Patent ID: 7199382

Claim:
A radiation therapy delivery system comprising: a gantry; a patient fixation device configured to secure a patient with respect to the patient fixation device; a patient positioner interconnected to the patient fixation device so as to position the patient fixation device along translational and rotational axes within the gantry; a plurality of fixed landmarks that provide a substantially non-moving frame of reference; a radiation therapy nozzle interconnected to the gantry and selectively delivering radiation therapy along a beam axis; a plurality of external measurement device which obtain position measurement of at least the patient fixation device and the nozzle in the substantially non-moving frame of reference; and a controller which receives the position measurements of at least the patient fixation device and the nozzle with respect to the substantially non-moving frame of reference and determines a difference between the position measurement in the substantially non-moving frame of reference and a desired orientation and provides control signals to the patient positioner to position the patient in the desired orientation with respect to the beam axis.