The focus for this RT Dose IOD is to address the requirements for transfer of dose distributions calculated by radiotherapy treatment planning systems. These distributions may be represented as 2D or 3D grids. This IOD may also contain dose-volume histogram data. This IOD does not provide for definition of doses in beam or other coordinate systems. The application is responsible for transforming data in other, Non-Patient-Based Coordinate Systems to the Patient-Based Coordinate System described in Section C.7.6.2.1.1.