Deep learning-based GTV contouring modeling inter- and intra- observer variability in sarcomas

•Deep-learning based GTV delineation modeling reader variability can predict confidence levels in GTV contours.•Learning of GTV confidence levels can be performed with a modified U-Net with an ordinal loss combined with a training strategy using discretization of target GTV confidence levels.•The agreement between CTV drawn from human and predicted GTV contours is even higher than the agreement between the GTV contours, approaching 90% Dice score.