A patient positioning/constraint apparatus and method of use thereof is described in combination with a charged particle cancer therapy system. In one embodiment, a patient is tilted about a longitudinal axis, such as rotation about a head-to-foot axis of the patient where the head-to-foot axis of the patient is horizontal. Optional side support constraints are optionally used to constrain radial movement of the patient on the tilted patient support. The side support constraints are optionally pre-formed to or coupled to a radially outer shape of an individual patient, such as the dexter or sinister side of the individuals head, arm, torso, hip, and/or leg. Patient tilt is optionally combined with rotation of the patient about a vertical axis, rotation of the entire patient about an axis not overlapped by the patient, and/or dynamic control of angles of incident charged particles directed by beamline magnets of the charged particle therapy system.
