Radiotherapy in head and neck cancer: A retrospective analysis of setup errors with base on 2D MV image

To perform the radiotherapy, the patient is positioned in the device and it is estimated that there are small differences in displacement of the patient's position throughout the treatment. To minimize complications and failure of dose delivery in tumors, the physician always adds a three-dimensional margin around all target volumes that will be treated. However, it is essential to know the correct misalignment error (setup error) of each RT (Radiotherapy) service in order to apply the correct margin around the tumor during treatment planning. The present study aims to evaluate the existing set up errors in the RT routine of Head and Neck patients at Hospital de Amor de Barretos, in comparison between technicians (online) and physicians (offline) and the systematic error in the comparison of portals. (author)