Digital image processing of radiation therapy portal films.

Digital image processing has the potential to enhance and improve several functions of a modern radiation oncology department. These functions may include improving perception of information for low contrast films, electronic transfer of images to remote facilities and back, and reducing storage space requirements for archiving once treatment is finished. This paper gives an overview of the digitization process and of image processing fundamentals. The clinical evaluation of digitized portal films is also discussed. The authors conclude that digitizing low contrast radiation therapy portal films is feasible with present technology and will produce images acceptable for routine clinical use in most instances. The role of image enhancement is less well established and remains investigational.