Patent ID: 7672705

Claim:
A method for determining a shift for aligning temporally displaced images of a lesion entirely within a patient for the purpose of administering radiation treatment to the lesion, the method comprising the steps of: (a) generating a first set of one or more surface elements from a first three-dimensional image of at least a portion of the lesion taken at a first time; (b) generating a second set of one or more surface elements from a second three-dimensional image of at least a portion of the lesion taken at a second time; (c) assigning a weight to (i) one or more of the first set of surface elements, and (ii) one or more of the second set of surface elements, wherein the weights represent a certainty that a surface element represents an edge boundary of the lesion; (d) mapping one or more of the weighted surface elements of the first set to corresponding weighted surface elements in the second set; (e) determining a proximity between one or more of the mapped surface elements; (f) determining an optimal shift for aligning the lesion in the first and second images based on the proximities between, and weights attributed to, corresponding surface elements; and (g) adjusting the patient to obtain the optimal shift.