A method and system for positioning a patient for receiving radiotherapy treatment by performing a computer tomography scan of the patient in a first position to acquire CT data, using the CT data to create one or more images of the patient in the first position, preparing the patient to receive treatment delivery in a second position, acquiring one or more images of the patient in the second position, using a means for comparing the one or more images of the patient in the first position to the one or more images of the patient in the second position, and repositioning the patient until the patient is in substantially the same position as shown in the one or more images of the patient in the first position.