The methods of monitoring the thermal ablation of tumor are compared and analyzed in recent years. The principle method results and insufficient of ultrasound elastography and quantitative ultrasound imaging are discussed. The results show that ultrasonic tissue signature has great development space in the field of real-time monitoring of thermal ablation, but there are still some problems such as insufficient monitoring accuracy difficulty in whole-course monitoring and insufficient
Catheter Ablation ; Elasticity Imaging Techniques ; Humans ; Hyperthermia, Induced ; Liver/surgery* ; Neoplasms/surgery* ; Ultrasonography

Atrial Fibrillation/surgery* ; Catheter Ablation ; Electrophysiologic Techniques, Cardiac ; Humans ; Pulmonary Veins/surgery* ; Recurrence ; Treatment Outcome

OBJECTIVE: To investigate the effects of on the acoustic characteristics of tumor tissue and how such acoustic changes affect the efficacy of high-intensity focused ultrasound (HIFU) ablation in nude mice. METHODS: Forty mice bearing human breast cancer cell (MDA-MB-231) xenograft were randomized into experimental group (=20) and control group (=20) for intravenous injection of suspension (200 μL, 4 × 10 cfu/mL) and PBS (200 μL) for 3 consecutive days, respectively. Before and at 3 and 7 days after the first injection, shear wave elastography was used to evaluate the hardness of the tumor tissue. On day 7 after the first injection, 10 mice from each group were sacrificed and the sound velocity and sound attenuation of the tumor tissues were measured. The changes in the collagen fibers in the tumors were evaluated using Masson staining, and neovascularization in the tumor was assessed with immunohistochemistry for platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31). The remaining 10 tumor-bearing mice in each group were subjected to HIFU ablation, and the ablation efficiency was evaluated by assessing the changes in irradiation gray values, coagulative necrosis volume, energy efficiency factor (EEF) and irradiation area and by pathological examination with HE staining. RESULTS: In the experimental group, the collagen fibers in the tumor tissues were strong and densely aligned, and the tumors contained fewer new blood vessels showing strip-or spot-like morphologies. In the control group, the collagen fibers in the tumors were thin and loosely arranged, and the tumors showed abundant elongated or round new blood vessels. colonized in the tumor 7 days after the injection, and the tumor hardness was significantly greater in the experimental group than in the control group (=0.01); the acoustic velocity (=0.001) and the acoustic attenuation (=0.000) of the tumor tissues were also greater in the experimental group. HIFU irradiation resulted in significantly greater changes in the gray scale of tumor (=0.0006) and larger coagulative necrosis volume (=0.0045) in the experimental group than in the control group, and the EEF was significantly smaller in the experimental group (=0.0134). CONCLUSIONS can cause changes in collagen fiber content, acoustic velocity and attenuation in the tumor tissue and reduce the EEF of HIFU irradiation, thereby improving the efficacy of HIFU irradiation.
Acoustics ; Animals ; Bifidobacterium ; pathogenicity ; Breast Neoplasms ; pathology ; Collagen ; Elasticity Imaging Techniques ; High-Intensity Focused Ultrasound Ablation ; Humans ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Random Allocation

OBJECTIVE: To determine the efficacy of second generation endometrial ablation (NovaSure) combined with levonorgestrel-releasing intrauterine system (Mirena) in the treatment of adenomyosis. METHODS: Clinical data of patients with adenomyosis admitted in Women's Hospital, Zhejiang University School of Medicine from January 2015 to December 2018 were retrospectively analyzed. Among 66 patients, 44 received Mirena placement only (control group) and 22 received Mirena placement and NovaSure treatment (study group). The menstruation blood loss, dysmenorrhea score, uterine size, expulsion rate of Mirena and the patients' satisfaction rate were assessed in two groups. RESULTS: There was a significant reduction in menstruation blood loss (<0.05) and significant improvement in dysmenorrhea (<0.05) after the treatment in both groups. The patients in study group had more marked improvement in menstruation blood loss than those in control group (<0.05). The patients' satisfaction was higher and the expulsion rate of Mirena was lower in study group than that in control group (all <0.05). The score of dysmenorrhea and the size of uterine had no significant difference between two groups (all >0.05). CONCLUSIONS NovaSure can improve the efficacy of Mirena in treatment of adenomyosis.
Adenomyosis ; therapy ; Dysmenorrhea ; Endometrial Ablation Techniques ; Female ; Humans ; Levonorgestrel ; administration & dosage ; Organ Size ; Retrospective Studies ; Uterus ; anatomy & histology

High-intensity focused ultrasound (HIFU) is a promising ablation technique for benign thyroid nodules. Current evidence has found good short- to medium-term outcomes, similar to those of better-established ablation techniques such as radiofrequency and laser ablation. The fact that it does not require insertion of a needle into the target makes HIFU a truly non-invasive treatment. Although it is not without risks, its low risk profile makes it an attractive alternative to surgery. There is much room for future development, starting from expanding the current indications to enhancing energy delivery. Relapsed Graves disease and papillary microcarcinoma are diseases that can benefit from HIFU treatment. Its role in the mediation of immune responses and synergistic effects with immunotherapy are promising in the fight against metastatic cancers.
Ablation Techniques ; Goiter, Nodular ; Graves Disease ; High-Intensity Focused Ultrasound Ablation ; Hyperthermia, Induced ; Immunotherapy ; Laser Therapy ; Needles ; Negotiating ; Thyroid Diseases ; Thyroid Gland ; Thyroid Nodule ; Ultrasonography ; Ultrasonography, Interventional

High-intensity focused ultrasound (HIFU) is a promising form of thermal ablation of benign thyroid nodules, but evidence supporting its use is scarce. The present review evaluated the efficacy and safety of single-session HIFU treatment of benign thyroid nodules. As reported in the literature, the extent of nodule shrinkage following treatment ranged from 48.8% to 68.8%. Like other forms of ablation, the shrinkage rate was greatest in the first 3-6 months, and the best responders were patients with small (≤10 mL) nodules. Complications were uncommon, but temporary vocal cord palsy occurred in 3%-4% of patients, and was related to the distance between the HIFU beam and the recurrent laryngeal nerve. Despite being safe and efficacious, a larger-scale prospective trial is required.
Ablation Techniques ; Goiter, Nodular ; High-Intensity Focused Ultrasound Ablation* ; Humans ; Hyperthermia, Induced ; Prospective Studies ; Recurrent Laryngeal Nerve ; Thyroid Gland* ; Thyroid Nodule* ; Ultrasonography ; Ultrasonography, Interventional ; Vocal Cord Paralysis

PURPOSE: The purpose of this study was to evaluate the accuracy of an active contour model for estimating the posterior ablative margin in images obtained by the fusion of real-time ultrasonography (US) and 3-dimensional (3D) US or magnetic resonance (MR) images of an experimental tumor model for radiofrequency ablation. METHODS: Chickpeas (n=12) and bovine rump meat (n=12) were used as an experimental tumor model. Grayscale 3D US and T1-weighted MR images were pre-acquired for use as reference datasets. US and MR/3D US fusion was performed for one group (n=4), and US and 3D US fusion only (n=8) was performed for the other group. Half of the models in each group were completely ablated, while the other half were incompletely ablated. Hyperechoic ablation areas were extracted using an active contour model from real-time US images, and the posterior margin of the ablation zone was estimated from the anterior margin. After the experiments, the ablated pieces of bovine rump meat were cut along the electrode path and the cut planes were photographed. The US images with the estimated posterior margin were compared with the photographs and post-ablation MR images. The extracted contours of the ablation zones from 12 US fusion videos and post-ablation MR images were also matched. RESULTS: In the four models fused under real-time US with MR/3D US, compression from the transducer and the insertion of an electrode resulted in misregistration between the real-time US and MR images, making the estimation of the ablation zones less accurate than was achieved through fusion between real-time US and 3D US. Eight of the 12 post-ablation 3D US images were graded as good when compared with the sectioned specimens, and 10 of the 12 were graded as good in a comparison with nicotinamide adenine dinucleotide staining and histopathologic results. CONCLUSION: Estimating the posterior ablative margin using an active contour model is a feasible way of predicting the ablation area, and US/3D US fusion was more accurate than US/MR fusion.
Ablation Techniques ; Catheter Ablation* ; Cicer ; Dataset ; Electrodes ; Meat ; NAD ; Shadowing (Histology) ; Transducers ; Ultrasonography*

BACKGROUND AND OBJECTIVES: Although ablation of complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) is one of the strategies for atrial substrate modification, the mechanism behind CFAE as an electrophysiological substrate remains unclear. We investigated structural differences between CFAE sites and their matched non-CFAE sites by comparing their histopathologic characteristics in canine AF models. METHODS: Atrial electrograms of four dogs were obtained from the epicardial site. AF was induced through burst atrial pacing at 600 bpm for 30 min. CFAE sites were identified during AF according to patterns visualized on the electrograms, and their matched non-CFAE sites were selected in the adjacent region, within 5 mm of each CFAE site. Tissues were harvested from CFAE sites and their matched non-CFAE sites at various locations in both atria. Histopathologic differences were identified between CFAE and non-CFAE sites. RESULTS: A total of 24 atrial tissues (12 with CFAE, 12 with non-CFAE) were evaluated. The atrial myocardium was significantly thicker at CFAE sites (1757.5±560.5 µm) than at non-CFAE sites (1279.5±337.2 µm) (p=0.036). At CFAE sites, it was filled with a significantly larger amount of fibrotic tissue than at non-CFAE sites (22.8±6.9% versus 7.2±4.7%, p < 0.001). Results were consistent across various tissue locations. The distribution of autonomic nerve innervation was similar between CFAE and non-CFAE sites. CONCLUSION: This study provides a better understanding of histological characteristics of CFAE sites, namely a thicker wall and greater amount of fibrosis. These findings may be associated with the development of CFAE and its pathophysiological contribution to AF.
Animals ; Atrial Fibrillation ; Autonomic Pathways ; Catheter Ablation ; Dogs ; Electrophysiologic Techniques, Cardiac ; Fibrosis ; Myocardium

Radiofrequency ablation (RFA) has emerged as an effective loco-regional treatment modality for malignant hepatic tumors. Indeed, studies have demonstrated that RFA of early stage hepatocellular carcinomas can provide comparable overall survival to surgical resection. However, the incidence of local tumor progression (LTP) after RFA is significantly higher than that of surgical resection. Thus, to overcome this limitation, multiple electrode radiofrequency (RF) systems that use a multi-channel RF generator have been developed, and they demonstrate better efficiency in creating larger ablation zones than that using the conventional RFA with a single electrode. Furthermore, RFA with multiple electrodes can allow the “no-touch” ablation technique which may also help to reduce LTP. Another technique that would be helpful in this regard is multi-modality-ultrasound fusion imaging, which helps to not only more accurately determine the target lesion by enabling the RFA of small, poorly visible or invisible tumors, but also improve the monitoring of procedures and determine the appropriateness of the ablation margin. In addition, new energy sources, including microwave and cryoablation, have been introduced in imaging-guided tumor ablation. In this review, these recently introduced ablation techniques and the results of the most current animal and clinical studies are discussed.
Ablation Techniques ; Animals ; Carcinoma, Hepatocellular ; Catheter Ablation* ; Cryosurgery ; Electrodes* ; Incidence ; Liver* ; Microwaves

Ablation Techniques ; adverse effects ; methods ; Humans ; Lung Neoplasms ; diagnostic imaging ; radiotherapy ; surgery ; Postoperative Complications ; prevention & control ; therapy ; Radio Waves ; therapeutic use ; Radiotherapy, Image-Guided ; adverse effects ; methods ; Treatment Outcome