PET Scan: Frequently Asked Questions

Contents:

Is PET Safe?

The risks associated with a PET scan are very minimal. The quantity of radiation is low and the FDG degrades quickly so that no detectable radioactivity is present after several hours. In addition to the radioactive decomposition, the remaining FDG is eliminated from the body through urine. Family members are not at risk for exposure since greater than 90% of the radioactivity has left the body or decomposed before the patient has left the center.

What is a radiopharmaceutical?

A radiopharmaceutical is a radioactive drug. The most commonly used PET radiopharmaceutical is FDG, which is a radioactive form of glucose (sugar). Radiopharmaceuticals are produced by physicists and chemists.

What is FDG?

FDG is a type of glucose (sugar) and is the most commonly radiopharmaceutical used in PET. To begin the PET procedure a small amount of glucose is injected into a patient's bloodstream. There is no danger to you from this injection. Glucose is a common substance that every cell in your body needs in order to function. Diabetic patients need not worry; it would take 1,000,000 doses of FDG to equal the glucose in 1 teaspoon of sugar.
FDG has a half-life of approximately 110 minutes, so it is quickly expelled from your body. FDG must pass multiple quality control measures before it is used for any patient injection.

What happens after my scan?

After your scan, you will get up from the scanner bed and check out with the receptionist. You will be notified when your results will be available to your physician.

Are there potential side effects to a PET scan?

No, there are no side effects to having a PET scan performed. The only pain involved is the needle prick when you receive the radiopharmaceutical injection and it doesn't differ from any other type of injection.

When will I get my results?

Your PET scan results will be sent to your physician generally within 24-48 hours of your PET scan.

How often should I have a PET scan?

If you are under a physician's care, you should follow your physician's recommendations for the frequency of having a PET scan. Typically, it is suggested that you have a follow-up scan at least every five years.
As for wellness scans, the frequency of having a scan is dependent on your family history, your lifestyle, and your age. Your physician can give you a better understanding of whether you are at risk for certain indications (i.e., cancers, brain disorders, heart problems) based on this information.
Regardless of how advanced science becomes, however, it should be noted that a PET scan cannot replace the benefits of a clinical exam and evaluation performed by your physician.

What do the results mean?

The results will be available from you physician usually within 24-48 hours of your PET scan. An interpretation by the radiologist, in layman's terms will accompany your PET scan results.

Can I see my results?

Yes, your physician will have the PET scan results usually within 1-2 business days of your PET scan, and you may request a review of the PET scan results with your physician.

Are there alternatives to PET?

Yes and no. There are examinations that you can have performed. However, there is no other metabolic (biological) scanning technique other than PET at this time. CT and MRI, for example, both examine the anatomical (physical) structure. Therefore, they can be useful in determining the size and location of a tumor; however, neither of them can determine the tumor's viability, whereas PET can determine whether a tumor is still active.
No other imaging tool exists that scans for brain disorders.

What should I do if my physician doesn't know about PET?

If your physician doesn't know about PET, you can direct them to http://www.petscaninfo.com/PhysicianPortal for additional information. You can also enter your physician's name and address into the form on the Patient Portal to have additional information mailed to him/her by clicking here. You may also wish to seek a second opinion.

Why is PET not well known? Why have I never heard of PET before?

While PET has been around for years (CTI, the leading manufacturer of PET scanners was founded in the mid-1980s), it has only been in the last few years that PET has moved from the research realm to the diagnostic/clinical sphere. You may have heard of PET when the CTI/Siemens jointly designed and developed PET/CT scanner won Time magazine's Invention of the Year, 2000

How many PET studies are performed per year?

Approximately 350,000 PET scans were performed in 2002. The numbers of PET scans are increasing dramatically, now that PET is no longer only for research purposes.

It is estimated that within the next five years, in excess of 2,000,000 PET scans will be performed per year.

How does a PET scan differ from CT or MRI scans?

CT and MRI scans are "anatomic" imaging modalities, which means they look at size and shape of organs and body structures. A PET scan is a "metabolic" imaging modality, which means it looks at function. The information received from a PET scan is different from any other test that is available.

Is a PET scan painless?

Yes, other than the needle stick to inject the FDG, there is no pain involved in a PET scan.

How much radiation will I get from a PET scan?

The amount of radiation you get from a PET scan is approximately equal to what you would get from a CT scan of your chest.

How much does a PET scan cost?

A PET scan generally costs anywhere from $2,000 to $4,000.

Updated August 02, 2004