Accuracy of Sentinel Lymph Node Biopsy in Nodal Staging of High Risk Endometrial Cancer

Inclusion Criteria: * Women with endometrial cancer with high risk histologic subtypes including grade 3 endometrioid, carcinosarcoma, serous, clear cell, undifferentiated adenocarcinoma, and and any mixed high risk histology. * Clinical stage 1 disease- no evidence of metastatic disease beyond the uterus by physical exam or preoperative imaging if performed. * Patients who have signed an approved informed consent. * Patients who will undergo surgery that includes a hysterectomy and bilateral pelvic and inframesenteric para-aortic lymphadenectomy via laparoscopy or robotic-assisted. Exclusion Criteria: * Women with grade 1 or 2 endometrioid adenocarcinoma * Patients with evidence of metastatic disease on preoperative imaging. * Patients with evidence of intraperitoneal metastatic disease intraoperatively (patients with suspicious retroperitoneal lymph nodes intraoperatively will still be included). * Patients with known allergy to iodine compounds * Pregnant patient. * Patients with previous retroperitoneal surgery. * Patients with previous history of pelvic/abdominal radiation. * Patients with recurrent endometrial cancer. * Any patient treated with neoadjuvant chemotherapy and/or radiation.