| Low intensity,low to medium frequency(100～300kHz,1～3V/cm)alternating electric fields have been found to inhibit the proliferation of a variety of tumor cells.These electric fields are called Tumor Treating Fields(TTFields).TTFields have no significant toxic side effects and can be used in combination with radiotherapy and chemotherapy,and have very good application prospects and advantages.Although the therapeutic effect of TTFields has been verified by cellular and clinical experiments,how to optimize its therapeutic effect still needs to be studied.In vitro experiments have shown that the magnitude and direction of the electric field in the tumor determine the therapeutic effect,but the complex geometric structure of the human body and the different electrical properties of various substances in it pose great difficulties in calculating the electric field distribution.Currently,numerical modeling is mostly used to calculate the electric field distribution inside human organs and tumors,but less research has been conducted on the treatment of liver tumors.In addition,TTFields-related studies mostly observe the proliferation of cells through cellular experiments to study the macroscopic effects of electric field inhibition,while studies on the mechanism of action mainly use single-cell models,and few studies have been conducted on the electric field distribution at the multicellular level.In order to solve these problems,this thesis was conducted to study the distribution of TTFields in a multicellular tumor model and human liver.In this thesis,the distribution of TTFields in the liver was firstly investigated.The CT images of the patient were segmented and 3D reconstructed to obtain a personalized and accurate 3D model.A finite element model was established using this 3D model,and the electric field distribution inside the human liver under the action of TTFields was simulated and calculated,and the electric field distribution pattern was analyzed by combining the simulation results.In addition,this thesis established various multi-cell models by analyzing and simplifying the tumor cells,and calculated and analyzed the distribution of electric fields within and between multiple tumor cells.The thesis provides a preliminary understanding of the distribution pattern of TTFields in the liver,and analyzes the effects of electrode distribution pattern,tumor location and frequency on the electric field distribution.The workflow from medical images to the finite element model of TTFields was established and its feasibility was verified,laying the foundation for the subsequent study.The distribution pattern of TTFields in the multicellular model was also investigated,and the correlation patterns of electric field mode size and direction inside and outside the tumor cells,as well as the frequency selectivity of electric field mode gradient size were summarized;The multicellular model was compared with the homogeneous tumor model,and it was found that the two models with the same electrical conductivity had similar electric field mode sizes. |
