RADIATION THERAPY TREATMENT VERIFICATION WITH ELECTRONIC PORTAL IMAGING DEVICE TRANSIT IMAGES

A method for radiation therapy treatment verification includes acquiring: treatment plan information from a radiation therapy system; patient image data; and transit image data received from an electronic portal imaging device during radiation therapy. The treatment plan information is divided into a plurality of segments. Predicted segment image data is determined utilizing a predicted image calculation algorithm and at least the patient image data and the treatment plan information. A predicted integrated image is determined through superposition of the predicted segment image data. Measured segment responses are determined from the transit image data utilizing the predicted segment image data and the predicted integrated image. The measured segment responses are converted to measured segment doses. A measured dose map having a sum of the measured segment doses is compared to a planned dose map based on the treatment plan information to assess radiation treatment delivery.