肿瘤电场治疗的精确电磁建模与仿真研究

【摘要】目的探讨肿瘤电场治疗中的电场变化规律，揭示肿瘤电场治疗中组织物理参数、电极片阵列特性、施加电压大小等因素影响大脑内电场强度分布的物理机制。方法通过构建不同的电极片阵元与阵列，系统地分析电极片阵列中电极片数量和电极片特性对电极片阵列间电场分布的影响。采用全波电磁仿真分析方法对健康大脑和带有模拟肿瘤大脑进行仿真。定性分析颅内电场强度的分布特点以及电极片分布对电场分布的影响，定量分析肿瘤及外周组织区域的电场强度。结果电极片数目变化对阵列间场强有明显影响，电极片阵元特性对阵列间场强影响较小。颅内组织电导率与相对介电常数不同，颅内的电场强度分布是不均匀的，大脑白质中靠近脑脊液的部分，往往有更高的电场强度。相对于肿瘤外周组织区域和肿瘤外壳区域的电场强度，肿瘤核心中的电场强度就要更弱一些。颅内电场强度大小与电极片施加电压大小基本呈线性关系。结论颅内电场强度及分布主要由电极片数目、电极片分布、电极片施加电压大小和组织物理参数决定。合理布置电极片位置，可以通过有限数目的电极片在病灶处实现最大的电场强度。

Abstract: Objective To discuss the law of electric field changes in tumor treating fields, and to reveal the physical mechanism of the influence of factors such as tissue physical parameters, electrode array characteristics, and the magnitude of applied voltage on the distribution of electric field intensity in the brain of tumor treating fields. Methods By constructing different transducer array elements and transducer arrays, the influence of the number of transducers in the transducer array and the characteristics of the transducers on the electric field distribution between the transducer arrays was systematically analyzed. The full-wave electromagnetic simulation analysis method was used to simulate healthy brains and brains with simulated tumors. The distribution characteristics of intracranial electric field intensity and the influence of transducers distribution on electric field distribution were analyzed qualitatively. The electric field intensity of tumors and peripheral tissue regions were analyzed quantitatively. Results The change in the number of transducers had a significant effect on the field intensity between the arrays, and the characteristics of the transducer array elements had little effect on the field intensity between the arrays. The electrical conductivity and relative permittivity of intracranial tissues were not the same, so the distribution of intracranial electric field intensity was uneven. The part of the brain’s white matter close to the cerebrospinal fluid tended to have higher electric field intensity. Compared with the electric field intensity in the tumor peripheral tissue area and the tumor shell area, the electric field intensity in the tumor core was weaker. The intensity of the intracranial electric field was basically linear with the voltage applied to the transducers. Conclusions The intensity and distribution of the intracranial electric field are mainly determined by the number of transducers, the transducers distribution, the voltage applied to the transducers, and the physical parameters of the tissue. Reasonably arrange the position of the transducers, and the maximum electric field intensity can be achieved at the lesion with a limited number of transducers.