基于PET/CT的IMRT数学模型及算法研究

【作者】 徐珍璐；

【导师】 赵维加； 崔新建；

【作者基本信息】 青岛大学 ， 计算数学， 2010， 硕士

【摘要】 利用适形调强(IMRT)医疗方法对肿瘤放射治疗方案进行优化,可以使放射线向肿瘤的活性组织集中而使得在有效杀伤癌细胞的前提下,人体的功能器官和组织受到有效保护,是近10多年来放射医学发展较快且应用普及的一项重要技术。近几年来,由于PET/CT检验技术的引入,人们不但能利用螺旋CT的肿瘤成像技术得到清晰的肿瘤几何轮廓,而且可以利用PET检验提供的肿瘤的生物信息,得到肿瘤细胞的活性指标和扩散信息,为放射治疗提供更准确地病灶信息。但PET生物信息图像给出的是肿瘤的生物信息,如何将这些信息以几何的形式表现出来并应用于适形调强医疗方案的优化是目前研究的热点问题,涉及到优化算法、图形、图像处理等一系列问题的研究,目前已有许多进展。在本文中,根据PET/CT的适形调强算法的特点和算法研究开发的需要,我们对以下几个问题进行了研究：(1)由于PET图像的清晰程度比较差,在图像的处理中需要引入图像的识别算法。我们基于离散数据,给出了图像识别模型及其相应的数值计算方法,算法可以应用于一般的n维空问上任意多面体的识别问题,且计算效率较高。(2)在对适形调强医疗方案的算法研究中,我们分析了对调强矩阵分解为放射子野组合的优化方法,基于两个基本的目标函数,导出了达到最优的条件并给出了证明。(3)对于基于PET/CT的放疗的临床靶区的确定,我们利用微分方程的热传导模型建立了一种基于肿瘤生物信息的临床靶区的确定方法。更多还原

【Abstract】 Intensity modulated radiation therapy (IMRT), a widely used optimizing approach for the radiation therapy in cancer treatment, is an important technology which has been developing rapidly in the last 10 years. In recent years, with the invention and development of PET/CT equipment, both geometric and biological information of cancer can be obtained through PET/CT diagnosis, which provide us more information about cancer such as the active index and diffusion trend of the tumor cells which show more accurate information for radiotherapy. However, PET shows only the biological information of the tumor with is of poor visibility. The current hot issues are how to demonstrate these information in the form of geometry.(1) Since PET image is of poor definition, image identification has to be introduced in the information treatment. Based on the discrete data of the image, an information identification model and a relative algorithm are introduced. The numerical algorithm is efficient, and can be used in N dimensional problems.(2) In the study of the numerical treatment of IMRT medical plans, the optimization combination of shape matrices to form a aperture is analyzed. The optimal conditions are derived and proved basing on two basic objective functions.(3) A method for defining clinical target volumn according to biological information is given by the revised heat conduction model of differential equations for defining clinical target volumn according to PET/CT radiotherapy.更多还原