Positron Emission Tomography (PET) Scanning is predominantly used in determining the presence and severity of cancers. It is currently the most effective way to check for cancer recurrences.

PET is based on measuring the metabolism of cells by attaching a “tracer” called F18 to a glucose (sugar) molecule. Cancer cells have a higher metabolic activity than normal cells and will accumulate higher levels of the F18-Glucose compound. The tumor cells will be seen as areas of “increased intensity” relative to the normal tissue in the body. As such, PET scanning is useful to prove if a tissue mass is likely a tumor as well as finding additional areas in the body which might represent tumor spread.

The F18 is given by injection into a vein followed by a waiting period of approximately 45 minutes to allow circulation. The images are obtained by a machine which appears similar to a CT scanner. It takes about 45 minutes to scan the body from neck to pelvis in three different projections or angles.

The only preparation is to fast for four hours prior to the exam. Diabetics are monitored more closely as abnormally high sugar levels can affect the exam.