Evaluation Of Tumor Target Changes Before And After Radiation Therapy Based On Deformation Image Registration

Patients with II or III non-small cell lung cancer(NSCLC)were still less likely to survive after radical chemo.There are still many recurrences in the target volume of radiation therapy,thus indicating insufficient dosage in radiotherapy.If you increase the dose,you must have a good understanding of the target area,which is to have the information about the organization and the metabolic information.However,the multimodal image PET/CT contains metabolic information and tissue information that is expected to guide the radiotherapy program through PET/CT images.PET image has a unique nature,is the ability to the tumor area using Standard Uptake Value(Standard Uptake Value,SUV)Value(90%,80%,70%,60%,50%,34%,SUVmax)to draw the outline of different regions,if found in the process of radiotherapy is not sensitive to gamma SUV Value area,can be considered when making treatment plan is increased in this area.Radiation results are better,and the damage to the crisis organs is controlled.During the RT,large volume of tumor shrinkage or deformation,weight loss or changes in patients’ body position during scanning,is likely to lead to significant anatomical structure deformation.Deformation registration is a useful method of medical image processing,registration technique is to have a purpose will be two pictures to find a kind of transform,transform in order to make the difference between the two pictures to the smallest degree,can be further applied in target organs and outline of deformation and calculation of the dose distribution.This thesis studies is Symmetric deformation Demons multi-resolution registration method of extracting CT images before and after radiotherapy,the scope of the PET image,and its role in before radiotherapy for PET image deformation before radiotherapy,radiotherapy before and after radiotherapy of PET image fusion is more accurate.Compared with radiotherapy after the PET images,by setting the image SUV(standard uptake value)of the threshold,the judge between contours overlap rate,in order to obtain high uptake in the image area,retrospective guide the precise radiotherapy.This study of 22 patients with non-small-cell lung cancer(NSCLC)PET/CT data of experiments and analysis,evaluation,concluded that based on fluorinated deoxidization glucose(FDG)Fludeoxyglucose,high intake area overlap rate as a result,show that the location of the lesion area before and after radiotherapy is relatively stable.The residual tumor after a kilo-volt or mba-level X ray irradiation(RRT)is basically the high drain area of 18f-fdg glucose in the pre-radiation target area.Preliminary experimental results prove that this study can be used to determine target areas of radiotherapy,retrospective guiding radiotherapy plan,can according to residual after radiotherapy target of increasing exposure dose,protect endanger organs and tissues,precise radiotherapy.