用于调强治疗计划设计的射野方向自动优选算法  

A Beam Orientations' Automatic Selection Algorithm in IMRT Planning

作　　者：李炜 张永谦 胡逸民 

机构地区：[1]武汉大学物理科学与技术学院,湖北武汉430072 [2]中国医学科学院/北京协和医科大学肿瘤医院放射治疗中心,北京100021

出　　处：《中国医学物理学杂志》2012年第4期3491-3495,共5页Chinese Journal of Medical Physics

摘　　要：目的:建立一种基于危机器官避让原理(Organ at Risk Avoidance Theory)及混合整数线性法(Mixed Integer LinearProgramming(MILP))的射野方向自动优选算法,并用于三源调强治疗装置提供的非共面射野池(Non-coplanar BeamsPool)的射野方向的优选。方法:(1)利用基于危机器官避让原理的自编程序从已知非共面射野池中初选出30个较优射野;(2)利用MILP程序LPSolve IDE对初选出的30个射野进行调强优化,筛选出预先设定的射野方向数组合,同时计算出射野强度分布;(3)对前列腺癌和鼻咽癌病例,对比分析了相同射野数的共面均分角射野计划和经射野方向优化的计划的DVH图,剂量分布图及危机器官平均剂量。结果:射野方向自动优选算法能够有效的筛选出临床所需要的射野方向数组合,得到相应的调强治疗计划,靶区剂量相同的情况下,危机器官所受剂量显著减少。结论:我们提出的自动优化非共面射野方向的算法可以很好的用于已知射野方向池(如三源调强治疗装置)的射野方向优选和射野强度优化问题。Objective： To develop an algorithm for choosing beam orientations based on organ at risk（OAR） avoidance theory and Mixed Integer Linear Programming（MILP） in IMRT planning from a known existing non-coplanar beams pool coming from the Three-Cross-Firing-Beam（TCFB） treatment unit,and to test its performance for a prostate and a NPC case.Methods：（1） To pre-select 30 potentially possible candidate beam orientations by self-developed program based on the OAR（organ at risk） avoidance theory from a known non-coplanar beam orientation’s pool;（2） to search out the best beam orientations for a pre-de termined required beam number from the 30 pre-selected candidate beams by using Mixed Integer Linear Programming（MILP）;（3） to work out the plans and compare with that of the same beam number but co-planar beams’.Results： The algorithm devel oped in the study for beam orientation automatic selection from a known existing pool of non-coplanar beams coming from the TCFB treatment unit works well for a prostate and a NPC case,that offering better normal tissue sparing.Conclusions： The algo rithm developed by our group for beam orientation automatic selection could be used to solve the beam orientations selection and the beam-lets’ intensity optimization problems from the optional pool of non-coplanar beams coming from the TCFB treatment unit.

关 键 词：射野方向优化 三源调强治疗装置 危机器官避让 混合整数线性法 

分 类 号：R730.55[医药卫生—肿瘤] R815.6[医药卫生—临床医学]