18F-FDG PET/CT imaging is increasingly being used to identify sites of cancer spread and recently groups have used an intra-operative gamma probe to better localize metastatic disease. In this pilot study, patients with newly diagnosed early stage, high-risk endometrial cancer undergoing primary surgery will have a pre-operative PET scan and intra-operative localization of metastatic lymph nodes with the use of a gamma probe. A complete lymphadenectomy will follow and ability to detect positive lymph nodes of both PET scan and the intra-operative probe will be calculated.