IMRT中射束强度分布优化问题的研究

发布时间：2018-08-03 16:51

【摘要】：放射治疗的基本目标是努力提高放射治疗的治疗增益比,即最大限度地将放射线的剂量集中到靶区内,在杀灭肿瘤细胞的同时减少或避免周围正常组织和器官的照射。调强放射治疗(Intensity Modulated Radiation Therapy, IMRT)作为一种先进的适形放疗技术,将会是21世纪初放射治疗技术的主流。作为调强放射治疗关键步骤的逆向治疗计划的目的是找到达到某一临床目标的治疗实施方案,即确定射线种类、能量、射野方向和数目、射野形状和权重等治疗实施参数。因为计划及实施的复杂性,通常需要通过使用计算机辅助的逆向治疗计划来求解问题,调强放疗射束强度分布优化问题的研究是实现逆向治疗计划的核心,因此对其的研究具有重要的意义。本文在国家自然科学基金项目"IMRT逆向计划中多目标优化算法及其目标函数的研究(60872112)”的资助下,对IMRT中射束强度分布优化问题进行了研究,主要工作为： 1对多目标优化算法的发展及其研究热点展开了讨论,并将应用于IMRT中的多目标优化算法进行概括总结； 2.对免疫算法进行了系统的阐述,并提出了一种改进的免疫克隆算法,通过与其他进化算法在五个典型测试函数上的结果的比较,证明该算法能使进化种群迅速收敛到理想的Pareto前沿面,并且能获得较均匀分布的Pareto最优解； 3将改进的免疫克隆算法应用到IMRT逆向计划实验平台,并通过实际算例来验证有效性。
[Abstract]:The basic goal of radiotherapy is to improve the therapeutic gain ratio of radiotherapy, that is, to concentrate the dose of radiation to the target area to reduce or avoid the exposure of normal tissues and organs around the tumor while killing tumor cells. Intensity modulated radiotherapy (Intensity Modulated Radiation Therapy, IMRT), as an advanced conformal radiotherapy technique, will be the mainstream of radiation therapy in the early 21st century. As the key step of intensity modulated radiotherapy, the aim of the reverse therapy plan is to find out the therapeutic implementation scheme to reach a certain clinical goal, that is, to determine the treatment implementation parameters such as the type of ray, energy, direction and number of field, shape and weight of field, etc. Because of the complexity of planning and implementation, it is usually necessary to solve the problem by using computer-aided reverse therapy plan. The study of intensity distribution optimization of intensity modulated radiation beam is the core of reverse treatment plan. Therefore, it is of great significance to study it. In this paper, the optimization of beam intensity distribution in IMRT is studied with the aid of the National Natural Science Foundation of China "Research on Multi-objective Optimization algorithm and its objective function in IMRT reverse Plan" (60872112). The main work is as follows: 1 the development of multi-objective optimization algorithm and its research hotspot are discussed, and the multi-objective optimization algorithm applied in IMRT is summarized. 2. The immune algorithm is described systematically, and an improved immune clone algorithm is proposed, which is compared with the results of other evolutionary algorithms on five typical test functions. It is proved that the proposed algorithm can rapidly converge to the ideal Pareto frontier and obtain the Pareto optimal solution with a more uniform distribution. 3 the improved immune clone algorithm is applied to the IMRT reverse plan experimental platform. A practical example is given to verify the validity.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R730.55;TP18

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