Phase II, open-label, randomized pilot study.

Patients will be randomized (1:1) to receive for sentinel node screening:

1. Radiotracer (RT) via cervical administration and TUMIR
2. Combination of RT with Indocyanine Green (RT + ICG) via cervical administration and TUMIR Patients will be followed up to 1 month after the last administration of radiotracer 70 patients will be included into the study.

Inclusion Criteria:

1. Age ≥ 18 years.
2. Histological diagnosis of endometrial cancer with criteria of high risk according to the following criteria: - unfavorable histology according to FIGO (adenocarcinoma serous, clear cell, or carcinosarcoma) - nuclear grade 3 - suspected myometrial invasion> 50% by resonance magnetic (MR) or transvaginal ultrasound
3. Women of childbearing age should have a transvaginal ultrasound who rule out pregnancy and must commit to using methods highly effective contraceptives (vasectomized couple and sexual abstinence) until the hysterectomy is performed.
4. Patient who gives written informed consent.

Exclusion Criteria:

1. Pregnancy or lactation.
2. Suspected lymph node or distant metastatic disease in the preoperative study.
3. History of previous surgery or radiotherapy in the pelvic and paraortic lymphatic drainage areas or nodal involvement of any other etiology.
4. Body mass index (BMI) greater than 45 Kg / m2.
5. Patients who, in the researcher's opinion, are not suitable for participate, regardless of reason, including medical or clinical, or participants potentially at risk of not comply with the study procedures.
6. Known hypersensitivity to some of the active substances or excipients from RT or ICG (including previous history of hypersensitivity to products containing human albumin).
7. Hypersensitivity to sodium iodide.
8. Patients allergic to iodine.
9. Patients with clinical hyperthyroidism, thyroid adenomas autonomic and diffuse focal and autonomic disturbances of the gland thyroid.