Digital processing of high-energy photon beam images

The potentialities of digital megavoltage radiation field images for image quality improvement and evaluation of patient treatment setup errors are investigated. A treatment verification film is digitized with a densitometer and a treatment planning computer. The 256 X 256 picture matrix is displayed on a viewing console of a computer tomograph. The results of some processed pictures show an improved visibility of anatomical structures, which is of importance for comparison of the treatment beam images with the corresponding localization radiograph made on the simulator. In addition, automated techniques for comparison of irradiation and simulation setup are now possible.