PET (or Positron Emission Tomography) imaging is a diagnostic procedure used to visualize metabolically active tissues using sugar (glucose) molecules labeled with the radiopharmaceutical FDG (Fluorine-18). The labeled glucose is incorporated into the actual cell and once the cell has metabolized the glucose, the low-level radioactivity can be detected by the PET scanner and then generate images used for diagnosis and treatment. PET scan results show the areas of abnormal glucose metabolism and exactly where the areas are located.

What is cell metabolism? All living cells utilize glucose to live and make the building blocks of life. Some cells metabolize glucose faster than others. Cancer cells are hyperactive and divide quickly, and therefore metabolize FDG (Fluorine-18) faster than normal cells. On a PET scan, cancer cells appear "hot" and significantly more prominent than normal cells.

Radiation from PET scans is not dangerous. The quantity of radiation is low and the FDG (Fluorine-18) radiopharmaceutical has a short half-life (110 minutes). The FDG (Fluorine-18) decays quickly so that no detectable radioactivity is present after several hours. In addition to the radioactive decay of FDG (Fluorine-18), the remaining FDG (Fluorine-18) is eliminated in the urine.

Family members are not at risk for exposure since greater than 90% of the radioactivity has left the body or decayed before the patient has left the PET Scan Department.