Abstract: A simultaneous imaging and particle therapy treatment system including a means for generating a particle beamline, a treatment bed to receive and support a patient having a treatment volume, a gantry to receive the particle beamline from the generating means and to redirect the beamline to the patient's treatment volume, the gantry rotating about the treatment bed with an axis of rotation substantially coplanar with the treatment bed and redirecting the beamline to encounter the treatment volume substantially perpendicular to the gantry's axis of rotation, and an image scanner having a plurality of detector arrays radially positioned around the treatment bed to capture images of the treatment volume; whereby the scanner and gantry simultaneously capture images of and treat the treatment volume with particle therapy.