Fig. 6
From: To propose adding index of achievement (IOA) to IMRT QA process
Example of rank maps for all of head and neck cases: (a) 3%/3 mm gamma evaluation, (b) IOA, (c) IOH, and (d) IOC for the global normalization. It consists of average rank from QA results with regard to each amount of dose difference from − 3 to + 3% by 1% intervals along lateral axis and/or spatial displacement by 1 mm intervals along longitudinal axis. Note that no change of levels among results indicates insensitivity, which means undistinguishable which plan is better