A New Planning Tool for Fast Online Dose Optimization of IMRT Plans

In an inverse planning system based on multicriteria optimization (MCO), a solution space can be explored interactively. The equivalent uniform dose (EUD) is used both as optimization objective for the precalculation of representative plans of the Pareto front and as a navigation instrument. This system was enhanced by two additional navigation options: First, the planner can now directly manipulate the dose-volume-histogram (DVH) of every structure within the physically possible solutions. Second, by directly selecting points in the 3D isodose visualization and prescribing a new dose, a new plan is generated and added to the navigation space, so that the planner can adjust and correct local dose characteristics (Fig. 1). So far the system is designed for step-and-shoot IMRT.