Abstract: A proton beam digital imaging system comprising an X-ray source which is movable into the treatment beam line that can produce an X-ray beam through a region of the patient. An X-ray receiver receives the X-ray beam after it has passed through the patient and the X-ray receiver generates photons that correspond to the X-ray image. The photons are directed to a TEC CCD camera to produce a patient orientation image which displays the orientation of the center of the beam relative to selected monuments in the patient's skeletal structure. The system also receives a master prescription image which displays the target isocenter with respect to the same selected monuments of the patient's skeletal structure.