Biases affecting tumor uptake measurements in FDG-PET

The influence of tumor diameter, tumor-to-background activity ratio, attenuation, spatial resolution, tumor location, tumor non-uniformity and spatial sampling on the biases affecting tumor-to-background activity ratio (TBR) estimates in FDG PET was studied using analytical simulations of an anthropomorphic phantom. Major parameters affecting the bias amplitudes appeared to be the tumor diameter, the tumor-to-background activity ratio, whether attenuation had been performed, the spatial resolution of the PET scanner and the spatial sampling used to define the anatomical regions of interest used for TBR estimation