An image-guided therapeutic apparatus (1) comprises- a treatment device (2), preferably a HIFU transducer, for treating tissue,- at least one imaging device (3) for guidance of a treatment,- means for providing an image (4),- a display (5) for displaying an image and- planning means (6) for planning a treatment.The planning means (6) is adapted to create a lesion representation (9) of a lesion that will be created in tissue on the image (7) and to overlay said lesion representation (9) over said image (7). The size and/or shape and/or position of the lesion representation (9) is changeable, in particular in dependence on the characteristics of the tissue.
