Fig. 2

a The irradiation field. Clinical target volume was defined as the whole rectum and is shown in orange. Planning target volume was defined as clinical target volume plus a 1 cm margin in all directions and is shown in green. The ovary and uterus are shown in yellow and pink, respectively. b Dose distribution of the axial cross section. Although a hot area of more than 110% spread to both sides of the soft tissue, the ventral side of the ovary and uterus remained outside the irradiation field