基于遗传算法的不可逆电穿孔（IRE）原位消融治疗恶性骨肿瘤的优化研究

Microwave ablation as a new biological reconstruction technique for malignant bone tumors limb salvage surgery have overcome the defects of mechanical failure of traditional prosthetic replacement. However, the devitalized bone in the thermal ablation have lost osteoinductive activity and it would take a long time to revascularize. Some patients suffer from fractures during a long rehabilitation time. Using a new method of ablation: irreversible electroporation (IRE) may improve the clinical efficacy. The ideal result is that completely abation of the malignant bone tumor and maximizing the protection of normal tissues.However, due to the extreme heterogeneity of bone tumor, this goal can not be achieved by empirical methods. The applicant proposed an optimization method to solve the expected electric field distribution. In order to realize the target zone electric field distribution of tumor tissues and avoid damage of healthy tissues, an fitness function and some related weighted coefficients were introduced. After then, based.on the finite element method (FEM) solutions of Laplace equation, the genetic algorithm (GA) recursively modify the IRE parametes to maximize the fitness function. Finally we get the optimal soltion of the ideal electric field distribution and the problem the best way to use IRE in malignant bone tumor clinical treatment is solved. This technology of target electric field control is believed to have an important practical value in the designation of electrode and clinical applications.

微波原位消融用于恶性骨肿瘤的保肢手术，克服了传统人工假体置换机械性失效的缺陷，开辟了一条生物性重建的新路。但由于热消融后残留骨丧失骨诱导活性，灭活骨再血管化缓慢，存在部分患者骨折及康复时间长等问题。拟引入新的消融方法：不可逆电穿孔（IRE）以改善临床疗效。IRE消融治疗中要求完全灭活恶性骨肿瘤组织并最大限度保护正常组织，但由于骨肿瘤组织的极度非均质性，通过经验方法无法达到这一目的。申请者提出一种优化求解预期电场分布逆问题的方法。思路是根据肿瘤组织电场强度必须超过阈值及正常组织电场低于阈值的要求，引入适应度函数和有关权重系数，在应用有限元法求解Laplace方程过程中，通过遗传算法迭代修正IRE参数，使适应度函数达到极大值，获得理想电场分布的优化解，来解决以最优的方式将IRE 应用于恶性骨肿瘤的临床治疗的问题。生物体内电场重构和优化控制技术对IRE电极设计和临床方案制定有重要应用价值

微波原位消融用于恶性骨肿瘤的保肢手术，克服了传统人工假体置换机械性失效的缺陷，开辟了一条生物性重建的新路。但由于热消融后残留骨丧失骨诱导活性，灭活骨再血管化缓慢，存在部分患者骨折及康复时间长等问题。不可逆电穿孔（IRE）做为一种新型的肿瘤消融方法，其安全性已在临床试验中得到验证，从理论上应用于骨肿瘤的治疗，可以改善临床疗效。我们通过根据肿瘤组织电场强度必须超过阈值及正常组织电场低于阈值的要求，引入适应度函数和有关权重系数，在应用有限元法求解Laplace方程过程中，通过遗传算法迭代修正IRE参数，使适应度函数达到极大值，获得理想电场分布的优化解。从理论上去优化IRE的电场分布。实验设计中包括了将IRE应用于骨肿瘤消融治疗中的一些基本问题的探讨。我们通过研究，建立了数值仿真及优化的方法，其结果与动物实验的结果相吻合，解决了将IRE应用于骨肿瘤消融中的一些具体问题，为治疗向临床过度奠定了基础。生物体内电场重构和优化控制技术对IRE电极设计和临床方案制定有重要应用价值。随着进一步研究的深入，有可能建立起系统的IRE应用于骨肿瘤治疗的方法及程序。