Igrt Involves Some Of The Image Registration Algorithm And Dose Reconstruction Algorithm

Techniques of radiotherapy have a quite great progress, in last two decades. IMRT(Intensity Modulated Radiation Therapy) and IGRT(Image Guide Radiation Therapy) are developed in this period. These techniques bring people to precision radiation therapy era, and IGRT become one of the most attractive fields at the same time. It is not a trivial work for clinical medical physicist to learn how to utilize the IGRT technique effectively. Although IGRT platform can correct patient's setup error, it is far from perfect. Some online information collected by IGRT platform is isolated. It needs a software level integration of all the online information to maximize the clinical outputs of IGRT platform. The aim of this thesis is to find the way for how to utilize IGRT effectively, which has two different levels. The basic level is ensuring the present function of IGRT running as what has been designed. The higher level is to extend the function of present IGRT platform.Under the IGRT platform, medical image registration is one of the most important techniques. Image guides in all forms rely on the results of medical image registration. It is a key step to utilize the IGRT platform effectively that clinical medical physicists take some work to ensure the results of registration accurate. In this thesis, we construct a research platform for medical image registration on the basis of ITK (Insight Segmentation and Registration Tool Kit) and VTK (Visualization Tool Kit). Under this research platform, we have done some research about medical image registration, and find some interesting common features of it. In this thesis, we discuss the factors influencing the performance of medical image registration algorithm, and also give some suggestions on utilizations of the medical image registration algorithms embedding in commercial software.How to integrate all the resources of IGRT platform has become an international hot point of research. We can infer the incident field fluence distribution based on measured portal image, and then calculate the dose distribution in patient body according to the incident fluence distribution. This technique is called "dose reconstruction". Dose reconstruction based on electronic portal image has various applications in radiotherapy. It can be used in machine parameters verification, the MLC position verification and treatment planning verification (especially IMRT planning) and so on. It can lighten the medical physicists' workload to much extent. Dose reconstruction is also the key technique to estimate and analyze the dose distribution in patient body after a fraction treatment. It is the foundation of adaptive radiation therapy based on dose. In this thesis, we develop a tool for portal image simulation, and use it to evaluate two different technique roads for dose reconstruction.