Fig. 3

Relationship between estimated dose (ED) and ratio of an OAR’s volume overlapping with PTV to the whole organ volume (V_overlap/V_whole) for the rectum and bladder in institute a (a), (b), (e), (f) and b (c), (d), (g), (h). The horizontal axis is the V_overlap/V_whole for the rectum (a, b, c, d) and V_overlap/V_whole for the bladder (e, f, g, h). The vertical axis is the V90 to rectum (a, c) or bladder (e, g). The vertical axis is the V50 for the rectum (b, d) or bladder (f, h). Yellow dots represent the upper limit of ED and blue dots, the lower limit of ED. Red dotted lines with coefficients of determination (R²) are quadratic regression curves between each organ dose and V_overlap/V_whole for organs. Black dots are calculated doses with knowledge-based planning (KBP) in cases I and II