1. An apparatus for imaging a tumor of a patient, the patient having a variable respiration rate during an irradiation period, said apparatus comprising: a statically positioned X-ray source; a respiration sensor configured to generate a respiration signal, said respiration signal corresponding to a respiration pattern of the patient, said respiration pattern representing the variable respiration rate of the patient; a rotatable platform configured to both (1) support the patient and (2) rotate the patient; means for collecting a set of X-ray images during the irradiation period, said set of X-ray images collected during a set of rotation positions of said rotatable platform, said set of rotation positions comprising at least five rotation positions covering at least ninety degrees of rotation, wherein at least five X-ray images of said set of X-ray images represent X-ray images of the patient at said at least five rotation positions of said rotatable platform, and wherein each of said five X-ray images represent a set time period of a respiration cycle occurring during one of said five rotation positions; and a charged particle system, configured to deliver protons to the patient, said charged particle system comprising a particle beam controller configured to control an intensity controller, said intensity controller configured to use a measure of a current, resulting from the protons striking an extraction foil, as a feedback control to a radio-frequency cavity system, said charged particle system configured to use the set of X-ray images in targeting the tumor.