Trial Parameters
Brief Summary
This study is designed as a single institution trial. The study utilizes safe and clinically-validated tools for preoperative workup of patients with small pituitary tumors. DDAVP stimulation and 18F-labeled fluoro-deoxyglucose (FDG) uptake for PET-imaging will be used to detect MRI-negative pituitary adenomas in patients with Cushing s disease. Patients who have MRI-negative pituitary microadenomas will undergo FDG PET-imaging with DDAVP stimulation. Intravenous FDG will be given approximately four hours following DDAVP administration. Within 12 weeks after completion of the FDG high-resolution PET scan, patients will undergo surgical resection of the pituitary adenoma. Surgical and histological confirmation of adenoma location will be noted. All images will be read independently by neuroradiologists blinded to clinical and histopathological outcomes. The diagnostic and localization accuracy of PET-imaging will be assessed by comparing the PET findings with histopathology.
Eligibility Criteria
* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Subjects aged 8 or older with biochemical evidence of Cushing s disease and a clinical MRI pituitary neuroradiology result of negative or possible adenoma (e.g. "no tumor" or "possible tumor") 2. MRI of the pituitary gland with and without contrast obtained within 9 months of screening 3. For newly diagnosed Cushing s disease cases, IPSS is required. 4. Ability to undergo PET-imaging without general anesthesia 5. Ability to provide informed consent for study participation (parents or guardians in the case of minors) 6. Clinical diagnosis of Cushing s disease based on documented medical records 7. Surgical candidate for and subject agrees to resection of ACTH producing pituitary adenoma within 24 weeks of PET-imaging 8. Normal liver function as evidenced by liver enzyme tests completed within 14 days before injection of radiopharmaceutical: SGOT, SGPT \<=