Different stages of optimization using the automatic interactive optimizer (AIO). A) shows the initial position of all OAR optimization objectives along with the graphical user interface of the AIO. B) shows the optimization window after 3 minutes while the AIO is being performed on a complex head and neck case. C) shows the optimization window after 11 minutes. In this case, the full optimization took approximately 29 minutes. Shown abbreviations: PTV = Planning target volume, PCM = Pharyngeal constrictor muscle and UES = Upper esophageal sphincter.