Positron Emission Tomography (PET) is a powerful imaging technique in Radiation Oncology that holds great promise in the diagnosis and treatment of many diseases, particularly cancer. A non-invasive test, PET scans accurately image the cellular function of the human body. In a single PET scan your physician can examine your entire body. PET scanning provides a more complete picture, making it easier for your doctor to diagnose problems, determine the extent of disease, prescribe treatment, and track progress.
PET (Positron Emission Tomography) and CT (Computed Tomography) scans are advanced imaging techniques that physicians use to locate and pinpoint disease states in the body. A PET scan shows the biological function of the body before anatomical changes take place, while the CT scan provides information about the body’s anatomy such as size, shape and location. By combining these two scanning technologies, a PET/CT scan enables physicians to more accurately diagnose and identify cancer, heart disease and brain disorders.
Procedure of PET scans
A little quantity of radioactive material is used in a PET scan. The tracer is then given by the means of a vein that is located within the elbow. The tissues and organs are then collected as the tracer is traveling through the blood. A patient is required to wait for about 1 hour as the body is absorbing the tracer. A patient then lies down on the table that slides into a big scanner. The signals from the tracer are then detected by a PET scan. These signals are then changed into 3-D images by the computer. A doctor then can read these images that are displayed on a monitor. Any physical movement of patient during the teat can cause errors and blur images. After the procedure, no problems can be seen in the position, size, or shape of an organ.
Importance of a PET scan
A PET scan helps in detecting the abnormalities of those areas of the body where chemical activity is happening. This scan is most effectively used for those people who have brain disorders, cancer or heart disease.
- Brain disorders : The different areas of the brain having majority of activities while performing various tasks can be revealed by a PET scan. Specific brain abnormalities can also be evaluated by this scan that includes:
- Memory disorders
- Cancer : Bright spot of cancer cells can be seen in a PET scan due to their high metabolism rate as compared to normal cells. The scan helps in determining:
- Whether the cancer has recurred
- The response of the cancer to the treatment
- The spread and extent of some cancers
- A proper interpretation of the PET scans is required as some non-cancerous conditions may look like cancer. It is also possible that certain cancer types may also not appear on PET scans. Following are the different cancer types that will appear on PET scans such as: