A PET scan may be combined with a CT scan at many cancer treatment centers. But you may hear your doctor refer to this procedure just as a PET scan. A PET-CT scan is one way to find cancer and learn its stage. Stage is a way to describe where the cancer is, if it has spread, and if it is changing how your organs work. Knowing this helps you and your doctor choose the best treatment. It also helps doctors predict your chance of recovery.
Doctors combine these tests because a CT scan and PET scan show different things. A CT scan shows detailed pictures of tissues and organs inside the body. A PET scan shows abnormal activity. The 2 scans together provide more information about the cancer.
A PET scan creates pictures of organs and tissues in the body. First, a technician gives you an injection of a small amount of a radioactive substance. Your organs and tissues pick up this substance. And areas that use more energy pick up more. Cancer cells pick up a lot, because they tend to use more energy than healthy cells. The PET scan shows where the radioactive substance is in your body. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these images into a detailed, 3-dimensional image that shows anything abnormal, including tumors. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image.
When you schedule a PET-CT scan, the staff will tell you how to get ready. For example, you might need to drink only clear liquids after midnight the night before the scan. Or you might need to stop eating and drinking at least 4 hours before the scan. For some scans, you might not need to stop eating and drinking. Therefore, it is important to tell your health care team if you have diabetes.
You should also tell your health care team about all the medications you take. Ask if you should take them the day of your scan. Also, mention any allergies and other medical conditions. If you are breastfeeding or might be pregnant, tell your doctor. A PET scan could be dangerous for the baby.
The Cost of Whole Body PET CT ranges from INR 18000 to INR 27000 depending upon centre to centre.
Your doctor may order a PET scan to inspect your blood flow, your oxygen intake, or the metabolism of your organs and tissues. PET scans show problems at the cellular level, giving your doctor the best view of complex systemic diseases. Cancer cells have a higher metabolic rate than noncancerous cells. Because of this high level of chemical activity, cancer cells show up as bright spots on PET scans. For this reason, PET scans are useful both for detecting cancer and for:
seeing if the cancer has spread
seeing if a cancer treatment is working
checking for a cancer recurrence
Drink plenty of fluids after the test to help flush the tracers out of your system. Generally, all tracers leave your body after two days.
Meanwhile, a trained specialist will interpret the PET scan images and share the information with your doctor. The results are usually ready for your doctor within two business days, and your doctor will go over the results with you at your follow-up appointment.