EP-2030: Examination of the automatic fiducial marker detection on the Vero system
M. Ziegler, T. Brandt, Saskia Lettmaier, R. Fietkau, Christoph Bert · Radiotherapy and Oncology · 2018
Purpose or ObjectiveKidneys are the principle dose-limiting organ for abdominal RT in children and young people.Centre of mass (COM) measurement is a frequently reported descriptor of respiratory-related organ motion but is insensitive to changes in organ shape.Deformable image registration of 4DCT is an alternative method of measuring intra-fraction changes in structure geometry reflecting both deformation and translation in x, y and z.This work is the first to apply this methodology to 4DCT in children and young people.Material and Methods 15 patients having upper abdominal RT and simulation 4DCT were analysed; median age 4 (range: 1 -17 years).13 right and 10 left kidneys in total were included.Following acquisition, 4DCTs were retrospectively sorted into 10 phase bins; 0 -90%.Kidneys were contoured on all image sets by the same clinician to minimise intraobserver delineation variation.Kidney structures were divided into three segments; upper, middle and lower, with respect to the renal hilum Figure 1.