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?
(A) Ovary (B) Vagina (C) Bladder (D) Rectum
(A) 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).