血氧水平依赖功能磁共振成像（BOLD-fMRI）在脑星形细胞瘤术后放射治疗中指导运动皮层区保护的临床应用研究

发布时间：2018-01-21 00:52

本文关键词： 血氧水平依赖功能磁共振成像运动皮层区脑星形细胞瘤放射治疗剂量保护　出处：《宁夏医科大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的探讨在制定脑星形细胞瘤术后放疗计划时，血氧水平依赖功能磁共振成像（Blood Oxygenation Level Dependent Functional Magnetic Resonance Imaging，BOLD-fMRI）指导实施运动皮层区剂量保护，进而达到功能保护的临床应用价值，并通过BOLD-fMRI研究脑星形细胞瘤及其外科肿瘤切除术对运动区的影响。方法27例脑星形细胞瘤术后拟行进一步放疗患者，瘤灶邻近运动皮层区，行常规MRI及BOLD-fMRI检查。以BOLD-fMRI检查结果（脑皮层运动功能区的激活图像）为指导将运动皮层区的位置、范围标记于放疗定位CT上，并将其作为危及器官（Organsat Risk，OAR）处理，即在确保靶区投照剂量的前提下尽量减少运动区的受照剂量，进而制定具有针对性区域保护作用的放疗计划，并与未行此保护的常规计划进行运动区受照剂量对比；并通过分析BOLD-fMRI检查所得运动功能区激活图，了解星形细胞瘤及其外科手术对脑皮层运动区的影响。结果①本组中18例靶区与正常生理状态下运动区距离较近，其中15例病灶呈明显浸润状态，并推挤甚至部分破坏运动区，通过“城垛样”时间-信号强度曲线确定的术后运动区相较于正常生理状态下的解剖位置及对侧未受肿瘤及手术影响的相应部位出现移位，9例运动区部分破坏的病例，其患侧运动激活区明显减小，6例激活信号出现在非传统运动区。②保护性较非保护性计划在运动皮层区的平均受照剂量减低程度：患侧—最少0.76%、最多59.20%、平均30.78%，健侧—最少23.33%、最多68.30%、平均48.07%；减低程度的变异系数，患侧71.41%，健侧36.71%；两种计划在双侧分别行配对t检验，结果均为P0.05；9例因患侧运动区与靶区毗邻甚至部分重叠，故其平均剂量减低程度较小，最少0.76%、最多18.61%、平均12.21%。结论应用BOLD-fMRI技术，，能够在放疗前直观的了解脑星形细胞瘤及其外科切除术对运动皮层区的影响；并在脑星形细胞瘤术后放疗计划的制定中，在保证靶区治疗剂量的同时，尽量减低运动区受量，进而使相应运动功能的保护成为可能，最终提高患者的生存质量。
[Abstract]:Objective to explore in the development of brain astrocytoma postoperative radiotherapy plan, blood oxygenation level dependent functional magnetic resonance imaging (Blood Oxygenation Level Dependent Functional Magnetic Resonance Imaging, BOLD-fMRI) the implementation of motor cortex dose guidance, and achieve the function of protecting the clinical value of BOLD-fMRI, and through the study of brain astrocytoma and its surgical tumor resection effect operation on the motor area.
Methods 27 cases of astrocytoma patients after undergoing further radiotherapy in patients with tumors near the motor cortex, underwent MRI and BOLD-fMRI examination. The examination results of BOLD-fMRI (activation of the motor cortex of the brain image) as the guide to the motor cortex position range of markers in radiotherapy on CT, and as the organs at risk (Organsat Risk, OAR), which in order to ensure the target projection dose under the premise of minimizing the dose of sports area, and has formulated plans for the protection of regional radiotherapy, conventional plan and not for the protection of motor area dose contrast; and through the analysis of BOLD-fMRI examination the motor cortex activation map, to understand the effect of astrocytoma and its surgical operation on the motor area of the cerebral cortex.
The results from the group of motor areas in 18 cases, the target and the normal physiological state is near, including 15 cases of lesions showed obvious infiltration, and even push the partial destruction of motor area, the corresponding parts are determined by the "battlements" time signal intensity curve of the postoperative anatomical position and normal physiological state of motor area compared to the next on the side without tumor and the effects of the operation shift, cases of partial destruction of the motor area in 9 cases, the ipsilateral motor activation areas decreased significantly, 6 cases of activation signals appeared in the non traditional sports area. The protection of a non protected plan average in the motor cortex area dose level: ipsilateral - at least 0.76%, up to 59.20%, average 30.78%, contralateral - at least 23.33%, up to 68.30%, average 48.07%; reduce the coefficient of variation of the degree of ipsilateral contralateral 36.71%; 71.41%, two respectively in the plan of bilateral paired t test results were P0.05 9 cases were adjacent to the target area and even partially overlapped, so the average dose decreased slightly, at least 0.76%, up to 18.61%, with an average of 12.21%.
Conclusion the application of BOLD-fMRI technology in radiotherapy intuitive understanding of brain astrocytoma and its surgical resection effect on motor cortex; and in astrocytoma postoperative radiotherapy planning, to ensure the target dose at the same time, to reduce motor area by volume, and make corresponding protection of motor function possible, eventually improve the life quality of patients.

【学位授予单位】：宁夏医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.2;R739.41

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