The Role of 68-Gallium-DOTATATE-PET/CT in the Imaging of Metastatic Thyroid Cancer

Background: About 5% to 10% of differentiated thyroid cancers become resistant to standard treatment with radioactive iodine. In these cases, treatment options are limited and generally not effective. Researchers want to see if they can better detect thyroid tumors by using a compound called 68Gallium-DOTATATE. This compound may bind to a tumor and make it visible during a positron emission tomography/computed tomography (PET/CT) scan. This information might help guide future research and treatment. Objective: To identify the people with thyroid cancer whose tumors have a high uptake of 68Gallium-DOTATATE as analyzed by imaging with PET/CT. Eligibility: People ages 18 years and older with thyroid cancer that has spread outside of the thyroid. Design: Participants will have a medical exam. They will give blood and urine samples. Some samples will be used for research. Participants will have imaging scans that follow standard of care. These scans may include: CT scan of the neck, chest, abdomen, and pelvis Bone scan Magnetic resonance imaging of the brain, spine, or liver 18-FDG-PET/CT as needed Participants will have a PET/CT scan. They will get an intravenous (IV) line. They will get an IV injection of 68Gallium-DOTATATE. It contains radioactive tracers. The PET/CT scanner is shaped like a large donut. It contains crystals. The crystals pick up small radiation signals that are given off by the tracers. The CT part of the scan uses low-dose x-rays. The pictures made by the scanner show where the tracers are in the body. The session will last 90 minutes. Participation will last for about 3 months.