752135.fig.001a
(a)
752135.fig.001b
(b)
Figure 1: Example of 2D kV image used for verification of patient positioning. A 2D projection was created from the planning CT, and the bony anatomy was contoured (solid line). This image was then overlapped with a kV image taken immediately prior to treatment delivery. The overlay is shown before (a) and after (b) adjustments are made.