An interventional therapy system may include at least one controller which may obtain a reference image dataset of an object of interest (OOI); segment the reference image dataset to determine peripheral outlines of the OOI in the plurality image slices; acquire a current image of the OOI using an ultrasound probe; select a peripheral outline of a selected image slice of the plurality of slices of the reference image dataset which is determined to correspond to the current image; and/or modify the selected peripheral outline of the image slice of the plurality of slices of the reference image dataset in accordance with at least one deformation vector.