Calculation result images in one case of pancreatic cancer. (a) DR. (b) DRR at the position of calculation result. (c) DRR at reference position. The red box indicates one vertebra on the DR; the red line indicates the diaphragm position. The blue boxes indicate the position of the same vertebra, and the blue lines indicate the position of the diaphragm. The ZNCC for the calculation position shown in (b) is 0.953; the ZNCC for the reference position shown in (c) is 0.757.