Patent ID: 6853702

Claim:
In a radiation therapy machine having a gantry mounted radiation source for producing a plurality of radiation beams directed toward a patient at selected gantry angles, the beams including a plurality of absorbing devices to shape and modify the intensity across the beam, the process of verifying the dose delivered to or to be delivered to the patient from a plurality of such beams consisting of the steps of: (a) measuring the output of each such intended treatment beam over the area of the beam in a plane perpendicular to the central ray of the beam using a pre-patient detector prior to impinging upon the patient, (b) using said measured output of each beam to calculate the dose to the patient from the beam using a dose algorithm, (c) accumulating the dose to the patient from all such treatment beams to produce a dose distribution, (d) using said dose distribution to compare to the intended dose to verify the correctness of the treatment.