue at the symmetry point x = 1.6 mm was 0.2 at 300 s. For the distance was 10 mm and the velocity was 0.1 m/s, the fraction of necrotic tissue at x = 3 mm that near the bifurcation vessel was 0.53 and was 0.69 at the symmetry point x = 17 mm. When the antenna is 15 mm away from the vessel, the fraction of necrotic tissue of symmetrical points on both sides of the antenna obtained after ablation were the same. Conclusions: The distance between the antenna and the bifurcation vessel over 15 mm, the blood flow has no effect on the coagulation zone. Besides, the distance between bifurcation vessel and antenna possesses a greater influence on the temperature distribution and coagulation zone than the blood flow velocity. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the feasibility, safety, and efficacy of computed tomography (CT)-guided percutaneous coaxial biopsy combined with microwave ablation (MWA) for the treatment of renal masses. The clinical data of ten patients (14 tumors) treated with CT-guided percutaneous coaxial biopsy combined with MWA from January 2017 to November 2019 were retrospectively analyzed. The patients were followed up for 2–33 months. The outcomes were evaluated with plain and contrast spiral CT scans. Renal function was assessed using the estimated glomerular filtration rate. No severe MWA-related complication was observed. All the tumors were successfully ablated. There was no imaging evidence of local residual tumor, local tumor recurrence, or disease progression during the follow-up period. CT-guided percutaneous coaxial biopsy combined with MWA might be an effective option for the diagnosis and treatment of renal masses in selected patients. [ABSTRACT FROM AUTHOR]

Purpose: The charring tissue formation in the ablated lesion during the microwave ablation (MWA) of tumors would induce various unwanted inflammatory responses. This paper aimed to deliver appropriate thermal dose for effective ablations while preventing tissue carbonization by optimizing the treatment protocol during MWA with the set combinations of temperature control and pulsed microwave energy delivery. Material and methods: The thermal phase transition of ex vivo porcine liver tissues were recorded by differential scanning calorimetry (DSC) to determine the temperature threshold during microwave output control. MWA was performed by an in-house built system with the ease of microwave output parameter adjustment and real-time temperature monitoring. The effects of continuous and pulsed microwave deliveries as well as various intermittent time-set of MWA were evaluated by measuring the dimensions of the coagulation zone and the carbonization zone. Results: The DSC scans demonstrated that the ex vivo porcine liver tissues have been in a state of endothermic heat during the heating process, where the maximum absorbed heat occurred at the temperature of 105 °C ± 5 °C. The temperature control during MWA resulted in effective coagulative necrosis while preventing tissue carbonization, after setting 100 °C as the upper threshold temperature and 60 °C as the lower threshold. Both the numerical simulation and ex vivo experiments have shown that, upon the optimization of the time-set parameters in the periodic intermittent pulsed microwave output, the tissue carbonization was significantly diminished. Conclusion: This study developed a straight-forward anti-carbonization strategy in MWA by modulating the pulsing mode and intermittent time. The programmed protocols of intermittent pulsing MWA have demonstrated its potentials toward future expansion of MWA technology in clinical application. [ABSTRACT FROM AUTHOR]

Background: Hyperparathyroidism (HPT) is classified into primary HPT (PHPT), secondary HPT (SHPT), tertiary HPT (THPT), and pseudohyperparathyroidism. Parathyroid surgery is generally reserved for patients with symptomatic PHPT and asymptomatic patients who meet the surgical guideline criteria. However, the risk of complications and mortality after parathyroid gland surgery increases with increasing patient age. Aim: This study aimed to review existing research on laser ablation, radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound in the treatment of HPT and analyze its application prospects. Conclusions: Thermal ablation is a good alternative treatment for patients with parathyroid hyperplasia who do not meet the criteria or decline surgery. Being a type of minimally invasive treatment, ultrasound-guided thermal ablation has the advantages of easy operation, rapid recovery, and reusability and is used widely. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy, feasibility and acceptability of microwave ablation (MWA) compared to uterine artery embolization (UAE) as treatment for uterine fibroids. Method: A randomized controlled superiority trial, including premenopausal women 30–55 years, with symptomatic uterine fibroids without any single fibroid exceeding mean diameter of eight centimeters. Patients were randomized to receive microwave ablation, performed abdominally or vaginally, or to uterine artery embolization. The primary outcome was volume difference of the three largest fibroids at 6 months post treatment evaluated by magnetic resonance imaging (MRI) by a blinded radiologist analyzed by Mann–Whitney U-test. Secondary outcomes included symptom severity score (SSS), health related quality of life (HR-QoL), amount of menstrual bleeding, postoperative pain, length of hospitalization, need for additional treatment, adverse events and if patients would recommend the treatment to a friend. Results: Patients were recruited from 30 January 2017 to 12 September 2019, with a total of 17 patients treated in each group from May 2017 to December 2019. Superiority of MWA could not be established. The volume reduction was 41.8% (Interquartile range, IQR, 14–63) in the MWA group compared to 62.2% (IQR 34.9–80.1) in the UAE group (p = 0.29). Effects on symptoms, HR-QoL and acceptability did not differ between groups. Days of hospitalization and sick leave were significantly fewer in the MWA group (p < 0.001 and p = 0.001). Conclusions: Although superiority of MWA could not be established, it is a promising technique for treating uterine fibroids. It was well tolerated and associated with lower use of health care resources. [ABSTRACT FROM AUTHOR]

Purpose: Bio-effects following thermal treatments are a function of the achieved temperature profile in tissue, which can be estimated across tumor volumes with real-time MRI thermometry (MRIT). Here, we report on expansion of a previously developed small-animal microwave hyperthermia system integrated with MRIT for delivering thermal ablation to subcutaneously implanted tumors in mice. Methods: Computational models were employed to assess suitability of the 2.45 GHz microwave applicators for delivering ablation to subcutaneous tumor targets in mice. Phantoms and ex-vivo tissues were heated to temperatures in the range 47–67 °C with custom-made microwave applicators for validating MRIT with the proton resonance frequency shift method against fiberoptic thermometry. HAC15 tumors implanted in nude mice (n = 6) were ablated in vivo and monitored with MRIT in multiple planes. One day post ablation, animals were euthanized, and excised tumors were processed for viability assessment. Results: Average absolute error between temperatures from fiberoptic sensors and MRIT was 0.6 °C across all ex-vivo ablations. During in-vivo experiments, tumors with volumes ranging between 5.4–35.9 mm³ (mean 14.2 mm³) were ablated (duration: 103–150 s) to achieve 55 °C at the tumor boundary. Thermal doses ≥240 CEM43 were achieved across 90.7–98.0% of tumor volumes for four cases. Ablations were incomplete for remaining cases, attributed to motion-affected thermometry. Thermal dose-based ablative tumor coverage agreed with viability assessment of excised tumors. Conclusions: We have developed a system for delivering microwave ablation to subcutaneous tumors in small animals under MRIT guidance and demonstrated its performance in-vivo. [ABSTRACT FROM AUTHOR]

Microwave ablation (MWA) is becoming an increasingly important minimally invasive treatment option for localized tumors in many organ systems due to recent advancements in microwave technology that have conferred many advantages over other tumor ablation modalities. Despite these improvements in technology and development of applicators for site-specific tumor applications, the vast majority of commercially available MWA applicators are generally designed to create large-volume, symmetric, ellipsoid or spherically-shaped treatment zones and often lack the consistency, predictability, and spatial control needed to treat tumor targets near critical structures that are vulnerable to inadvertent thermal injury. The relatively new development and ongoing translation of directional microwave ablation (DMWA) technology, however, has the potential to confer an added level of control over the treatment zone shape relative to applicator position, and shows great promise to expand MWA’s clinical applicability in treating tumors in challenging locations. This paper presents a review of the industry-standard commercially available MWA technology, its clinical applications, and its limitations when used for minimally-invasive tumor treatment in medical practice followed by discussion of new advancements in experimental directional microwave ablation (DMWA) technology, various techniques and approaches to its use, and examples of how this technology may be used to treat tumors in challenging locations that may otherwise preclude safe treatment by conventional omni-directional MWA devices. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the performance of Sonazoid-based contrast-enhanced ultrasound (CEUS) in the microwave ablation (MWA) of primary hyperparathyroidism (pHPT). Methods: Forty patients with pHPT were enrolled and treated with percutaneous ultrasound (US)- guided MWA assisted by CEUS. All patients underwent immediate CEUS examinations following MWA. On post-ablation day 1, patients who did not display a decrease in intact parathyroid hormone (iPTH) levels to the norm were examined by CEUS to evaluate an incomplete ablation. We compared the serum iPTH and calcium levels and the nodule volumes before and after MWA. The complications were evaluated during and after treatment. Results: Immediately following MWA, CEUS demonstrated complete ablation with all 44 parathyroid nodules. On post-ablation day 1, five nodules in five patients displayed annular enhancement around the ablation zone on CEUS. The average maximum diameters of the nodules and the ablation zone were 1.09 ± 0.28 cm and 1.36 ± 0.23 cm, respectively. An ablation zone larger than the primary lesion (p < 0.05) generated a higher rate of complete ablation. Compared with pre-MWA, serum iPTH and calcium levels were significantly improved. Treatment success was achieved in 38 patients (95%). Hoarseness was a major complication in six patients (15%); however, it improved spontaneously within 1–4 months. We observed two recurrences (2/40, 5%) at 9 months and 11 months following MWA, respectively. Conclusion: US-guided percutaneous MWA assisted by CEUS for pHPT is an effective and safe therapy. CEUS can avoid operative failure and improve the cure rate. [ABSTRACT FROM AUTHOR]

Purpose: To compare the accuracy and safety of robotic laser position (RLP) versus freehand for antenna CT-guided microwave ablation (MWA) of single hepatocellular carcinoma (HCC) (diameter < 3 cm). Materials and methods: This retrospective study was conducted between May 2020 and June 2021. A total of 40 patients with early HCC who underwent CT-guided MWA were divided into two groups: a freehand group (n = 20) and a RLP group (n = 20). Based on in-plane and out-of-plane data, the actual puncture point error (APPE), number of repositioning procedures, and operative duration were compared using the Mann–Whitney U test. Ablation-related complications were compared using the Chi-squared test. Results: The mean diameter of HCC patients who received MWA was 2.4 ± 0.5 cm. For in-plane APPE, APPE was comparable between the two groups (p = 0.299). However, for the out-of-plane position, the APPE in the freehand group was higher than that in the RLP group (p = 0.027). The number of repositioning procedures was 0 (range, 0–0) for RLP-guided procedures and 3 (range, 2–5) for freehand procedures, showing a statistically significant difference between the two groups (p < 0.001). The mean operative duration for freehand procedures was 39 min, compared with 26 min for RLP-guided procedures, showing a significant difference (p = 0.013). No deaths or major complications were directly related to MWA. Minor complications in the freehand group were comparable with those in the RLP group (p = 0.313). Conclusion: RLP guidance significantly reduces the number of antenna repositioning procedures in MWA and improves puncture accuracy for target HCC out-of-plane. In addition, the operative duration of robotic guidance was shorter than that of freehand guidance. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the potential risk factors influencing cure rate of ultrasound-guided microwave ablation (MWA) for primary hyperparathyroidism (PHPT). Materials and methods: Seventy five patients (25 males and 50 females; mean age, 56.80 ± 12.34; age range, 26–85) with PHPT undergoing MWA under ultrasound guidance were enrolled between May 2017 and December 2020. The cure rate and complications were evaluated after treatment. The potential factors influencing cure rate of ultrasound-guided MWA for PHPT were analyzed by univariate and multivariate binary logistic regression. Results: Fifty six of 75 patients had normal PTH and serum calcium levels after at least 6 months after one session MWA, and the cure rate was 74.7% (56/75). 6 uncured patients received the second session MWA during follow-up, and the cure rate achieved 81.3% (61/75) after the second session MWA. Voice changes occurred in 4 patients (5.33%) and recovered within 3 months after ablation without special treatment. Nodule volume was the independent risk factor associated with cure in PHPT patients undergoing MWA, whether after one session (p = 0.0224; odds ratio, 0.67) or the second session MWA (p = 0.0408; odds ratio, 0.74). The cutoff value for nodule volume in predicting the cure was 0.96 cm³ (one session: sensitivity, 76.8%; specificity, 73.7%; the second session: sensitivity, 72.1%; specificity, 71.4%). Conclusion: In conclusion, parathyroid nodule volume was the independent risk factor associated with cure in PHPT patients undergoing MWA. [ABSTRACT FROM AUTHOR]

Background: To evaluate the changes of immune environment of distant tumors after combined microwave ablation (MWA) and anti- programmed death receptor 1 (anti-PD-1) therapy, and assess the changes of systemic immune response. Methods: Bilateral hepatocellular carcinoma model was established in mice, which were then subsequently treated with MWA, or anti-PD-1, or no treatment, or MWAþ anti-PD-1. The contralateral tumor volume and mice survival time were recorded. Flow cytometry and immunohistochemistry were used for evaluation of the immune cells subgroup change of contralateral tumor. In addition, tumor rechallenge tests were conducted on unilateral tumor-bearing mice to examine the systemic immune effects of the combination therapy. Results: We found that MWA treatment alone failed to produce a significant abscopal effect. In contrast, the combination group had longer survival than the MWA or anti-PD-1 group alone, with slower distant tumor growth. Moreover, the tumor-specific immune responses induced by combination therapy are stronger than anti-PD-1 or MWA alone. Combination therapy also elevated the levels of Th1- type cytokines in peripheral blood. In addition, after tumor rechallenge, the combination group showed more rejection to the reimplanted tumors (6 out of 10 mice). Conclusions: The combination of MWA and anti-PD-1 therapy resulted in the inhibition of distant tumor growth and the construction of a systemic anti-tumor immune environment that can reduce recurrence. [ABSTRACT FROM AUTHOR]

Objective: To assess the effect and safety of subpleural multisite anesthesia based on the area of thermal radiation during CT-guided lung malignancy microwave ablation (MWA) on the incidence of moderate or severe pain and the analgesic drug usage. Materials and methods: Consecutive patients with lung malignancies were retrospectively evaluated between January 2016 and December 2019. Patients undergoing CT-guided lung malignancy MWA were either given in the method of (a) standard subpleural puncture point anesthesia between January 2016 and June 2018 and (b) subpleural multisite anesthesia based on the area of thermal radiation between July 2018 and December 2019. The relationship between local anesthesia mode and moderate or severe pain, and pain medications usage was assessed by using multivariable logistic regression models. Results: A total of 243 consecutive patients were included in the study. Moderate or severe pain occurred in 84 of 124 (67.7%) patients with subpleural puncture point anesthesia and in 20 of 119 (16.8%) patients with subpleural anesthesia in the area of thermal radiation (p = .001). The intravenous pain medication was required in 56 of 124 (45.2%) patients with subpleural puncture point anesthesia and in 9 of 119 (7.6%) patients with subpleural multisite anesthesia based on the area of thermal radiation (p = .001). Local anesthesia methods (p = 0.001), pleura-to-lesion distance (p = .02) and tumor size (p = .015) were independent risk factors for developing moderate or severe pain. There were no differences in adverse events and local tumor progression rate. Conclusions: Subpleural multisite anesthesia based on the area of thermal radiation for peripheral lung malignancy MWA can result in lower intraprocedural pain compared with the subpleural puncture point anesthesia. Thus, a subpleural multisite anesthesia technique may be most helpful when performing MWA of peripheral malignancy in patients who are not sedated with general or intravenous anesthesia. [ABSTRACT FROM AUTHOR]

Objective: To study long-term effects in patients treated with microwave ablation (MWA) for symptomatic uterine fibroids and investigate fibroid characteristics predictive of successful treatment. Method: Women who received MWA treatment for uterine fibroids in a previous study were included. A total of 16 patients underwent contrast enhanced MRI before treatment, postoperatively at 6 months and at long-term follow-up, to assess volumes of treated fibroids (n = 42). Long-term MRI was performed between 16 and 36 months after treatment [median 22 months, interquartile range (IQR) 18.5 - 27]. Validated questionnaires for evaluation of uterine fibroid symptoms and menstrual bleeding (UFS-QoL and PBAC) were used to assess long-term effects on symptoms. The degree of shrinkage was correlated to vascularization and T2 signal intensity (SI) at preoperative MRI and location of fibroids according to the FIGO classification, using the Mann–Whitney U test. Results: Most patients (82%) reported improvement up to 3 years after treatment. Out of 42 treated fibroids, 35 (83%) continued to shrink over time with median relative volume reduction of 77% (IQR 39–95). For eight fibroids (19%) which showed low vascularization on the pretreatment MRI, there was less shrinkage compared to well-vascularized fibroids (p = 0.01). Most fibroids (79%) showed iso- to hyperintense T2 signal on preoperative MRI and showed a higher grade of shrinkage than hypointense fibroids (p = 0.02). Conclusion: After microwave treatment improvement is maintained for most patients up to 36 months and most fibroids showed continuous shrinkage. Preoperative vascularization, high T2 SI and submucosal location predicted continuous volume reduction. However, to confirm this, larger studies are needed. [ABSTRACT FROM AUTHOR]

Objective: To compare the long-term efficacy of microwave ablation (MWA) for subcapsular and nonsubcapsular hepatocellular carcinomas (HCCs) using propensity score matching (PSM). Materials and methods: Using a multicenter database, we enrolled 430 patients (347 men, 83 women; age range, 15–71 years) with HCCs who received percutaneous ultrasound-guided MWA, between January 2012 and December 2018. The patients were grouped as follows, based on whether the tumor was adjacent to the capsule: subcapsular group (n = 142) and non-subcapsular group (n = 142). To evaluate the correlation between subcapsular position and efficacy of MWA, a Cox proportional hazards model was used to calculate disease-free survival (DFS) and overall survival (OS) based on PSM data. Results: In total, 142 pairs of patients were matched. In the PSM cohort, the 1-year, 3-year, and 5-year DFS rates of the subcapsular and non-subcapsular groups were 84%, 61%, and 47%, respectively, and 85%, 67%, and 58%, respectively, while the 1-year, 3-year, and 5-year OS rates were 98%, 90%, and 84%, respectively, and 98%, 90%, and 88%, respectively. In the PSM cohort, subcapsular position was not an independent risk factor for DFS (hazard ratio [HR] = 1.291, p = 0.196) or OS (HR = 0.926, p = 0.866). Additionally, there were no significant differences in the incidence of local tumor progression, major complications, technical success rate, number of puncture needles, and postoperative hospital stay between the two groups (p > 0.05). Conclusion: There were no significant differences in DFS, OS, incidence of local tumor progression, and major complications between patients with subcapsular and non-subcapsular HCCs treated with MWA. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate whether liposomal quercetin (LQ) could enhance the effects of microwave ablation (MVA) in treating the rabbit VX2 liver tumor model. Methods: Rabbits with VX2 liver tumors were randomly divided into three groups: intravenous LQ group (LQ group), MWA group and LQ combined with MWA (LQ+MWA) group. Five rabbits were randomly selected and sacrificed from each group at 12 h and on days 3, 7 and 14 of the operation. The tumor samples were detected and quantified by immunohistochemistry, Western blot, and reverse transcription polymerase chain reaction (RT-PCR). Results: For up to 7 days, the coagulation necrosis volume (CV) of the LQ+MWA group was larger than that of MWA and LQ groups (p < 0.05). Fourteen days after the operation, the total tumor volume of the LQ+MWA group was smaller than that of the LQ group and the MWA group (p < 0.05). The survival time of the LQ+MWA group was significantly longer than that of the MWA and LQ groups (p < 0.01). Heat shock protein 70 (HSP70), hypoxia inducible factor-1 a (HIF-1 a), vascular endothelial growth factor (VEGF), tumor microvessel density (MVD) were lower in the LQ+MWA group than the MWA and LQ groups at 12 h, on days 3 and 7. At hour 12 and on days 3 and 7, HSP70 mRNA and HIF-1a mRNA expression of MWA group were significantly higher than that of the LQ and LQ+MWA groups (p < 0.001). At 12 h, and on days 3 and 7, apoptotic rate of tumor cells in LQ+MWA group was higher than that of the MWA and LQ groups (p < 0.05). At 12 h and on days 3, 7 and 14, the proliferation index of tumor cells in residual tumor in LQ+MWA group was lower than that in the MWA and LQ groups (p < 0.05). Conclusion: Preoperative infusion of LQ can significantly enhance the MWA effects of liver VX2 tumor, inhibit the excessive proliferation of residual tumor and angiogenesis, and decrease metastasis and prolong the survival period of experimental animals. [ABSTRACT FROM AUTHOR]

Purpose: To assess the feasibility of delivering microwave ablation for targeted treatment of aldosterone producing adenomas using image-based computational models. Methods: We curated an anonymized dataset of diagnostic 11C-metomidate PET/CT images of 14 patients with aldosterone producing adenomas (APA). A semi-automated approach was developed to segment the APA, adrenal gland, and adjacent organs within 2 cm of the APA boundary. The segmented volumes were used to implement patient-specific 3D electromagnetic-bioheat transfer models of microwave ablation with a 2.45 GHz directional microwave ablation applicator. Ablation profiles were quantitatively assessed based on the extent of the APA target encompassed by an ablative thermal dose, while limiting thermal damage to the adjacent normal adrenal tissue and sensitive critical structures. Results: Across the 14 patients, adrenal tumor volumes ranged between 393 mm3 and 2,395 mm3 . On average, 70% of the adrenal tumor volumes received an ablative thermal dose of 240CEM43, while limiting thermal damage to non-target structures, and thermally sparing 83.5–96.4% of normal adrenal gland. Average ablation duration was 293 s (range: 60–600 s). Simulations indicated coverage of the APA with an ablative dose was limited when the axis of the ablation applicator was not well aligned with the major axis of the targeted APA. Conclusions: Image-based computational models demonstrate the potential for delivering microwave ablation to APA targets within the adrenal gland, while limiting thermal damage to surrounding nontarget structures. [ABSTRACT FROM AUTHOR]

Purpose: To assess short-term tissue shrinkage in patients with liver malignancies undergoing computed tomography (CT)-guided microwave ablation (MWA) using Jacobian determinant (JD). Materials and methods: Twenty-nine patients with 29 hepatic malignancies (primary n ¼ 24; metastases n ¼ 5; median tumor diameter 18 mm) referred to CT-guided MWA (single position; 10 min, 100 W) were included in this retrospective IRB-approved study, after exclusion of five patients. Following segmentation of livers and tumors on pre-interventional images, segmentations were registered on postinterventional images. JD mapping was applied to quantify voxelwise tissue volume changes after MWA. Percentual volume changes were evaluated in the ablated tumor, a 5-cm tumor perimeter and in the whole liver and compared in different clinical conditions (tumor entity: primary vs. secondary; tumor location: subcapsular vs. non-subcapsular; tumor volume: >/<6 ml: cirrhosis: yes vs. no; prior chemotherapy: yes vs. no using Shapiro–Wilk, v2 and Wilcoxon rank sum tests, respectively (with p < 0.05 deemed significant). Results: Tissue volume change was 0.6% in the ablated tumor, 1.6% in the 5-cm perimeter and 0.3% in the whole liver. Shrinkage in the ablated tumor was pronounced in non-subcapsular located tumors, whereas tissue expansion was noted in subcapsular tumors (median 3.5 vs. 1.1%; p ¼ 0.0195). Shrinkage in the whole liver was higher in tumor volumes >6ml, compared with smaller tumors, in which tissue expansion was noted (median 1.0 vs. 2.5%; p ¼ 0.002). Other clinical conditions had no significant influence on the extent of tissue shrinkage (p > 0.05). Conclusion: 3D Jacobian analysis shows that hepatic tissue deformation following MWA is most pronounced in a 5-cm area surrounding the treated tumor. Tumor location and tumor volume may have an impact on the extent of tissue shrinkage which may affect estimation of the safety margin. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the safety and efficacy of microwave ablation (MWA) versus repeat surgery for treating metastatic lymph nodes (MLNs) in papillary thyroid carcinoma (PTC). Methods: Between July 2017 and October 2020, 67 patients were enrolled in this retrospective study. 19 and 48 patients underwent MWA and repeat surgery, respectively. The primary and secondary endpoints were recurrence-free survival and complication rates, respectively. The largest diameter, volume and volume reduction ratio (VRR) were analyzed before and after MWA. The effects of different ablation powers on the largest diameter, volume and VRR were investigated. Pre and posttreatment variables (e.g., baseline characteristics, serum thyroglobulin [Tg] levels, hospitalization time, treatment costs, recurrence-free survival and complication rates) were compared between groups. Results: The largest diameter and volume postablation at each follow-up were smaller than the preablation levels (p < 0.05), except at the 1-month follow-up (p > 0.05). The largest diameter, volume, and VRR among the different ablation powers were not significantly different (p > 0.05). The mean serum Tg levels and biochemical remission rates were not significantly different between the groups (p > 0.05). Compared to reoperation, MWA had a shorter hospitalization time and lower treatment cost (p < 0.001). Total and minor complications were higher in the reoperation group (p < 0.05), but major complications were comparable (p > 0.05). The recurrence-free survival rate between groups was not significantly different (p ¼ 0.401). The 1- and 3-year recurrence-free survival rates were comparable between the groups. Conclusions: MWA may be a safe and effective alternative to repeat surgery for treating MLNs of PTC in select patients. [ABSTRACT FROM AUTHOR]

Purpose: To develop and evaluate susceptibility corrected 2D proton resonance frequency (PRF)-based magnetic resonance (MR)-thermometry for the accurate assessment of the ablation zone of hepatic microwave ablation (MWA). Methods and materials: Twelve hepatic MWA were performed in five LEWE minipigs with human-like fissure-free liver. Temperature maps during ablation of PRF-based MR-thermometry were corrected by modeling heat induced susceptibility changes. Ablation zones were determined using cumulative equivalent minutes at 43 C (CEM43) as tissue damage model. T1 weighted (w) post-ablation contrastenhanced (CE) MR-imaging and manually segmented postmortem histology were used for validation. The agreement of uncorrected (raw) and susceptibility corrected (corr) MR-thermometry with T1w post-ablation CE MR-imaging and histology was evaluated. The Wilcoxon-signed rank test and Bland–Altman analysis were applied. Results: With the susceptibility corrected MR-thermometry a significantly increased dice coefficient (raw: 77% vs. corr: 83%, p < 0.01) and sensitivity (raw: 72% vs. corr: 82%, p < 0.01) was found for the comparison to T1w-CE imaging as well as histopathology (dice coefficients: raw: 76% vs. corr: 79%, p < 0.001; sensitivity: raw: 72% vs. corr: 74%, p < 0.001). While major axis length was significantly increased (7.1 mm, p < 0.001) and minor axis length significantly decreased (2.2 mm, p < 0.001) in uncorrected MR-thermometry compared to T1w-CE MR-imaging, no significant bias was found after susceptibility correction. Conclusion: Using susceptibility corrected 2D PRF-based MR-thermometry to predict the ablation zones of hepatic MWA provided a good agreement in comparison to T1w post-ablation CE MR-imaging and histopathology. [ABSTRACT FROM AUTHOR]

Objectives: Radiofrequency ablation (RFA) and microwave ablation (MWA) are widely used in combination with transarterial chemoembolization (TACE) for intermediate-stage hepatocellular carcinoma (HCC) in clinical practice. We aim to compare the efficacy and safety of TACE combined with RFA or MWA versus TACE monotherapy for intermediate-stage HCC. Methods: We searched PubMed, Embase, Web of Science, and the Cochrane Library for relevant studies. The outcomes included overall survival (OS), progression-free survival (PFS), local tumor control (LTC) rate, and major complication. Subgroup analysis for different TACE combination therapies was performed. Results: Ten studies with 1799 patients with intermediate-stage HCC were included. The pooled hazard ratio (HR) for OS was in favor of TACE combination therapy (HR, 0.50, 95% confidence interval [CI], 0.40–0.62). Specifically, the TACE combination therapy was associated with higher 1-, 3-, and 5-year OS rates. Regarding tumor progression, the TACE combination therapy showed significantly better PFS (HR, 0.47, 95% CI, 0.37–0.61) and higher 1-, 2- and 3-year PFS rates than TACE monotherapy. The pooled odds ratio (OR) for the LTC was also in favor of TACE combination therapy (OR, 0.36, 95% CI, 0.24–0.53). No significant difference was found between the two groups regarding the major complication rate (OR, 1.26, 95% CI, 0.74–2.16). These results were consistent across subgroups of TACE þ RFA versus TACE and TACE þ MWA versus TACE. Conclusion: TACE combined with RFA or MWA can provide significantly better OS, PFS and LTC than TACE monotherapy for patients with intermediate-stage HCC, without increasing the risk of major complications. [ABSTRACT FROM AUTHOR]