Repositionnement du patient en radiothérapie conformationnelle du cancer de la prostate par recalage d'images échographiques et d'images de résonance magnétique Patient Setup in Conformal Radiotherapy of Prostate Cancer by Registration of Ultrasound and Magnetic Resonance Images

and key words In conformal radiotherapy, beam set up and dose calculations are achieved using images obtained from computed tomography (CT) or magnetic resonance (MR). These images are taken before the treatment which is performed on several sessions on several weeks. At the beginning of each session, the patient has to be positioned on the treatment couch under the linear accelerator in the same position as during MR or CT imaging and planning, and the organs are