Fig. 1

GTV delineation and soft tissue match to GTV on CBCT. Figs. a and b demonstrate the following contours as delineated on MR fusion (a) and planning CT (b): GTV – blue; High Risk PTV (HRPTV) – red; Bladder - pink; Intermediate Risk PTV (IRPTV) – purple and Low Risk PTV (LRPTV) – light brown. Figs. c and d show these contours overlaid on the cone beam CT to facilitate soft tissue match