pet scan results

I did a pet scan to check an enlarged thymus gland post thyroid cancer.  Results I got today say "diffuse thymic FDG activity with SUV max of 2.9.  What does this mean? Should cancer be suspected?

[Fernando Roque, MD]

Hi.  Fluorodeoxyglucose (FDG) is a radioactive form of glucose which is avidly taken up by cells with a high metabolic rate.  The assumption is that cancer cells would have high metabolic rates compared with normal cells, and would more readily take up FDG.  So cancer will appear as discrete areas where FDG has accumulated (areas of high FDG activity).  "Diffuse thymic FDG activity" means that the FDG is spread throughout the thymus gland, implying that there are no areas with high activity and suspicious for cancer.