The invention comprises a method and apparatus for imaging and treating a tumor of a patient using positively charged particles and X-rays. A mounting rail, supporting a scintillation detection system element and an X-ray detection system element, is alternatingly extended/retracted to position the required detection system element opposite a patient tumor position from an exit nozzle of a beam transport system connected to an accelerator of the positively charged particles, where the positively charged particles are alternatingly used to treat the tumor via irradiation. The mounting rail optionally rotates with rotation of the exit nozzle about the patient, such as with rotation of a support gantry.