TY - JOUR A1 - Gorges, Verena A1 - Zylka, Waldemar T1 - Reducing dose of Cone-Beam CT used for patient positioning in radiooncology T2 - Current Directions in Biomedical Engineering N2 - Cone-Beam computed tomography (CBCT) has become the most important component of modern radiotherapy for positioning tumor patients directly before treatment. In this work we investigate alternations to standard acquisition protocol, called preset, for patients with a tumor in the thoracic region. The effects of the changed acquisition parameters on the image quality are evaluated using the Catphan Phantom and the image analysis software Smári. The weighted CT dose index (CTDIW) is determined in each case and the effects of the different acquisition protocols on the patient dose are classified accordingly. Additionally, the clinical suitability of alternative presets is tested by investigating correctness of image registration using the CIRS thorax phantom. The results show that a significant dose reduction can be achieved. It can be reduced by 51% for a full rotation by adjusting the gantry speed. Y1 - 2021 UR - https://whge.opus.hbz-nrw.de/frontdoor/index/index/docId/4047 SN - 2364-5504 VL - 7 IS - 2 SP - 227 EP - 230 ER -