机械误差对肿瘤精确旋转放疗射野变形的影响及补偿算法研究

发布时间：2018-02-11 00:24

本文关键词： 机械误差精确放疗射野形状补偿多叶光栅　出处：《机械工程学报》2015年15期 　论文类型：期刊论文

【摘要】：放疗设备的机械误差是影响肿瘤放射治疗精确性的重要因素,且随设备使用时间呈现逐渐增大趋势,因此研究机械误差对治疗效果的影响和相应解决方法具有重要意义。首先对旋转放疗设备射线投递的过程进行数学建模,得到治疗头各自由度机械误差对等中心面射野形状的影响规律,并提出了一种用于衡量射野变形的有限点二维搜索方法;然后,通过进行射野区域分割、最佳逼近射野计算以及多叶光栅顶点坐标反算,提出了一种基于多叶光栅的射野变形补偿算法;最后,对四个临床上的实际射野进行了算法的数值仿真试验。结果表明,算法可以有效减少50%左右由机械误差引起的射野形状误差,显著提高了放射治疗精度。
[Abstract]:The mechanical error of radiotherapy equipment is an important factor affecting the accuracy of radiotherapy, and it increases gradually with the use of the equipment. Therefore, it is of great significance to study the effect of mechanical error on the therapeutic effect and the corresponding solutions. Firstly, the mathematical modeling of the radiographic delivery process of rotating radiotherapy equipment is carried out. The effects of mechanical errors of different degrees of freedom on the shape of the projectile field are obtained, and a two-dimensional finite point search method is proposed to measure the deformation of the field. In this paper, an algorithm based on multi-leaf grating is proposed to compensate the deformation of the ejection field based on the best approximation field calculation and the inverse calculation of the vertex coordinates of the multi-leaf grating. Finally, the numerical simulation experiments of the four practical projectile fields are carried out. The results show that, The algorithm can effectively reduce the shape error caused by mechanical error of about 50%, and improve the accuracy of radiotherapy.
【作者单位】：清华大学机械工程系;清华大学摩擦学国家重点实验室;中国人民解放军总医院;
【基金】：北京市科技计划(Z141100000514015) 清华大学摩擦学国家重点实验室重点(SKLT12A03) 清华大学自主科研计划课题学科交叉专项(20111081026)资助项目
【分类号】：R730.55

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