1. A method comprising: creating a first self-calibration curve that relates a first array image to a first acquired image, the first array image being recorded from application of a first radiation treatment plan to a detector array, the first acquired image being recorded from application of the first radiation treatment plan to a radiation detector; and creating at least one subsequent self-calibration curve that relates at least one subsequent array image to at least one subsequent acquired image, the at least one subsequent array image being recorded from application of at least one subsequent radiation treatment plan to the detector array, the at least one subsystem acquired image being recorded from application of the at least one subsequent radiation treatment plan to the radiation detector.