New imaging techniques in colorectal cancer.

The ability to visualize biochemical processes in tumor tissues by PET and correlate these findings with anatomic imaging such as CT and MRI gives new insight into the metabolic and physiologic aspects of the tumor tissue. This may permit discrimination between recurrent colorectal carcinoma and some benign lesions. The potential for its use in pharmacology or in monitoring drug therapy is just beginning to be explored. Improvements in acquisition techniques such as whole body imaging, and in methods of absolute quantitation will be important for standardizing image information and making it more widely applicable. Careful evaluation of the impact on patient outcome and clinical decision making are vital in determining the further use of this technology and the planned multicenter trial evaluating cost-effectiveness is welcome step in this direction.