PET Scan
Doctors use various diagnostic tools to determine whether a patient has a particular disease or to keep tabs on that disease and its remission or progression. While conventional x-rays were once the diagnostic tool of choice, much more sophisticated imaging tools are now the norm for the diagnosis and treatment of cancers like mesothelioma. One of these tools is the PET scan.
What is a PET Scan?
PET is short for Positron Emission Tomography. This very sophisticated scan, which falls under the category of "nuclear medicine", can produce images of the cellular function of the human body. It does this by detecting the radiation from the emission of positrons, created by a radioactive substance administered to the patient prior to the test. Different colors or degrees of brightness that appear during the test will indicate different levels of organ and tissue function, which may represent the presence of a disease or disorder.
PET scans are generally used to determine whether or not a tumor is malignant, the extent of a cancer, and if it has spread to other organs. It is also used to monitor cancer reoccurrences and to determine the success of treatments such as chemotherapy or radiation.
Administering the Test
The PET scan is a non-invasive, painless procedure performed in a hospital or a facility that specializes in nuclear medicine. The test begins with the injection of a radioactive material, usually mixed with glucose. (The injection may cause some localized pain.) It takes 30 to 90 minutes for the material to circulate through the body after which time the scan may begin.
The scan is similar to a CT scan or MRI in that the patient lies on a table that moves through a donut-shaped machine which, in turn, produces images of the inside of the body. The patient must be as still as possible to insure good images and eliminate the need to repeat the test. Patients with claustrophobia may experience some anxiety. The technician should be informed before the test if the patient has problems with claustrophobia, and a light sedative may be given.
The images are displayed on a nearby computer to be reviewed by a radiologist at a later time. Results will be available from the patient's doctor or oncologist.
Benefits of the PET Scan
Because this scan studies body function, it can detect problems before changes in anatomy - usually detected by CT scan or MRI - are apparent. This means early diagnosis may be possible. In addition, relatively low levels of radiation are used in the PET scan, making it much safer than some other diagnostic tools.
Last modified: December 17 2007.
