基于遗传算法的不可逆电穿孔肿瘤消融治疗计划的优化  

Optimization of the Treatment Planning for the Tumor Ablation of Irreversible Electroporation Based on Genetic Algorithm

作　　者：赵亚军[1] 姚陈果[1] 董守龙[1] 陈锐[1] 刘红梅[1] 廖瑞金[1] 

机构地区：[1]重庆大学电气工程学院输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2017年第2期627-636,共10页High Voltage Engineering

基　　金：国家创新研究群体基金(51321063);国家自然科学基金(51477022);重庆市杰出青年基金(cstc2014jcyjjq90001);中央高校基本科研业务费(106112015CDJZR158804)~~

摘　　要：不可逆电穿孔作为一种新型微创肿瘤治疗方案,经过近10 a的发展已进入临床实验阶段。临床实验发现不可逆电穿孔肿瘤治疗效果在很大程度上取决于治疗计划是否完善。然而目前缺乏对于不可逆电穿孔临床治疗计划的优化,仅借助于简单的电场分布计算以及实验经验来确定方案。为解决这一问题,运用有限元分析软件COMSOL Multiphysics建立了不同尺寸的球形、椭球形肿瘤模型及其周边正常组织数值模型;基于遗传算法对电极布置以及脉冲参数进行了优化,实现肿瘤组织完全消融而正常组织损伤最小的优化目标。考虑到实际硬件条件以及安全情况,脉冲电压幅值不可能无限增大,所以限制脉冲电压幅值在3 000 V以内。当肿瘤体积较小时,2针足以完全消融肿瘤,但是随着肿瘤体积的增大,所需电压以及对正常组织的损伤也随之增大,2针下正常组织损伤体积与肿瘤体积之比最大达到0.986 2。随着肿瘤体积进一步增加,需要增加电极针数,此时完全消融肿瘤所需电压有所降低,减少了对正常组织的损伤。借助遗传算法实现了对不同尺寸、不同形状肿瘤的完全消融,得出了最佳的电极布置以及脉冲参数的最优选择,为不可逆电穿孔临床应用推广奠定坚实的基础。Irreversible electroporation, as a novel minimally invasive cancer treatment program, has some clinical trials after nearly 10 years of development. Clinical trials reveal that the effect of the treatment depends largely on the treatment planning. However, due to the lack of the optimization in irreversible electroporation treatment planning in clinical, only the simple calculations of electric field distribution and experiences were used to determine the treatment program. To solve this problem, we used the finite element analysis software COMSOL Multiphysics to create different sizes of spherical, ellipsoid tumor model, and the surrounding normal tissue numerical model; the electrode arrangement and pulse parameters were optimized based on genetic algorithms to achieve complete ablation of tumor tissue and minimal normal tissue damage. Considering the actual equipment conditions and the security situation, pulse amplitude could not increase without limit, thus, the amplitude of the pulse was limited within 3 000 V. When the tumor is small, two electrodes are enough to ablate the tumor completely. However, with the increase of the tumor volume, the higher amplitude of the voltage is needed, and the ratio of the normal tissue damaged by irreversible electroporation volume and the tumor volume increases too. The maximum value of the ratio under two electrodes reaches 0.986 2. With further increase in the tumor volume, the more electrodes are needed to decrease the voltage amplitude and the damage to the normal tissue when ablating the tumor completely. The optimal arrangement of electrodes and pulse parameters for tumors with different shapes and sizes can be obtained through genetic algorithms. These optimal parameters lay a good foundation for the irreversible electroporation clinical application and its promotion.

关 键 词：不可逆电穿孔 肿瘤治疗 临床实验 治疗计划 遗传算法 有限元法 

分 类 号：R730.5[医药卫生—肿瘤]