Abstract: A system for radiographic patient positioning includes at least one laser. An orientation sensor is associated with a laser and the orientation sensor produces tilt data indicative of an orientation of a laser. A computer compares a later received tilt data from the orientation sensor to the stored tilt data to identify an error in the alignment of the laser. A method of operating a computer tomography patient positioning system includes providing a plurality of lasers and orientation sensors. A processor obtains tilt data from the orientation sensor of an associated laser and the tilt data is representative of an orientation of the associated laser. The processor compares new tilt data to the stored tilt data and identifies an error in an alignment of at least one laser of the plurality of laser units based upon the comparison of the new tilt data to the stored tilt data.

Abstract: A system and method of delivering a radiation therapy treatment plan to a patient. The treatment plan is delivered using a radiation therapy system including a moveable support for supporting a patient, a gantry moveable relative to the support and supporting a radiation source and multi-leaf collimator for modulating the radiation source. The support and gantry are moved during delivery of the treatment plan.