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Varble NA, Bakhutashvili I, Reed SL, Delgado J, Tokoutsi Z, Frackowiak B, Baragona M, Karanian JW, Wood BJ, Pritchard WF. Morphometric characterization and temporal temperature measurements during hepatic microwave ablation in swine. PLoS One 2023; 18:e0289674. [PMID: 37540658 PMCID: PMC10403086 DOI: 10.1371/journal.pone.0289674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 07/24/2023] [Indexed: 08/06/2023] Open
Abstract
PURPOSE Heat-induced destruction of cancer cells via microwave ablation (MWA) is emerging as a viable treatment of primary and metastatic liver cancer. Prediction of the impacted zone where cell death occurs, especially in the presence of vasculature, is challenging but may be achieved via biophysical modeling. To advance and characterize thermal MWA for focal cancer treatment, an in vivo method and experimental dataset were created for assessment of biophysical models designed to dynamically predict ablation zone parameters, given the delivery device, power, location, and proximity to vessels. MATERIALS AND METHODS MWA zone size, shape, and temperature were characterized and monitored in the absence of perfusion in ex vivo liver and a tissue-mimicking thermochromic phantom (TMTCP) at two power settings. Temperature was monitored over time using implanted thermocouples with their locations defined by CT. TMTCPs were used to identify the location of the ablation zone relative to the probe. In 6 swine, contrast-enhanced CTs were additionally acquired to visualize vasculature and absence of perfusion along with corresponding post-mortem gross pathology. RESULTS Bench studies demonstrated average ablation zone sizes of 4.13±1.56cm2 and 8.51±3.92cm2, solidity of 0.96±0.06 and 0.99±0.01, ablations centered 3.75cm and 3.5cm proximal to the probe tip, and temperatures of 50 ºC at 14.5±13.4s and 2.5±2.1s for 40W and 90W ablations, respectively. In vivo imaging showed average volumes of 9.8±4.8cm3 and 33.2±28.4cm3 and 3D solidity of 0.87±0.02 and 0.75±0.15, and gross pathology showed a hemorrhagic halo area of 3.1±1.2cm2 and 9.1±3.0cm2 for 40W and 90W ablations, respectfully. Temperatures reached 50ºC at 19.5±9.2s and 13.0±8.3s for 40W and 90W ablations, respectively. CONCLUSION MWA results are challenging to predict and are more variable than manufacturer-provided and bench predictions due to vascular stasis, heat-induced tissue changes, and probe operating conditions. Accurate prediction of MWA zones and temperature in vivo requires comprehensive thermal validation sets.
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Affiliation(s)
- Nicole A. Varble
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
- Philips, Best, The Netherlands
| | - Ivane Bakhutashvili
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
| | - Sheridan L. Reed
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
| | - Jose Delgado
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, United States of America
| | | | | | | | - John W. Karanian
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
| | - Bradford J. Wood
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
- Bioengineering and National Cancer Institute Center, Bethesda, Maryland, United States of America
| | - William F. Pritchard
- Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National, Institutes of Health, Bethesda, Maryland, United States of America
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Pohlman RM, Hinshaw JL, Ziemlewicz TJ, Lubner MG, Wells SA, Lee FT, Alexander ML, Wergin KL, Varghese T. Differential Imaging of Liver Tumors before and after Microwave Ablation with Electrode Displacement Elastography. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2138-2156. [PMID: 34011451 PMCID: PMC8243838 DOI: 10.1016/j.ultrasmedbio.2021.03.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 05/17/2023]
Abstract
Liver cancer is a leading cause of cancer-related deaths; however, primary treatment options such as surgical resection and liver transplant may not be viable for many patients. Minimally invasive image-guided microwave ablation (MWA) provides a locally effective treatment option for these patients with an impact comparable to that of surgery for both cancer-specific and overall survival. MWA efficacy is correlated with accurate image guidance; however, conventional modalities such as B-mode ultrasound and computed tomography have limitations. Alternatively, ultrasound elastography has been used to demarcate post-ablation zones, yet has limitations for pre-ablation visualization because of variability in strain contrast between cancer types. This study attempted to characterize both pre-ablation tumors and post-ablation zones using electrode displacement elastography (EDE) for 13 patients with hepatocellular carcinoma or liver metastasis. Typically, MWA ablation margins of 0.5-1.0 cm are desired, which are strongly correlated with treatment efficacy. Our results revealed an average estimated ablation margin inner quartile range of 0.54-1.21 cm with a median value of 0.84 cm. These treatment margins lie within or above the targeted ablative margin, indicating the potential to use EDE for differentiating index tumors and ablated zones during clinical ablations. We also obtained a high correlation between corresponding segmented cross-sectional areas from contrast-enhanced computed tomography, the current clinical gold standard, when compared with EDE strain images, with r2 values of 0.97 and 0.98 for pre- and post-ablation regions.
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Affiliation(s)
- Robert M Pohlman
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
| | - James L Hinshaw
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Timothy J Ziemlewicz
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Meghan G Lubner
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Shane A Wells
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Fred T Lee
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Marci L Alexander
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kelly L Wergin
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Tomy Varghese
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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3
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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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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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Meloni MF, Francica G, Chiang J, Coltorti A, Danzi R, Laeseke PF. Use of Contrast-Enhanced Ultrasound in Ablation Therapy of HCC: Planning, Guiding, and Assessing Treatment Response. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2021; 40:879-894. [PMID: 32936485 DOI: 10.1002/jum.15471] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Contrast-enhanced ultrasonography (CEUS) plays an important role in the management of patients treated with ablation therapies, in the diagnostic, therapeutic and monitoring phases. Compared to contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging, CEUS presents several advantages in imaging HCC, including real time imaging capability, high sensitivity for tumor vascularity, absence of renal toxicity, no ionizing radiation, repeatability of injections, good compliance by the patient and low cost. The purpose of this review is to evaluate the role of CEUS in the management of the patients with HCC treated with ablation therapies and describe how in our protocol CEUS is integrated with the other imaging modalities such as contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging.
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Affiliation(s)
- Maria Franca Meloni
- Radiology Department, University of Pavia, Italy and Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Giampiero Francica
- Interventional Ultrasound Unit, Pineta Grande Hospital, Castel Volturno, Italy
| | - Jason Chiang
- Department of Radiology, Ronald Reagan UCLA Medical Center, Los Angeles, USA
| | - Andrea Coltorti
- Department of Radiology, Federico II University, Naples, Italy
| | - Roberta Danzi
- Department of Radiology, Pineta Grande Hospital, Castel Volturno, Italy
| | - Paul F Laeseke
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
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Murat C, Palandoken M, Kaya I, Kaya A. A novel ISM band reflector type applicator design for microwave ablation systems. Electromagn Biol Med 2021; 40:286-300. [PMID: 33583285 DOI: 10.1080/15368378.2021.1885434] [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: 10/22/2022]
Abstract
In this paper, a radiation performance improved novel applicator is proposed which is called as reflector type microwave applicator as a part of microwave ablation (MWA) system operating at 2.45 GHz with experimentally measured bandwidth of 300 MHz in Industrial Scientific Medical (ISM) band for the local extermination of tumor with highly localized microwave power. The design principle of MW applicator is based on the structural formation of coaxial transmission line fed dielectric loaded with the metallic circular reflector for the near field energy concentration inside the tumorous tissue. To generate localized electromagnetic waves, a novel reflector type microwave applicator is designed by placing an aluminum disk near the 10 mm dielectric radiator section. The proposed applicator design has been numerically studied with finite integration technique (FIT) in CST Microwave Studio to develop the near field radiation pattern affecting the ablation level of tumorous tissue. In the light of performed numerical calculations, maximum SAR (Specific Absorption Rate) value on 1.76 g tumorous sample can be achieved to 208 W/kg under 15 W microwave power accepted by proposed probe. The experimental results confirm that proposed applicator can be utilized highly localized MWA applicator for cancer treatment hence the surface temperature of cylindrical shaped tumor sample which has the dimensions of 14.4 mm diameter and 8 mm height reaches from 25 to 68.3°C in 10 min.
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Affiliation(s)
- Caner Murat
- Department of Electrical and Electronics Engineering, Izmir Katip Celebi University, Izmir, Turkey
| | - Merih Palandoken
- Department of Electrical and Electronics Engineering, Izmir Katip Celebi University, Izmir, Turkey
| | - Irfan Kaya
- Department of Mechanical Engineering, Eskisehir Technical University, Eskisehir, Turkey
| | - Adnan Kaya
- Department of Electrical and Electronics Engineering, Izmir Katip Celebi University, Izmir, Turkey
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7
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Etoz S, Brace CL. Computed Tomography-Based Modeling of Water Vapor-Induced Changes in Permittivity During Microwave Ablation. IEEE Trans Biomed Eng 2020; 67:2427-2433. [DOI: 10.1109/tbme.2019.2962363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Karaki W, Rahul, Lopez CA, Borca Tasciuc DA, De S. A continuum thermomechanical model for the electrosurgery of soft hydrated tissues using a moving electrode. Comput Methods Biomech Biomed Engin 2020; 23:1317-1335. [PMID: 32744457 DOI: 10.1080/10255842.2020.1798415] [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: 10/23/2022]
Abstract
Electrosurgical radio-frequency heating of tissue is widely applied in minimally invasive surgical procedures to dissect tissue with simultaneous coagulation to obtain hemostasis. The tissue effect depends on the cumulative heating that occurs in the vicinity of the moving blade electrode. In this work, a continuum thermomechanical model based on mixture theory, which accounts for the multiphase nature of soft hydrated tissues and includes transport and evaporation losses, is used to capture the transient heating effect of a moving electrode. The model takes into account the dependence of electrical conductivity and the evaporation rate on the water content in the tissue, as it changes in response to heating. Temperature prediction is validated with mean experimental temperature measured during in situ experiments performed on porcine liver tissue at different power settings of the electrosurgical unit. The model is shown to closely capture the temperature variation in the tissue for three distinct scenarios; with no visible cutting or coagulation damage at a low 10 W power setting, with coagulation damage but no tissue cutting at an intermediate power setting of 25 W, and with both coagulation and tissue cutting at a higher power setting of 50 W. Furthermore, an Arrhenius model is shown to capture tissue damage observed in the experiments. Increase in applied power was found to correlate with tissue cutting and concentrated damage near the electrode, but had little effect on the observed coagulation damage width. The proposed model provides, for the first time, an accurate tool for predicting temperature rise and evolving damage resulting from a moving electrode in pure-cut electrosurgery.
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Affiliation(s)
- Wafaa Karaki
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Rahul
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Carlos A Lopez
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Diana-Andra Borca Tasciuc
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Suvranu De
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
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9
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He ZH, Wu QL, Ye H, Wang KY, Li LQ, Peng NF. Microwave ablation of liver cancer: An updated review. Shijie Huaren Xiaohua Zazhi 2020; 28:371-377. [DOI: 10.11569/wcjd.v28.i10.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The treatment methods for early liver cancer include surgical resection, liver transplantation, and local ablation. Among them, microwave ablation (MWA) is widely used in clinical practice because of its outstanding advantages, such as minimal invasiveness, radical curative effect, short treatment time, few complications, and no heat-sink effect, especially for the treatment of tumors adjacent to major vessels and hepatic metastases. However, MWA also has limitations such as unpredictable size and shape of the ablation area. This review systematically illustrates the effectiveness and safety of MWA in the treatment of liver cancer. Meanwhile, the relative superiority of the new generation of MWA is discussed, with an aim to provide reference for MWA of liver cancer.
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Affiliation(s)
- Ze-Hua He
- Department of General Surgery, Langdong Hospital of Guangxi Medical University, Nanning 530022, Guangxi Zhuang Autonomous Region, China
| | - Qiu-Lin Wu
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
| | - Hang Ye
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
| | - Kai-Yuan Wang
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
| | - Le-Qun Li
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
| | - Ning-Fu Peng
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
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10
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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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11
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Accurate segmentation of inflammatory and abnormal regions using medical thermal imagery. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:647-657. [PMID: 30953251 DOI: 10.1007/s13246-019-00753-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 03/30/2019] [Indexed: 10/27/2022]
Abstract
Methodologies reported in the existing literature for identification of a region of interest (ROI) in medical thermograms suffer from over- and under-extraction of the abnormal and/or inflammatory region, thereby causing inaccurate diagnoses of the spread of an abnormality. We overcome this limitation by exploiting the advantages of a logarithmic transformation. Our algorithm extends the conventional region growing segmentation technique with a modified similarity criteria and a stopping rule. In this method, the ROI is generated by taking common information from two independent regions produced by two different versions of a region-growing algorithm that use different parameters. An automatic multi-seed selection procedure prevents missed segmentations in the proposed approach. We validate our technique by experimentation on various thermal images of the inflammation of affected knees and abnormal breasts. The images were obtained from three databases, namely the Knee joint dataset, the DBT-TU-JU dataset, and the DMR-IR dataset. The superiority of the proposed technique is established by comparison to the performance of state-of-the-art competing methodologies. This study performed temperature emitted inflammatory area segmentation on thermal images of knees and breasts. The proposed segmentation method is of potential value in thermal image processing applications that require expediency and automation.
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12
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Karaki W, Lopez C, Rahul F, Borca-Tasciuc DDA, De S. Waveform Dependent Electrosurgical Effects on Soft Hydrated Tissues. J Biomech Eng 2019; 141:2725822. [PMID: 30778563 DOI: 10.1115/1.4042898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Indexed: 11/08/2022]
Abstract
Electrosurgical procedures are ubiquitously used in surgery. The commonly used power modes, including the coagulation and blend modes, utilize non-sinusoidal or modulated current waveforms. For the same power setting, the coagulation, blend and pure cutting modes have different heating and thermal damage outcomes due to the frequency dependence of electrical conductivity of soft hydrated tissues. In this paper, we propose a multi-physics model of soft tissues to account for the effects of multi-frequency electrosurgical power modes within the framework of a continuum thermomechanical model based on mixture theory. Electrical and frequency spectrum results from different power modes at low and high power settings are presented. Model predictions are compared with in vivo electrosurgical heating experiments on porcine liver tissue. The accuracy of the model in predicting experimentally observed temperature profiles is found to be overall greater when frequency-dependence is included. An Arrhenius type model indicates that more tissue damage is correlated with larger duty cycles in multi-frequency modes.
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Affiliation(s)
- Wafaa Karaki
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Carlos Lopez
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Fnu Rahul
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | | | - Suvranu De
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
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Karaki W, Lopez CA, Borca-Tasciuc DA, De S. A continuum thermomechanical model of in vivo electrosurgical heating of hydrated soft biological tissues. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2018; 127:961-974. [PMID: 30739950 PMCID: PMC6366672 DOI: 10.1016/j.ijheatmasstransfer.2018.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Radio-frequency (RF) heating of soft biological tissues during electrosurgical procedures is a fast process that involves phase change through evaporation and transport of intra- and extra-cellular water, and where variations in physical properties with temperature and water content play significant role. Accurately predicting and capturing these effects would improve the modeling of temperature change in the tissue allowing the development of improved instrument design and better understanding of tissue damage and necrosis. Previous models based on the Pennes' bioheat model neglect both evaporation and transport or consider evaporation through numerical correlations, however, do not account for changes in physical properties due to mass transport or phase change, nor capture the pressure increase due to evaporation within the tissue. While a porous media approach can capture the effects of evaporation, transport, pressure and changes in physical properties, the model assumes free diffusion of liquid and gas without a careful examination of assumptions on transport parameters in intact tissue resulting in significant under prediction of temperature. These different approaches have therefore been associated with errors in temperature prediction exceeding 20% when compared to experiments due to inaccuracies in capturing the effects of evaporation losses and transport. Here, we present a model of RF heating of hydrated soft tissue based on mixture theory where the multiphase nature of tissue is captured within a continuum thermomechanics framework, simultaneously considering the transport, deformation and phase change losses due to evaporation that occur during electrosurgical heating. The model predictions are validated against data obtained for in vivo ablation of porcine liver tissue at various power settings of the electrosurgical unit. The model is able to match the mean experimental temperature data with sharp gradients in the vicinity of the electrode during rapid low and high power ablation procedures with errors less than 7.9%. Additionally, the model is able to capture fast vaporization losses and the corresponding increase in pressure due to vapor buildup which have a significant effect on temperature prediction beyond 100 °C.
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Affiliation(s)
- Wafaa Karaki
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Carlos A Lopez
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Diana-Andra Borca-Tasciuc
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Suvranu De
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, USA
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14
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Gao H, Wu S, Wang X, Hu R, Zhou Z, Sun X. Temperature simulation of microwave ablation based on improved specific absorption rate method compared to phantom measurements. Comput Assist Surg (Abingdon) 2017; 22:9-17. [DOI: 10.1080/24699322.2017.1378605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Hongjian Gao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Xiaoru Wang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Rui Hu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Zhuhuang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Xuecong Sun
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
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15
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Li Y, Sun C, Kuang J, Ji C, Feng S, Wu J, You H. An In Vitro and Numerical Study of Moxibustion Therapy on Biological Tissue. IEEE Trans Biomed Eng 2017. [PMID: 28650805 DOI: 10.1109/tbme.2017.2719633] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Moxibustion therapy achieves satisfactory therapeutic effects largely depending on the heat stimulation of burning moxa. Understanding the thermal characteristics of heating process is an effective way to reveal the underlying mechanisms of moxibustion therapy. METHODS This paper performs experimental study on temperature distributions of burning moxa sticks and fresh in vitro porcine abdominal tissue using an infrared camera and thermocouples. Meanwhile, a moxibustion model incorporating moxa stick burning model and tissue heat transfer model was established with consideration of radiation propagation and water evaporation. RESULTS The burning features of moxa sticks were acquired and the radiation energy generated by the burning moxa stick was absorbed and scattered in biological tissue, resulting in a large temperature gradient in the skin layer. And the water evaporation led to a mass loss and reduced skin surface temperature. The numerical model was verified by experimental results and the effects of moxibustion treatment distance and duration can be quantified based on model calculation. CONCLUSION The detailed heat transfer process of moxibustion was obtained experimentally and numerically. During moxibustion, the radiation attenuation and water evaporation have a significant influence on the energy transport in biological tissue which cannot be ignored. The treatment distance of 3 cm is the recommended value to achieve the treatment efficacy without thermal damage and pain. SIGNIFICANCE This research would reveal the underlying mechanisms of moxibustion therapy. Besides, the developed models are expected to establish a guideline for moxibustion clinical treatment.
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16
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Liu D, Brace CL. Numerical simulation of microwave ablation incorporating tissue contraction based on thermal dose. Phys Med Biol 2017; 62:2070-2086. [PMID: 28151729 DOI: 10.1088/1361-6560/aa5de4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tissue contraction plays an important role during high temperature tumor ablation, particularly during device characterization, treatment planning and imaging follow up. We measured such contraction in 18 ex vivo bovine liver samples during microwave ablation by tracking fiducial motion on CT imaging. Contraction was then described using a thermal dose dependent model and a negative thermal expansion coefficient based on the empirical data. FEM simulations with integrated electromagnetic wave propagation, heat transfer, and structural mechanics were evaluated using temperature-dependent dielectric properties and the negative thermal expansion models. Simulated temperature and displacement curves were then compared with the ex vivo experimental results on different continuous output powers. The optimized thermal dose model indicated over 50% volumetric contraction occurred at the temperature over 102.1 °C. The numerical simulation results on temperature and contraction-induced displacement showed a good agreement with experimental results. At microwave powers of 55 W, the mean errors on temperature between simulation and experimental results were 8.25%, 2.19% and 5.67% at 5 mm, 10 mm and 20 mm radially from the antenna, respectively. The simulated displacements had mean errors of 16.60%, 14.08% and 23.45% at the same radial locations. Compared to the experimental results, the simulations at the other microwave powers had larger errors with 10-40% mean errors at 40 W, and 10-30% mean errors at 25 W. The proposed model is able to predict temperature elevation and simulate tissue deformation during microwave ablation, and therefore may be incorporated into treatment planning and clinical translation from numerical simulations.
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Affiliation(s)
- Dong Liu
- Department of Radiology and Biomedical Engineering, University of Wisconsin-Madison, 1111 Highland Ave, Madison WI 53705, United States of America
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17
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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: 43] [Impact Index Per Article: 5.4] [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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18
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Meloni MF, Chiang J, Laeseke PF, Dietrich CF, Sannino A, Solbiati M, Nocerino E, Brace CL, Lee FT. Microwave ablation in primary and secondary liver tumours: technical and clinical approaches. Int J Hyperthermia 2016; 33:15-24. [PMID: 27416729 DOI: 10.1080/02656736.2016.1209694] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Thermal ablation is increasingly being utilised in the treatment of primary and metastatic liver tumours, both as curative therapy and as a bridge to transplantation. Recent advances in high-powered microwave ablation systems have allowed physicians to realise the theoretical heating advantages of microwave energy compared to other ablation modalities. As a result there is a growing body of literature detailing the effects of microwave energy on tissue heating, as well as its effect on clinical outcomes. This article will discuss the relevant physics, review current clinical outcomes and then describe the current techniques used to optimise patient care when using microwave ablation systems.
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Affiliation(s)
- Maria Franca Meloni
- a Department of Radiology , Interventional Ultrasound, Institute of Care IGEA , Milan , Italy
| | - Jason Chiang
- b Department of Radiology , University of Wisconsin , Madison , Wisconsin , USA
| | - Paul F Laeseke
- b Department of Radiology , University of Wisconsin , Madison , Wisconsin , USA
| | - Christoph F Dietrich
- c Department of Internal Medicine , Caritas Krankenhas Bad Mergentheim , Bad Mergentheim , Germany
| | - Angela Sannino
- d Department of Clinical Medicine and Surgery , University of Naples Federico II , Naples , Italy
| | - Marco Solbiati
- e Department of Electronics, Information and Bioengineering , Politecnico Milano , Milan , Italy
| | - Elisabetta Nocerino
- f Department of Radiology , San Paolo Hospital, University of Milan , Milan , Italy
| | - Christopher L Brace
- b Department of Radiology , University of Wisconsin , Madison , Wisconsin , USA
| | - Fred T Lee
- b Department of Radiology , University of Wisconsin , Madison , Wisconsin , USA
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19
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Kassab GS, An G, Sander EA, Miga MI, Guccione JM, Ji S, Vodovotz Y. Augmenting Surgery via Multi-scale Modeling and Translational Systems Biology in the Era of Precision Medicine: A Multidisciplinary Perspective. Ann Biomed Eng 2016; 44:2611-25. [PMID: 27015816 DOI: 10.1007/s10439-016-1596-4] [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] [Received: 11/01/2015] [Accepted: 03/18/2016] [Indexed: 12/18/2022]
Abstract
In this era of tremendous technological capabilities and increased focus on improving clinical outcomes, decreasing costs, and increasing precision, there is a need for a more quantitative approach to the field of surgery. Multiscale computational modeling has the potential to bridge the gap to the emerging paradigms of Precision Medicine and Translational Systems Biology, in which quantitative metrics and data guide patient care through improved stratification, diagnosis, and therapy. Achievements by multiple groups have demonstrated the potential for (1) multiscale computational modeling, at a biological level, of diseases treated with surgery and the surgical procedure process at the level of the individual and the population; along with (2) patient-specific, computationally-enabled surgical planning, delivery, and guidance and robotically-augmented manipulation. In this perspective article, we discuss these concepts, and cite emerging examples from the fields of trauma, wound healing, and cardiac surgery.
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Affiliation(s)
- Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, 92121, USA
| | - Gary An
- Department of Surgery, University of Chicago, Chicago, IL, 60637, USA
| | - Edward A Sander
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Michael I Miga
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, USA
| | - Julius M Guccione
- Department of Surgery, University of California, San Francisco, CA, 94143, USA
| | - Songbai Ji
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA.,Department of Surgery and of Orthopaedic Surgery, Geisel School of Medicine, Dartmouth College, Hanover, NH, 03755, USA
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh, W944 Starzl Biomedical Sciences Tower, 200 Lothrop St., Pittsburgh, PA, 15213, USA. .,Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15219, USA.
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20
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Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery. Ann Biomed Eng 2015; 44:128-38. [PMID: 26354118 DOI: 10.1007/s10439-015-1433-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 08/18/2015] [Indexed: 01/14/2023]
Abstract
With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications.
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