Optimal radiation therapy (RT) can be achieved when accurate knowledge about the exact location of the target volume to be treated with respect to all organs at risk is available. A whole body atlas (WBA) can be utilized to convert the anatomy of a “standard man” into individual patients by applying warping on anatomical images and the anatomy of the atlas can be adjusted to an individual patient 2,3. The purpose of this work is to propose a semi-automatic segmentation procedure that utilizes polynomial warping together with active contour models, which could be used with WBA to delineate different organs in RT planning [4].