A method of computer aided treatment planning is performed by generating and manipulating a three dimensional (3D) image of a region which includes at least one anatomical structure for which treatment, such as surgery, biopsy, tissue component analysis, prosthesis implantation, radiation, chemotherapy and the like, is contemplated. A virtual intervention, which simulates at least a portion of the contemplated treatment, is performed in the 3D image. The user can then determine the effect of the intervention and interactively modify the intervention for improved treatment results. Preferably, a warning is automatically provided if the intervention poses a risk of detrimental effect. The user can navigate through the contemplated region in the 3D image and assess the results. The treatment plans can be saved for comparison and post treatment evaluation.