A Study Of Adaptive Radiotherapy Based On Cone Beam CT For Cervical Cancer

In recent years, intensity-modulated radiation therapy has become the main treatment technology for cervical cancer with the development of radiotherapy. The tumor shrink between radiation therapy and setup error of organs movement, which were not considered during intensity-modulated radiation therapy treatment, have heavy influence on the dose received by patient. For that the treatment plan should be adjusted with tumor variation, adaptive radiation therapy is necessary for tumor patient.The setup error including translational and rotation setup error can be acquired by matching the cone beam CT image and the primary CT image. Through monitoring the volume change and spatial displacement of tumor and organs during radiation therapy,we can evaluated quantitative of volume change rate and DICE dice similarity coefficient. The tumor and organs on CBCT images were contoured with using commercial software automatically. The auto contour and manual contour outlined by a experienced physician were transmitted to Pinnacle treatment plan system,and the evaluation parameters were DSC, volume and cost time. Manual radiation treatment plans and auto plan were developed using Pinnacle script designed by a same experienced physicist. The parameters such as dose volume histogram(DVH),conformity index(CI), homogeneity index(HI),and the cost time for plan designing.are used to evaluate the clinical result between manual plan and auto planIndividualized adaptive radiation therapy(ART) plan was extremely necessarily for cervical carcinoma patient and the treatment plan was adjusted due to tumor and organ variation to ensure that the patient had received the right dose and the normal tissue get better protection. ART can improve tumor control rates and reduces the toxic effect of normal tissue.