Imaging for Physicists

Auto-contouring algorithms improve consistency

• Source to Background ratio (SBR) determines a threshold level, determined from phantom experiments (FDG-filled spheres in background) • 5 observers delineated the tumor manualy (a) and edited an SBR- based contour if they deemed necessary (b) • The SBR-based and edited contours show much less variability Baardwijk et al. 2007; Int J Radiat Oncol Biol Phys. 68:771-778