Inclusion Criteria:  Surgery consisting of a total abdominal or laparoscopic hysterectomy, bilateral salpingectomy, pelvic lymphadenectomy or sentinel lymph node mapping and dissection, with or without para-aortic lymphadenectomy, oophorectomy  Histologically confirmed endometrioid type endometrial carcinoma, International Federation of Gynecology and Obstetrics (FIGO) 2009 stage I, with one of the following combinations of stage and grade:  Stage IA, grade 3 Stage IB, grade 1 or 2 Stage IB, grade 3 Stage II  World Health Organization (WHO)-performance status 0-2 Written informed consent  Exclusion Criteria:  With residual disease Any other stage and type of endometrial carcinoma Histological types serous carcinoma or clear cell carcinoma (at least 10% if mixed type), or undifferentiated or neuroendocrine carcinoma Uterine sarcoma (including carcinosarcoma) Previous malignancy (except for non-melanomatous skin cancer) Previous pelvic radiotherapy Expected interval between the operation and start of radiotherapy exceeding 8 weeks