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Audigier C, Mohaiu AT, Alzaga A, Bale R, Mansi T. A comparative study on computational models of multi-electrode radiofrequency ablation of large liver tumors. Int J Comput Assist Radiol Surg 2022; 17:1489-1496. [PMID: 35776400 DOI: 10.1007/s11548-022-02689-x] [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: 02/21/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Thermal ablation of liver tumors has emerged as a first-line curative treatment for single small tumors (diameter < 2.5 cm) due to similar overall survival rates as surgical resection. Moreover, it is far less invasive, has lower complication rates, a superior cost-effectiveness, and an extremely low treatment-associated mortality. However, in many cases, complete tumor coverage cannot be achieved only with a single electrode and several electrodes are used to create overlapping ablations. Multi-electrode planning is a challenging 3D task with many contradictive constraints to consider, a dimensionality difficult to assess even for experts. It requires extremely long planning time since it is mostly performed mentally by clinicians looking at 2D CT views. An accurate and reliable prediction of the ablation zone would help to turn thermal ablation into a first-line curative treatment also for large liver tumors treated with multiple electrodes. In order to determine the level of model simplification that can be acceptable, we compared three computational models, a simple spherical model, a biophysics-based model and an Eikonal model. METHODS RF ablation electrodes were virtually placed at a desired position in the patient pre-operative CT image and the models predicted the ablation zone generated by multiple electrodes. The last two models are patient-specific. In these cases, hepatic structures were automatically segmented from the pre-operative CT images to predict a patient-specific ablation zone. RESULTS The three models were used to simulate multiple electrode ablations on 12 large tumors from 11 patients for which the procedure information was available. Biophysics-based simulations approximate better the post-operative ablation zone in term of Hausdorff distance, Dice Similarity Coefficient, radius, and volume compared to two other methods. It also predicts better the coverage percentage and thus the tumor ablation margin. CONCLUSION The results obtained with the biophysics-based model indicate that it could improve ablation planning by accurately predicting the ablation zone, avoiding over or under-treatment. This is particularly beneficial for multi-electrode radiofrequency ablation of larger liver tumors where the planning phase is particularly challenging.
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Affiliation(s)
- Chloé Audigier
- Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland.
| | | | | | - Reto Bale
- Innsbruck University Hospital, Innsbruck, Austria
| | - Tommaso Mansi
- Siemens Healthineers, Digital Technology and Innovation, Princeton, NJ, USA
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Nolte T, Vaidya N, Baragona M, Elevelt A, Lavezzo V, Maessen R, Schulz V, Veroy K. Study of flow effects on temperature-controlled radiofrequency ablation using phantom experiments and forward simulations. Med Phys 2021; 48:4754-4768. [PMID: 34320224 DOI: 10.1002/mp.15138] [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: 12/03/2020] [Revised: 05/24/2021] [Accepted: 07/16/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Blood flow is known to add variability to hepatic radiofrequency ablation (RFA) treatment outcomes. However, few studies exist on its impact on temperature-controlled RFA. Hence, we investigate large-scale blood flow effects on temperature-controlled RFA in flow channel experiments and numerical simulations. METHODS Ablation zones were induced in tissue-mimicking, thermochromic phantoms with a single flow channel, using an RF generator with temperature-controlled power delivery and a monopolar needle electrode. Channels were generated by molding the phantom around a removable rod. Channel radius and saline flow rate were varied to study the impact of flow on (i) the ablated cross-sectional area, (ii) the delivered generator power, and (iii) the occurrence of directional effects on the thermal lesion. Finite volume simulations reproducing the experimental geometry, flow conditions, and generator power input were conducted and compared to the experimental ablation outcomes. RESULTS Vessels of different channel radii r affected the ablation outcome in different ways. For r = 0.275 mm, the ablated area decreased with increasing flow rate while the energy input was hardly affected. For r = 0.9 mm and r = 2.3 mm, the energy input increased toward larger flow rates; for these radii, the ablated area decreased and increased toward larger flow rates, respectively, while still being reduced overall as compared to the reference experiment without flow. Directional effects, that is, local shrinking of the lesion upstream of the needle and an extension thereof downstream, were observed only for the smallest radius. The simulations qualitatively confirmed these observations. As compared to performing the simulations without flow, including flow effects in the simulations reduced the mean absolute error between experimental and simulated ablated areas from 0.23 to 0.12. CONCLUSION While the temperature control mechanism did not detect the heat sink effect in the case of the smallest channel radius, it counteracted the heat sink effect in the case of the larger channel radii with an increased energy input; this explains the increase in ablated area toward high flow rates (for r = 2.3 mm). The experiments in a simple phantom setup, thus, contribute to a good understanding of the phenomenon and are suitable for model validation.
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Affiliation(s)
- Teresa Nolte
- Department of Physics of Molecular Imaging systems, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Nikhil Vaidya
- Faculty of Civil Engineering, RWTH Aachen University, Aachen, Germany
| | | | | | | | | | - Volkmar Schulz
- Department of Physics of Molecular Imaging systems, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.,Hyperion Hybrid Imaging Systems GmbH, Aachen, Germany.,Physics Institute III B, RWTH Aachen University, Aachen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Karen Veroy
- Center for Analysis, Scientific Computing, and Applications, Eindhoven University of Technology, Eindhoven, The Netherlands
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Andreozzi A, Brunese L, Iasiello M, Tucci C, Vanoli GP. Numerical analysis of the pulsating heat source effects in a tumor tissue. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 200:105887. [PMID: 33280933 DOI: 10.1016/j.cmpb.2020.105887] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND OBJECTIVES Hyperthermia treatment is nowadays recognized as the fourth additional cancer therapy technique following surgery, chemotherapy, and radiation; it is a minimally or non-invasive technique which involves fewer complications, a shorter hospital stay, and fewer costs. In this paper, pulsating heat effects on heat transfer in a tumor tissue under hyperthermia are analyzed. The objective of the paper is to find and quantify the advantages of pulsatile heat protocols under different periodical heating schemes and for different tissue morphologies. METHODS The tumor tissue is modeled as a porous sphere made up of a solid phase (tissue, interstitial space, etc.) and a fluid phase (blood). A Local Thermal Non-Equilibrium (LTNE) model is employed to consider the local temperature difference between the two phases. Governing equations with the appropriate boundary conditions are solved with the finite-element code COMSOL Multiphysics®. The pulsating effect is modeled with references to a cosine function with different frequencies, and such different heating protocols are compared at equal delivered energy, i. e. different heating times at equal maximum power. RESULTS Different tissue properties in terms of blood vessels sizes and blood volume fraction in tissue (porosity) are investigated. The results are shown in terms of tissue temperature and percentage of necrotic tissue obtained. The most powerful result achieved using a pulsating heat source instead of a constant one is the decreasing of maximum temperature in any considered case, even reaching about 30% lower maximum temperatures. Furthermore, the evaluation of tissue damage at the end of treatment shows that pulsating heat allows to necrotize the same tumoral tissue area of the non-pulsating heat source. CONCLUSIONS Modeling pulsating heat protocols in thermal ablation under different periodical heating schemes and considering different tissues morphologies in a tumor tissue highlights how the application of pulsating heat sources allows to avoid high temperature peaks, and simultaneously to ablate the same tumoral area obtained with a non-pulsating heat source. This is a powerful result to improve medical protocols and devices in thermal ablation of tumors.
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Affiliation(s)
- Assunta Andreozzi
- Dipartimento di Ingegneria Industriale, Università degli studi di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
| | - Luca Brunese
- Dipartimento di Medicina e Scienze della Salute "Vincenzo Tiberio", Università del Molise, Via Francesco De Sanctis 1, 86100, Campobasso, ITALY
| | - Marcello Iasiello
- Dipartimento di Ingegneria Industriale, Università degli studi di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
| | - Claudio Tucci
- Dipartimento di Medicina e Scienze della Salute "Vincenzo Tiberio", Università del Molise, Via Francesco De Sanctis 1, 86100, Campobasso, ITALY.
| | - Giuseppe Peter Vanoli
- Dipartimento di Medicina e Scienze della Salute "Vincenzo Tiberio", Università del Molise, Via Francesco De Sanctis 1, 86100, Campobasso, ITALY
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Singh S, Melnik R. Domain Heterogeneity in Radiofrequency Therapies for Pain Relief: A Computational Study with Coupled Models. Bioengineering (Basel) 2020; 7:E35. [PMID: 32272567 PMCID: PMC7355452 DOI: 10.3390/bioengineering7020035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 03/25/2020] [Accepted: 04/02/2020] [Indexed: 12/11/2022] Open
Abstract
The objective of the current research work is to study the differences between the predicted ablation volume in homogeneous and heterogeneous models of typical radiofrequency (RF) procedures for pain relief. A three-dimensional computational domain comprising of the realistic anatomy of the target tissue was considered in the present study. A comparative analysis was conducted for three different scenarios: (a) a completely homogeneous domain comprising of only muscle tissue, (b) a heterogeneous domain comprising of nerve and muscle tissues, and (c) a heterogeneous domain comprising of bone, nerve and muscle tissues. Finite-element-based simulations were performed to compute the temperature and electrical field distribution during conventional RF procedures for treating pain, and exemplified here for the continuous case. The predicted results reveal that the consideration of heterogeneity within the computational domain results in distorted electric field distribution and leads to a significant reduction in the attained ablation volume during the continuous RF application for pain relief. The findings of this study could provide first-hand quantitative information to clinical practitioners about the impact of such heterogeneities on the efficacy of RF procedures, thereby assisting them in developing standardized optimal protocols for different cases of interest.
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Affiliation(s)
- Sundeep Singh
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada;
| | - Roderick Melnik
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada;
- BCAM—Basque Center for Applied Mathematics, Alameda de Mazarredo 14, E-48009 Bilbao, Spain
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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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Clinical evaluation of in silico planning and real-time simulation of hepatic radiofrequency ablation (ClinicIMPPACT Trial). Eur Radiol 2019; 30:934-942. [DOI: 10.1007/s00330-019-06411-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/27/2019] [Accepted: 08/07/2019] [Indexed: 12/22/2022]
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Zhang J, Zhong Y, Gu C. Neural network modelling of soft tissue deformation for surgical simulation. Artif Intell Med 2019; 97:61-70. [DOI: 10.1016/j.artmed.2018.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 11/25/2022]
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Computer-assisted planning for a concentric tube robotic system in neurosurgery. Int J Comput Assist Radiol Surg 2018; 14:335-344. [PMID: 30478533 DOI: 10.1007/s11548-018-1890-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE Laser-induced thermotherapy in the brain is a minimally invasive procedure to denature tumor tissue. However, irregularly shaped brain tumors cannot be treated using existing commercial systems. Thus, we present a new concept for laser-induced thermotherapy using a concentric tube robotic system. The planning procedure is complex and consists of the optimal distribution of thermal laser ablations within a volume as well as design and configuration parameter optimization of the concentric tube robot. METHODS We propose a novel computer-assisted planning procedure that decomposes the problem into task- and robot-specific planning and uses a multi-objective particle swarm optimization algorithm with variable length. RESULTS The algorithm determines a Pareto-front of optimal ablation distributions for three patient datasets. It considers multiple objectives and determines optimal robot parameters for multiple trajectories to access the tumor volume. CONCLUSIONS We prove the effectiveness of our planning procedure to enable the treatment of irregularly shaped brain tumors. Multiple trajectories further increase the applicability of the procedure.
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Kim Y, Audigier C, Ziegle J, Friebe M, Boctor EM. Ultrasound thermal monitoring with an external ultrasound source for customized bipolar RF ablation shapes. Int J Comput Assist Radiol Surg 2018; 13:815-826. [PMID: 29619610 PMCID: PMC6573022 DOI: 10.1007/s11548-018-1744-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/19/2018] [Indexed: 11/29/2022]
Abstract
PURPOSE Thermotherapy is a clinical procedure which delivers thermal energy to a target, and it has been applied for various medical treatments. Temperature monitoring during thermotherapy is important to achieve precise and reproducible results. Medical ultrasound can be used for thermal monitoring and is an attractive medical imaging modality due to its advantages including non-ionizing radiation, cost-effectiveness and portability. We propose an ultrasound thermal monitoring method using a speed-of-sound tomographic approach coupled with a biophysical heat diffusion model. METHODS We implement an ultrasound thermometry approach using an external ultrasound source. We reconstruct the speed-of-sound images using time-of-flight information from the external ultrasound source and convert the speed-of-sound information into temperature by using the a priori knowledge brought by a biophysical heat diffusion model. RESULTS Customized treatment shapes can be created using switching channels of radio frequency bipolar needle electrodes. Simulations of various ablation lesion shapes in the temperature range of 21-59 [Formula: see text]C are performed to study the feasibility of the proposed method. We also evaluated our method with ex vivo porcine liver experiments, in which we generated temperature images between 22 and 45 [Formula: see text]C. CONCLUSION In this paper, we present a proof of concept showing the feasibility of our ultrasound thermal monitoring method. The proposed method could be applied to various thermotherapy procedures by only adding an ultrasound source.
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Affiliation(s)
- Younsu Kim
- Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - Chloé Audigier
- Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - Jens Ziegle
- Otto-von-Guericke University, Universitaetsplatz 2, 39106, Magdeburg, Saxony-Anhalt, Germany
| | - Michael Friebe
- Otto-von-Guericke University, Universitaetsplatz 2, 39106, Magdeburg, Saxony-Anhalt, Germany
| | - Emad M Boctor
- Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA.
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