A proton beam delivery system including a proton beam nozzle to emit a proton beam to a targeted region of a patient, a gantry wheel to support the proton beam nozzle, the gantry wheel being configured to rotate the proton beam nozzle about a rotation axis of the gantry wheel such that the proton beam nozzle emits the proton beam to an isocenter of the gantry wheel corresponding to the targeted region, a beamline deflector configured to be rotated by the gantry wheel to transport the proton beam along a curvilinear path from the rotation axis to the proton beam nozzle using a predetermined power setting of the beamline deflector, and a rigid support structure to support the beamline deflector when the gantry wheel is rotated such that the beam nozzle directs the proton beam to the isocenter from a plurality of radial directions using the same predetermined power setting.
