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Fang Z, Wu C, Cao L, Wang T, Hong X, Moser MAJ, Zhang W, Zhang B. Development of non-invasive flexible directional microwave ablation for central lung cancer: a simulation study. Phys Med Biol 2024; 69:09NT04. [PMID: 38527368 DOI: 10.1088/1361-6560/ad3795] [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: 10/13/2023] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
Transbronchial microwave ablation (MWA) with flexible antennas has gradually become an attractive alternative to percutaneous MWA for lung cancer due to its characteristic of non-invasiveness. However, flexible antennas for the precision ablation of lung tumors that are adjacent to critical bronchial structures are still not available. In this study, a non-invasive flexible directional (FD) antenna for early stage central lung tumors surrounding the bronchia was proposed. A comprehensive numerical MWA model with the FD antenna was developed in a real human-sized left lung model. The structure of the antenna and the treatment protocol were optimized by a generic algorithm for the precision ablation of two cases of early stage central lung cancer (i.e. spherical-like and ellipsoidal tumors). The electromagnetic efficiency of the optimized antenna was also improved by implementing an optimizedπ-matching network for impedance matching. The results indicate that the electromagnetic energy of MWA can be restricted to a particular area for precision ablation of specific lung tumors using the FD antenna. This study contributes to the field of lung cancer management with MWA.
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Affiliation(s)
- Zheng Fang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, People's Republic of China
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Chen Wu
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, People's Republic of China
| | - Lin Cao
- Department of Automatic Control and Systems Engineering, the University of Sheffield, Sheffield, United Kingdom
| | - Tao Wang
- Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaowu Hong
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, People's Republic of China
- Research Institute of Fudan University, Ningbo, People's Republic of China
| | - Michael A J Moser
- Department of Surgery, University of Saskatchewan, Saskatoon, Canada
| | - Wenjun Zhang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Bing Zhang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, People's Republic of China
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2
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Satish V, Repaka R. The influence of microwave ablation parameters on the positioning of trocar in different cancerous tissues: a numerical study. Electromagn Biol Med 2024:1-10. [PMID: 38533761 DOI: 10.1080/15368378.2024.2333802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
The present study analyzed the microwave ablation of cancerous tumors located in six major cancer-prone organs and estimated the significance of input power and treatment time parameters in the apt positioning of the trocar into the tissue during microwave ablation. The present study has considered a three-dimensional two-compartment tumour-embedded tissue model. FEA based COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids, and laminar flow physics has been used to obtain the numerical results. Based on the mortality rates caused by cancer, the present study has considered six major organs affected by cancer, viz. lung, breast, stomach/gastric, liver, liver (with colon metastasis), and kidney for MWA analysis. The input power (100 W) and ablation times (4 minutes) with apt and inapt positioning of the trocar have been considered to compare the ablation volume of various cancerous tissues. The present study addresses one of the major problems clinicians face, i.e. the proper placement of the trocar due to poor imaging techniques and human error, resulting in incomplete tumor ablation and increased surgical procedures. The highest values of the ablation region have been observed for the liver, colon metastatic liver and breast cancerous tissues compared with other organs at the same operating conditions.
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Affiliation(s)
- Vellavalapalli Satish
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India
| | - Ramjee Repaka
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India
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3
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Servin F, Collins JA, Heiselman JS, Frederick-Dyer KC, Planz VB, Geevarghese SK, Brown DB, Jarnagin WR, Miga MI. Simulation of Image-Guided Microwave Ablation Therapy Using a Digital Twin Computational Model. IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2023; 5:107-124. [PMID: 38445239 PMCID: PMC10914207 DOI: 10.1109/ojemb.2023.3345733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/14/2023] [Accepted: 12/04/2023] [Indexed: 03/07/2024] Open
Abstract
Emerging computational tools such as healthcare digital twin modeling are enabling the creation of patient-specific surgical planning, including microwave ablation to treat primary and secondary liver cancers. Healthcare digital twins (DTs) are anatomically one-to-one biophysical models constructed from structural, functional, and biomarker-based imaging data to simulate patient-specific therapies and guide clinical decision-making. In microwave ablation (MWA), tissue-specific factors including tissue perfusion, hepatic steatosis, and fibrosis affect therapeutic extent, but current thermal dosing guidelines do not account for these parameters. This study establishes an MR imaging framework to construct three-dimensional biophysical digital twins to predict ablation delivery in livers with 5 levels of fat content in the presence of a tumor. Four microwave antenna placement strategies were considered, and simulated microwave ablations were then performed using 915 MHz and 2450 MHz antennae in Tumor Naïve DTs (control), and Tumor Informed DTs at five grades of steatosis. Across the range of fatty liver steatosis grades, fat content was found to significantly increase ablation volumes by approximately 29-l42% in the Tumor Naïve and 55-60% in the Tumor Informed DTs in 915 MHz and 2450 MHz antenna simulations. The presence of tumor did not significantly affect ablation volumes within the same steatosis grade in 915 MHz simulations, but did significantly increase ablation volumes within mild-, moderate-, and high-fat steatosis grades in 2450 MHz simulations. An analysis of signed distance to agreement for placement strategies suggests that accounting for patient-specific tumor tissue properties significantly impacts ablation forecasting for the preoperative evaluation of ablation zone coverage.
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Affiliation(s)
- Frankangel Servin
- Department of Biomedical EngineeringVanderbilt UniversityNashvilleTN37235USA
- Vanderbilt Institute for Surgery and EngineeringVanderbilt UniversityNashvilleTN37235USA
| | - Jarrod A. Collins
- Department of Biomedical EngineeringVanderbilt UniversityNashvilleTN37235USA
| | - Jon S. Heiselman
- Department of Biomedical EngineeringVanderbilt UniversityNashvilleTN37235USA
- Vanderbilt Institute for Surgery and EngineeringVanderbilt UniversityNashvilleTN37235USA
- Department of Surgery, Hepatopancreatobiliary ServiceMemorial Sloan Kettering Cancer CenterNew YorkNY10065USA
| | | | - Virginia B. Planz
- Department of RadiologyVanderbilt University Medical CenterNashvilleTN37235USA
| | | | - Daniel B. Brown
- Department of RadiologyVanderbilt University Medical CenterNashvilleTN37235USA
| | - William R. Jarnagin
- Department of Surgery, Hepatopancreatobiliary ServiceMemorial Sloan Kettering Cancer CenterNew YorkNY10065USA
| | - Michael I. Miga
- Department of Biomedical EngineeringVanderbilt UniversityNashvilleTN37235USA
- Vanderbilt Institute for Surgery and EngineeringVanderbilt UniversityNashvilleTN37235USA
- Department of RadiologyVanderbilt University Medical CenterNashvilleTN37235USA
- Department of Neurological SurgeryVanderbilt University Medical CenterNashvilleTN37235USA
- Department of OtolaryngologyVanderbilt University Medical CenterNashvilleTN37235USA
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4
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Wu C, Huang H, Liu Y, Chen L, Yu S, Moser MAJ, Zhang W, Fang Z, Zhang B. Optimal design of aperiodic tri-slot antennas for the conformal ablation of liver tumors using an experimentally validated MWA computer model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107799. [PMID: 37703699 DOI: 10.1016/j.cmpb.2023.107799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/03/2023] [Accepted: 09/03/2023] [Indexed: 09/15/2023]
Abstract
OBJECTIVE This study aims to demonstrate that the conformal microwave ablation (MWA) of liver tumors could be attained by optimizing the structure of an aperiodic tri-slot coaxial antenna, its insertion depth, and input power. METHODS A computational MWA model with an aperiodic tri-slot coaxial antenna operating at the frequency of 2.45 GHz was built and validated by both an ex vivo and a pilot in vivo experiment with porcine healthy livers. The validated in vivo computational MWA model implemented with a liver tumor was then used as a testbed to investigate the conformal ablation of liver tumors. Five liver tumors in different sizes and shapes were investigated. A genetic algorithm optimization method (NSGA-II) was used to optimize the structure of antenna, insertion depth of antenna, and microwave antenna input power for the conformal ablation of liver tumors. RESULTS The validation results showed that a good agreement in both the spatiotemporal temperature distribution and ablation zone was found between the computer model and the ex vivo experiments at both 45 W, 5 min and 60 W, 3 min treatments and the in vivo experiment at 45 W, 5 min treatment. The optimized simulation results confirmed that five cases of liver tumors in different sizes and shapes can be conformally ablated by optimizing the aperiodic tri-slot coaxial antenna, antenna insertion depth, and microwave antenna input power. CONCLUSION This paper demonstrates that the aperiodic tri-slot coaxial antenna can be optimized with the insertion depth and input power for the conformal ablation of liver tumors, regardless the size and shape of liver tumors.
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Affiliation(s)
- Chen Wu
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
| | - Hangming Huang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
| | - Yongfang Liu
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201412, China
| | - Lingchao Chen
- Department of Neurosurgery, Huashan Hospital Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Shuangquan Yu
- Department of Neurosurgery, Huashan Hospital Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Michael A J Moser
- Department of Surgery, University of Saskatchewan, Saskatoon, Canada
| | - Wenjun Zhang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Zheng Fang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.
| | - Bing Zhang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China.
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Satish V, Repaka R. Safety and efficacy of intracavitary microwave ablation in hepatic gland tumours: Numerical and in vitro studies. Proc Inst Mech Eng H 2023:9544119231179136. [PMID: 37300398 DOI: 10.1177/09544119231179136] [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: 06/12/2023]
Abstract
The microwave ablation (MWA) of large hepatic gland tumour using multiple trocars operated at 2.45/6 GHz frequencies has been analysed. The ablation region (in vitro) obtained using parallel and non-parallel insertion of multiple trocars into the tissue has been analysed and compared with the numerical studies. The present study has considered a typical triangular-shaped hepatic gland model for experimental and numerical analysis. COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids and laminar flow physics has been used to obtain the numerical results. Experimental analysis has been conducted on egg white using a market-available microwave ablation device. It has been found from the present study that MWA operated at 2.45/6 GHz with the non-parallel position of multiple trocars into the tissue leads to a considerable increase in the ablation region as compared to the parallel insertion of trocars. Hence, non-parallel insertion of trocars is suitable to treat irregular-shaped large cancerous tumours (>3 cm). The non-parallel simultaneous insertion of trocars can overcome the healthy tissue ablation issue as well as the problem associated with indentation. Further, reasonable accuracy (with the difference being nearly ±0.1 cm in ablation diameter) has been achieved in comparing the ablation region and temperature variation between experimental and numerical studies. The present study may create a new path in the ablation of large size tumours (>3 cm) with multiple trocars of all shapes by sparing the healthy tissue.
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Affiliation(s)
- Vellavalapalli Satish
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India
| | - Ramjee Repaka
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India
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6
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Microwave ablation trocar for ablating cancerous tumors: a numerical analysis. Med Biol Eng Comput 2023; 61:1113-1131. [PMID: 36680706 DOI: 10.1007/s11517-023-02781-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 01/11/2023] [Indexed: 01/22/2023]
Abstract
Microwave ablation (MWA) is a newly developing minimally invasive thermal therapies technology. The ablation region obtained during MWA mainly depends on the type and efficiency of the trocar as well as the energy transfer from the generator to the biological tissue. In the present article, a novel trocar for MWA therapies has been proposed. A 3-dimensional tumor-embedded hepatic gland ablated with the novel MWA trocar has been numerically analyzed using finite element method-based software. The novel trocar consists of a flexible dual tine supplied with a microwave power of 15 W at 2.45/6 GHz for an ablation time of 10 min for all the cases. Various combinations of supplied energy and deploying lengths result in tumor ablations ranging from 2.7 to 4 cm in diameter. Supplying energy at high frequency (6 GHz) to the trocar results in ablating tumors (> 4 cm) with spherical ablation region. The novel trocar generated large ablation regions which are 2-3 times bigger than the tumors obtained using existing single-slot non-cooled trocars. This research on novel trocar may help clinicians in treating large size tumors of symmetric and asymmetric shapes by overcoming the problem associated with precise position of trocar into the tissue.
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7
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Bottiglieri A, Brace C, O’Halloran M, Farina L. MWA Performed at 5.8 GHz through 'Side Firing' Approach: An Exploratory Study. SENSORS (BASEL, SWITZERLAND) 2022; 22:9320. [PMID: 36502019 PMCID: PMC9735527 DOI: 10.3390/s22239320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Recent studies have shown that ablation techniques have the potential to eradicate adrenal adenomas while preserving the functionalities of the adrenal gland and the surrounding anatomical structures. This study explores a new microwave ablation (MWA) approach operating at 5.8 GHz and using anatomical and dielectric characteristics of the target tissue to create directional heating patterns. Numerical simulations are executed in planar and 3D adrenal models, considering two energy doses. The numerical study is refined accounting for the vaporization of the tissue water content. Ex vivo experimental evaluations on porcine adrenal models complete the study. The numerical and experimental results show that spherical ablation zones are able to cover the target for both energy doses considered. Nonetheless, most of the non-targeted tissues can be preserved from excessive heating when low energy level is used. Numerical models accounting for water vaporization are capable to foresee the experimental temperature values. This study shows that the proposed MWA directional approach operating at 5.8 GHz can be considered for creating effective and selective ablation zones.
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Affiliation(s)
- Anna Bottiglieri
- Electrical and Electronic Engineering, National University of Ireland Galway, H91 TK33 Galway, Ireland
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland
| | - Christopher Brace
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA
- Department of Radiology, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA
| | - Martin O’Halloran
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland
| | - Laura Farina
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland
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8
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Bottiglieri A, O'Halloran M, Ruvio G, Farina L. Management of adreno-cortical adenomas using microwave ablation: study of the effects of the fat tissue. Int J Hyperthermia 2022; 39:1179-1194. [PMID: 36096484 DOI: 10.1080/02656736.2022.2114611] [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: 10/14/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Adrenocortical neoplasms are the main causes of secondary hypertension and related comorbidities including hypokalemia and cardiovascular diseases. Conventional techniques for the management of this condition are often invasive and not resolutive. Recent studies proposed microwave thermal ablation (MWA) to eradicate adrenocortical adenomas arising in proximity to sensitive structures. This study explores a new MWA approach to selectively direct the electromagnetic energy into the target and shield the surrounding tissues. The new solution relies on the anatomical and dielectric characteristics of the adrenal gland and the surrounding fat capsule. METHODS A 3 D model of the adrenal gland is developed, and a cooled microwave applicator is placed parallel to the interface between the fat and adrenal tissue. Numerical simulations are conducted at 2.45 GHz accounting for two energy delivery settings, two orientations of the applicator and blood perfusion of the tissues. Ex vivo and in vivo ablation procedures are conducted on ovine adrenal glands. Histology analysis completes the experimental studies. RESULTS Numerical results show asymmetric ablation profiles in ex vivo and in vivo conditions. The asymmetry ratio is influenced by the procedure settings and orientation of the applicator. Ablation zones obtained experimentally agree with those predicted by the numerical simulations. Histology analysis confirms irreversible cellular changes only in the adrenal tissue close to the applicator. CONCLUSIONS The outcomes show that the dielectric contrast between the fat layer and tissue target can be a tool in MWA to shape ablation zones to protect the surrounding structures from excessive temperature increases.
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Affiliation(s)
- Anna Bottiglieri
- Electrical and Electronic Engineering, National University of Ireland Galway, Galway, Ireland.,Translational Medical Device Lab, National University of Ireland Galway, Galway, Ireland
| | - Martin O'Halloran
- Translational Medical Device Lab, National University of Ireland Galway, Galway, Ireland
| | | | - Laura Farina
- Translational Medical Device Lab, National University of Ireland Galway, Galway, Ireland.,Endowave Ltd, Galway, Ireland
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Zuo D, Sun M, Mu H, Shen J, Wang C, Sun W, Cai Z. O-arm-guided percutaneous microwave ablation and cementoplasty for the treatment of pelvic acetabulum bone metastasis. Front Surg 2022; 9:929044. [PMID: 36171820 PMCID: PMC9510637 DOI: 10.3389/fsurg.2022.929044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Objective This study aims to evaluate the indications, safety, and efficacy of microwave ablation combined with cementoplasty under O-arm navigation for the treatment of painful pelvic bone metastasis. Methods We retrospectively collected data from 25 patients with acetabulum bone metastasis who underwent microwave ablation combined with cementoplasty. All patients underwent percutaneous microwave ablation combined with cementoplasty under O-arm navigation. The postoperative follow-up included evaluations of pain, quality of life, function, the incidence of bone cement leakage, and the presence of perioperative complications. Pain and quality of life were evaluated using the visual analog scale (VAS) and the QLQ-BM22 quality of life questionnaire for patients with bone metastases, respectively. The functional scores were calculated using the MSTS93 scoring system of the Bone and Soft Tissue Oncology Society. Results There were 10 males and 15 females with an average age of 52.5 ± 6.5 years, all 25 patients received percutaneous procedures, and no technical failure occurred. Major complications, including pulmonary embolism, vascular or nervous injury, hip joint cement leakage, and infection, were not observed in the current study. Pain regression was achieved in 24 of 25 patients. The mean VAS scores significantly decreased to 3.4 ± 1.0, 2.5 ± 1.2, and 1.2 ± 0.6 points at 1 week, 1 month, and 3 months after the procedure, respectively, compared with 7.0 points before the procedure (P < .05). The mean QLQ-BM22 score significantly decreased to 36.2 ± 4.9, 30 ± 5.6, and 25.4 ± 2.3 points at 1 week, 1 month, and 3 months after the procedure, respectively, compared with 55.8 points before the procedure (P < .05). The preoperative Musculoskeletal tumour society (MSTS) functional score of 25 patients was 18.5 ± 5.3 points, and MSTS score was 20.0 ± 3.0, 21.4 ± 4.9, and 22.8 ± 2.3 at 1 week, 1 month, and 3 months after the procedure, respectively (P < .05). The average bone cement injection volume was 8.8 ± 4.6 ml. Conclusion The use of O-arm-guided percutaneous microwave ablation combined with cementoplasty for the treatment of pelvic metastases could quickly and significantly alleviate local pain, prevent pathological fracture, and improve the quality of life of patients with reduced complications.
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Affiliation(s)
- Dongqing Zuo
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengxiong Sun
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haoran Mu
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Bone Tumor Institute, Shanghai, China
| | - Jiakang Shen
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chongren Wang
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Sun
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Correspondence: Wei Sun
| | - Zhengdong Cai
- Department of Orthopedic Oncology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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10
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Servin F, Collins JA, Heiselman JS, Frederick-Dyer KC, Planz VB, Geevarghese SK, Brown DB, Miga MI. Fat Quantification Imaging and Biophysical Modeling for Patient-Specific Forecasting of Microwave Ablation Therapy. Front Physiol 2022; 12:820251. [PMID: 35185606 PMCID: PMC8850958 DOI: 10.3389/fphys.2021.820251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/29/2021] [Indexed: 11/14/2022] Open
Abstract
Computational tools are beginning to enable patient-specific surgical planning to localize and prescribe thermal dosing for liver cancer ablation therapy. Tissue-specific factors (e.g., tissue perfusion, material properties, disease state, etc.) have been found to affect ablative therapies, but current thermal dosing guidance practices do not account for these differences. Computational modeling of ablation procedures can integrate these sources of patient specificity to guide therapy planning and delivery. This paper establishes an imaging-data-driven framework for patient-specific biophysical modeling to predict ablation extents in livers with varying fat content in the context of microwave ablation (MWA) therapy. Patient anatomic scans were segmented to develop customized three-dimensional computational biophysical models and mDIXON fat-quantification images were acquired and analyzed to establish fat content and determine biophysical properties. Simulated patient-specific microwave ablations of tumor and healthy tissue were performed at four levels of fatty liver disease. Ablation models with greater fat content demonstrated significantly larger treatment volumes compared to livers with less severe disease states. More specifically, the results indicated an eightfold larger difference in necrotic volumes with fatty livers vs. the effects from the presence of more conductive tumor tissue. Additionally, the evolution of necrotic volume formation as a function of the thermal dose was influenced by the presence of a tumor. Fat quantification imaging showed multi-valued spatially heterogeneous distributions of fat deposition, even within their respective disease classifications (e.g., low, mild, moderate, high-fat). Altogether, the results suggest that clinical fatty liver disease levels can affect MWA, and that fat-quantitative imaging data may improve patient specificity for this treatment modality.
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Affiliation(s)
- Frankangel Servin
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute for Surgery and Engineering, Vanderbilt University, Nashville, TN, United States
| | - Jarrod A. Collins
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Jon S. Heiselman
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute for Surgery and Engineering, Vanderbilt University, Nashville, TN, United States
| | - Katherine C. Frederick-Dyer
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Virginia B. Planz
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sunil K. Geevarghese
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Daniel B. Brown
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Michael I. Miga
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Institute for Surgery and Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
- *Correspondence: Michael I. Miga,
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Sebek J, Cappiello G, Rahmani G, Zeinali N, Keating M, Fayemiwo M, Harkin J, McDaid L, Gardiner B, Sheppard D, Senanayake R, Gurnell M, O’Halloran M, Dennedy MC, Prakash P. Image-based computer modeling assessment of microwave ablation for treatment of adrenal tumors. Int J Hyperthermia 2022; 39:1264-1275. [PMID: 36137605 PMCID: PMC9820798 DOI: 10.1080/02656736.2022.2125590] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To assess the feasibility of delivering microwave ablation for targeted treatment of aldosterone producing adenomas using image-based computational models. METHODS We curated an anonymized dataset of diagnostic 11C-metomidate PET/CT images of 14 patients with aldosterone producing adenomas (APA). A semi-automated approach was developed to segment the APA, adrenal gland, and adjacent organs within 2 cm of the APA boundary. The segmented volumes were used to implement patient-specific 3D electromagnetic-bioheat transfer models of microwave ablation with a 2.45 GHz directional microwave ablation applicator. Ablation profiles were quantitatively assessed based on the extent of the APA target encompassed by an ablative thermal dose, while limiting thermal damage to the adjacent normal adrenal tissue and sensitive critical structures. RESULTS Across the 14 patients, adrenal tumor volumes ranged between 393 mm3 and 2,395 mm3. On average, 70% of the adrenal tumor volumes received an ablative thermal dose of 240CEM43, while limiting thermal damage to non-target structures, and thermally sparing 83.5-96.4% of normal adrenal gland. Average ablation duration was 293 s (range: 60-600 s). Simulations indicated coverage of the APA with an ablative dose was limited when the axis of the ablation applicator was not well aligned with the major axis of the targeted APA. CONCLUSIONS Image-based computational models demonstrate the potential for delivering microwave ablation to APA targets within the adrenal gland, while limiting thermal damage to surrounding non-target structures.
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Affiliation(s)
- Jan Sebek
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
| | - Grazia Cappiello
- Translational Medical Devices Lab, National University of Ireland, Galway, Republic of Ireland
| | - George Rahmani
- Department of Radiology, Galway University Hospitals, Galway, Republic Ireland
| | - Nooshin Zeinali
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
| | - Muireann Keating
- School of Medicine, National University of Ireland, Galway, Republic Ireland
| | - Michael Fayemiwo
- School of Computing, Engineering, and Intelligent Systems, Ulster University, Londonderry, Northern Ireland
| | - Jim Harkin
- School of Computing, Engineering, and Intelligent Systems, Ulster University, Londonderry, Northern Ireland
| | - Liam McDaid
- School of Computing, Engineering, and Intelligent Systems, Ulster University, Londonderry, Northern Ireland
| | - Bryan Gardiner
- School of Computing, Engineering, and Intelligent Systems, Ulster University, Londonderry, Northern Ireland
| | - Declan Sheppard
- Department of Radiology, Galway University Hospitals, Galway, Republic Ireland
| | | | - Mark Gurnell
- Institute of Metabolic Science, University of Cambridge, United Kingdom
| | - Martin O’Halloran
- Translational Medical Devices Lab, National University of Ireland, Galway, Republic of Ireland
| | - M. Conall Dennedy
- School of Medicine, National University of Ireland, Galway, Republic Ireland
| | - Punit Prakash
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA.,Author to whom correspondence should be addressed: Punit Prakash, 3078 Engineering Hall, 1701D Platt St, Kansas State University, Manhattan, KS 66506, USA.
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12
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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: 2.0] [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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13
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Donlon P, Dennedy MC. Thermal ablation in adrenal disorders: a discussion of the technology, the clinical evidence and the future. Curr Opin Endocrinol Diabetes Obes 2021; 28:291-302. [PMID: 33741778 PMCID: PMC8183491 DOI: 10.1097/med.0000000000000627] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW To summarise the emerging role of thermal ablation as a therapeutic modality in the management of functioning adrenal tumours and metastases to the adrenal gland. RECENT FINDINGS Observational evidence has demonstrated the benefit of thermal ablation in (i) resolving adrenal endocrinopathy arising from benign adenomas, (ii) treating solitary metastases to the adrenal and (iii) controlling metastatic adrenocortical carcinoma and phaeochromocytoma/paraganglioma. SUMMARY Microwave thermal ablation offers a promising, minimally invasive therapeutic modality for the management of functioning adrenocortical adenomas and adrenal metastases. Appropriate technological design, treatment planning and choice of imaging modality are necessary to overcome technical challenges associated with this emerging therapeutic approach.
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Affiliation(s)
- Padraig Donlon
- Adrenal Research Laboratory, The Discipline of Pharmacology and Therapeutics, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, Ireland
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14
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Zia G, Sebek J, Schenck J, Prakash P. Transcervical microwave ablation in type 2 uterine fibroids via a hysteroscopic approach: analysis of ablation profiles. Biomed Phys Eng Express 2021; 7. [PMID: 33975302 DOI: 10.1088/2057-1976/abffe4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022]
Abstract
Type 2 uterine fibroids are challenging to resect surgically as ≥ 50% volume of myoma lies within the myometrium. A hysteroscopic approach for ablating fibroids is minimally-invasive, but places a considerable burden on the operator to accurately place the ablation applicator within the target. We investigated the sensitivity of transcervical microwave ablation outcome with respect to position of the ablation applicator within 1 - 3 cm type 2 fibroids.Methods:A finite element computer model was developed to simulate 5.8 GHz microwave ablation of fibroids and validated with experiments inex vivotissue. The ablation outcome was evaluated with respect to applicator insertion angles (30°, 45°, 60°) , depth and offset from the fibroid center (±2 mm for 3 cm fibroid and ±1 mm for 1 cm fibroid) with 35 W and 15 W applied power for 3 cm and 1 cm fibroids, respectively. Power deposition was stopped when thermal dose of 40 cumulative equivalent minutes at 43 °C (CEM43) was accrued in adjacent myometrium.Results:Within the range of all evaluated insertion angles, depths and offsets, the ablation coverage was less sensitive to variation in angle as compared to depth and offset, and ranged from 34.9 - 83.6% for 3 cm fibroid in 140 - 400 s and 34.1 - 67.9% for 1 cm fibroid in 30 - 50 s of heating duration. Maximum achievable ablation coverage in both fibroid cases reach ∼ 90% if thermal dose is allowed to exceed 40 CEM43 in myometrium.Conclusion:The study demonstrates the technical feasibility of transcervical microwave ablation for fibroid treatment and the relationship between applicator position within the fibroid and fraction of fibroid that can be ablated while limiting thermal dose in adjacent myometrium.
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Affiliation(s)
- Ghina Zia
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas, United States of America
| | - Jan Sebek
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas, United States of America.,Department of Circuit Theory, Czech Technical University in Prague, Prague, Czech Republic
| | - Jessica Schenck
- Hologic, Inc., Marlborough, Massachusetts, United States of America
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas, United States of America
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15
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Sebek J, Taeprasartsit P, Wibowo H, Beard WL, Bortel R, Prakash P. Microwave ablation of lung tumors: A probabilistic approach for simulation-based treatment planning. Med Phys 2021; 48:3991-4003. [PMID: 33964020 DOI: 10.1002/mp.14923] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Microwave ablation (MWA) is a clinically established modality for treatment of lung tumors. A challenge with existing application of MWA, however, is local tumor progression, potentially due to failure to establish an adequate treatment margin. This study presents a robust simulation-based treatment planning methodology to assist operators in comparatively assessing thermal profiles and likelihood of achieving a specified minimum margin as a function of candidate applied energy parameters. METHODS We employed a biophysical simulation-based probabilistic treatment planning methodology to evaluate the likelihood of achieving a specified minimum margin for candidate treatment parameters (i.e., applied power and ablation duration for a given applicator position within a tumor). A set of simulations with varying tissue properties was evaluated for each considered combination of power and ablation duration, and for four different scenarios of contrast in tissue biophysical properties between tumor and normal lung. A treatment planning graph was then assembled, where distributions of achieved minimum ablation zone margins and collateral damage volumes can be assessed for candidate applied power and treatment duration combinations. For each chosen power and time combination, the operator can also visualize the histogram of ablation zone boundaries overlaid on the tumor and target volumes. We assembled treatment planning graphs for generic 1, 2, and 2.5 cm diameter spherically shaped tumors and also illustrated the impact of tissue heterogeneity on delivered treatment plans and resulting ablation histograms. Finally, we illustrated the treatment planning methodology on two example patient-specific cases of tumors with irregular shapes. RESULTS The assembled treatment planning graphs indicate that 30 W, 6 min ablations achieve a 5-mm minimum margin across all simulated cases for 1-cm diameter spherical tumors, and 70 W, 10 min ablations achieve a 3-mm minimum margin across 90% of simulations for a 2.5-cm diameter spherical tumor. Different scenarios of tissue heterogeneity between tumor and lung tissue revealed 2 min overall difference in ablation duration, in order to reliably achieve a 4-mm minimum margin or larger each time for 2-cm diameter spherical tumor. CONCLUSIONS An approach for simulation-based treatment planning for microwave ablation of lung tumors is illustrated to account for the impact of specific geometry of the treatment site, tissue property uncertainty, and heterogeneity between the tumor and normal lung.
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Affiliation(s)
- Jan Sebek
- Department of Electrical and Computer Engineering, Kansas State University Manhattan, KS, 66506, USA.,Department of Circuit Theory, Czech Technical University in Prague, Prague, Czech Republic
| | - Pinyo Taeprasartsit
- PhenoMapper, LLC, San Jose, CA, 95112, USA.,Department of Computing, Faculty of Science, Silpakorn University, Thailand
| | | | - Warren L Beard
- Department of Clinical Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Radoslav Bortel
- Department of Circuit Theory, Czech Technical University in Prague, Prague, Czech Republic
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University Manhattan, KS, 66506, USA
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16
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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: 7] [Impact Index Per Article: 2.3] [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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17
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Ni Y, Xu H, Ye X. Image-guided percutaneous microwave ablation of early-stage non-small cell lung cancer. Asia Pac J Clin Oncol 2020; 16:320-325. [PMID: 32969192 DOI: 10.1111/ajco.13419] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 06/07/2020] [Indexed: 12/24/2022]
Abstract
Although surgical lobectomy with systematic mediastinal lymph node evaluation is considered as the "gold standard" for management of early stage non-small cell lung cancer (NSCLC), image-guided percutaneous thermal ablation has been increasingly used for medically inoperable patients. Radiofrequency ablation (RFA) is a research-based technique that has the most studies for medically inoperable early-stage NSCLC. Other thermal ablation techniques used to treat pulmonary tumors include microwave ablation (MWA), cryoablation and laser ablation. MWA has several advantages over RFA including reduced procedural time, reduced heat-sink effect, large ablation zones, decreased susceptibility to tissue impedance, and simultaneous use of multiple antennae. This review article highlights the most relevant updates of MWA for the treatment of early-stage NSCLC, including mechanism of action, clinical outcomes, potential complications, the existing technique problems and future directions.
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Affiliation(s)
- Yang Ni
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong Province, China
| | - Hui Xu
- Department of Oncology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong Province, China
| | - Xin Ye
- Department of Oncology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong Province, China
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18
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Bottiglieri A, Ruvio G, O’Halloran M, Farina L. Exploiting Tissue Dielectric Properties to Shape Microwave Thermal Ablation Zones. SENSORS 2020; 20:s20143960. [PMID: 32708680 PMCID: PMC7411896 DOI: 10.3390/s20143960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/07/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023]
Abstract
The dielectric characterization of tissue targets of microwave thermal ablation (MTA) have improved the efficacy and pre-procedural planning of treatment. In some clinical scenarios, the tissue target lies at the interface with an external layer of fat. The aim of this work is to investigate the influence of the dielectric contrast between fat and target tissue on the shape and size of the ablation zone. A 2.45 GHz monopole antenna is placed parallel to an interface modelled by fat and a tissue characterized by higher dielectric properties and powered at 30 and 60 W for 60 s. The performances of MTA are numerically investigated considering different interface scenarios (i.e., different widths of fat layer, shifts in the antenna alignment) and a homogeneous reference scenario. Experiments (N = 10) are conducted on ex vivo porcine tissue to validate the numerical results. Asymmetric heating patterns are obtained in the interface scenario, the ablation zone in the target tissue is two-fold to ten-fold the size of the zone in the adipose tissue, and up to four times larger than the homogenous scenario. The adipose tissue reflects the electromagnetic energy into the adjacent tissue target, reducing the heating in the opposite direction.
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Affiliation(s)
- Anna Bottiglieri
- Electrical and Electronic Engineering, National University of Ireland Galway, H91 TK33 Galway, Ireland
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (G.R.); (L.F.)
- Correspondence: (A.B.); (M.O.)
| | - Giuseppe Ruvio
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (G.R.); (L.F.)
- Endowave Ltd., National University of Ireland Galway, H91 TK33 Galway, Ireland
| | - Martin O’Halloran
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (G.R.); (L.F.)
- Correspondence: (A.B.); (M.O.)
| | - Laura Farina
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (G.R.); (L.F.)
- CÚRAM, SFI Research Centre for Medical Devices, H91 TK33 Galway, Ireland
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19
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Optimization of power used in liver cancer microwave therapy by injection of Magnetic Nanoparticles (MNPs). Comput Biol Med 2020; 120:103741. [DOI: 10.1016/j.compbiomed.2020.103741] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 02/08/2023]
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20
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Directional Microwave Ablation: Experimental Evaluation of a 2.45-GHz Applicator in Ex Vivo and In Vivo Liver. J Vasc Interv Radiol 2020; 31:1170-1177.e2. [PMID: 32171539 DOI: 10.1016/j.jvir.2020.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To experimentally characterize a microwave (MW) ablation applicator designed to produce directional ablation zones. MATERIALS AND METHODS Using a 14-gauge, 2.45-GHz side-firing MW ablation applicator, 36 ex vivo bovine liver ablations were performed. Ablations were performed at 60 W, 80 W, and 100 W for 3, 5, and 10 minutes (n = 4 per combination). Ablation zone forward and backward depth and width were measured and directivity was calculated as the ratio of forward to backward depth. Thirteen in vivo ablations were performed in 2 domestic swine with the applicator either inserted into the liver (80 W, 5 min, n = 3; 100 W, 5 min, n = 3; 100 W, 10 min, n = 2) or placed on the surface of the liver with a nontarget tissue placed on the back side of the applicator (80 W, 5 min, n = 5). The animals were immediately euthanized after the procedure; the livers were harvested and sectioned perpendicular to the axis of the applicator. In vivo ablation zones were measured following viability staining and assessed on histopathology. RESULTS Mean ex vivo ablation forward depth was 8.3-15.5 mm. No backward heating was observed at 60 W, 3-5 minutes; directivity was 4.7-11.0 for the other power and time combinations. In vivo ablation forward depth was 10.3-11.5 mm, and directivity was 11.5-16.1. No visible or microscopic thermal damage to nontarget tissues in direct contact with the back side of the applicator was observed. CONCLUSIONS The side-firing MW ablation applicator can create directional ablation zones in ex vivo and in vivo tissues.
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21
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Donlon PT, Fallahi H, Beard WL, Shahzad A, Heflin L, Cox W, Bloomberg B, Lillich JD, Ganta CK, O'Sullivan GJ, Ruvio G, O'Shea PM, O'Halloran M, Prakash P, Dennedy MC. Using microwave thermal ablation to develop a subtotal, cortical-sparing approach to the management of primary aldosteronism. Int J Hyperthermia 2020; 36:905-914. [PMID: 31466482 DOI: 10.1080/02656736.2019.1650205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Objective: To investigate the feasibility and efficacy of localized, subtotal, cortical-sparing microwave thermal ablation (MTA) as a potential curative management for primary aldosteronism. The study investigated with equal importance the selected ablation of small volumes of adrenal cortex while sparing adjacent cortex. Method: An in-vivo study was carried out in swine (n = 8) where MTA was applied under direct visualization, to the adrenal glands at 45 W or 70 W for 60 s, using a lateral, side-firing probe and a non-penetrative approach. Animals were survived for 48 h post-procedurally. Animals were investigated for markers of histological, immunohistochemical and biochemical evidence of adrenal function and adrenal damage by assessing samples drawn intra-operatively and at the time of euthanasia. Results: Selected MTA (70 W for 60 s) successfully ablated small adrenocortical volumes (∼0.8 cm3) characterized by coagulative necrosis and abnormal expression of functional markers (CYP11B1 and CYP17). Non-ablated, adjacent cortex was not affected and preserved normal expression of functional markers, without increased expression of markers of heat damage (HSP-70 and HMGB-1). Limited adrenal medullary damage was demonstrated histologically, clinically and biochemically. Conclusion: MTA offers potential as an efficient methodology for delivering targeted subtotal cortical-sparing adrenal ablation. Image-guided targeted MTA may also represent a safe future modality for curative management of PA, in the setting of both unilateral and bilateral disease.
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Affiliation(s)
- Padraig T Donlon
- Discipline of Pharmacology and Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
| | - Hojjatollah Fallahi
- Department of Electrical and Computer Engineering, Kansas State University , Manhattan , KS , USA
| | - Warren L Beard
- College of Veterinary Medicine, Kansas State University , Manhattan , KS , USA
| | - Atif Shahzad
- Translational Medical Device Laboratory, Discipline of Medicine, National University of Ireland , Galway , Ireland
| | - Lindsay Heflin
- College of Veterinary Medicine, Kansas State University , Manhattan , KS , USA
| | - Whitney Cox
- Department of Electrical and Computer Engineering, Kansas State University , Manhattan , KS , USA
| | - Brooke Bloomberg
- College of Veterinary Medicine, Kansas State University , Manhattan , KS , USA
| | - James D Lillich
- College of Veterinary Medicine, Kansas State University , Manhattan , KS , USA
| | - Chanran K Ganta
- College of Veterinary Medicine, Kansas State University , Manhattan , KS , USA
| | | | - Giuseppe Ruvio
- Translational Medical Device Laboratory, Discipline of Medicine, National University of Ireland , Galway , Ireland
| | - Paula M O'Shea
- Department of Clinical Biochemistry, Galway University Hospital , Galway , Ireland
| | - Martin O'Halloran
- Translational Medical Device Laboratory, Discipline of Medicine, National University of Ireland , Galway , Ireland
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University , Manhattan , KS , USA
| | - Michael Conall Dennedy
- Discipline of Pharmacology and Therapeutics, School of Medicine, National University of Ireland , Galway , Ireland
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22
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Faridi P, Bossmann SH, Prakash P. Simulation-based design and characterization of a microwave applicator for MR-guided hyperthermia experimental studies in small animals. Biomed Phys Eng Express 2020; 6:015001. [PMID: 32999735 PMCID: PMC7521833 DOI: 10.1088/2057-1976/ab36dd] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Purpose The objective of this study was to design and characterize a 2.45 GHz microwave hyperthermia applicator for delivering hyperthermia in experimental small animals to 2 - 4 mm diameter targets located 1 - 3 mm from the skin surface, with minimal heating of the surrounding tissue, under 14.1 T MRI real-time monitoring and feedback control. Materials and methods An experimentally validated 3D computational model was employed to design and characterize a non-invasive directional water-cooled microwave hyperthermia applicator. We assessed the effects of: reflector geometry, monopole shape, cooling water temperature, and flow rate on spatial-temperature profiles. The system was integrated with real-time MR thermometry and feedback control to monitor and maintain temperature elevations in the range of 4 - 5 °C at 1 - 3 mm from the applicator surface. The quality of heating was quantified by determining the fraction of the target volume heated to the desired temperature, and the extent of heating in non-targeted regions. Results Model-predicted hyperthermic profiles were in good agreement with experimental measurements (Dice Similarity Coefficient of 0.95 - 0.99). Among the four considered criteria, a reflector aperture angle of 120 °, S-shaped monopole antenna with 0.6 mm displacement, and coolant flow rate of 150 ml/min were selected as the end result of the applicator design. The temperature of circulating water and input power were identified as free variables, allowing considerable flexibility in heating target sizes within varying distances from the applicator surface. 2 - 4 mm diameter targets positioned 1 - 3 mm from the applicator surface were heated to hyperthermic temperatures, with target coverage ratio ranging between 76 - 93 % and 11 - 26 % of non-targeted tissue heated. Conclusion We have designed an experimental platform for MR-guided hyperthermia, incorporating a microwave applicator integrated with temperature-based feedback control to heat deep-seated targets for experimental studies in small animals.
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Affiliation(s)
- Pegah Faridi
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
| | - Stefan H. Bossmann
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
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23
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Abstract
Microwave (MW) ablation has emerged as a minimally invasive therapeutic modality and is in clinical use for treatment of unresectable tumors and cardiac arrhythmias, neuromodulation, endometrial ablation, and other applications. Components of image-guided MW ablation systems include high-power MW sources, ablation applicators that deliver power from the generator to the target tissue, cooling systems, energy-delivery control algorithms, and imaging guidance systems tailored to specific clinical indications. The applicator incorporates a MW antenna that radiates MW power into the surrounding tissue. A variety of antenna designs have been developed for MW ablation with the objective of efficiently transferring MW power to tissue, with a radiation pattern well matched to the size and shape of the targeted tissue. Here, we survey advances in percutaneous, endocavitary, and endoscopic antenna designs as an integral element of MW ablation applicators for a diverse set of clinical applications.
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Affiliation(s)
- Hojjatollah Fallahi
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas
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24
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Sebek J, Bortel R, Prakash P. Broadband lung dielectric properties over the ablative temperature range: Experimental measurements and parametric models. Med Phys 2019; 46:4291-4303. [PMID: 31286530 PMCID: PMC6893909 DOI: 10.1002/mp.13704] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Computational models of microwave tissue ablation are widely used to guide the development of ablation devices, and are increasingly being used for the development of treatment planning and monitoring platforms. Knowledge of temperature-dependent dielectric properties of lung tissue is essential for accurate modeling of microwave ablation (MWA) of the lung. METHODS We employed the open-ended coaxial probe method, coupled with a custom tissue heating apparatus, to measure dielectric properties of ex vivo porcine and bovine lung tissue at temperatures ranging between 31 and 150 ∘ C, over the frequency range 500 MHz to 6 GHz. Furthermore, we employed numerical optimization techniques to provide parametric models for characterizing the broadband temperature-dependent dielectric properties of tissue, and their variability across tissue samples, suitable for use in computational models of microwave tissue ablation. RESULTS Rapid decreases in both relative permittivity and effective conductivity were observed in the temperature range from 94 to 108 ∘ C. Over the measured frequency range, both relative permittivity and effective conductivity were suitably modeled by piecewise linear functions [root mean square error (RMSE) = 1.0952 for permittivity and 0.0650 S/m for conductivity]. Detailed characterization of the variability in lung tissue properties was provided to enable uncertainty quantification of models of MWA. CONCLUSIONS The reported dielectric properties of lung tissue, and parametric models which also capture their distribution, will aid the development of computational models of microwave lung ablation.
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Affiliation(s)
- Jan Sebek
- Department of Electrical and Computer Engineering, Kansas State University, 1701D Platt st., Manhattan, KS, 66506, USA
- Department of Circuit Theory, Czech Technical University, Technicka 2, 160 00, Praha 6, Czech Republic
| | - Radoslav Bortel
- Department of Circuit Theory, Czech Technical University, Technicka 2, 160 00, Praha 6, Czech Republic
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, 1701D Platt st., Manhattan, KS, 66506, USA
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Almekkawy M, Chen J, Ellis MD, Haemmerich D, Holmes DR, Linte CA, Panescu D, Pearce J, Prakash P, Zderic V. Therapeutic Systems and Technologies: State-of-the-Art Applications, Opportunities, and Challenges. IEEE Rev Biomed Eng 2019; 13:325-339. [PMID: 30951478 PMCID: PMC7341980 DOI: 10.1109/rbme.2019.2908940] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this review, we present current state-of-the-art developments and challenges in the areas of thermal therapy, ultrasound tomography, image-guided therapies, ocular drug delivery, and robotic devices in neurorehabilitation. Additionally, intellectual property and regulatory aspects pertaining to therapeutic systems and technologies are addressed.
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26
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Sebek J, Curto S, Eaton-Evans J, Bouchier-Hayes J, Ruvio G, Ganta C, Beard W, Buttar N, Song LWK, Prakash P. Feasibility Assessment of Microwave Ablation for Treating Esophageal Varices. J Med Device 2017. [DOI: 10.1115/1.4037187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Esophageal varices are a significant complication of portal hypertension. Endoscopic variceal ligation (EVL) is one of the clinical standards for treating these varices and preventing their hemorrhage. Limitations of EVL include the risk of stricture formation and postband ulcer bleeding due to the damage caused to the esophageal mucosa, as well as the need for multiple endoscopic treatment sessions to eradicate the varices. The goal of this study is to develop a device and evaluate the technical feasibility of microwave ablation to seal esophageal varices, while preventing thermal damage to the surface mucosal tissue. A microwave applicator with a directional radiation pattern was developed for endoscopic ablation of esophageal varices. Electromagnetic and bioheat transfer computational models were employed to optimize the design of the microwave applicator and evaluate energy delivery strategies for this application. Experiments in ex vivo and in vivo tissue were employed to verify simulation results. Simulations predicted enhanced heating performance of the antenna using an angled monopole radiating element. Further, simulations indicate that while the endoscopic cap attenuated electric fields in tissue, it also enhanced surface cooling of tissue, increasing the likelihood of preserving mucosal tissue. Experiments in ex vivo tissue indicated the feasibility of sealing veins with 77 W microwave power delivered for 30 s. In vivo experiments demonstrated the ability to seal veins, while preserving surface tissue. This study demonstrated the technical feasibility of microwave thermal ablation for treating esophageal varices using a 2.45 GHz water-cooled directional microwave applicator.
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Affiliation(s)
- Jan Sebek
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506; Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, Praha 6 166 27, Czech Republic e-mail:
| | - Sergio Curto
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506 e-mail:
| | - Jimmy Eaton-Evans
- School of Engineering and Informatics, NUIG, Galway H91 TK33, Ireland e-mail:
| | | | - Giuseppe Ruvio
- School of Engineering and Informatics, NUIG, Galway H91 TK33, Ireland e-mail:
| | - Chanran Ganta
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, 1800 Denison Avenue, Manhattan, KS 66506 e-mail:
| | - Warren Beard
- Department of Clinical Sciences, Kansas State University, 1800 Denison Avenue, Manhattan, KS 66506 e-mail:
| | - Navtej Buttar
- Division of Gastroenterology and Hepatology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905 e-mail:
| | - Louis Wong Kee Song
- Division of Gastroenterology and Hepatology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905 e-mail:
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506 e-mail:
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