Differences in maximum diameter derived from tumour delineation methods and that obtained from pathology. Difference in maximum tumour diameter between manual CT delineation (A) or various PET-based tumour volume delineation methods (B-C) and pathological size as function of pathological diameter. The arrows indicate two patients with heterogeneous lung tumours. Note that two outliers each from VOI50, VOIA41, VOISchaefer and GradWT1 fall outside the range of the figure (i.e. >220%).