Clinical merit of simulation images generated from CT.

The region-of-interest (ROI) capabilities of most computed tomography (CT) scanners provide the data necessary to transcribe transverse-sectional CT data and tumor and target contours to other planes, and to create a treatment-simulation type of image. Comparison of such computer-generated images with actual simulation images gives a direct and quantitative means of verifying patient alignment prior to treatment. We illustrate this technique using a Rando-Alderson phantom and a patient who received treatment with pions at the LAMPF Biomedical Facility. The clinical merits and suggestions for further development of this technique are discussed.