放射治疗方案的优化方法研究
发布时间：2018-09-06 15:23
【摘要】： 优化是放射治疗计划系统的重要组成部分之一。针对放射治疗方案的优化问题,本文提出了一系列解决方案,主要包括以下几个方面: 1)较全面地介绍了现代最优化理论及方法,对NSGA-II多目标优化遗传算法进行了较深入的研究,提出了在该方法中加入局部搜索算子及外部精英收集池的改进算法-NSGA-II多目标混合遗传算法。 2)针对伽玛刀立体定向放射治疗计划系统中的优化问题提出了一个两步优化的方案。首先采用一种改进的基于距离变换的几何优化方法,优化靶点的数目、位置及相应准直器直径;然后根据几何优化获得的靶点参数,研究了基于混合遗传算法GA-BFGS方法优化靶点权重的方法,以避免梯度法可能会陷入局部极小的问题。 3)针对全身伽玛刀治疗体部肿瘤的靶点设计优化问题,提出了一种新颖的靶点设计及优化解决方案,建立了基于包围盒的优化模型,然后采用遗传算法进行求解,使治疗过程更为简便快捷,并有利于减少治疗过程中的定位误差,填补了全身伽玛刀靶点设计优化研究的空白。 4)针对全身伽玛刀治疗体部肿瘤的治疗路径优化问题,在靶点优化的基础上,提出了采用遗传算法进行治疗路径优化的解决方案,使治疗过程更为简便快捷,有利于减少治疗过程中医生的劳动强度。当靶点数过多时,我们给出了一种分层优化的解决方案,以减少优化时间,满足临床的实际要求。 5)实现了一种基于NSGA-Ⅱ多目标混合遗传算法的调强放射治疗逆向计划的优化方法,其中局部搜索采用L-BFGS算法。该方法得到的非劣解在目标空间分布均匀,计算速度快,鲁棒性好。 6)在Windows平台上开发了一套用于周围血管内放射治疗计划优化的主动漫游虚拟现实系统,用于提取血管的几何结构;建立血管内放射治疗计划的优化模型,采用适宜的优化方法进行优化,该方法综合运用了混合遗传算法GA-BFGS方法和快速模拟退火算法优化相关的参数,其中GA-BFGS算法用于优化连续参数即放射源的照射时间,快速模拟退火算法用于优化离散参数即放射源的位置。这一策略综合考虑了目标函数的形式,BFGS的快速收敛性,遗传算法的全局收敛性,以及模拟退火算法的全局收敛性。
[Abstract]:Optimization is one of the important components of radiotherapy planning system. Aiming at the optimization of radiotherapy scheme, this paper puts forward a series of solutions, including the following aspects: 1) the modern optimization theory and method are introduced comprehensively. The genetic algorithm of NSGA-II multi-objective optimization is studied deeply. An improved algorithm-NSGA-II hybrid genetic algorithm is proposed to add local search operator and external elite collection pool to the method. 2) for gamma knife stereotactic orientation A two-step optimization scheme for radiotherapy planning system is proposed. Firstly, an improved geometric optimization method based on distance transform is used to optimize the number, position and corresponding collimator diameter of the target, and then according to the geometric optimization of the target parameters, The method of target weight optimization based on hybrid genetic algorithm (GA-BFGS) is studied. In order to avoid the gradient method may fall into the problem of local minimization. 3) for the whole body gamma knife treatment of body tumor target design optimization problem, In this paper, a novel target design and optimization solution is proposed, and an optimization model based on bounding box is established. Then genetic algorithm is used to solve the problem, which makes the treatment process simpler and faster, and helps to reduce the positioning error in the treatment process. Fill in the blank of the whole body gamma knife target design optimization research. 4) aiming at the whole body gamma knife treatment body tumor treatment path optimization problem, on the basis of the target optimization, The genetic algorithm is used to optimize the treatment path, which makes the treatment process simpler and faster, and helps to reduce the labor intensity of doctors in the course of treatment. When there are too many targets, we present a hierarchical optimization solution to reduce the optimization time, 5) an optimization method of intensity modulated radiotherapy reverse planning based on NSGA- 鈪，
本文编号：2226765
[Abstract]:Optimization is one of the important components of radiotherapy planning system. Aiming at the optimization of radiotherapy scheme, this paper puts forward a series of solutions, including the following aspects: 1) the modern optimization theory and method are introduced comprehensively. The genetic algorithm of NSGA-II multi-objective optimization is studied deeply. An improved algorithm-NSGA-II hybrid genetic algorithm is proposed to add local search operator and external elite collection pool to the method. 2) for gamma knife stereotactic orientation A two-step optimization scheme for radiotherapy planning system is proposed. Firstly, an improved geometric optimization method based on distance transform is used to optimize the number, position and corresponding collimator diameter of the target, and then according to the geometric optimization of the target parameters, The method of target weight optimization based on hybrid genetic algorithm (GA-BFGS) is studied. In order to avoid the gradient method may fall into the problem of local minimization. 3) for the whole body gamma knife treatment of body tumor target design optimization problem, In this paper, a novel target design and optimization solution is proposed, and an optimization model based on bounding box is established. Then genetic algorithm is used to solve the problem, which makes the treatment process simpler and faster, and helps to reduce the positioning error in the treatment process. Fill in the blank of the whole body gamma knife target design optimization research. 4) aiming at the whole body gamma knife treatment body tumor treatment path optimization problem, on the basis of the target optimization, The genetic algorithm is used to optimize the treatment path, which makes the treatment process simpler and faster, and helps to reduce the labor intensity of doctors in the course of treatment. When there are too many targets, we present a hierarchical optimization solution to reduce the optimization time, 5) an optimization method of intensity modulated radiotherapy reverse planning based on NSGA- 鈪，
本文编号：2226765
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