Abstract: A radiation image generating system for providing planar and tomographic views of portions of a patient's anatomy for use in radiation therapy procedures comprises a fluoroscopic simulator apparatus having a radiation source; a computer system for acquisition and processing of radiation transmission images; a manual input; display and storage devices for such images; means for simulation of an irradiation beam; and, apparatus for the cutting of blocker contour templates, blocker patterns and blockers. The system provides planar transmission images and tomographic views associated and correlated therewith. The system's radiation image detecting means includes an area solid state camera having a planar detector array that is cooled below ambient temperatures. The system further includes means for passively converting radiation transmission images into light images for detection by the camera.