The quality assurance (QA) of the consistency of radiation treatment delivery with the prescription is a continual concern, locally as well as nationally. The ROB employs graticules, projecting alignment and size information directly on both simulator films of the intended treatment fields and all corresponding portal images. This project is to overlay images from digitized simulator and port films, electronic portal images and digitally reconstructed segmental images from CT data in order to determine the accuracy and repeatability of radiation field alignment with respect to the target and critical anatomical structures. Digitized films are now included as part of every patient's chart. This feature is being integrated into the new Record-and Verify system. Additionally, we have developed software to acquire film images from any imaging modality and to rotate and scale them so that they can be available for immediate comparison. Additional software has been developed to interactively fuse CT and MRI image data of any given patient to accurately determine target volumes. Current research involves the development of a multimodality implantable fiducial system for improving patient positioning accuracy, which will result in improved image registration accuracy. Research is being conducted to determine the feasibility of the commercial digital imaging phosphor plates currently used in the Radiology Department as a substitute for wet film emulsions.