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Keshavamurthy KN, Eickhoff C, Ziv E. Pre-operative lung ablation prediction using deep learning. Eur Radiol 2024:10.1007/s00330-024-10767-8. [PMID: 38775950 DOI: 10.1007/s00330-024-10767-8] [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: 02/09/2024] [Revised: 02/09/2024] [Accepted: 03/07/2024] [Indexed: 07/31/2024]
Abstract
OBJECTIVE Microwave lung ablation (MWA) is a minimally invasive and inexpensive alternative cancer treatment for patients who are not candidates for surgery/radiotherapy. However, a major challenge for MWA is its relatively high tumor recurrence rates, due to incomplete treatment as a result of inaccurate planning. We introduce a patient-specific, deep-learning model to accurately predict post-treatment ablation zones to aid planning and enable effective treatments. MATERIALS AND METHODS Our IRB-approved retrospective study consisted of ablations with a single applicator/burn/vendor between 01/2015 and 01/2019. The input data included pre-procedure computerized tomography (CT), ablation power/time, and applicator position. The ground truth ablation zone was segmented from follow-up CT post-treatment. Novel deformable image registration optimized for ablation scans and an applicator-centric co-ordinate system for data analysis were applied. Our prediction model was based on the U-net architecture. The registrations were evaluated using target registration error (TRE) and predictions using Bland-Altman plots, Dice co-efficient, precision, and recall, compared against the applicator vendor's estimates. RESULTS The data included 113 unique ablations from 72 patients (median age 57, interquartile range (IQR) (49-67); 41 women). We obtained a TRE ≤ 2 mm on 52 ablations. Our prediction had no bias from ground truth ablation volumes (p = 0.169) unlike the vendor's estimate (p < 0.001) and had smaller limits of agreement (p < 0.001). An 11% improvement was achieved in the Dice score. The ability to account for patient-specific in-vivo anatomical effects due to vessels, chest wall, heart, lung boundaries, and fissures was shown. CONCLUSIONS We demonstrated a patient-specific deep-learning model to predict the ablation treatment effect prior to the procedure, with the potential for improved planning, achieving complete treatments, and reduce tumor recurrence. CLINICAL RELEVANCE STATEMENT Our method addresses the current lack of reliable tools to estimate ablation extents, required for ensuring successful ablation treatments. The potential clinical implications include improved treatment planning, ensuring complete treatments, and reducing tumor recurrence.
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Affiliation(s)
| | - Carsten Eickhoff
- University of Tübingen Geschwister-Scholl-Platz, 72074, Tübingen, Germany
| | - Etay Ziv
- Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA
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2
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Frackowiak B, Van den Bosch V, Tokoutsi Z, Baragona M, de Greef M, Elevelt A, Isfort P. First validation of a model-based hepatic percutaneous microwave ablation planning on a clinical dataset. Sci Rep 2023; 13:16862. [PMID: 37803064 PMCID: PMC10558472 DOI: 10.1038/s41598-023-42543-x] [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: 04/05/2023] [Accepted: 09/12/2023] [Indexed: 10/08/2023] Open
Abstract
A model-based planning tool, integrated in an imaging system, is envisioned for CT-guided percutaneous microwave ablation. This study aims to evaluate the biophysical model performance, by comparing its prediction retrospectively with the actual ablation ground truth from a clinical dataset in liver. The biophysical model uses a simplified formulation of heat deposition on the applicator and a heat sink related to vasculature to solve the bioheat equation. A performance metric is defined to assess how the planned ablation overlaps the actual ground truth. Results demonstrate superiority of this model prediction compared to manufacturer tabulated data and a significant influence of the vasculature cooling effect. Nevertheless, vasculature shortage due to branches occlusion and applicator misalignment due to registration error between scans affects the thermal prediction. With a more accurate vasculature segmentation, occlusion risk can be estimated, whereas branches can be used as liver landmarks to improve the registration accuracy. Overall, this study emphasizes the benefit of a model-based thermal ablation solution in better planning the ablation procedures. Contrast and registration protocols must be adapted to facilitate its integration into the clinical workflow.
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Affiliation(s)
- Bruno Frackowiak
- Philips Research, Data Science & Digital Twin, 5656 AE, Eindhoven, The Netherlands.
| | - Vincent Van den Bosch
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, 52074, Aachen, Germany
| | - Zoi Tokoutsi
- Philips Research, Data Science & Digital Twin, 5656 AE, Eindhoven, The Netherlands
| | - Marco Baragona
- Philips Research, Data Science & Digital Twin, 5656 AE, Eindhoven, The Netherlands
| | - Martijn de Greef
- Philips Research, Data Science & Digital Twin, 5656 AE, Eindhoven, The Netherlands
| | - Aaldert Elevelt
- Philips Research, Data Science & Digital Twin, 5656 AE, Eindhoven, The Netherlands
| | - Peter Isfort
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, 52074, Aachen, Germany
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3
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Lakshmi Narasimhan P, Tokoutsi Z, Baroli D, Baragona M, Veroy K, Maessen R, Ritter A. Global sensitivity study for irreversible electroporation: Towards treatment planning under uncertainty. Med Phys 2023; 50:1290-1304. [PMID: 36635955 DOI: 10.1002/mp.16220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Electroporation-based cancer treatments are minimally invasive, nonthermal interventional techniques that leverage cell permeabilization to ablate the target tumor. However, the amount of permeabilization is susceptible to the numerous uncertainties during treatment, such as patient-specific variations in the tissue, type of the tumor, and the resolution of imaging equipment. These uncertainties can reduce the extent of ablation in the tissue, thereby affecting the effectiveness of the treatment. PURPOSE The aim of this work is to understand the effect of these treatment uncertainties on the treatment outcome for irreversible electroporation (IRE) in the case of colorectal liver metastasis (CRLM). Understanding the nature and extent of these effects can help us identify the influential treatment parameters and build better models for predicting the treatment outcome. METHODS This is an in silico study using a static computational model with a custom applicator design, spherical tissue, and tumor geometry. A nonlinear electrical conductivity, dependent on the local electric field, is considered. Morris analysis is used to identify the influential treatment parameters on the treatment outcome. Seven treatment parameters pertaining to the relative tumor location with respect to the applicator, the tumor growth pattern, and the electrical conductivity of tissue are analyzed. The treatment outcome is measured in terms of the relative tumor ablation with respect to the target ablation volume and total ablation volume. RESULTS The Morris analysis was performed with 800 model evaluations, sampled from the seven dimensional input parameter space. Electrical properties of the tissue, especially the electrical conductivity of the tumor before ablation, were found to be the most influential parameter for relative tumor ablation and total ablation volume. This parameter was found to be about 4-15 times more influential than the least influential parameter, depending on the tumor size. The tumor border configuration was identified as the least important parameter for treatment effectiveness. The most desired treatment outcome is obtained by a combination of high healthy liver conductivity and low tumor conductivity. This information can be used to tackle worst-case scenarios in treatment planning. Finally, when the safety margins used in the clinical applications are accounted for, the effects of uncertainties in the treatment parameters reduce drastically. CONCLUSIONS The results of this work can be used to create an efficient surrogate estimator for uncertainty quantification in the treatment outcome, that can be utilized in optimal real-time treatment planning solutions.
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Affiliation(s)
- Prashanth Lakshmi Narasimhan
- Philips Research, Eindhoven, AE, The Netherlands
- Centre for Analysis, Scientific Computing, and Applications, Eindhoven University of Technology, Eindhoven, AZ, The Netherlands
| | - Zoi Tokoutsi
- Philips Research, Eindhoven, AE, The Netherlands
| | - Davide Baroli
- Euler Institute (Instituto Eulero) and Cardiocentro Ticino, Faculty of Informatics, Universitá della Svizzera italiana, Viganello-Lugano, Switzerland
| | | | - Karen Veroy
- Centre for Analysis, Scientific Computing, and Applications, Eindhoven University of Technology, Eindhoven, AZ, The Netherlands
| | | | - Andreas Ritter
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Aachen, Germany
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Jin X, Liu W, Li Y, Qian L, Zhu Q, Li W, Qian Z. Evaluation method of ex vivo porcine liver reduced scattering coefficient during microwave ablation based on temperature. BIOMED ENG-BIOMED TE 2022; 67:491-501. [DOI: 10.1515/bmt-2022-0189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 08/01/2022] [Indexed: 11/15/2022]
Abstract
Abstract
The principle of microwave ablation (MWA) is to cause irreversible damage (protein coagulation, necrosis, etc.) to tumor cells at a certain temperature by heating, thereby destroying the tumor. We have long used functional near-infrared spectroscopy (fNIRs) to monitor clinical thermal ablation efficacy. After a lot of experimental verification, it can be found that there is a clear correlation between the reduced scattering coefficient and the degree of tissue damage. During the MWA process, the reduced scattering coefficient has a stable change. Therefore, both temperature (T) and reduced scattering coefficient (
μ
s
′
${\mu }_{s}^{\prime }$
) are related to the thermal damage of the tissue. This paper mainly studies the changing law of T and
μ
s
′
${\mu }_{s}^{\prime }$
during MWA and establishes a relationship model. The two-parameter simultaneous acquisition system was designed and used to obtain the T and
μ
s
′
${\mu }_{s}^{\prime }$
of the ex vivo porcine liver during MWA. The correlation model between T and
μ
s
′
${\mu }_{s}^{\prime }$
is established, enabling the quantitative estimation of
μ
s
′
${\mu }_{s}^{\prime }$
of porcine liver based on T. The maximum and the minimum relative errors of
μ
s
′
${\mu }_{s}^{\prime }$
are 79.01 and 0.39%, respectively. Through the electromagnetic simulation of the temperature field during MWA, 2D and 3D fields of reduced scattering coefficient can also be obtained using this correlation model. This study contributes to realize the preoperative simulation of the optical parameter field of microwave ablation and provide 2D/3D therapeutic effect for clinic.
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Affiliation(s)
- Xiaofei Jin
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Wenwen Liu
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Yiran Li
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Lu Qian
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Qiaoqiao Zhu
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Weitao Li
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
| | - Zhiyu Qian
- Department of Biomedical Engineering , College of Automation Engineering, Nanjing University of Aeronautics and Astronautics , Nanjing , China
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Jin X, Feng Y, Zhu R, Qian L, Yang Y, Yu Q, Zou Z, Li W, Liu Y, Qian Z. Temperature control and intermittent time-set protocol optimization for minimizing tissue carbonization in microwave ablation. Int J Hyperthermia 2022; 39:868-879. [PMID: 35858640 DOI: 10.1080/02656736.2022.2075041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE The charring tissue formation in the ablated lesion during the microwave ablation (MWA) of tumors would induce various unwanted inflammatory responses. This paper aimed to deliver appropriate thermal dose for effective ablations while preventing tissue carbonization by optimizing the treatment protocol during MWA with the set combinations of temperature control and pulsed microwave energy delivery. MATERIAL AND METHODS The thermal phase transition of ex vivo porcine liver tissues were recorded by differential scanning calorimetry (DSC) to determine the temperature threshold during microwave output control. MWA was performed by an in-house built system with the ease of microwave output parameter adjustment and real-time temperature monitoring. The effects of continuous and pulsed microwave deliveries as well as various intermittent time-set of MWA were evaluated by measuring the dimensions of the coagulation zone and the carbonization zone. RESULTS The DSC scans demonstrated that the ex vivo porcine liver tissues have been in a state of endothermic heat during the heating process, where the maximum absorbed heat occurred at the temperature of 105 °C ± 5 °C. The temperature control during MWA resulted in effective coagulative necrosis while preventing tissue carbonization, after setting 100 °C as the upper threshold temperature and 60 °C as the lower threshold. Both the numerical simulation and ex vivo experiments have shown that, upon the optimization of the time-set parameters in the periodic intermittent pulsed microwave output, the tissue carbonization was significantly diminished. CONCLUSION This study developed a straight-forward anti-carbonization strategy in MWA by modulating the pulsing mode and intermittent time. The programmed protocols of intermittent pulsing MWA have demonstrated its potentials toward future expansion of MWA technology in clinical application.
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Affiliation(s)
- Xiaofei Jin
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yu Feng
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Roujun Zhu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Lu Qian
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yamin Yang
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Qindong Yu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhihan Zou
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Weitao Li
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yangyang Liu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhiyu Qian
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
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Sebek J, Shrestha TB, Basel MT, Chamani F, Zeinali N, Mali I, Payne M, Timmerman SA, Faridi P, Pyle M, O’Halloran M, Dennedy MC, Bossmann SH, Prakash P. System for delivering microwave ablation to subcutaneous tumors in small-animals under high-field MRI thermometry guidance. Int J Hyperthermia 2022; 39:584-594. [DOI: 10.1080/02656736.2022.2061727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Jan Sebek
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
- Department of Circuit Theory, Czech Technical University in Prague, Prague, Czech Republic
| | - Tej B. Shrestha
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA
| | - Matthew T. Basel
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA
| | - Faraz Chamani
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Nooshin Zeinali
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Ivina Mali
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Macy Payne
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Sarah A. Timmerman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA
| | - Pegah Faridi
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Marla Pyle
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA
| | - Martin O’Halloran
- College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Republic of Ireland
| | - M. Conall Dennedy
- College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Republic of Ireland
| | - Stefan H. Bossmann
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Punit Prakash
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
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Asadi S, Korganbayev S, Xu W, Mapanao AK, Voliani V, Lehto VP, Saccomandi P. Experimental Evaluation of Radiation Response and Thermal Properties of NPs-Loaded Tissues-Mimicking Phantoms. NANOMATERIALS 2022; 12:nano12060945. [PMID: 35335758 PMCID: PMC8950154 DOI: 10.3390/nano12060945] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/06/2022] [Accepted: 03/09/2022] [Indexed: 02/04/2023]
Abstract
Many efforts have recently concentrated on constructing and developing nanoparticles (NPs) as promising thermal agent for optical hyperthermia and photothermal therapy. However, thermal energy transfer in biological tissue is a complex process involving different mechanisms such as conduction, convection, radiation. Therefore, having information about thermal properties of tissue especially when NPs are embedded in is a necessity for predicting the heat transfer during hyperthermia. In this work, the thermal properties of solid phantom based on agar in the presence of three different nanoparticles (BPSi, tNAs, GNRs) and alone were measured and reported as a function of temperature (ranging from 22 to 62 °C). The thermal response of these NPs to an 808 nm laser beam with three different powers were studied in the water comparatively. Agar and tNAs have almost constant thermal properties in the considered range. Among the three NPs, gold has the highest conductivity and diffusivity. At 62 °C BPSi NPs have the similar amount of increase for the diffusivity. The thermal parameters reported in this paper can be useful for the mathematical modeling. Irradiation of the NPs-loaded water phantom displayed the highest radiosensitivity of gold among the three mentioned NPs. However, for the higher power of irradiation, BPSi and tNAs NPs showed the increased absorption of heat during shorter time and the increased temperature gradient slope for the initial 15 s after the irradiation started. The three NPs showed different thermal and irradiation response behavior; however, this comparison study notes the worth of having information about thermal parameters of NPs-loaded tissue for pre-clinical planning.
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Affiliation(s)
- Somayeh Asadi
- Department of Mechanical Engineering, Politecnico di Milano, 20156 Milan, Italy; (S.K.); (P.S.)
- Correspondence: ; Tel.: +39-022-399-8572
| | - Sanzhar Korganbayev
- Department of Mechanical Engineering, Politecnico di Milano, 20156 Milan, Italy; (S.K.); (P.S.)
| | - Wujun Xu
- Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland; (W.X.); (V.-P.L.)
| | - Ana Katrina Mapanao
- Center for Nanotechnology Innovation, Istituto Italiano di Tecnologia, 56127 Pisa, Italy; (A.K.M.); (V.V.)
| | - Valerio Voliani
- Center for Nanotechnology Innovation, Istituto Italiano di Tecnologia, 56127 Pisa, Italy; (A.K.M.); (V.V.)
| | - Vesa-Pekka Lehto
- Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland; (W.X.); (V.-P.L.)
| | - Paola Saccomandi
- Department of Mechanical Engineering, Politecnico di Milano, 20156 Milan, Italy; (S.K.); (P.S.)
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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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9
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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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10
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Kok HP, Cressman ENK, Ceelen W, Brace CL, Ivkov R, Grüll H, Ter Haar G, Wust P, Crezee J. Heating technology for malignant tumors: a review. Int J Hyperthermia 2021; 37:711-741. [PMID: 32579419 DOI: 10.1080/02656736.2020.1779357] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.
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Affiliation(s)
- H Petra Kok
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Erik N K Cressman
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Wim Ceelen
- Department of GI Surgery, Ghent University Hospital, Ghent, Belgium
| | - Christopher L Brace
- Department of Radiology and Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert Ivkov
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.,Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Holger Grüll
- Department of Diagnostic and Interventional Radiology, Faculty of Medicine, University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Gail Ter Haar
- Department of Physics, The Institute of Cancer Research, London, UK
| | - Peter Wust
- Department of Radiation Oncology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Crezee
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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11
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Barnat N, Grisey A, Gerold B, Yon S, Anquez J, Aubry JF. Vein wall shrinkage induced by thermal coagulation with high-intensity-focused ultrasound: numerical modeling and in vivo experiments in sheep. Int J Hyperthermia 2021; 37:1238-1247. [PMID: 33164625 DOI: 10.1080/02656736.2020.1834626] [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] Open
Abstract
BACKGROUND Varicose veins are a common disease that may significantly affect quality of life. Different approaches are currently used in clinical practice to treat this pathology. MATERIALS AND METHODS In thermal therapy (radiofrequency or laser therapy), the vein is directly heated to a high temperature to induce vein wall coagulation, and the heat induces denaturation of the intramural collagen, which results macroscopically in vein shrinkage. Thermal vein shrinkage is a physical indicator of the efficiency of endovenous treatment. High-intensity focused ultrasound (HIFU) is a noninvasive technique that can thermally coagulate vein walls and induce vein shrinkage. In this study, we evaluated the vein shrinkage induced in vivo by extracorporeal HIFU ablation of sheep veins: six lateral saphenous veins (3.4mm mean diameter) were sonicated for 8 s with 3MHz continuous waves. Ultrasound imaging was performed before and immediately post-HIFU to quantify the HIFU-induced shrinkage. RESULTS Luminal constriction was observed in 100% (6/6) of the treated veins. The immediate findings showed a mean diameter constriction of 53%. The experimental HIFU-induced shrinkage data were used to validate a numerical model developed to predict the thermally induced vein contraction during HIFU treatment. CONCLUSIONS This model is based on the use of the k-wave library and published contraction rates of vessels immersed in hot water baths. The simulation results agreed well with those of in vivo experiments, showing a mean percent difference of 5%. The numerical model could thus be a valuable tool for optimizing ultrasound parameters as functions of the vein diameter, and future clinical trials are anticipated.
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Affiliation(s)
- Nesrine Barnat
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research University, Paris, France.,Theraclion, Malakoff, France
| | | | | | | | | | - Jean-François Aubry
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research University, Paris, France
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12
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Mohammadi A, Bianchi L, Asadi S, Saccomandi P. Measurement of Ex Vivo Liver, Brain and Pancreas Thermal Properties as Function of Temperature. SENSORS (BASEL, SWITZERLAND) 2021; 21:4236. [PMID: 34205567 PMCID: PMC8235733 DOI: 10.3390/s21124236] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/04/2021] [Accepted: 06/17/2021] [Indexed: 12/11/2022]
Abstract
The ability to predict heat transfer during hyperthermal and ablative techniques for cancer treatment relies on understanding the thermal properties of biological tissue. In this work, the thermal properties of ex vivo liver, pancreas and brain tissues are reported as a function of temperature. The thermal diffusivity, thermal conductivity and volumetric heat capacity of these tissues were measured in the temperature range from 22 to around 97 °C. Concerning the pancreas, a phase change occurred around 45 °C; therefore, its thermal properties were investigated only until this temperature. Results indicate that the thermal properties of the liver and brain have a non-linear relationship with temperature in the investigated range. In these tissues, the thermal properties were almost constant until 60 to 70 °C and then gradually changed until 92 °C. In particular, the thermal conductivity increased by 100% for the brain and 60% for the liver up to 92 °C, while thermal diffusivity increased by 90% and 40%, respectively. However, the heat capacity did not significantly change in this temperature range. The thermal conductivity and thermal diffusivity were dramatically increased from 92 to 97 °C, which seems to be due to water vaporization and state transition in the tissues. Moreover, the measurement uncertainty, determined at each temperature, increased after 92 °C. In the temperature range of 22 to 45 °C, the thermal properties of pancreatic tissue did not change significantly, in accordance with the results for the brain and liver. For the three tissues, the best fit curves are provided with regression analysis based on measured data to predict the tissue thermal behavior. These curves describe the temperature dependency of tissue thermal properties in a temperature range relevant for hyperthermia and ablation treatments and may help in constructing more accurate models of bioheat transfer for optimization and pre-planning of thermal procedures.
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Affiliation(s)
| | | | | | - Paola Saccomandi
- Department of Mechanical Engineering, Politecnico di Milano, 20156 Milan, Italy; (A.M.); (L.B.); (S.A.)
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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: 12] [Impact Index Per Article: 4.0] [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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Fallahi H, Sebek J, Prakash P. Broadband Dielectric Properties of Ex Vivo Bovine Liver Tissue Characterized at Ablative Temperatures. IEEE Trans Biomed Eng 2020; 68:90-98. [PMID: 32746009 DOI: 10.1109/tbme.2020.2996825] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To investigate the thermal and frequency dependence of dielectric properties of ex vivo liver tissue - relative permittivity and effective conductivity - over the frequency range 500 MHz to 6 GHz and temperatures ranging from 20 to 130 °C. METHODS We measured the dielectric properties of fresh ex vivo bovine liver tissue using the open-ended coaxial probe method (n = 15 samples). Numerical optimization techniques were utilized to obtain parametric models for characterizing changes in broadband dielectric properties as a function of temperature and thermal isoeffective dose. The effect of heating tissue at rates over the range 6.4-16.9 °C/min was studied. The measured dielectric properties were used in simulations of microwave ablation to assess changes in simulated antenna return loss compared to experimental measurements. RESULTS Across all frequencies, both relative permittivity and effective conductivity dropped sharply over the temperature range 89 - 107 °C. Below 91 °C, the slope of the effective conductivity changes from positive values at lower frequencies (0.5-1.64 GHz) to negative values at higher frequencies (1.64-6 GHz). The maximum achieved correlation values between transient reflection coefficients from measurements and simulations ranged between 0.83 - 0.89 and 0.68 - 0.91, respectively, when using temperature-dependent and thermal-dose dependent dielectric property parameterizations. CONCLUSION We have presented experimental measurements and parametric models for characterizing changes in dielectric properties of bovine liver tissue at ablative temperatures. SIGNIFICANCE The presented dielectric property models will contribute to the development of ablation systems operating at frequencies other than 2.45 GHz, as well as broadband techniques for monitoring growth of microwave ablation zones.
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17
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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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18
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Faridi P, Keselman P, Fallahi H, Prakash P. Experimental assessment of microwave ablation computational modeling with MR thermometry. Med Phys 2020; 47:3777-3788. [PMID: 32506550 DOI: 10.1002/mp.14318] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/22/2020] [Accepted: 05/24/2020] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Computational models are widely used during the design and characterization of microwave ablation (MWA) devices, and have been proposed for pretreatment planning. Our objective was to assess three-dimensional (3D) transient temperature and ablation profiles predicted by MWA computational models with temperature profiles measured experimentally using magnetic resonance (MR) thermometry in ex vivo bovine liver. MATERIALS AND METHODS We performed MWA in ex vivo tissue under MR guidance using a custom, 2.45 GHz water-cooled applicator. MR thermometry data were acquired for 2 min prior to heating, during 5-10 min microwave exposures, and for 3 min following heating. Fiber-optic temperature sensors were used to validate the accuracy of MR temperature measurements. A total of 13 ablation experiments were conducted using 30-50 W applied power at the applicator input. MWA computational models were implemented using the finite element method, and incorporated temperature-dependent changes in tissue physical properties. Model-predicted ablation zone extents were compared against MRI-derived Arrhenius thermal damage maps using the Dice similarity coefficient (DSC). RESULTS Prior to heating, the observed standard deviation of MR temperature data was in the range of 0.3-0.7°C. Mean absolute error between MR temperature measurements and fiber-optic temperature probes during heating was in the range of 0.5-2.8°C. The mean DSC between model-predicted ablation zones and MRI-derived Arrhenius thermal damage maps for 13 experimental set-ups was 0.95. When comparing simulated and experimentally (i.e. using MRI) measured temperatures, the mean absolute error (MAE %) relative to maximum temperature change was in the range 5%-8.5%. CONCLUSION We developed a system for characterizing 3D transient temperature and ablation profiles with MR thermometry during MWA in ex vivo liver tissue, and applied the system for experimental validation of MWA computational models.
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Affiliation(s)
- Pegah Faridi
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - Paul Keselman
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Hojjatollah Fallahi
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - Punit Prakash
- Mike Wiegers Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, 66506, USA
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19
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Singh S, Melnik R. Thermal ablation of biological tissues in disease treatment: A review of computational models and future directions. Electromagn Biol Med 2020; 39:49-88. [PMID: 32233691 DOI: 10.1080/15368378.2020.1741383] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Percutaneous thermal ablation has proven to be an effective modality for treating both benign and malignant tumours in various tissues. Among these modalities, radiofrequency ablation (RFA) is the most promising and widely adopted approach that has been extensively studied in the past decades. Microwave ablation (MWA) is a newly emerging modality that is gaining rapid momentum due to its capability of inducing rapid heating and attaining larger ablation volumes, and its lesser susceptibility to the heat sink effects as compared to RFA. Although the goal of both these therapies is to attain cell death in the target tissue by virtue of heating above 50°C, their underlying mechanism of action and principles greatly differs. Computational modelling is a powerful tool for studying the effect of electromagnetic interactions within the biological tissues and predicting the treatment outcomes during thermal ablative therapies. Such a priori estimation can assist the clinical practitioners during treatment planning with the goal of attaining successful tumour destruction and preservation of the surrounding healthy tissue and critical structures. This review provides current state-of-the-art developments and associated challenges in the computational modelling of thermal ablative techniques, viz., RFA and MWA, as well as touch upon several promising avenues in the modelling of laser ablation, nanoparticles assisted magnetic hyperthermia and non-invasive RFA. The application of RFA in pain relief has been extensively reviewed from modelling point of view. Additionally, future directions have also been provided to improve these models for their successful translation and integration into the hospital work flow.
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Affiliation(s)
- Sundeep Singh
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Roderick Melnik
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, Waterloo, Ontario, Canada.,BCAM - Basque Center for Applied Mathematics, Bilbao, Spain
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20
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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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21
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Numerical Analysis of Human Cancer Therapy Using Microwave Ablation. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app10010211] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Microwave ablation is one type of hyperthermia treatment of cancer that involves heating tumor cells. This technique uses electromagnetic wave effects to kill cancer cells. A micro-coaxial antenna is introduced into the biological tissue. The radiation emitted by the antenna is absorbed by the tissue and leads to the heating of cancer cells. The diffuse increase in temperature should reach a certain value to achieve the treatment of cancer cells but it should be less than a certain other value to avoid damaging normal cells. This is why hyperthermia treatment should be carefully monitored. A numerical simulation is useful and may provide valuable information. The bio-heat equation and Maxwell’s equations are solved using the finite element method. Electro-thermal effects, temperature distribution profile, specific absorption rate (SAR), and fraction of necrotic tissue within cancer cells are analyzed. The results show that SAR and temperature distribution are strongly affected by input microwave power. High microwave power causes a high SAR value and raises the temperature above 50 °C, which may destroy healthy cells. It is revealed that with a power of 10 W, the tumor cells will be killed without damaging the surrounding tissue.
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22
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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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23
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Collins JA, Heiselman JS, Clements LW, Weis JA, Brown DB, Miga MI. Toward Image Data-Driven Predictive Modeling for Guiding Thermal Ablative Therapy. IEEE Trans Biomed Eng 2019; 67:1548-1557. [PMID: 31494543 DOI: 10.1109/tbme.2019.2939686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Accurate prospective modeling of microwave ablation (MWA) procedures can provide powerful planning and navigational information to physicians. However, patient-specific tissue properties are generally unavailable and can vary based on factors such as relative perfusion and state of disease. Therefore, a need exists for modeling frameworks that account for variations in tissue properties. METHODS In this study, we establish an inverse modeling approach to reconstruct a set of tissue properties that best fit the model-predicted and observed ablation zone extents in a series of phantoms of varying fat content. We then create a model of these tissue properties as a function of fat content and perform a comprehensive leave-one-out evaluation of the predictive property model. Furthermore, we validate the inverse-model predictions in a separate series of phantoms that include co-recorded temperature data. RESULTS This model-based approach yielded thermal profiles in close agreement with experimental measurements in the series of validation phantoms (average root-mean-square error of 4.8 °C). The model-predicted ablation zones showed compelling overlap with observed ablations in both the series of validation phantoms (93.4 ± 2.2%) and the leave-one-out cross validation study (86.6 ± 5.3%). These results demonstrate an average improvement of 17.3% in predicted ablation zone overlap when comparing the presented property-model to properties derived from phantom component volume fractions. CONCLUSION These results demonstrate accurate model-predicted ablation estimates based on image-driven determination of tissue properties. SIGNIFICANCE The work demonstrates, as a proof-of-concept, that physical modeling parameters can be linked with quantitative medical imaging to improve the utility of predictive procedural modeling for MWA.
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24
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Strigari L, Minosse S, D'Alessio D, Farina L, Cavagnaro M, Cassano B, Pinto R, Vallati G, Lopresto V. Microwave thermal ablation using CT-scanner for predicting the variation of ablated region over time: advantages and limitations. Phys Med Biol 2019; 64:115021. [PMID: 30995620 DOI: 10.1088/1361-6560/ab1a67] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study aims at investigating in real-time the structural and dynamical changes occurring in an ex vivo tissue during a microwave thermal ablation (MTA) procedure. The experimental set-up was based on ex vivo liver tissue inserted in a dedicated box, in which 3 fibre-optic (FO) temperature probes were introduced to measure the temperature increase over time. Computed tomography (CT) imaging technique was exploited to experimentally study in real-time the Hounsfield Units (HU) modification occurring during MTA. The collected image data were processed with a dedicated MATLAB tool, developed to analyse the FO positions and HU modifications from the CT images acquired over time before and during the ablation procedures. The radial position of a FO temperature probe (rFO) and the value of HU in the region of interest (ROI) containing the probe (HUo), along with the corresponding value of HU in the contralateral ROI with respect to the MTA antenna applicator (HUc), were determined and registered over time during and after the MTA procedure. Six experiments were conducted to confirm results. The correlation between temperature and the above listed predictors was investigated using univariate and multivariate analysis. At the multivariate analysis, the time, rFO and HUc resulted significant predictive factors of the logarithm of measured temperature. The correlation between predicted and measured temperatures was 0.934 (p < 0.001). The developed tool allows identifying and registering the image-based parameters useful for predicting the temperature variation over time in each investigated voxel by taking into consideration the HU variation.
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Affiliation(s)
- L Strigari
- Laboratory of Medical Physics and Expert Systems, IRCCS Regina Elena National Cancer Institute, IFO, via Elio Chianesi, 53, 00144, Rome, Italy. Current address: Department of Medical Physics, St. Orsola-Malpighi University Hospital, via Massarenti 9 40138 Bologna, Italy
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Lopresto V, Argentieri A, Pinto R, Cavagnaro M. Temperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures. ACTA ACUST UNITED AC 2019; 64:105016. [DOI: 10.1088/1361-6560/ab1663] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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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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Multi-Objective Calibration of a Distributed Hydrological Model in a Highly Glacierized Watershed in Central Asia. WATER 2019. [DOI: 10.3390/w11030554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Understanding glacio-hydrological processes is crucial to water resources management, especially under increasing global warming. However, data scarcity makes it challenging to quantify the contribution of glacial melt to streamflow in highly glacierized catchments such as those in the Tienshan Mountains. This study aims to investigate the glacio-hydrological processes in the SaryDjaz-Kumaric River (SDKR) basin in Central Asia by integrating a degree-day glacier melt algorithm into the macro-scale hydrological Soil and Water Assessment Tool (SWAT) model. To deal with data scarcity in the alpine area, a multi-objective sensitivity analysis and a multi-objective calibration procedure were used to take advantage of all aspects of streamflow. Three objective functions, i.e., the Nash–Sutcliffe efficiency coefficient of logarithms (LogNS), the water balance index (WBI), and the mean absolute relative difference (MARD), were considered. Results show that glacier and snow melt-related parameters are generally sensitive to all three objective functions. Compared to the original SWAT model, simulations with a glacier module match fairly well to the observed streamflow, with the Nash–Sutcliffe efficiency coefficient (NS) and R2 approaching 0.82 and an absolute percentage bias less than 1%. Glacier melt contribution to runoff is 30–48% during the simulation period. The approach of combining multi-objective sensitivity analysis and optimization is an efficient way to identify important hydrological processes and recharge characteristics in highly glacierized catchments.
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Faridi P, Fallahi H, Prakash P. Evaluation of the Effect of Uterine Fibroids on Microwave Endometrial Ablation Profiles. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:3236-3239. [PMID: 30441081 DOI: 10.1109/embc.2018.8513051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Thermal ablation of the endometrial lining of the uterus is a minimally-invasive technique for treatment of menorrhagia. We have previously presented a 915 MHz microwave triangular loop antenna for endometrial ablation. Uterine fibroids are benign pelvic tumors, of considerably different water content compared to normal uterus, and may change the shape of the uterus. Collectively, these changes introduced by fibroids may alter the pattern of microwave endometrial ablation. In this study, we have investigated the effect of 1 - 3 cm diameter uterine fibroids in different locations around the uterine cavity on ablation profiles following 60 W, 150 s microwave exposure with a loop antenna. Our computational model predicts ablation zone extents within 1 ± 0.8 of ablation zones observed in experiments in ex vivo tissue. The maximum change in simulated ablation depths due to the presence of fibroids was 1.1 mm. In summary, this simulation study suggests that 1 - 3 cm diameter uterine fibroids can be expected to have minimal impact on the extent of microwave endometrial ablation patterns.
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Farina L, Nissenbaum Y, Cavagnaro M, Goldberg SN. Tissue shrinkage in microwave thermal ablation: comparison of three commercial devices. Int J Hyperthermia 2017; 34:382-391. [DOI: 10.1080/02656736.2017.1362115] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Laura Farina
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, Rome, Italy
| | - Yitzhak Nissenbaum
- Department of Radiology, Hadassah Hebrew University, Medical Center, Jerusalem, Israel
| | - Marta Cavagnaro
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, Rome, Italy
| | - S. Nahum Goldberg
- Department of Radiology, Hadassah Hebrew University, Medical Center, Jerusalem, Israel
- Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA
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Deshazer G, Hagmann M, Merck D, Sebek J, Moore KB, Prakash P. Computational modeling of 915 MHz microwave ablation: Comparative assessment of temperature-dependent tissue dielectric models. Med Phys 2017; 44:4859-4868. [DOI: 10.1002/mp.12359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 04/20/2017] [Accepted: 04/20/2017] [Indexed: 12/28/2022] Open
Affiliation(s)
- Garron Deshazer
- Department of Radiation Oncology; Siteman Cancer Center; Barnes-Jewish Hospital & Washington University School of Medicine; 4921 Parkview Pl St. Louis MO 63110 USA
- Department of Diagnostic Imaging; Rhode Island Hospital; 593 Eddy Street Providence RI 02903 USA
| | - Mark Hagmann
- Perseon Medical; 2188 W 2200 S Salt Lake City UT 84119 USA
| | - Derek Merck
- Department of Diagnostic Imaging; Rhode Island Hospital; 593 Eddy Street Providence RI 02903 USA
| | - Jan Sebek
- Department of Electrical and Computer Engineering; Kansas State University; Manhattan KS 66506 USA
| | - Kent B. Moore
- Perseon Medical; 2188 W 2200 S Salt Lake City UT 84119 USA
| | - Punit Prakash
- Department of Electrical and Computer Engineering; Kansas State University; Manhattan KS 66506 USA
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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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Lopresto V, Pinto R, Farina L, Cavagnaro M. Microwave thermal ablation: Effects of tissue properties variations on predictive models for treatment planning. Med Eng Phys 2017. [PMID: 28647287 DOI: 10.1016/j.medengphy.2017.06.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Microwave thermal ablation (MTA) therapy for cancer treatments relies on the absorption of electromagnetic energy at microwave frequencies to induce a very high and localized temperature increase, which causes an irreversible thermal damage in the target zone. Treatment planning in MTA is based on experimental observations of ablation zones in ex vivo tissue, while predicting the treatment outcomes could be greatly improved by reliable numerical models. In this work, a fully dynamical simulation model is exploited to look at effects of temperature-dependent variations in the dielectric and thermal properties of the targeted tissue on the prediction of the temperature increase and the extension of the thermally coagulated zone. In particular, the influence of measurement uncertainty of tissue parameters on the numerical results is investigated. Numerical data were compared with data from MTA experiments performed on ex vivo bovine liver tissue at 2.45GHz, with a power of 60W applied for 10min. By including in the simulation model an uncertainty budget (CI=95%) of ±25% in the properties of the tissue due to inaccuracy of measurements, numerical results were achieved in the range of experimental data. Obtained results also showed that the specific heat especially influences the extension of the thermally coagulated zone, with an increase of 27% in length and 7% in diameter when a variation of -25% is considered with respect to the value of the reference simulation model.
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Affiliation(s)
- Vanni Lopresto
- ENEA, Division of Health Protection Technologies, Casaccia Research Centre, Rome, Italy.
| | - Rosanna Pinto
- ENEA, Division of Health Protection Technologies, Casaccia Research Centre, Rome, Italy
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Kok HP, Kotte ANTJ, Crezee J. Planning, optimisation and evaluation of hyperthermia treatments. Int J Hyperthermia 2017; 33:593-607. [PMID: 28540779 DOI: 10.1080/02656736.2017.1295323] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hyperthermia treatment planning using dedicated simulations of power and temperature distributions is very useful to assist in hyperthermia applications. This paper describes an advanced treatment planning software package for a wide variety of applications. METHODS The in-house developed C++ software package Plan2Heat runs on a Linux operating system. Modules are available to perform electric field and temperature calculations for many heating techniques. The package also contains optimisation routines, post-treatment evaluation tools and a sophisticated thermal model enabling to account for 3D vasculature based on an angiogram or generated artificially using a vessel generation algorithm. The use of the software is illustrated by a simulation of a locoregional hyperthermia treatment for a pancreatic cancer patient and a spherical tumour model heated by interstitial hyperthermia, with detailed 3D vasculature included. RESULTS The module-based set-up makes the software flexible and easy to use. The first example demonstrates that treatment planning can help to focus the heating to the tumour. After optimisation, the simulated absorbed power in the tumour increased with 50%. The second example demonstrates the impact of accurately modelling discrete vasculature. Blood at body core temperature entering the heated volume causes relatively cold tracks in the heated volume, where the temperature remains below 40 °C. CONCLUSIONS A flexible software package for hyperthermia treatment planning has been developed, which can be very useful in many hyperthermia applications. The object-oriented structure of the source code allows relatively easy extension of the software package with additional tools when necessary for future applications.
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Affiliation(s)
- H P Kok
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A N T J Kotte
- b Department of Radiotherapy , University Medical Center Utrecht , Utrecht , The Netherlands
| | - J Crezee
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
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Chan JY, Ooi EH. Sensitivity of thermophysiological models of cryoablation to the thermal and biophysical properties of tissues. Cryobiology 2016; 73:304-315. [DOI: 10.1016/j.cryobiol.2016.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 10/18/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
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Deshazer G, Prakash P, Merck D, Haemmerich D. Experimental measurement of microwave ablation heating pattern and comparison to computer simulations. Int J Hyperthermia 2016; 33:74-82. [PMID: 27431040 DOI: 10.1080/02656736.2016.1206630] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION For computational models of microwave ablation (MWA), knowledge of the antenna design is necessary, but the proprietary design of clinical applicators is often unknown. We characterised the specific absorption rate (SAR) during MWA experimentally and compared to a multi-physics simulation. METHODS An infrared (IR) camera was used to measure SAR during MWA within a split ex vivo liver model. Perseon Medical's short-tip (ST) or long-tip (LT) MWA antenna were placed on top of a tissue sample (n = 6), and microwave power (15 W) was applied for 6 min, while intermittently interrupting power. Tissue surface temperature was recorded via IR camera (3.3 fps, 320 × 240 resolution). SAR was calculated intermittently based on temperature slope before and after power interruption. Temperature and SAR data were compared to simulation results. RESULTS Experimentally measured SAR changed considerably once tissue temperatures exceeded 100 °C, contrary to simulation results. The ablation zone diameters were 1.28 cm and 1.30 ± 0.03 cm (transverse), and 2.10 cm and 2.66 ± -0.22 cm (axial), for simulation and experiment, respectively. The average difference in temperature between the simulation and experiment were 5.6 °C (ST) and 6.2 °C (LT). Dice coefficients for 1000 W/kg SAR iso-contour were 0.74 ± 0.01 (ST) and 0.77 (± 0.03) (LT), suggesting good agreement of SAR contours. CONCLUSION We experimentally demonstrated changes in SAR during MWA ablation, which were not present in simulation, suggesting inaccuracies in dielectric properties. The measured SAR may be used in simplified computer simulations to predict tissue temperature when the antenna geometry is unknown.
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Affiliation(s)
- Garron Deshazer
- a Department of Diagnostic Imaging , Rhode Island Hospital , Providence , Rhode Island , USA
| | - Punit Prakash
- b Department of Electrical and Computer Engineering , Kansas State University , Manhattan , Kansas , USA
| | - Derek Merck
- a Department of Diagnostic Imaging , Rhode Island Hospital , Providence , Rhode Island , USA
| | - Dieter Haemmerich
- c Department of Pediatrics , Medical University of South Carolina , Charleston , South Carolina , USA
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Sebek J, Albin N, Bortel R, Natarajan B, Prakash P. Sensitivity of microwave ablation models to tissue biophysical properties: A first step toward probabilistic modeling and treatment planning. Med Phys 2016; 43:2649. [DOI: 10.1118/1.4947482] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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