Positron Lymphography Via Intracervical 18F-FDG Injection for Pre-surgical Lymphatic Mapping in Stage IB1 Cervical Cancer and High-grade Endometrial Cancer

Inclusion Criteria: * The study population will include women with stage IB1 cervical cancer (any histologic subtype) deemed eligible for surgery, and women with a clinical stage I high-grade endometrial cancer planning to undergo surgical staging. High grade is defined by the following: * Uterine serous carcinoma * Clear cell endometrial carcinoma * Grade 3 endometrioid carcinoma * Endometrial carcinosarcoma * Clinical stage I grade 1-2 endometrial cancer also eligible with deep myoinvasion ≥ 50% shown on preop MRI and/or elevated preop CA-125 \> 35 U/ml. * Age ≥18 years * Hemoglobin ≥10 g/dL * Plasma albumin ≥3 g/dL * GOG performance status ≤2 * Plasma glucose ≤200 mg/dL * Plasma creatinine ≤1.6 * Well-controlled hypertension * Medical clearance for surgery and considered an appropriate surgical candidate * Negative serum pregnancy test, if of child-bearing potential * If, based on surgeon's assessment, the patient is recommended to undergo surgical staging for histologically confirmed endometrial cancer or if IB1 cervical cancer is deemed eligible for surgical treatment of disease * Participation in other research protocols does not exclude a patient from participation in this study Exclusion Criteria: * Hemoglobin \<10 g/dL * Plasma albumin \<3 g/dL * GOG performance status \>2 * Plasma glucose \>200 mg/dL * Renal insufficiency with plasma creatinine \>1.6 * Uncontrolled hypertension * Patient does not meet medical clearance for surgery and is not considered an appropriate surgical candidate * Pregnancy For Stage 2: * Patient who are unwilling or unable to undergo MRI including patients with contraindications to MRI such as the presence of cardiac pacemakers of non-compatible intracranial vascular clips, claustrophobia, inability to lie flat for the duration of the study etc. * Patients with a metallic hip implant or any other metallic implant or device in the pelvis that might distort local magnetic field and compromise quality of MRI