Patients with endometrial cancer who have planned robotic laparoscopic hysterectomy and full bilateral pelvic and para-aortic lymphadenectomy will receive injections of a fluorescent dye, Indocyanine green (ICG). ICG spreads through the lymphatic system, and will be visualized using near-infrared (NIR) imagers. Upon visualization of the path of the ICG, sentinel lymph nodes (SLNs), the first nodes to receive drainage from the primary tumor, will be identified. SLNs will be surgically removed and provided to Pathology for evaluation. Non-sentinel nodes will also be surgically removed, as is consistent with routine medical care for these patients, and given to Pathology for evaluation. A positive SLN may be the most accurate identifier of the extra-uterine spread of disease, and will provide information about the extent of surgical node removal necessary.

Inclusion Criteria:

• Adult women patients (>18 years of age and <90 years of age)
• Research authorization (consent)
• Pre-operative diagnosis of clinical Stage 1 endometrial cancer
• Pre-operative indications of grade 3 tumor, and/or tumor size greater than 2 cm in size
• Scheduled and consented to undergo robotic hysterectomy and surgical staging, including bilateral pelvic and para-aortic lymphadenectomy

Exclusion Criteria:

• Severe coagulopathy or severe thrombocytopenia
• Severe anemia
• Severe cardio-pulmonary comorbidities demanding minimization of operative time
• History of liver disease
• Iodide allergy
• Emergent operation
• Additional surgical risk as determined during surgery at the discretion of the attending
• Impaired capacity to make informed medical decisions