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Li R, Zhang Y, Cheng L, Zheng S, Li H, Zhang H, Du L, He W, Zhang W. Experimental study on monitoring microwave ablation efficacy by real-time shear wave elastography in ex vivo porcine brain. Int J Hyperthermia 2023; 41:2297649. [PMID: 38159561 DOI: 10.1080/02656736.2023.2297649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/03/2024] Open
Abstract
Objective: Glioma constitutes the most common primary malignant tumor in the central nervous system. In recent years, microwave ablation (MWA) was expected to be applied in the minimally invasive treatment of brain tumors. This study aims to evaluate the feasibility and accuracy of microwave ablation in ex vivo brain tissue by Shear Wave Elastography (SWE) to explore the application value of real-time SWE in monitoring the process of MWA of brain tissue.Methods: Thirty ex vivo brain tissues were treated with different microwave power and ablation duration. The morphologic and microscopic changes of MWA tissues were observed, and the diameter of the ablation areas was measured. In this experiment, SWE is used to quantitatively evaluate brain tissue's degree of thermal injury immediately after ablation.Results: This study It is found that the ablation range measured by SWE after ablation is in good consistency with the pathological range [ICCSWEL1-L1 = 0.975(95% CI:0.959 - 0.985), ICCSWEL2-L2 = 0.887(95% CI:0.779 - 0.938)]. At the same time, the SWE value after ablation is significantly higher than before (mean ± SD,9.88 ± 2.64 kPa vs.23.6 ± 13.75 kPa; p < 0.001). In this study, the SWE value of tissues in different pathological states was further analyzed by the ROC curve (AUC = 0.86), and the threshold for distinguishing normal tissue from tissue after ablation was 13.7 kPa. The accuracy of evaluating ablation tissue using SWE can reach 84.72%, providing data support for real-time quantitative observation of the ablation range.Conclusion: In conclusion the accurate visualization and real-time evaluation of the organizational change range of the MWA process can be realized by real-time SWE.
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Affiliation(s)
- Rui Li
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yukang Zhang
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Linggang Cheng
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shuai Zheng
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Hongbing Li
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Hongxia Zhang
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Lijuan Du
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wen He
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wei Zhang
- Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Mankertz F, Gemeinhardt O, Felbor U, Hadlich S, Hosten N. Spacer-Supported Thermal Ablation to Prevent Carbonisation and Improve Ablation Size: A Proof of Concept Study. Biomedicines 2023; 11:biomedicines11020575. [PMID: 36831111 PMCID: PMC9952941 DOI: 10.3390/biomedicines11020575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/13/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Thermal ablation offers a minimally invasive alternative in the treatment of hepatic tumours. Several types of ablation are utilised with different methods and indications. However, to this day, ablation size remains limited due to the formation of a central non-conductive boundary layer. In thermal ablation, this boundary layer is formed by carbonisation. Our goal was to prevent or delay carbonisation, and subsequently increase ablation size. We used bovine liver to compare ablation diameter and volume, created by a stand-alone laser applicator, with those created when utilising a spacer between laser applicator and hepatic tissue. Two spacer variants were developed: one with a closed circulation of cooling fluid and one with an open circulation into hepatic tissue. We found that the presence of a spacer significantly increased ablation volume up to 75.3 cm3, an increase of a factor of 3.19 (closed spacer) and 3.02 (open spacer) when compared to the stand-alone applicator. Statistical significance between spacer variants was also present, with the closed spacer producing a significantly larger ablation volume (p < 0.001, MDiff = 3.053, 95% CI[1.612, 4.493]) and diameter (p < 0.001, MDiff = 4.467, 95% CI[2.648, 6.285]) than the open spacer. We conclude that the presence of a spacer has the potential to increase ablation size.
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Affiliation(s)
- Fiona Mankertz
- Institute for Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, 17475 Greifswald, Germany
- Correspondence:
| | - Ole Gemeinhardt
- Department of Radiology, Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ute Felbor
- Institute for Human Genetics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Stefan Hadlich
- Institute for Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Norbert Hosten
- Institute for Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, 17475 Greifswald, Germany
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Luo C, Li T, Li Z, Zuo Y, He G, Lin J, Liu G, Dai L. Evaluation of Microwave Ablation Efficacy by Strain Elastography and Shear Wave Elastography in ex Vivo Porcine Liver. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2636-2645. [PMID: 34140168 DOI: 10.1016/j.ultrasmedbio.2021.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 05/04/2021] [Accepted: 05/09/2021] [Indexed: 06/12/2023]
Abstract
The aim of this study was to evaluate the efficacy of microwave ablation by ultrasound (US), strain elastography (SE) and shear-wave elastography (SWE). An ex vivo model of porcine liver was adopted. According to ablation power and duration, 30 samples were divided into three groups: group 1 (45 W, 30 s), group 2 (45 W, 15 s) and group 3 (30 W, 30 s). US was used to measure the largest transverse diameter (D1), vertical diameter (D2) and anteroposterior diameter (D3) of the ablated area. SE was used to measure the largest transverse diameter (SEL1), vertical diameter (SEL2) and anteroposterior diameter (SEL3). The actual size of the ablated area was measured as the largest transverse diameter (L1), vertical diameter (L2) and anteroposterior diameter (L3). SWE values and temperatures were measured in the central lesion (region a), marginal area (region b) and unablated area (region c). At 1 h post-ablation, the values measured by US (D1, D2, D3) were all significantly smaller than the ablated area (L1, L2, L3) in all three groups. Except for SEL2 in group 1, there was no significant difference in the results between SEL and L among the three groups. All SWE results were significantly higher post-ablation than pre-ablation in the central lesion (region a) and marginal area (region b, all p values <0.05). In regions a, b and c, the temperatures measured immediately and 5 min post-ablation were all higher than that measured pre-ablation. These results suggest that SE and SWE can be used to evaluate the ablation efficacy of liver tissue.
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Affiliation(s)
- Chunyue Luo
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Tao Li
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Zuojia Li
- Medical Apparatus and Equipment Department, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yanling Zuo
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Guangmin He
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Jianying Lin
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Guancheng Liu
- Department of Ultrasound Imaging, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Lu Dai
- Department of Thoracic Surgery, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, China.
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Radosevic A, Prieto D, Burdío F, Berjano E, Prakash P, Trujillo M. Short pulsed microwave ablation: computer modeling and ex vivo experiments. Int J Hyperthermia 2021; 38:409-420. [PMID: 33719808 DOI: 10.1080/02656736.2021.1894358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE To study the differences between continuous and short-pulse mode microwave ablation (MWA). METHODS We built a computational model for MWA including a 200 mm long and 14 G antenna from Amica-Gen and solved an electromagnetic-thermal coupled problem using COMSOL Multiphysics. We compared the coagulation zone (CZ) sizes created with pulsed and continuous modes under ex vivo and in vivo conditions. The model was used to compare long vs. short pulses, and 1000 W high-powered short pulses. Ex vivo experiments were conducted to validate the model. RESULTS The computational models predicted the axial diameter of the CZ with an error of 2-3% and overestimated the transverse diameter by 9-11%. For short pulses, the ex vivo computer modeling results showed a trend toward larger CZ when duty cycles decreases. In general, short pulsed mode yielded higher CZ diameters and volumes than continuous mode, but the differences were not significant (<5%), as in terms of CZ sphericity. The same trends were observed in the simulations mimicking in vivo conditions. Both CZ diameter and sphericity were similar with short and long pulses. Short 1000 W pulses produced smaller sphericity and similar CZ sizes under in vivo and ex vivo conditions. CONCLUSIONS The characteristics of the CZ created by continuous and pulsed MWA show no significant differences from ex vivo experiments and computer simulations. The proposed idea of enlarging coagulation zones and improving their sphericity in pulsed mode was not evident in this study.
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Affiliation(s)
- Aleksandar Radosevic
- Department of Radiology, Hospital del Mar, Universitat Pompeu Fabra, Barcelona, Spain
| | - Diego Prieto
- BioMIT, Department of Applied Mathematics, Universitat Politècnica de València, Valencia, Spain
| | | | - Enrique Berjano
- BioMIT, Department of Electronic Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Macarena Trujillo
- BioMIT, Department of Applied Mathematics, Universitat Politècnica de València, Valencia, Spain
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Huang H, Zhang L, Moser MAJ, Zhang W, Zhang B. A review of antenna designs for percutaneous microwave ablation. Phys Med 2021; 84:254-264. [PMID: 33773908 DOI: 10.1016/j.ejmp.2021.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 12/15/2022] Open
Abstract
Microwave (MW) antenna is a key element in microwave ablation (MWA) treatments as the means that energy is delivered in a focused manner to the tumor and its surrounding area. The energy delivered results in a rise in temperature to a lethal level, resulting in cell death in the ablation zone. The delivery of energy and hence the success of MWA is closely dependent on the structure of the antennas. Therefore, three design criteria, such as expected ablation zone pattern, efficiency of energy delivery, and minimization of the diameter of the antennas have been the focus along the evolution of the MW antenna. To further improve the performance of MWA in the treatment of various tumors through inventing novel antennas, this article reviews the state-of-the-art and summarizes the development of MW antenna designs regarding the three design criteria.
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Affiliation(s)
- Hangming Huang
- Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China
| | - Lifeng Zhang
- Department of General Surgery, the First Affiliated Hospital of Soochow University,Soochow University, Jiangsu, China
| | - Michael A J Moser
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Wenjun Zhang
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Bing Zhang
- Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China.
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Sano MB, DeWitt MR. Thermochromic Tissue Phantoms for Evaluating Temperature Distribution in Simulated Clinical Applications of Pulsed Electric Field Therapies. Bioelectricity 2020; 2:362-371. [PMID: 34476365 PMCID: PMC8370349 DOI: 10.1089/bioe.2020.0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: Irreversible electroporation (IRE) induces cell death through nonthermal mechanisms, however, in extreme cases, the treatments can induce deleterious thermal transients. This study utilizes a thermochromic tissue phantom to enable visualization of regions exposed to temperatures above 60°C. Materials and Methods: Poly(vinyl alcohol) hydrogels supplemented with thermochromic ink were characterized and processed to match the electrical properties of liver tissue. Three thousand volt high-frequency IRE protocols were administered with delivery rates of 100 and 200 μs/s. The effect of supplemental internal applicator cooling was then characterized. Results: Baseline treatments resulted thermal areas of 0.73 cm2, which decreased to 0.05 cm2 with electrode cooling. Increased delivery rates (200 μs/s) resulted in thermal areas of 1.5 and 0.6 cm2 without and with cooling, respectively. Conclusions: Thermochromic tissue phantoms enable rapid characterization of thermal effects associated with pulsed electric field treatments. Active cooling of applicators can significantly reduce the quantity of tissue exposed to deleterious temperatures.
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Affiliation(s)
- Michael B. Sano
- UNC/NCSU Joint Department of Biomedical Engineering, Raleigh, North Carolina, USA
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Trujillo M, Prakash P, Faridi P, Radosevic A, Curto S, Burdio F, Berjano E. How large is the periablational zone after radiofrequency and microwave ablation? Computer-based comparative study of two currently used clinical devices. Int J Hyperthermia 2020; 37:1131-1138. [PMID: 32996794 PMCID: PMC7714001 DOI: 10.1080/02656736.2020.1823022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Purpose: To compare the size of the coagulation (CZ) and periablational (PZ) zones created with two commercially available devices in clinical use for radiofrequency (RFA) and microwave ablation (MWA), respectively. Methods: Computer models were used to simulate RFA with a 3-cm Cool-tip applicator and MWA with an Amica-Gen applicator. The Arrhenius model was used to compute the damage index (Ω). CZ was considered when Ω> 4.6 (>99% of damaged cells). Regions with 0.6<Ω< 2.1 were considered as the PZ (tissue that has undergone moderate sub-ablative hyperthermia). The ratio of PZ volume to CZ volume (PZ/CZ) was regarded as a measure of performance, since a low value implies achieving a large CZ while keeping the PZ small. Results: Ten-min RFA (51 W) created smaller periablational zones than 10-min MWA (11.3 cm3 vs. 17.2 22.9 cm3, for 60 100 W MWA, respectively). Prolonging duration from 5 to 10 min increased the PZ in MWA more than in RFA (2.7 cm3 for RFA vs. 8.3–11.9 cm3 for 60–100 W MWA, respectively). PZ/CZ for RFA were relatively high (65–69%), regardless of ablation time, while those for MWA were highly dependent on the duration (increase of up to 25% between 5 and 10 min) and on the applied power (smaller values as power was raised, 102% for 60 W vs. 81% for 100 W, both for 10 min). The lowest PZ/CZ across all settings was 56%, obtained with 100 W-5 min MWA. Conclusions: Although RFA creates smaller periablational zones than MWA, 100 W-5 min MWA provides the lowest PZ/CZ.
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Affiliation(s)
- Macarena Trujillo
- BioMIT, Department of Applied Mathematics, Universitat Politècnica de València, Valencia, Spain
| | - Punit Prakash
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Pegah Faridi
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | | | - Sergio Curto
- Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | | | - Enrique Berjano
- BioMIT, Department of Electronic Engineering, Universitat Politècnica de València, Valencia, Spain
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Shehata MAH, El-Kady N, Hasaballah M, Mansour L, El-Gazzar N, Abd-Elsalam S. Hypervascular Nodules and Stiffer Liver are Associated with Recurrence after Microwave Ablation in Patients with Hepatocellular Carcinoma: A Double-Center Analysis. South Asian J Cancer 2020; 9:153-157. [PMID: 34189134 PMCID: PMC8236330 DOI: 10.1055/s-0041-1723102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background and Aims The aim of this study was to detect the most important risk factors for recurrence after microwave ablation (MWA) of hepatocellular carcinoma (HCC). Methods A total of 92 patients with 110 HCC focal lesions (FLs) underwent MWA therapy. All the patients underwent triphasic CT before and after 1 and 3 months of MWA therapy. Complete ablation and recurrence rates were recorded, and the risk factors associated with recurrence were analyzed. Results Regarding the 110 HCC FLs that were detected pre-MWA, adequate ablation was recorded post-MWA procedure in 88 FLs (80%) and incomplete ablation in 22 FLs (showed residual contrast enhancement). However, there were newly detected lesions (17 FLs). The rate of recurrence was significantly higher in patients with multiple larger (> 4 cm) sized and hypervascular nodules. Diabetics were significantly associated with a higher recurrence rate of HCC. The rate of recurrence was significantly higher in patients with baseline level of serum alfa-fetoprotein (AFP) ≥200 ng/mL. Stiffer liver> 25 kPa had higher incidence for recurrence after ablation. Conclusion Meticulous follow-up is mandatory in diabetic patients, patients with AFP > 200 ng/dL starting value, hypervascular large hepatic FL, and in stiffer liver> 25 kPa, as these patients have higher incidence for recurrence after ablation.
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Affiliation(s)
- Mona A. H. Shehata
- Department of Tropical Medicine and Infectious Disease, Tanta University, Tanta, Egypt
| | - Nabeel El-Kady
- Department of Tropical Medicine and Infectious Disease, Cairo University, Cairo, Egypt
| | - Maha Hasaballah
- Department of Tropical Medicine and Infectious Disease, Cairo University, Cairo, Egypt
| | - Loai Mansour
- Department of Tropical Medicine and Infectious Disease, Tanta University, Tanta, Egypt
| | - Nabila El-Gazzar
- Department of Tropical Medicine and Infectious Disease, Tanta University, Tanta, Egypt
| | - Sherief Abd-Elsalam
- Department of Tropical Medicine and Infectious Disease, Tanta University, Tanta, Egypt
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Zhai HY, Zhou QF, Dou JP, Liu FY, Zhu XY, Yu J, Liang P. Hepatic Microwave Ablation-Induced Tumor Destruction and Animal End Point Survival Can Be Improved by Suppression of Heat Shock Protein 90. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2020; 39:1223-1232. [PMID: 31880357 DOI: 10.1002/jum.15212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 11/13/2019] [Accepted: 12/11/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES To investigate the effect of heat shock protein 90 (HSP90) modulation on tumor necrosis, apoptosis, tumor growth delay, and end point survival by combining microwave ablation (MWA) with an HSP90 inhibitor in a nude mouse model. METHODS This study was approved by the Ethics Committee. Forty mice with HepG2 subcutaneous xenograft tumors (10 ± 1 mm) were randomized into 4 groups: (1) no treatment, (2) MWA only, (3) the HSP90 inhibitor ganetespib only, and (4) ganetespib combined with MWA. Tumors were harvested 24 hours after treatment, and gross coagulation diameters were measured. The effect of ganetespib on HSP90 and caspase 3 expression in the periablational rim was assessed. Another 40 mice with the same tumors and groupings were observed after treatment. Tumor growth curve and Kaplan-Meier survival analyses were performed with a tumor diameter of 2.2 cm and 40 days of survival as the defined survival end points. RESULTS Combination treatment significantly increased the coagulation size compared to tumors treated with MWA or ganetespib alone (P < 0.05). The combination of MWA and ganetespib decreased HSP90 expression and increased cleaved caspase 3 expression 24 hours after treatment. Compared with MWA or ganetespib only, combination treatment could lengthen the end point survival and reduce the tumor growth rate. CONCLUSIONS Modulation of HSP production can improve MWA-induced tumor apoptosis and destruction, reduce residual tumor growth rates, and prolong end point survival.
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Affiliation(s)
- Hong-Yan Zhai
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
- Department of Ultrasound, Tianjin Medical University General Hospital, Tianjin, China
| | - Qun-Fang Zhou
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Jian-Ping Dou
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Fang-Yi Liu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Xin-Yuan Zhu
- Cardiovascular Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
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Electro-Thermal Therapy Algorithms and Active Internal Electrode Cooling Reduce Thermal Injury in High Frequency Pulsed Electric Field Cancer Therapies. Ann Biomed Eng 2020; 49:191-202. [PMID: 32415482 DOI: 10.1007/s10439-020-02524-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 04/27/2020] [Indexed: 10/24/2022]
Abstract
Thermal tissue injury is an unintended consequence in current irreversible electroporation treatments due to the induction of Joule heating during the delivery of high voltage pulsed electric fields. In this study active temperature control measures including internal electrode cooling and dynamic energy delivery were investigated as a process for mitigating thermal injury during treatment. Ex vivo liver was used to examine the extent of thermal injury induced by 5000 V treatments with delivery rates up to five times faster than current clinical practice. Active internal cooling of the electrode resulted in a 36% decrease in peak temperature vs. non-cooled control treatments. A temperature based feedback algorithm (electro-thermal therapy) was demonstrated as capable of maintaining steady state tissue temperatures between 30 and 80 °C with and without internal electrode cooling. Thermal injury volumes of 2.6 cm3 were observed for protocols with 60 °C temperature set points and electrode cooling. This volume reduced to 1.5 and 0.1 cm3 for equivalent treatments with 50 °C and 40 °C set points. Finally, it was demonstrated that the addition of internal electrode cooling and active temperature control algorithms reduced ETT treatment times by 84% (from 343 to 54 s) vs. non-cooled temperature control strategies with equivalent thermal injury volumes.
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11
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Gao H, Wang X, Wu S, Zhou Z, Bai Y, Wu W. Conformal coverage of liver tumors by the thermal coagulation zone in 2450-MHz microwave ablation. Int J Hyperthermia 2020; 36:591-605. [PMID: 31172824 DOI: 10.1080/02656736.2019.1617437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose: To optimize treatment schemes using 2450-MHz microwave ablation (MWA), a novel conformal coverage method based on bipolar-angle mapping is proposed that determines whether a liver tumor is completely encompassed by thermal coagulation zones. Materials and methods: Firstly, three-dimensional (3-D) triangular mesh data of liver tumors were reconstructed from clinical computed tomography (CT) slices using the Marching cubes (MC) algorithm. Secondly, characterization models of thermal coagulation zones were established based on finite element simulation results of 40, 45, 50, 55, and 60 W ablations. Finally, coagulation zone models and tumor surface data were mapped and fused on a two-dimensional (2-D) plane to achieve conformal coverage of liver tumors by comparing the corresponding polar radii. Results: Optimal parameters for ablation treatment of liver tumors were efficiently obtained with the proposed conformal coverage method. Fifteen liver tumors were obtained with maximal diameters of 12.329-78.612 mm (mean ± standard deviation, 39.094 ± 19.447 mm). The insertion positions and orientations of the MWA antenna were determined based on 3-D reconstruction results of these tumors. The ablation patterns and durations of tumors were planned according to the minimum mean standard deviations between the ablative margin and tumor surface. Conclusion: The proposed method can be applied to computer-assisted MWA treatment planning of liver tumors, and is expected to guide clinical procedures in future.
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Affiliation(s)
- Hongjian Gao
- a College of Life Science and Bioengineering , Beijing University of Technology , Beijing , China
| | - Xiaoru Wang
- a College of Life Science and Bioengineering , Beijing University of Technology , Beijing , China
| | - Shuicai Wu
- a College of Life Science and Bioengineering , Beijing University of Technology , Beijing , China
| | - Zhuhuang Zhou
- a College of Life Science and Bioengineering , Beijing University of Technology , Beijing , China
| | - Yanping Bai
- a College of Life Science and Bioengineering , Beijing University of Technology , Beijing , China
| | - Weiwei Wu
- b College of Biomedical Engineering , Capital Medical University , Beijing , China
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Guo J, Tian G, Zhao Q, Jiang T. Fast hemostasis: a win-win strategy for ultrasound and microwave ablation. Onco Targets Ther 2018; 11:1395-1402. [PMID: 29559797 PMCID: PMC5856047 DOI: 10.2147/ott.s151219] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Introduction Hemorrhage is a serious complication following percutaneous biopsy requiring detecting and immediate treatment of active bleeding. This study aimed to explore the potential benefits of ultrasound (US)-guided microwave ablation (MWA) to treat acute hemorrhage in risky locations. Materials and methods We present seven patients (four males and three females) aged 19–69 years with solid-organ arterial hemorrhage treated by US-guided MWA and followed up with contrast-enhanced US (CEUS). Results All seven cases successfully underwent MWA for hemostasis, and their vital signs subsequently stabilized. During the follow-up from 13 to 36 days, the ablation area decreased slowly in five patients and was still stable in two cases. There were no complications observed in this study after MWA treatment. We also reviewed a total of 12 publications in the past 10 years. Conclusion This study suggested that US-guided MWA may be an effective and safe strategy for acute hemorrhage in the emergency setting. To confirm this method and benefit more patients, more prospective studies with larger samples and longer follow-ups are recommended.
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Affiliation(s)
- Jiabao Guo
- Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Guo Tian
- Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Hangzhou, China
| | - Qiyu Zhao
- Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Tian'an Jiang
- Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Hangzhou, China
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Liu J, Liu Y, Huang J, Huang L, Zhao P. Real-time Monitoring of Contrast-enhanced Ultrasound for Radio Frequency Ablation. Open Med (Wars) 2017; 12:474-480. [PMID: 29318194 PMCID: PMC5757354 DOI: 10.1515/med-2017-0066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/17/2017] [Indexed: 12/15/2022] Open
Abstract
Background This study compared the realtime monitoring effects of conventional ultrasound and contrast-enhanced ultrasound (CEUS) on evaluating radio frequency ablation (RFA) in a living swine liver model. Methodology Liver RFA was performed on 10
young swine. Conventional ultrasound and CEUS were performed immediately. After the animals were sacrificed, ablation lesions were removed to histopathologically examine the range of the lesions. Ablation completeness based on three methods were compared using histopathology as the gold standard. Results Forty-three ablation lesions were produced in the animals. The horizontal diameter, vertical diameter and ablation lesion area based on conventional ultrasound were all significantly smaller than those based on the gross sample, but no significant differences existed between the results of the CEUS and the gross sample. Histopathology showed that 30 lesions were incompletely ablated and 13 were completely ablated, while CEUS showed that 28 lesions were incompletely ablated and 15 were completely ablated. Compared with histopathology, CEUS had an accuracy of 81.4%, a sensitivity of 83.3%, and a specificity of 76.9%. No significant difference in ablation completeness judgment between CEUS and histopathology was observed. Conclusion CEUS provides a real-time radiological foundation for evaluating RFA lesion ranges and completeness in a living swine liver model.
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Affiliation(s)
- Jiangwei Liu
- Department of Hepatobiliary Surgery, Guizhou Provincial People's Hospital, Guizhou550002, China
| | - Yan Liu
- Department of Hepatobiliary Surgery, Guizhou Provincial People's Hospital, Guizhou550002, China
| | - Jianzhao Huang
- Department of Hepatobiliary Surgery, Guizhou Provincial People's Hospital, Guizhou550002, China
| | - Lei Huang
- Department of Hepatobiliary Surgery, Guizhou Provincial People's Hospital, Guizhou550002, China
| | - Pengwei Zhao
- Department of Hepatobiliary Surgery, Guizhou Provincial People's Hospital, Guizhou550002, China
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14
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McCarthy CJ, Gervais DA. Decision Making: Thermal Ablation Options for Small Renal Masses. Semin Intervent Radiol 2017; 34:167-175. [PMID: 28579684 DOI: 10.1055/s-0037-1602708] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Renal cell carcinoma is a relatively common tumor, with an estimated 63,000 new cases being diagnosed in the United States in 2016. Surgery, be it with partial or total nephrectomy, is considered the mainstay of treatment for many patients. However, those patients with small renal masses, typically less than 3 to 4 cm in size who are deemed unsuitable for surgery, may be suitable for percutaneous thermal ablation. We review the various treatment modalities, including radiofrequency ablation, microwave ablation, and cryoablation; discuss the advantages and disadvantages of each method; and review the latest data concerning the performance of the various ablative modalities compared with each other, and compared with surgery.
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Affiliation(s)
- Colin J McCarthy
- Division of Abdominal Imaging, Massachusetts General Hospital, Boston, Massachusetts
| | - Debra A Gervais
- Division of Abdominal Imaging, Massachusetts General Hospital, Boston, Massachusetts
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15
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Liu F, Cheng Z, Han Z, Yu X, Yu M, Liang P. A three-dimensional visualization preoperative treatment planning system for microwave ablation in liver cancer: a simulated experimental study. Abdom Radiol (NY) 2017; 42:1788-1793. [PMID: 28161824 DOI: 10.1007/s00261-017-1065-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To evaluate the application value of three-dimensional (3D) visualization preoperative treatment planning system (VPTPS) for microwave ablation (MWA) in liver cancer. MATERIALS AND METHODS The study was a simulated experimental study using the CT imaging data of patients in DICOM format in a model. Three students (who learn to interventional ultrasound for less than 1 year) and three experts (who have more than 5 years of experience in ablation techniques) in MWA performed the preoperative planning for 39 lesions (mean diameter 3.75 ± 1.73 cm) of 32 patients using two-dimensional (2D) image planning method and 3D VPTPS, respectively. The number of planning insertions, planning ablation rate, and damage rate to surrounding structures were compared between2D image planning group and 3D VPTPS group. RESULTS There were fewer planning insertions, lower ablation rate and higher damage rate to surrounding structures in 2D image planning group than 3D VPTPS group for both students and experts. When using the 2D ultrasound planning method, students could carry out fewer planning insertions and had a lower ablation rate than the experts (p < 0.001). However, there was no significant difference in planning insertions, the ablation rate, and the incidence of damage to the surrounding structures between students and experts using 3D VPTPS. CONCLUSIONS 3DVPTPS enables inexperienced physicians to have similar preoperative planning results to experts, and enhances students' preoperative planning capacity, which may improve the therapeutic efficacy and reduce the complication of MWA.
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Affiliation(s)
- Fangyi Liu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Zhigang Cheng
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Zhiyu Han
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Xiaoling Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Mingan Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
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16
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Sartori S, Di Vece F, Ermili F, Tombesi P. Laser ablation of liver tumors: An ancillary technique, or an alternative to radiofrequency and microwave? World J Radiol 2017; 9:91-96. [PMID: 28396723 PMCID: PMC5368631 DOI: 10.4329/wjr.v9.i3.91] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 12/23/2016] [Accepted: 01/11/2017] [Indexed: 02/06/2023] Open
Abstract
Radiofrequency ablation (RFA) is currently the most popular and used ablation modality for the treatment of non surgical patients with primary and secondary liver tumors, but in the last years microwave ablation (MWA) is being technically improved and widely rediscovered for clinical use. Laser thermal ablation (LTA) is by far less investigated and used than RFA and MWA, but the available data on its effectiveness and safety are quite good and comparable to those of RFA and MWA. All the three hyperthermia-based ablative techniques, when performed by skilled operators, can successfully treat all liver tumors eligible for thermal ablation, and to date in most centers of interventional oncology or interventional radiology the choice of the technique usually depends on the physician's preference and experience, or technical availability. However, RFA, MWA, and LTA have peculiar advantages and limitations that can make each of them more suitable than the other ones to treat patients and tumors with different characteristics. When all the three thermal ablation techniques are available, the choice among RFA, MWA, and LTA should be guided by their advantages and disadvantages, number, size, and location of the liver nodules, and cost-saving considerations, in order to give patients the best treatment option.
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17
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Dou JP, Yu J, Han ZY, Liu FY, Cheng ZG, Liang P. Microwave ablation for hepatocellular carcinoma associated with Budd-Chiari syndrome after transarterial chemoembolization: an analysis of ten cases. Abdom Radiol (NY) 2017; 42:962-968. [PMID: 27688061 DOI: 10.1007/s00261-016-0923-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
PURPOSE To evaluate the feasibility, efficacy, and safety of microwave ablation (MWA) in the treatment of hepatocellular carcinoma associated with Budd-Chiari syndrome (BCS) after transarterial chemoembolization (TACE). METHODS A total of 10 patients (mean 50.0 ± 7.5 years) with 15 BCS-associated HCC lesions were retrospectively evaluated. All patients received MWA treatment for residual tumors after 1 to 3 sessions of TACE. The diagnosis of residual tumors was confirmed by at least two types of enhanced imaging. CEUS images were performed to confirm the residual lesions and guide the placement of antenna before MWA. Thermal monitoring and artificial pleural effusion or ascites were used to guarantee ablative accuracy and safety for patients with tumors adjacent to vital structures. Technical success, technique efficacy, local tumor progression, survival rate, and the incidence of complications were comprehensively analyzed. RESULTS Technical success and technique effectiveness were achieved in all patients. Thirteen lesions achieved complete ablation for the first time, and 2 lesions needed two sessions. Thermal monitoring was used in 2 patients, artificial pleural effusion was used in 1 patient, and artificial ascites in 2 patients. In a median follow-up of 34.5 months (range 21-52 months), no LTP was founded in all patients. Intrahepatic recurrence was found in 5 patients. 1-, 2-, 3-, and 4-year survival rates were 100%, 100%, 74.1%, and 37.0%, respectively. No major or minor complications were observed. CONCLUSION Microwave ablation is a feasible and effective way to treat residual tumors after TACE treatment in patients with BCS-associated HCC.
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Affiliation(s)
- Jian-Ping Dou
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Zhi-Yu Han
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Fang-Yi Liu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Zhi-Gang Cheng
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
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18
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D’Onofrio M, Ciaravino V, De Robertis R, Barbi E, Salvia R, Girelli R, Paiella S, Gasparini C, Cardobi N, Bassi C. Percutaneous ablation of pancreatic cancer. World J Gastroenterol 2016; 22:9661-9673. [PMID: 27956791 PMCID: PMC5124972 DOI: 10.3748/wjg.v22.i44.9661] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/13/2016] [Accepted: 10/19/2016] [Indexed: 02/06/2023] Open
Abstract
Pancreatic ductal adenocarcinoma is a highly aggressive tumor with an overall 5-year survival rate of less than 5%. Prognosis and treatment depend on whether the tumor is resectable or not, which mostly depends on how quickly the diagnosis is made. Chemotherapy and radiotherapy can be both used in cases of non-resectable pancreatic cancer. In cases of pancreatic neoplasm that is locally advanced, non-resectable, but non-metastatic, it is possible to apply percutaneous treatments that are able to induce tumor cytoreduction. The aim of this article will be to describe the multiple currently available treatment techniques (radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation), their results, and their possible complications, with the aid of a literature review.
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19
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Lopresto V, Pinto R, Farina L, Cavagnaro M. Treatment planning in microwave thermal ablation: clinical gaps and recent research advances. Int J Hyperthermia 2016; 33:83-100. [PMID: 27431328 DOI: 10.1080/02656736.2016.1214883] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Microwave thermal ablation (MTA) is a minimally invasive therapeutic technique aimed at destroying pathologic tissues through a very high temperature increase induced by the absorption of an electromagnetic field at microwave (MW) frequencies. Open problems, which are delaying MTA applications in clinical practice, are mainly linked to the extremely high temperatures, up to 120 °C, reached by the tissue close to the antenna applicator, as well as to the ability of foreseeing and controlling the shape and dimension of the thermally ablated area. Recent research was devoted to the characterisation of dielectric, thermal and physical properties of tissue looking at their changes with the increasing temperature, looking for possible developments of reliable, automatic and personalised treatment planning. In this paper, a review of the recently obtained results as well as new unpublished data will be presented and discussed.
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Affiliation(s)
- V Lopresto
- a Division of Health Protection Technologies , Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) , Rome , Italy
| | - R Pinto
- a Division of Health Protection Technologies , Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) , Rome , Italy
| | - L Farina
- b Department of Information Engineering, Electronics and Telecommunications , Sapienza University of Rome , Rome , Italy
| | - M Cavagnaro
- b Department of Information Engineering, Electronics and Telecommunications , Sapienza University of Rome , Rome , Italy
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20
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Sun Y, Zhang G, Yu J, Dong L, Liu W, Liang P. Evaluation of percutaneous microwave coagulation therapy for hepatic artery injury. Heliyon 2016; 1:e00030. [PMID: 27441219 PMCID: PMC4939808 DOI: 10.1016/j.heliyon.2015.e00030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 11/16/2022] Open
Abstract
Objectives To evaluate the in vivo efficacy of 915 MHz percutaneous coagulation in the treatment of hepatic artery injury. Methods After inducing hepatic artery injury, 8 dogs in each group underwent 915 MHz microwave percutaneous coagulation therapy and 8 dogs were injected with batroxobin and α-cyanoacrylate. Results The hemostatic effects of 915 MHz microwave were better than drug injection, and the amount of bleeding was significantly lower (p < 0.05). Pathological examination showed that vessel wall necrosis were greater. Conclusion Contrast ultrasound guided 915 MHz microwave percutaneous coagulation treatment has potent hemostatic effects in the repair of in vivo hepatic artery injury.
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Affiliation(s)
- Yuanyuan Sun
- Department of Ultrasound, The General Hospital of Jinan Military Region, Jinan 250031, China
| | - Guoming Zhang
- Department of Cardiology, The General Hospital of Jinan Military Region, Jinan 250031, China
| | - Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing 100853, China
| | - Lei Dong
- Department of Ultrasound, The General Hospital of Jinan Military Region, Jinan 250031, China
| | - Wei Liu
- The Nanjing Kangyou Institute of Microwave Energy, Nanjing 210000, China
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing 100853, China
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21
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Hinshaw JL, Lubner MG, Ziemlewicz TJ, Lee FT, Brace CL. Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why? Radiographics 2015; 10:47-57. [PMID: 25208284 DOI: 10.1053/j.tvir.2007.08.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.
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Affiliation(s)
- J Louis Hinshaw
- From the Departments of Radiology (J.L.H., M.G.L., T.J.Z., F.T.L., C.L.B.), Biomedical Engineering (C.L.B.), and Medical Physics (C.L.B.), University of Wisconsin, 600 Highland Ave, E3 366, Madison, WI 53792-3252
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22
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Hinshaw JL, Lubner MG, Ziemlewicz TJ, Lee FT, Brace CL. Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why? Radiographics 2015; 34:1344-62. [PMID: 25208284 DOI: 10.1148/rg.345140054] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.
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Affiliation(s)
- J Louis Hinshaw
- From the Departments of Radiology (J.L.H., M.G.L., T.J.Z., F.T.L., C.L.B.), Biomedical Engineering (C.L.B.), and Medical Physics (C.L.B.), University of Wisconsin, 600 Highland Ave, E3 366, Madison, WI 53792-3252
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23
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Biffi Gentili G, Ignesti C. Dual applicator thermal ablation at 2.45 GHz: a numerical comparison and experiments on synchronous versus asynchronous and switched-mode feeding. Int J Hyperthermia 2015; 31:528-37. [DOI: 10.3109/02656736.2015.1032369] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Guido Biffi Gentili
- Department of Information Engineering, University of Florence, Florence, Italy
| | - Cosimo Ignesti
- Department of Information Engineering, University of Florence, Florence, Italy
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24
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Farina L, Weiss N, Nissenbaum Y, Cavagnaro M, Lopresto V, Pinto R, Tosoratti N, Amabile C, Cassarino S, Goldberg SN. Characterisation of tissue shrinkage during microwave thermal ablation. Int J Hyperthermia 2014; 30:419-28. [PMID: 25323026 DOI: 10.3109/02656736.2014.957250] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE The aim of this study was to characterise changes in tissue volume during image-guided microwave ablation in order to arrive at a more precise determination of the true ablation zone. MATERIALS AND METHODS The effect of power (20-80 W) and time (1-10 min) on microwave-induced tissue contraction was experimentally evaluated in various-sized cubes of ex vivo liver (10-40 mm ± 2 mm) and muscle (20 and 40 mm ± 2 mm) embedded in agar phantoms (N = 119). Post-ablation linear and volumetric dimensions of the tissue cubes were measured and compared with pre-ablation dimensions. Subsequently, the process of tissue contraction was investigated dynamically during the ablation procedure through real-time X-ray CT scanning. RESULTS Overall, substantial shrinkage of 52-74% of initial tissue volume was noted. The shrinkage was non-uniform over time and space, with observed asymmetry favouring the radial (23-43 % range) over the longitudinal (21-29%) direction. Algorithmic relationships for the shrinkage as a function of time were demonstrated. Furthermore, the smallest cubes showed more substantial and faster contraction (28-40% after 1 min), with more considerable volumetric shrinkage (>10%) in muscle than in liver tissue. Additionally, CT imaging demonstrated initial expansion of the tissue volume, lasting in some cases up to 3 min during the microwave ablation procedure, prior to the contraction phenomenon. CONCLUSIONS In addition to an asymmetric substantial shrinkage of the ablated tissue volume, an initial expansion phenomenon occurs during MW ablation. Thus, complex modifications of the tissue close to a radiating antenna will likely need to be taken into account for future methods of real-time ablation monitoring.
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Affiliation(s)
- Laura Farina
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome , Italy
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25
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Zhang G, Dong L, Tai Y, Sun Y, Liang P, Liu X, Wang H, Zhang Y, Shen H, Sun N. Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation therapy compared to local hemostatic drug injection in a renal artery injury model. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2014; 33:611-621. [PMID: 24658940 DOI: 10.7863/ultra.33.4.611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVES The purpose of this study was to show the contrast-enhanced sonographic features of various levels of renal artery rupture and to validate the therapeutic effects of percutaneous 915-MHz microwave ablation compared to hemostatic drug injection (batroxobin) using an in vivo canine renal artery injury model. METHODS Three renal artery hemorrhage models (A, diameter <1 mm, subcapsular artery; B, diameter 1-2 mm, interlobar artery; and C, diameter 2-3 mm, segmental artery) were created in 24 canines for this study. Contrast-enhanced sonography was used to show the bleeding features and guide hemostatic therapies using 915-MHz microwave ablation and local batroxobin injection. Success rates were assessed according to amounts of bleeding, times required for hemostatic action, and volumes of fluid infusion required using pathologic examination as a reference standard. RESULTS Contrast-enhanced sonography clearly showed renal artery ruptures with active bleeding at various levels and degrees and was very useful to make diagnoses and guide therapies. The success rate in the microwave treatment group was higher than that in the drug injection group (except group A; P< .05). The time required for hemostasis and the volume of fluid infusion required in the microwave group were notably less than those in the drug injection group (P < .05). CONCLUSIONS Contrast-enhanced sonography is a useful imaging method for assessing renal vessel injury and guide interventional therapies. Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation is a preferred hemostatic technique for treatment of renal artery injury, with greater effectiveness and less tissue damage compared to local drug injection.
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Affiliation(s)
- Guoming Zhang
- MS, Department of Ultrasound, or Hong Shen, MS, Department of Cardiology, General Hospital of Jinan Military Command, 250031 Jinan, China.
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26
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Huang S, Yu J, Liang P, Yu X, Cheng Z, Han Z, Li Q. Percutaneous microwave ablation for hepatocellular carcinoma adjacent to large vessels: a long-term follow-up. Eur J Radiol 2013; 83:552-8. [PMID: 24418287 DOI: 10.1016/j.ejrad.2013.12.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 12/05/2013] [Accepted: 12/12/2013] [Indexed: 02/08/2023]
Abstract
PURPOSE To retrospectively evaluate the effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) in the treatment of hepatocellular carcinoma (HCC) adjacent to large vessels. MATERIALS AND METHODS From February 2006 to February 2013, 452 patients with 605 HCC nodules were treated with US-guided percutaneous MWA. Into large vessels group (Group L), 139 patients with 163 lesions (diameter, 1.0-7.0 cm; mean, 2.5±1.1 cm) located less than 5mm away from large vessels were enrolled. And 313 patients with 442 lesions (diameter, 1.0-8.0 cm; mean, 2.5±1.2 cm) located more than 5mm away from hepatic surface, large vessels, gallbladder and gastrointestinal tract were included in control group (Group C). During the ablation, the temperature of marginal ablation tissues was monitored and controlled. RESULTS The median follow-up time was 24.5 months (range 2.1-87.7 months) in Group L, and 25.7 months (range 1.6-93.9 months) in Group C. Technical effectiveness was achieved in 157 of 163 (96.3%) tumors in Group L and 429 of 442 (97.1%) tumors in Group C, respectively (p>0.05). The 1-, 3- and 5-year local tumor progression rates and the 1-, 3- and 5-year accumulative survival rates in the two groups have no significantly statistical differences. In addition, no immediate or periprocedural major complications, no delayed complication of vessels or bile ducts injury were found in both of the two groups. CONCLUSIONS With strict temperature monitoring, US-guided percutaneous MWA is an efficient and safe technology in treating hepatocellular carcinoma adjacent to large vessels.
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Affiliation(s)
- Shijia Huang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Ping Liang
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Xiaoling Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Zhigang Cheng
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Zhiyu Han
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Qinying Li
- No. 135, Shengli East Road, Huanglong District, Puyang City, Henan Province 475000, China.
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Cao XL, Li H, Yu XL, Liang P, Dong BW, Fan J, Li M, Liu FY. Predicting early intrahepatic recurrence of hepatocellular carcinoma after microwave ablation using SELDI-TOF proteomic signature. PLoS One 2013; 8:e82448. [PMID: 24349287 PMCID: PMC3862627 DOI: 10.1371/journal.pone.0082448] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/03/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND/AIMS Despite great progress in the treatment of hepatocellular carcinoma (HCC) over the last-decade, intrahepatic recurrence is still the most frequent serious adverse event after all the treatments including microwave ablation. This study aimed to predict early recurrence of HCC after microwave ablation using serum proteomic signature. METHODS After curative microwave ablation of HCC, 86 patients were followed-up for 1 year. Serum samples were collected before microwave ablation. The mass spectra of proteins were generated using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Serum samples from 50 patients were randomly selected as a training set and for biomarkers discovery and model development. The remaining serum samples were categorized for validation of the algorithm. RESULTS According to preablation serum protein profiling obtained from the 50 HCC samples in the training set, nine significant differentially-expressed proteins were detected in the serum samples between recurrent and non-recurrent patients. Decision classification tree combined with three candidate proteins with m/z values of 7787, 6858 and 6646 was produced using Biomarker Patterns Software with sensitivity of 85.7% and specificity of 88.9% in the training set. When the SELDI marker pattern was tested with the blinded testing set, it yielded a sensitivity of 80.0%, a specificity of 88.5% and a positive predictive value of 86.1%. CONCLUSIONS Differentially-expressed protein peaks in preablation serum screened by SELDI are associated with prognosis of HCC. The decision classification tree is a potential tool in predicting early intrahepatic recurrence in HCC patients after microwave ablation.
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Affiliation(s)
- Xiao-lin Cao
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
- Department of Ultrasound, Southern Building Clinic Division, General Hospital of People's Liberation Army, Beijing, China
| | - Hua Li
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
- Department of Ultrasound, the 306 Hospital of Chinese People's Liberation Army, Beijing, China
| | - Xiao-ling Yu
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
- * E-mail: (XlY); (PL)
| | - Ping Liang
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
- * E-mail: (XlY); (PL)
| | - Bao-wei Dong
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
| | - Jin Fan
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
| | - Meng Li
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
| | - Fang-yi Liu
- Department of Interventional Ultrasound, General Hospital of People's Liberation Army, Beijing, China
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Di Vece F, Tombesi P, Ermili F, Maraldi C, Sartori S. Coagulation Areas Produced by Cool-Tip Radiofrequency Ablation and Microwave Ablation Using a Device to Decrease Back-Heating Effects: A Prospective Pilot Study. Cardiovasc Intervent Radiol 2013; 37:723-9. [DOI: 10.1007/s00270-013-0733-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 08/09/2013] [Indexed: 12/17/2022]
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Zhang G, Sun Y, Yu J, Dong L, Mu N, Liu X, Liu L, Zhang Y, Wang X, Liang P. Microwave coagulation therapy and drug injection to treat splenic injury. J Surg Res 2013; 186:226-33. [PMID: 23992856 DOI: 10.1016/j.jss.2013.07.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 07/17/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND The present study compares the efficacy of 915- and 2450-MHz contrast-enhanced ultrasound (CEUS)-guided percutaneous microwave coagulation with that of CEUS-guided thrombin injection for the treatment of trauma-induced spleen hemorrhage. MATERIALS AND METHODS In a canine splenic artery hemorrhage model with two levels of arterial diameter (A, <1 mm and B, between 1 and 2 mm), hemostatic therapy was performed using 915- and 2450-MHz microwaves and drug injection. Therapy efficacy was measured by comparing bleeding rate, hemostatic time, bleeding index, bleeding volume, and pathology. RESULTS The most efficient technique was CEUS-guided 915-MHz percutaneous microwave coagulation therapy in terms of action time and total blood loss. The success rate of the 915-MHz microwave group was higher than that of the 2450-MHz microwave and the drug injection groups (except A level, P < 0.05). Hemostatic time, bleeding index, and bleeding volume were significantly less in the 915-MHz microwave group than those in the 2450-MHz microwave and drug injection groups (P < 0.05). Obvious degeneration and necrosis of parenchyma and large intravascular thrombosis were observed in the cavity of larger vessels in the 915-MHz microwave group, but pathologic changes of light injury could be seen in the other groups. CONCLUSIONS The present study provides evidence that microwave coagulation therapy is more efficient than thrombin injection for the treatment of splenic hemorrhage. Furthermore, treatment with 915-MHz microwaves stops bleeding more rapidly and generates a wider cauterization zone than does treatment with 2450-MHz microwaves.
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Affiliation(s)
- Guoming Zhang
- Department of Cardiology, The General Hospital of Jinan Military Region, Jinan, China
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Ward RC, Healey TT, Dupuy DE. Microwave ablation devices for interventional oncology. Expert Rev Med Devices 2013; 10:225-38. [PMID: 23480091 DOI: 10.1586/erd.12.77] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microwave ablation is one of the several options in the ablation armamentarium for the treatment of malignancy, offering several potential benefits when compared with other ablation, radiation, surgical and medical treatment modalities. The basic microwave system consists of the generator, power distribution system and antennas. Often under image (computed tomography or ultrasound) guidance, a needle-like antenna is inserted percutaneously into the tumor, where local microwave electromagnetic radiation is emitted from the probe's active tip, producing frictional tissue heating, capable of causing cell death by coagulation necrosis. Half of the microwave ablation systems use a 915 MHz generator and the other half use a 2450 MHz generator. To date, there are no completed clinical trials comparing microwave devices head-to-head. Prospective comparisons of microwave technology with other treatment alternatives, as well as head-to-head comparison with each microwave device, is needed if this promising field will garner more widespread support and use in the oncology community.
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Affiliation(s)
- Robert C Ward
- Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy St, Providence, RI 02903, USA
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Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison. Eur J Radiol 2013; 82:e350-5. [DOI: 10.1016/j.ejrad.2013.02.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 02/07/2013] [Accepted: 02/11/2013] [Indexed: 02/08/2023]
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Hoffmann R, Rempp H, Erhard L, Blumenstock G, Pereira PL, Claussen CD, Clasen S. Comparison of four microwave ablation devices: an experimental study in ex vivo bovine liver. Radiology 2013; 268:89-97. [PMID: 23440327 DOI: 10.1148/radiol.13121127] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE To compare volume, sphericity, and short-axis diameter of the coagulation zone of four commercially available microwave ablation systems with three technical concepts in an ex vivo setting and to formulate mathematical models to predict these quantities. MATERIALS AND METHODS Two high-power systems (systems A and B), a system that enables simultaneous use of three antennas (system C), and a non-perfusion-cooled system that automatically adapts power and frequency (system D) were tested in ex vivo bovine livers (108 ablations). Coagulation volume, sphericity, and mean short-axis diameter were assessed, and mathematical functions were fitted for each system and assessed with the coefficient of determination (R(2)). Analysis of variance and Tukey post hoc tests were used for interdevice comparison after 5 and 10 minutes and after maximum recommended ablation time. RESULTS Volume and short-axis diameter were determined by using a mathematical model for every system, with coefficients of determination of 0.75-0.98 and 0.70-0.97, respectively. Correlation for determination of sphericity was lower (R(2) = 0.01-0.68). Mean results with ablation performed according to manufacturer recommendations were as follows: Volume, sphericity, and short-axis diameter were 57.5 cm(3), 0.75, and 43.4 mm, respectively, for system A; 72.3 cm(3), 0.68, and 45.5 mm, respectively, for system B; 17.1 cm(3), 0.58, and 26.8 mm, respectively, for system C (one antenna); 76.5 cm(3), 0.89, and 50.6 mm, respectively, for system C (three antennas); and 56.0 cm(3), 0.64, and 40.9 mm, respectively, for system D. Systems A (mean volume, 52.4 cm(3) ± 4.5 [standard deviation]) and B (39.4 cm(3) ± 1.7) reach large ablation zones with 5-minute ablation. CONCLUSION The largest ablation zone is obtained with systems B and C (three antennas) under maximum recommended ablation duration and with system A under short ablation time. The most spherical zone is obtained with system C (three antennas).
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Affiliation(s)
- Rüdiger Hoffmann
- Department of Diagnostic and Interventional Radiology and Department of Medical Biometry, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
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Tombesi P, Vece FD, Sartori S. Resection vs thermal ablation of small hepatocellular carcinoma: What's the first choice? World J Radiol 2013; 5:1-4. [PMID: 23493926 PMCID: PMC3596563 DOI: 10.4329/wjr.v5.i1.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 12/17/2012] [Accepted: 01/11/2013] [Indexed: 02/06/2023] Open
Abstract
Nowadays, hepatocellular carcinoma (HCC) is frequently diagnosed at an early stage, opening good perspectives to radical treatment by means of liver transplantation, surgical resection, or percutaneous ablation. Liver transplantation is considered the best option, but the lack of liver donors represents a major limitation. Therefore, surgical resection, offering a 5-year-survival rate of over 50%, is considered the first-choice treatment for patients with early stage HCC, whereas percutaneous ablation is usually reserved to patients who are not candidate to surgery. However, in the recent years some trials showed that percutaneous radiofrequency ablation (RFA) can be as effective as surgical resection in terms of overall survival and recurrence-free survival rates in patients with small HCC, and a retrospective comparative study reported 1-, 3-, and 5-year overall survival rates and recurrence-free survival rates significantly better in patients with central HCC measuring 2 cm or smaller treated with RFA than in those treated with surgical resection. RFA is less expensive, less invasive, with lower complication rate and shorter hospital stay than surgical resection, and on the basis of the results of these studies it should be considered the first option in the treatment of very early HCC. However, RFA is size-dependent, so at present the need to achieve an adequate safety margin around the tumor limits to about 2 cm the diameter of the nodules that can be ablated with long-term outcomes comparable to or better than surgical resection. The main goal of the next technical developments of the thermal ablation systems should be the achievement of larger ablation areas with a single needle insertion. In this regard, the recent improvements in microwave energy delivery systems seem to open interesting perspectives to percutaneous microwave ablation, which could become the ablation technique of choice in the next future.
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Ong SL, Gravante G, Metcalfe MS, Dennison AR. History, ethics, advantages and limitations of experimental models for hepatic ablation. World J Gastroenterol 2013; 19:147-54. [PMID: 23345935 PMCID: PMC3547565 DOI: 10.3748/wjg.v19.i2.147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 09/10/2012] [Accepted: 09/19/2012] [Indexed: 02/06/2023] Open
Abstract
Numerous techniques developed in medicine require careful evaluation to determine their indications, limitations and potential side effects prior to their clinical use. At present this generally involves the use of animal models which is undesirable from an ethical standpoint, requires complex and time-consuming authorization, and is very expensive. This process is exemplified in the development of hepatic ablation techniques, starting experiments on explanted livers and progressing to safety and efficacy studies in living animals prior to clinical studies. The two main approaches used are ex vivo isolated non-perfused liver models and in vivo animal models. Ex vivo non perfused models are less expensive, easier to obtain but not suitable to study the heat sink effect or experiments requiring several hours. In vivo animal models closely resemble clinical subjects but often are expensive and have small sample sizes due to ethical guidelines. Isolated perfused ex vivo liver models have been used to study drug toxicity, liver failure, organ transplantation and hepatic ablation and combine advantages of both previous models.
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Wang F, Zhang J, Han ZY, Cheng ZG, Zhou HY, Feng L, Hu DM. Imaging manifestation of conventional and contrast-enhanced ultrasonography in percutaneous microwave ablation for the treatment of uterine fibroids. Eur J Radiol 2012; 81:2947-52. [DOI: 10.1016/j.ejrad.2011.12.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 12/12/2011] [Accepted: 12/13/2011] [Indexed: 11/28/2022]
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Ai H, Wu S, Gao H, Zhao L, Yang C, Zeng Y. Temperature distribution analysis of tissue water vaporization during microwave ablation: Experiments and simulations. Int J Hyperthermia 2012; 28:674-85. [DOI: 10.3109/02656736.2012.710769] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Abstract
CLINICAL ISSUE The majority of patients with hepatic malignancies are not amenable to surgical resection. In some of these cases minimally invasive ablative therapies are a treatment option. STANDARD TREATMENT Besides radiofrequency ablation, the most common ablative therapies are cryoablation, laser ablation and microwave ablation. TREATMENT INNOVATIONS The classic fields of application of microwave ablation are the treatment of malignancies of the liver, kidneys and lungs. Furthermore, cases of treatment of bone tumors and tumors of the adrenal gland have been reported as well as treatment of secondary hypersplenism. PERFORMANCE The manufacturers of microwave systems pursue different strategies to reach an optimal ablation zone, such as water or gas cooling of the antenna, the simultaneous use of different antennas or an automatic modulation of the microwave energy and frequency. ACHIEVEMENTS In contrast to other tumor ablation methods microwave ablation causes a direct heating of a tissue volume, thus this method is less vulnerable to the cooling effect of vessels in the ablation zone. Moreover the electric conductivity of the treated tissue does not influence microwave radiation so that microwave ablation has advantages for the treatment of high-resistance organs, such as the lungs or bone. Some publications have shown that microwave ablation causes larger ablation zones in less time in comparison to radiofrequency ablation. PRACTICAL RECOMMENDATIONS Classic indications for microwave ablation are the treatment of malignancies of the liver, lungs and kidneys. Initial technical problems have been solved, so that an increasing significance of the microwave ablation among the ablative therapies is to be expected.
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Affiliation(s)
- R Hoffmann
- Abteilung für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Deutschland.
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Lubner MG, Hinshaw JL, Andreano A, Sampson L, Lee FT, Brace CL. High-powered microwave ablation with a small-gauge, gas-cooled antenna: initial ex vivo and in vivo results. J Vasc Interv Radiol 2012; 23:405-11. [PMID: 22277272 DOI: 10.1016/j.jvir.2011.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/01/2011] [Accepted: 11/06/2011] [Indexed: 02/08/2023] Open
Abstract
PURPOSE To evaluate the performance of a gas-cooled, high-powered microwave system. MATERIALS AND METHODS Investigators performed 54 ablations in ex vivo bovine livers using three devices-a single 17-gauge cooled radiofrequency(RF) electrode; a cluster RF electrode; and a single 17-gauge, gas-cooled microwave (MW) antenna-at three time points (n = 6 at 4 minutes, 12 minutes, and 16 minutes). RF power was applied using impedance-based pulsing with maximum 200 W generator output. MW power of 135 W at 2.45 GHz was delivered continuously. An approved in vivo study was performed using 13 domestic pigs. Hepatic ablations were performed using single applicators and the above-mentioned MW and RF generator systems at treatment times of 2 minutes (n = 7 MW, n = 6 RF), 5 minutes (n = 23 MW, n = 8 RF), 7 minutes (n = 11 MW, n = 6 RF), and 10 minutes (n = 7 MW, n = 9 RF). Mean transverse diameter and length of the ablation zones were compared using analysis of variance (ANOVA) with post-hoc t tests and Wilcoxon rank-sum tests. RESULTS Single ex vivo MW ablations were larger than single RF ablations at all time points (MW mean diameter range 3.5-4.8 cm 4-16 minutes; RF mean diameter range 2.6-3.1 cm 4-16 minutes) (P < .05). There was no difference in mean diameter between cluster RF and MW ablations (RF 3.3-4.4 cm 4-16 minutes; P = .4-.9). In vivo lesion diameters for MW (and RF) were as follows: 2.6 cm ± 0.72 (RF 1.5 cm ± 0.14), 3.6 cm ± 0.89 (RF 2.0 cm ± 0.4), 3.4 cm ± 0.87 (RF 1.8 cm ± 0.23), and 3.8 cm ± 0.74 (RF 2.1 cm ± 0.3) at 2 minutes, 5 minutes, 7 minutes, and 10 minutes (P < .05 all time points). CONCLUSIONS Gas-cooled, high-powered MW ablation allows the generation of large ablation zones in short times.
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Affiliation(s)
- Meghan G Lubner
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-3252, USA.
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Gao F, Gu YK, Shen JX, Li CL, Jiang XY, Huang JH. Experimental study of destruction to porcine spleen in vivo by microwave ablation. World J Gastroenterol 2011; 17:5014-20. [PMID: 22174552 PMCID: PMC3236583 DOI: 10.3748/wjg.v17.i45.5014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 05/06/2011] [Accepted: 05/13/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To discuss the safety, feasibility and regularity of destruction to porcine spleen in vivo with congestion and tumescence by microwave ablation (MWA).
METHODS: Ligation of the splenic vein was used to induce congestion and tumescence in vivo in five porcine spleens, and microwave ablation was performed 2-4 h later. A total of 56 ablation points were ablated and the ablation powers were 30-100 W. The ablation time (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 min) was performed at a power of 60 W. After ablation, the ablation size was measured in pigs A, C, D and E and spleen resection. In pig B, the ablation size was measured and 2 ablation points were sent for pathology analysis and all tissues were sutured following ablation. Pig B was killed 1 wk later and the ablation points were sent for pathology analysis. Bleeding, tissue carbonization surrounding electrodes, and pathological changes were observed, and the effect on destruction volume relative to different ablation powers, times and positions was analyzed.
RESULTS: The incidence of bleeding (only small am-ounts, < 20 mL) in the course of ablation was 5.4% (3/56) and was attributed to tissue carbonization surrounding electrodes, which also exhibited an incidence of 5.4% (3/56). The destruction volume was influenced by different ablation powers, times and points. It showed that the ablation lesion size increased with increased ablation time, from 1 to 10 min, when the ablation power was 60 W. Also, the ablation lesion size increased with the increase of ablation power, ranging from 30 to 100 W when the ablation time was set to 3 min. A direct correlation was seen between the destruction volume and ablation time by the power of 60 W (r = 0.97542, P < 0.0001, and also between the destruction volume and ablation powers at an ablation time of 3 min (r = 0.98258, P < 0.0001). The destruction volume of zone II (the extra-2/3 part of the spleen, relative to the first or second class vascular branches), which was near the hilum of the spleen, was noteably larger than the destruction volume of zoneI(the intra-1/3 part of the spleen) which was distal from the hilum of the spleen (P = 0.0015). Pathological changes of ablation occurring immediately and 1 wk after MWA showed large areas of coagulation. Immediately following ablation, intact spleen tissues were observed in the areas of coagulation necrosis, mainly around arterioles, and there were no obvious signs of hydropsia and inflammation, while 1 wk following the ablation, the coagulation necrosis was well distributed and complete, as many nuclear fragmentations were detected, and there were obvious signs of hydropsia and inflammation.
CONCLUSION: In vivo treatment of congestion and tumescence in the spleen using microwave ablation of water-cooled antenna is a safe and feasible method that is minimally invasive.
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Yu J, Liang P, Yu XL, Cheng ZG, Han ZY, Dong BW. Needle track seeding after percutaneous microwave ablation of malignant liver tumors under ultrasound guidance: analysis of 14-year experience with 1462 patients at a single center. Eur J Radiol 2011; 81:2495-9. [PMID: 22137097 DOI: 10.1016/j.ejrad.2011.10.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/21/2011] [Accepted: 10/27/2011] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To determine the incidence and risk factors associated with needle tract seeding after percutaneous microwave ablation (MWA) of liver cancer under ultrasound guidance. MATERIALS AND METHODS Over a 14-year period, a total of 1462 patients with 2530 malignant nodules were treated by MWA. The influence of age, sex, Child-pugh classification, tumor size, tumor position, previous biopsy, insertion number and antenna type on the risk of neoplastic seeding was assessed. The survival of seeding patients after the MWA was analyzed. RESULTS Eleven patients with 12 nodules (0.47% per tumor, 0.75% per patient) were identified with needle tract seeding with an interval time of 6-37 (median 10) months after MWA. The mean size of the seeding nodule was 2.3 ± 0.7 cm (from 1.3 to 3.9 cm). Only previous biopsy was significantly associated with neoplastic seeding (P=0.02). All the seeding lesions were successfully treated by resection, MWA, radiation or high intensity focus ultrasound. The median survival period of the 11 patients after the MWA was 36.0 months. The cumulative survival rates of the 11 patients after the MWA at 1-, 2-, 3-, 4- and 5-year were 90.9%, 72.7%, 62.3%, 31.2% and 15.6%, respectively. CONCLUSION The results showed that the neoplastic seeding was a low risk complication of percutaneous MWA of liver cancer and was considered acceptable in general.
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Affiliation(s)
- Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
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Li X, Zhang L, Fan W, Zhao M, Wang L, Tang T, Jiang H, Zhang J, Liu Y. Comparison of microwave ablation and multipolar radiofrequency ablation, both using a pair of internally cooled interstitial applicators: results in ex vivo porcine livers. Int J Hyperthermia 2011; 27:240-8. [PMID: 21501025 DOI: 10.3109/02656736.2010.536967] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To compare the effectiveness of microwave ablation (MWA) and multipolar radiofrequency ablation (RFA) in ex vivo porcine livers, in both cases using a pair of internally cooled interstitial applicators. MATERIALS AND METHODS MWA was performed on ex vivo porcine livers (n = 60) using a pair of simultaneously powered, internally cooled shaft interstitial antennae. Four power settings were used: 50 W, 60 W, 70 W and 80 W (n = 15 per setting). Multipolar RFA was also performed on ex vivo porcine livers (n = 30), also using a pair of simultaneously powered, internally cooled shaft interstitial bipolar applicators. This was performed for two applicator types T30 (3 cm length) and T40 (4 cm length) at a manufacturer prescribed power of 60 W and 80 W, respectively (n = 15 per applicator). Spacing between the two probes was 2 cm in all cases. Each power setting was applied for 15 ablations for 10 min each. The long-axis diameter (Dl), short-axis diameter (Ds) and the ratio Ds/Dl for each ablation were measured. Temperature data were recorded at 10 positions. Temperature curves were recorded at 3 locations, as well as the time required for the temperature to rise to 50°C. RESULTS Dl and Ds for all the power settings of MWA were significantly larger than that of both kinds of multipolar RFA (P < 0.05). The rates of temperature to rise to 50°C in all the MW ablations power settings were significantly faster than those in both multipolar RF ablations. CONCLUSION MWA by the simultaneous application of double antennae may be more advantageous for treating larger liver tumour than multipolar RFA.
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Affiliation(s)
- Xin Li
- Department of Medical Imaging and Interventional Radiology, Cancer Centre and State Key Laboratory of Oncology in South China, Sun Yat-Sen University, No. 651 Dongfeng East Road, Guangzhou, Guangdong Province, China
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Yu J, Liang P, Yu X, Wang Y, Gao Y. Ultrasound-guided percutaneous microwave ablation of splenic metastasis: report of four cases and literature review. Int J Hyperthermia 2011; 27:517-22. [PMID: 21609274 DOI: 10.3109/02656736.2011.563768] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To investigate the feasibility, safety and efficacy of ultrasound guided percutaneous microwave (MW) ablation for small splenic metastasis. MATERIALS AND METHODS A total of four patients with five pathologically proven splenic metastases (from ovarian, pulmonary, gastric adenocarcinoma and hepatocellular carcinoma, respectively) 1.3 to 2.9 cm in diameter were treated with microwave ablation. A cooled-shaft needle antenna was percutaneously inserted into the tumour under ultrasound guidance. One thermocouple was placed about 0.5 cm away from the tumour to monitor temperature in real time during ablation. Microwaves were emitted at 60 W for 600 s routinely and prolonged as necessary to attain temperatures sufficient to ensure tumour killing. Treatment efficacy was assessed by contrast-enhanced imaging at 1, 3 and 6 months, and every 6 months thereafter. RESULTS All tumours were completely ablated at a single session and no complications occurred. No local tumour progression was observed at a mean follow up of 22 ± 17.1 months (range 4 to 43 months). The ablation zone was well defined on contrast-enhanced imaging and it gradually shrank with time. One new metastatic lesion was detected in the spleen at 11 months after the ablation and was successfully treated by another MW ablation. The post-ablation survival was mean 22 months. No other complications were observed except for fever and abdominal pain. CONCLUSIONS Ultrasound-guided percutaneous MW ablation appears to be a safe and effective minimally invasive technique for management of small splenic metastasis in selected patients.
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Affiliation(s)
- Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital , Beijing, China
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Zhou P, Liang P, Dong B, Yu X, Han X, Wang Y, Han Z. Long-term results of a phase II clinical trial of superantigen therapy with staphylococcal enterotoxin C after microwave ablation in hepatocellular carcinoma. Int J Hyperthermia 2011; 27:132-9. [DOI: 10.3109/02656736.2010.506670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Ahmed M, Brace CL, Lee FT, Goldberg SN. Principles of and advances in percutaneous ablation. Radiology 2011; 258:351-69. [PMID: 21273519 DOI: 10.1148/radiol.10081634] [Citation(s) in RCA: 557] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Image-guided tumor ablation with both thermal and nonthermal sources has received substantial attention for the treatment of many focal malignancies. Increasing interest has been accompanied by continual advances in energy delivery, application technique, and therapeutic combinations with the intent to improve the efficacy and/or specificity of ablative therapies. This review outlines clinical percutaneous tumor ablation technology, detailing the science, devices, techniques, technical obstacles, current trends, and future goals in percutaneous tumor ablation. Methods such as chemical ablation, cryoablation, high-temperature ablation (radiofrequency, microwave, laser, and ultrasound), and irreversible electroporation will be discussed. Advances in technique will also be covered, including combination therapies, tissue property modulation, and the role of computer modeling for treatment optimization.
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Affiliation(s)
- Muneeb Ahmed
- Laboratory for Minimally Invasive Tumor Therapy, Section of Interventional Radiology, and Section of Abdominal Imaging, Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 1 Deaconess Rd, Boston, MA 02215, USA.
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Jiao D, Qian L, Zhang Y, Zhang F, Li C, Huang Z, Zhang L, Zhang W, Wu P, Han X, Duan G, Han J. Microwave ablation treatment of liver cancer with 2,450-MHz cooled-shaft antenna: an experimental and clinical study. J Cancer Res Clin Oncol 2010; 136:1507-16. [PMID: 20174824 DOI: 10.1007/s00432-010-0808-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 01/28/2010] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate effects of microwave ablation with a 2,450-MHz internally cooled-shaft antenna in animal experiments and in a clinical study. METHODS Microwave ablation was performed using a cooled-shaft antenna in eight in vivo (36 ablations) porcine livers. The coagulation diameters achieved in different microwave ablation parameter groups were compared. Sixty patients (44 men, 16 women; mean age 53 years) with 96, 1-8 cm (mean 3.20 +/- 0.17 cm) liver cancers were treated with the same microwave ablation technique. Complete ablation (CA), local tumor progression (LTP) rates and complications were determined. RESULTS In vivo livers, short axis diameter correlated with the coagulation duration in a sigmoidal curve fashion (60-W group R(2) = 0.76, 80-W group R(2) = 0.87), with a relative plateau achieved within 10 min for power settings of 60 or 80 W. Within 10 min in the 60 and 80-W groups, respectively, 89 and 85.76% of maximum short axis diameter were achieved. CA rates in small (3.0 cm), intermediate (3.1-5.0 cm) and large (5.1-8.0 cm) liver cancers were 96.43% (54/56), 92.31% (24/26) and 78.57% (11/14), respectively. During a mean follow-up period of 17.17 +/- 6.52 months, LTP occurred in five (5.21%) treated cancers. There was no significant difference in the CA and LTP rate between the HCC and liver metastasis patient subgroups (P > 0.05). CONCLUSIONS The short axis diameter enlargement has a relative plateau within 10 min by fixing power output to 60 or 80 W, using the 2,450-MHz internally cooled-shaft antenna in vivo porcine livers. Effective local tumor control was achieved during one microwave ablation session.
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Affiliation(s)
- Dechao Jiao
- Department of Medical Imaging and Interventional Radiology, Cancer Center and State Key Laboratory of Oncology in South China, Sun Yat-sen University, 651 Dongfeng Road, East, Guangzhou, 510060 Guangdong, People's Republic of China
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Lubner MG, Brace CL, Hinshaw JL, Lee FT. Microwave tumor ablation: mechanism of action, clinical results, and devices. J Vasc Interv Radiol 2010; 21:S192-203. [PMID: 20656229 PMCID: PMC3065977 DOI: 10.1016/j.jvir.2010.04.007] [Citation(s) in RCA: 486] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 03/03/2010] [Accepted: 04/29/2010] [Indexed: 02/06/2023] Open
Abstract
Microwave ablation uses dielectric hysteresis to produce direct volume heating of tissue. Microwaves are capable of propagating through many tissue types, even those with high impedance such as lung or bone, with less susceptibility to "heat-sink" effects along vessels. Microwaves are highly conducive to the use of multiple applicators, showing the synergy seen with other energies, but also the potential capability for phasing of the electromagnetic field. As a result, larger, more customizable ablation zones may be created in less time. Although multiple microwave ablation systems are currently available, further study and continued development are needed.
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Affiliation(s)
- Meghan G Lubner
- Department of Radiology, University of Wisconsin, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI 53792-3252, USA.
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He N, Wang W, Ji Z, Li C, Huang B. Microwave ablation: An experimental comparative study on internally cooled antenna versus non-internally cooled antenna in liver models. Acad Radiol 2010; 17:894-9. [PMID: 20540911 DOI: 10.1016/j.acra.2010.03.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/28/2010] [Accepted: 03/07/2010] [Indexed: 01/28/2023]
Abstract
RATIONAL AND OBJECTIVES Microwave ablation is an alternative therapy with high cost-effectiveness for liver malignancy. The authors designed this experiment to compare the effect of microwave ablation using a non-internally cooled (NIC) antenna with that using an internally cooled (IC) antenna in both an ex vivo and an in vivo liver models. MATERIALS AND METHODS Sixty-two microwave ablations were performed in ex vivo porcine and in vivo canine liver models (NIC antenna, 28 coagulations; IC antenna, 34 coagulations). Pair comparisons were executed in terms of the coagulation parameters, including short-axis diameter (SD), long-axis diameter (LD), and spherical ratio (SR, SD/LD). The distributions of tissue temperatures were compared in ex vivo ablation. During in vivo ablation, the temperatures of antenna shaft were measured and unintended tissue coagulation were observed and compared. RESULTS In both ex vivo and in vivo ablations, less charring areas were found around the IC antenna shaft. With a longer SD (P < .01) and a shorter LD (P < .01), the coagulations of IC antenna appeared to be more spherical than those of NIC antenna (P < .01). During ablations in vivo, the temperatures of NIC antennas shaft were up to 90 degrees C or even higher, which resulted in some unintended tissue coagulation, whereas the temperatures of IC antennas shaft were lower than 20 degrees C in all ablation processes without any unintended tissue coagulation (P < .01). CONCLUSION The IC antenna performed better than NIC antenna in microwave ablation for liver models and might be more suitable for therapy for liver malignancy in clinical practice.
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Affiliation(s)
- Nianan He
- Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
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Cheng Z, Xiao Q, Wang Y, Sun Y, Lu T, Liang P. 915MHz microwave ablation with implanted internal cooled-shaft antenna: initial experimental study in in vivo porcine livers. Eur J Radiol 2010; 79:131-5. [PMID: 20074887 DOI: 10.1016/j.ejrad.2009.12.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 12/11/2009] [Indexed: 01/01/2023]
Abstract
PURPOSE To explore a preferred power output for further clinical application based on the ablated lesions induced by the four power outputs of 915 MHz microwave in experimental study of in vivo porcine livers. MATERIALS AND METHODS A KY 2000-915 microwave ablation system with an implanted 915 MHz internal cooled-shaft antenna was used in this study. A total of 24 ablations were performed in eight in vivo porcine livers. The energy was applied for 10 min at microwave output powers of 50 W, 60 W, 70 W, and 80 W. Long-axis and short-axis diameters of the coagulation zone were measured on all gross specimens. RESULTS The shapes of the 915 MHz microwave ablation lesions were elliptical commonly. As the power increased, the long-axis and short-axis diameters of the coagulation zone had a tendency to rise. But the long-axis diameter of the ablated lesion at 50 W was not significantly smaller than that of the ablated lesion at 60 W (P>0.05) and there were no statistical differences in short-axis diameters of the ablated lesion among the three power outputs of 60 W, 70 W and 80 W (P>0.05). After 10 min irradiation of 60 W, the long-axis and short-axis diameters of the coagulation zone were 5.02±0.60 cm and 3.65±0.46 cm, respectively. CONCLUSIONS For decreasing the undesired damages of liver tissues along the shaft and the number of antenna in further clinically percutaneous microwave ablation treatment, the power of 60 W may be a preferred setting among the four power outputs used in present study.
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Affiliation(s)
- Zhigang Cheng
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28#, Fuxing Road, Haidian District, Beijing 100853, China.
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Yu J, Liang P, Yu X, Liu F, Chen L, Wang Y. A comparison of microwave ablation and bipolar radiofrequency ablation both with an internally cooled probe: results in ex vivo and in vivo porcine livers. Eur J Radiol 2010; 79:124-30. [PMID: 20047812 DOI: 10.1016/j.ejrad.2009.12.009] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/03/2009] [Accepted: 12/04/2009] [Indexed: 02/08/2023]
Abstract
PURPOSE The purpose of this study was to compare the effectiveness of microwave (MW) ablation and radiofrequency (RF) ablation using a single internally cooled probe in a hepatic porcine model. MATERIALS AND METHODS In the ex vivo experiment, MW ablations (n=40) were performed with a 2450MHz and 915MHz needle antenna, respectively at 60W, 70W power settings. Bipolar RF ablations (n=20) were performed with a 3-cm (T30) and 4-cm (T40) active tip needle electrodes, respectively at a rated power 30W and 40W according to automatically systematic power setting. In the in vivo experiment, the 2450 MHz and 915 MHz MW ablation both at 60W and T30 bipolar RF ablation at 30 W were performed (n=30). All of the application time were 10 min. Long-axis diameter (Dl), short-axis diameter (Ds), ratio of Ds/Dl, the temperature data 5mm from the needle and the time of temperature 5mm from the needle rising to 54°C were measured. RESULTS Both in ex vivo and in vivo models, Ds and Dl of 915 MHz MW ablations were significantly larger than all the RF ablations (P<0.05); the Ds for all the 2450MHz MW ablations were significantly larger than that of T30 RF ablations (P<0.05). 2450MHz MW and T30 RF ablation tended to produce more elliptical-shaped ablation zone. Tissue temperatures 5mm from the needle were considerably higher with MW ablation, meanwhile MW ablation achieved significantly faster rate of temperature rising to 54°C than RF ablation. For in vivo study after 10 min of ablation, the Ds and Dl of 2450 MHz MW, 915 MHz MW and Bipolar RF were 2.35±0.75, 2.95±0.32, 1.61±0.33 and 3.86±0.81, 5.79±1.03, 3.21±0.51, respectively. Highest tissue temperatures 5mm from the needle were 80.07±12.82°C, 89.07±3.52°C and 65.56±15.31°C and the time of temperature rising to 54°C were respectively 37.50±7.62s, 24.50±4.09s and 57.29±23.24s for three applicators. CONCLUSION MW ablation may have higher potential for complete destruction of liver tumors than RF ablation.
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Affiliation(s)
- Jie Yu
- Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
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Yoshida M, Watanabe Y, Sato M, Maehara T, Aono H, Naohara T, Hirazawa H, Horiuchi A, Yukumi S, Sato K, Nakagawa H, Yamamoto Y, Sugishita H, Kawachi K. Feasibility of chemohyperthermia with docetaxel-embedded magnetoliposomes as minimally invasive local treatment for cancer. Int J Cancer 2009; 126:1955-1965. [DOI: 10.1002/ijc.24864] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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