Patient with carcinoma endometrium treated with pelvic external beam irradiation to whole pelvis. Which of the following organs is most radiosensitive in the pelvic region?
Ovary
Vagina
Bladder
Rectum
Ans: A. Ovary(Ref Perez and Brady's Principles of Radiation Oncology 6/e p65)Among the given options, most radiosensitive organ is ovary >rectum >bladder >vagina.(Radiation tolerance dose: Ovary = 2-3 Gy; Rectum = 60 Gy; Bladder = 65 Gy; Vagina = 90 Gy).