Figure 4: The dose-volume-histogram for the critical volume. ‘3D stationary’ represents 3D planning without considering motion. ‘3D moving’ simulates the 3D plan when organs move, but beams stay fix. ‘3D motion compensated’ shows results when the 3D plan is delivered and both, organs and beams move. ‘4D motion compensated’ shows results when the 4D plan is delivered and both, organs and beams move. If a 3D plan is used with motion compensation, some parts of the critical volume get overdosed (red line).