Numerical simulations of microwave liver tumor ablation

Dr Branislav Radjenović and Dr Marija Radmilović-Radjenović
Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia

Abstract: Hepatocellular carcinoma accounts for around 75% of all liver cancers, and represents the fourthmost common cause of cancer-related deaths. Microwave ablation is a well esatblished treatmentof hepatocellular carcinoma. The success rate for completely eliminating small liver tumors inpatients treated with microwave ablation isgreater than 85%. Microwave ablation is also highlyrecommended for COVID-19 patients with liver tumors as a fast treatment with a short recoverytime. The involvement of the temperature dependence of the heat capacity, the thermalconductivity, and blood perfusion, is pivotal for establishing the correct ablation process andpreserving the healthy tissue.Every mathematical model for the simulation of microwave ablation consists of threefundamental components. The first component is the model of the antenna probe (or applicator)that generates a microwave field in the tissue. The antennas are usually mechanically andgeometrically complex, and the simulation relies on having accurate electromagnetic materialand tissue properties. In this study, we use a compact 10-slot microwave antenna with animpedance pi-matching network that creates near-spherical ablation zones. The secondcomponent describes the heat distribution in the tissue including sources and sinks and the phasechanges. Heat transfer during the MWA process can be accurately described by the Pennesbioheat equation. In our case, the microwave field is the source of heat, and the heat sinks arerepresented by the blood perfusion term in the heat transfer equation. The third part deals withthe effect of heat on tumor cells and their destruction. All these components of the ablationmodel depend on a variety of material parameters, which themselves depend on the variousstates of the tissue. Finally, to define realistic simulation model, we were using the data from the3D-IRCADb-01 database of hepatocellular carcinoma.The 3D finite elements method (FEM) is used to solve coupled electromagnetic-field and heat-transfer equations, including all details of antenna design and properties of healthy and tumoraltissue. Our 3D model is created within the COMSOL Multiphysics FEM-based simulationplatform.

Biography: Branislav Radjenović was born in 1954. He received the B.Eng., M.Sc., and Ph.D. degrees(1990) from the Faculty of Electrical Engineering, University of Belgrade. He joined the Military Technical Institute, Belgrade, in 1980, where he worked on the design of weapon systems and telecommunication devices. Since 1993, he taught courses in solid state electronics,electromagnetics, optoelectronics, television technique and digital electronics at the Military Technical Academy, Belgrade. Since 2008, he has been the principal research fellow at the Institute of Physics Belgrade, University of Belgrade, He also has been a visiting professor at POSTECH, University of Science and Technology in Pohang, S. Korea and at Comenius University, Faculty of Mathematics, Informatics and Physics in Bratislava, Republic of Slovakia.He has been a Supervisor to several Ph.D. and M.Sc. theses. He has won the National Scholarship Programme by Slovak Academic Information (2018). Currently, Dr. Radjenović is a member of the Program IDEAS project-SimSurgery. Dr. Branislav Radjenović was the author/co-author of more than 140 articles in international scientific journals, 7 chapters in the books, one certified Technical solution, and more than 30 lectures at the international conferences. His research interests include computational physics, level set method, finite element method, biomedical applications, MEMS technologies, etc. Also, he is a principal software developer at the MaSaTECH research and development company in Bratislava, specialized in Ion Mobility Spectrometry devices. 

Prof. Dr. Marija Radmilović-Radjenović obtained her B.Sc. degree at the Faculty of Mathematics, University of Belgrade and completed her M.Sc. and Ph.D. degrees at the Faculty of Physics, University of Belgrade. She is the principal research fellow at the Institute of Physics Belgrade and a part-time professor at the Faculty of Physics, University of Belgrade, for the course “Methods of numerical simulations in physics of ionized gases and plasmas”. Dr. Radmilović-Radjenović has been a visiting professor at POSTECH, University of Science and Technology in Pohang, S. Korea and at Comenius University, Faculty of Mathematics, Informatics and Physics in Bratislava. She also spent shorter sabbaticals at Ruhr University in Bochum, Germany and at the Faculty of Informatics and Information Technologies, the Slovak University of Technology in Bratislava, Republic of Slovakia. She has won the annual award of the Institute of Physics Belgrade (2008) and the National Scholarship Programme by Slovak Academic Information twice (2015) and (2020). Marija Radmilović-Radjenović is a member of the Editorial Board of the Open Physics (previously Central European Journal of Physics) and was co-editor of the books “Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas” and “Argon: Production, Characteristics and Applications.” She is a member of the scientific committees of two international conferences -International Conference on Phenomena in Ionized Gases (ICPIG) and Symposium on Applications of Plasma Processes (SAPP), She was a Secretary and a member of the scientific committee of 5th EU-Japan Workshop on Plasma Processing and a member of the Council of Multidisciplinary Studies at the University of Belgrade. Dr. Radmilović-Radjenovićis a member of the Center of Excellence in Photonics and was a member of numerous national and international projects. Currently, she is a leader of the Program IDEAS project-SimSurgery.Dr. Marija Radmilović-Radjenović was author/co-author of more than 150 articles ininternational scientific journals, 5 chapters in the books, one certified Technical solution, andmore than 40 lectures at international conferences. Her research interests include computational physics, level set method, finite element method, biomedical applications, plasma-based technologies, plasma surface interactions, etc.