title: Optoelectronic techniques for patient repositioning in radiotherapy.
abstract: In modern radiotherapy practice, patient mispositionings and movements at therapy units are considered one of the major source of error in the irradiation and, consequently, a decisive factor in relapse rate and in radiation damages occurrence. Movement analysis system ELITE has been used to carry out a new conceived control on patient repositioning procedure and to implement an automatic correction of the detected position errors. Two marker disposition models have been defined for the supine position with reliable and easily identifiable body landmarks. Analytical comparison between current and reference 3D co-ordinates of these points has constituted the core of the whole method. The detection of patient's breathing phases has allowed to synchronize the co-ordinates calculation to patient's FRC, increasing accuracy and reliability of the comparison. Results point out the relative accuracy of the commonly adopted optical laser repositioning systems and confirm the significant role that ELITE can have in radiotherapy, in order to reach a suitable tradeoff between a quick irradiation set-up and a clinically correct patient irradiation.
authors.affiliation: Centro di Bioingegneria, Politecnico di Milano, Fondazione Pro Juventute Don Gnocchi, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Baroni
authors.forename: G
authors.initials: G
authors.lastname: Ferrigno
authors.forename: A
authors.initials: A
authors.lastname: Pedotti
mesh_terms: D016018:Least-Squares Analysis; D008838:Microcomputers; D008954:Models, Biological; D009068:Movement; D055095:Optics and Photonics / Q000295:instrumentation*; D011786:Quality Control; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation*; D011881:Radiotherapy, Computer-Assisted / Q000295:instrumentation*; D012016:Reference Values; D012119:Respiration / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D016683:Supine Position