Method and device for delivering radiotherapy

A method of aligning a patient for delivery of radiation therapy to a treatment area of the patient, the patient being positioned on a patient positioner configured to move the patient with respect to a radiation delivery device, the method comprising:

• (a) at a first location,
• determining a relationship between the treatment area and a reference point of the patient positioner;
• calculating location coordinates for the patient positioner based on the relationship between the treatment area and the reference point;
• and
• (b) at a second location,
• immobilizing the patient on the patient positioner;
• adjusting a position of the patient positioner according to the calculated location coordinates so that the treatment area is approximately aligned with a beamline center of the radiation delivery device, wherein the time required for alignment of the patient at the second location is minimized due to the calculation of location coordinates at the first location.