Treatment verification using a computer workstation.

Abstract

The outcome of radiation therapy is clearly dependent upon the accuracy with which dose is delivered to the target volume. With the ever increasing use of oblique and even non-coplaner beams, verification issues have become more significant. Presently, radiation oncologists verify the accuracy with which treatments are delivered by comparing a reference ("prescription," usually simulator) on-film image to a portal on-film image on a lightbox. This process is fraught with difficulties as the images are usually rendered with different magnifications, orientations, and contrast. Using a computer workstation, a system has been created that allows a physician to enhance, register, and transparently overlay the portal image on the prescription image. As the prescription and portal images are rendered in shades-of-yellow and shades-of-gray, respectively, a physician can interactively adjust the images and can easily detect set-up errors and/or beam placement errors. Thus greater treatment accuracy should be achievable, especially for unfamiliar beam orientations.