1. Department of Radiation Oncology, St. Vincent's Hospital, The Catholic University of Korea School of Medicine, Suwon, Korea.
2. Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea School of Medicine, Seoul, Korea.
3. Department of Obstetrics and Gynecology, St. Vincent's Hospital, The Catholic University of Korea School of Medicine, Suwon, Korea.