You will receive a small amount of fluorodeoxyglucose (FDG) solution by vein. Cancer cells use sugar at a higher rate than normal cells do. FDG is a radioactive form of glucose (sugar) commonly used during a PET scan. The FDG helps show areas in the body where there is cancer cell growth. After receiving the FDG solution, you will rest in a quiet, darkened room for 45-60 minutes before the PET/CT scan. The entire procedure should take about 3 hours.