Figure 1From: Analysis of motion of the rectum during preoperative intensity modulated radiation therapy for rectal cancer using cone-beam computed tomography Contouring of the rectum on planning CT (a) and CBCT on 7 days (b). In Figure 1a, the inner red line is CTV (= rectal volume) countured on planning CT, the outside red line is CTV plus 5 mm margin, the pink line is CTV on CBCT on 7 days, and the blue mesh is CTV on CBCT exceeding CTV on planning CT plus 5 mm.Back to article page