Fig. 2

Left panel: Histogram displaying VOIs that increase (green) or decrease (red) their local similarity by the manual expert-correction in respect to the bony pre-match. The blue line, belonging to one exemplary fraction and patient, reflects the trade-off in the VOI alignment process. While for this selected patient geometry the structure alignment for spinal cord (boost) was improved, the whole spinal cord structure experienced a degradation of alignment. Right panel: CT views of the selected patient 003 visualizing the trade-off in the alignment quality of local structures. The VOIs indicate corresponding positions in the planning situation. The dotted line indicates the cc extension of the spinal cord (boost) substructure. The green arrows mark location with visible improvement of the alignment quality of the fraction scan in regard to the planning CT. The red arrows are the counterpart of the green ones, marking a decline of alignment quality