About DVH and Dose Review 3D Layout
The main objective of a treatment plan is to treat a high percentage of tumor volume with a specific dose, while keeping the dose received by normal tissue as low as possible. This ratio can constitute a good criterion for assessing the degree of optimization and can be calculated directly from the dose-volume histogram (DVH) display by reading out the percentage of dose delivered to normal tissue at a vertical position where a sufficiently high fraction of the tumor is covered by the required dose.
A DVH is displayed for each object in the Dose Review 3D layout. The layout shows a cumulative histogram where you can see how much of the volume receives the selected dose.
The DVH representation must not be the only decision criterion for a treatment plan (e.g., consider another criterion, such as the dose distribution display).