[Preliminary results with digital luminescence radiography in radiotherapy].

Port films in radiation therapy suffer from low image contrast und exposure errors. We examined the potential of computed radiography with a storage phosphor system (FCR-901/Siemens Digiscan) to overcome these drawbacks. Port films of various treatment sites were obtained for both, conventional films and digital storage phosphor screens with a DuPont cassette and steel intensifier screens under identical exposure settings. We examined port films from a linear accelerator and from a 60Co source. We found a superior contrast in the digital images and an almost total elimination of exposure errors. The differences between digital and conventional images, however, were less pronounced with films from the 60Co source. Unsharp mask filtering (medium kernel size, moderate enhancement) further improved image quality. Several sources of artefacts in the digital images could be described.