Example DO-IMRT dose distribution showing 95% (51.3 Gy isodose in cyan) coverage of PlanPTV5400 (red) compromised only in the region of PlanSMPCM (blue) in order to reduce dose whilst maintaining coverage elsewhere. Parotid outlines are displayed in green and brainstem outline in pink. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)