Fig. 3.
Left: Sagittal images of a prostate RT treatment plan with dose calculated on (top) the PCTorig; (middle) PCTCBCT; and (bottom) the CBCT. The rectum is shown as an orange contour and the dose is shown in color wash relative to the prescribed dose. Right: dose–volume histogram of the rectum for the dose calculated on the PCTorig scan (orange line); the PCTCBCT (blue line); and the CBCT (red dashed line). The RSauto method was used for CTN adjustment of the CBCT image. The rectum OAR was similar in size and shape on the CBCT and the PCTCBCT but was very different to that seen on the PCTorig scan. PCT planning computed tomography, CBCT cone beam CT, CTN CT number, OAR organ at risk