الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The ultimate goal of radiotherapy is to treat the tumor tissue with minimizing the dose to the surrounding normal tissue and with minimal set - up errors. There are different imaging methods used in radiotherapy which needed at all stages of radiotherapy treatment process. These methods include x-ray portal imaging, ultrasound images, C.T images, MRI and functional biological imaging IGRT depends on a combination of radiotherapy machine with imaging facility , the available IGRT approaches are x-ray portal imaging devices , ultrasound devices , MRI devices and CT devices. With using imaging data sets with radiotherapy planning and treatment ,it becomes clear that in view of patient weight loss , shrinkage of the tumor , movement of body by physiological movement , day to day variations in patient in patient position (set-up errors) and variations in radiotherapy fields even by few millimeters , inaccurate radiotherapy dose is delievered to the target tumor tissue , so it needs a second plan on the basis of the new information and to adapt these changes and it is known as ART. Objectives of ART include improving treatment accuracy by reducing the systematic variations , Reduction of the treated volume ,improving the dose distribution by reducing the systematic variations and compensating for patient specific random variations and Improving treatment efficacy by alternating daily dose per fraction and number of fractions. ART is clinicaly applied in lung cancer , prostate cancer , rectal cancer , head and neck cancers and in cancer cervix .