基于中国数字人男性模型骨骼的放疗辐射剂量研究

发布时间：2018-05-04 11:55

本文选题：晶格模型 + 红骨髓　；参考：《华中科技大学》2013年硕士论文

【摘要】：随着人类科学发展,电离辐射在医学、科研、工业等领域得到广泛的使用，，不过随着而来的辐射造成人体组织器官危害逐渐增多，尤其是对辐射最为敏感的红骨髓组织。在临床肿瘤图像引导的放射治疗过程中，由于CT和MRI等医学成像方法无法区分骨骼中的红骨髓等成分，红骨髓一般是和骨骼其他部分作为均匀的混合组织进行分析，因此会造成剂量评估偏差。基于中国数字人（VCH）男性模型，研究骨骼细分结构的剂量分布对临床肿瘤放疗有重要参考意义。本文在VCH男性晶格模型基础上，对模型中的骨骼系统进行精细分割，骨骼系统被细分成红骨髓、皮质骨、骨小梁和黄骨髓等四部分，同时对167块骨骼的位置进行标识。基于XHA600直线加速头，使用BEAMnrc和DOSXYZnrc蒙特卡罗模拟系统实现放疗中剂量计算过程。在此基础上，本文对前列腺癌放疗下人体骨骼辐射剂量进行了评估研究。主要研究结果如下：（1）通过对骨骼分割结果分析可知，各类骨骼占总骨骼的质量分数与文献参考值相差大部分都在2%以内，与ICRP89参考值的误差范围相差也不会大于1%。构建了能够比较真实的反映出人体的解剖结构的数字人骨骼系统。（2）构建加速器治疗头的虚拟源模型。经过计算比较，水箱检测的模拟计算数据和测量数据的误差小于3%，低于文献所规定的剂量计算误差标准。（3）前列腺癌放疗下，通过剂量比较发现：红骨髓与皮质骨、骨小梁受到的辐射剂量差异达20%，而红骨髓与黄骨髓差异在3.1%以内。只对红骨髓剂量影响进行分析，红骨髓的辐射剂量与靶区体积正相关，但由于受到靶区与红骨髓几何结构的影响，以0°（左侧）与180°（右侧）射野在外扩0.6cm后红骨髓受剂量的体积分数基本保持不变。由骨骼各部分剂量分布结果可知，当红骨髓在计算模型中难以区分时，均匀处理骨髓的辐射剂量近似作为红骨髓的结果是可行的。本研究构建的包含有精细骨骼系统的VCH模型，能够在对癌症放疗方案中射野角度、相应射野权重以及计划靶区范围选择时提供骨骼各部分尤其是红骨髓受到的辐射剂量参考。
[Abstract]:With the development of human science, ionizing radiation has been widely used in medicine, scientific research, industry and other fields. However, with the radiation, the harm of human tissues and organs is increasing gradually, especially the most sensitive red bone marrow tissue. In the course of radiotherapy guided by clinical tumor images, because medical imaging methods such as CT and MRI can not distinguish the components of bone such as red bone marrow, red bone marrow and other parts of bone are generally analyzed as homogeneous mixed tissues. This can result in a dose assessment bias. Based on the Chinese digital human VCH male model, it is important to study the dose distribution of bone subdivision structure for clinical tumor radiotherapy. Based on the VCH male lattice model, the skeletal system in the model is divided into four parts: red bone marrow, cortical bone, trabecular bone and yellow bone marrow. Based on XHA600 linear accelerator, BEAMnrc and DOSXYZnrc Monte Carlo simulation system are used to calculate dose in radiotherapy. On this basis, we evaluated the radiation dose of human bone under radiotherapy for prostate cancer. The main findings are as follows: Through the analysis of the result of bone segmentation, it can be seen that the difference between the mass fraction of all kinds of bone and the reference value of the literature is less than 2%, and the error range of the reference value of ICRP89 is not larger than that of the reference value of ICRP89. A digital human skeleton system which can reflect the anatomical structure of human body is constructed. The virtual source model of accelerator therapy head was constructed. Through calculation and comparison, the error between the simulated calculation data and the measured data of water tank detection is less than 3, which is lower than the standard of dose calculation error stipulated in the literature. 3) under radiotherapy for prostate cancer, the difference of radiation dose between red bone marrow and cortical bone, trabecular bone was 20, but the difference between red bone marrow and yellow bone marrow was less than 3.1%. The radiation dose of the red bone marrow was positively correlated with the volume of the target, but was affected by the geometric structure of the target and the red bone marrow. After 0 掳(left) and 180 掳(right) field were used to expand 0.6cm, the volume fraction of red bone marrow dose remained unchanged. According to the results of dose distribution in different parts of bone, when it is difficult to distinguish the red bone marrow in the calculation model, it is feasible to treat the radiation dose of bone marrow uniformly as the result of the red bone marrow. The VCH model with fine bone system can provide the radiation dose reference for all parts of bone, especially the red bone marrow, when the angle of radiation field, the weight of radiation field and the selection of target range are selected.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R814.2

【参考文献】