Positron Emission Tomography (PET)

Mobile positron emission tomography (PET) scanning is available on Guthrie’s Sayre campus one day a week. The unit will be located in the radiation therapy parking lot adjacent to Robert Packer Hospital’s Department of Radiology.

PET, a nuclear medicine procedure, involves a patient receiving an injection of glucose and fluorine prior to the scan. Since every cell in the body utilizes glucose, cells with a high metabolic rate (such as tumors) will absorb more glucose and will appear brighter on the scan because of the fluorine. PET is most typically used in oncology, cardiology and neurology to identify diseases such as cancer, Alzheimer’s, Parkinson’s, Huntington’s, epilepsy and more. The PET scanner is similar in appearance to an MRI scanner, and the procedure is painless except for any minor discomfort related to the glucose IV injection.

PET has many benefits – it is cost effective, can eliminate some invasive procedures, allows for whole-body metastatic surveys, is effective in diagnosing and staging various cancers and more. PET also allows for image fusion – practitioners can overlay a CT or MRI scan (which produces clear images of the brain, kidneys and many other organs and structures) on top of the image produced by PET to see what both tests reveal, providing a useful diagnostic and surgical guide. Although PET was developed in the late 1970’s, recent developments have resulted in its recognition as an invaluable clinical test for tumor imaging, and it is currently recognized as the cutting edge of a new class of diagnostic and therapeutic procedures called molecular imaging.

A large portion of patients who will utilize the PET will be radiation therapy/oncology patients receiving pre- or post-procedure assessments. For more information or to schedule a patient for PET, call (570) 882-4040.

If you are nursing or it is possible that you may be pregnant, please let your physician know prior to scheduling a PET scan.

Frequently Asked Questions

• How does PET scanning work?
• Why is a PET scan ordered?
• Who can I call if I have questions before the scan?
• How do I prepare for my PET scan appointment?
• How will I receive my scan results?

PET (positron emission tomography) is a diagnostic procedure that provides your physician with information about the cells in your body. Because the PET scanner creates images at the cellular level, it can detect changes that do not show up on other types of tests, and can often detect these differences before structural changes occur.

To begin the test, you will receive an injection of a simple sugar (glucose) that has a radiotracer (called fluorodeoxyglucose, or FDG) linked to it. After the solution is infused via an intravenous line, you rest quietly. The FDG solution travels through your bloodstream and is picked up by all the cells in the body. All cells use glucose as fuel, but cancer cells grow at an increased rate and demand higher levels of glucose, causing them to absorb more glucose and appear brighter on the final scan image.

After about an hour of resting, the FDG begins to break down and particles called positrons are emitted (given off). At that time, you will be escorted to the scanner for the approximately one-hour long scan. The scanner creates an image that shows which areas of the body have a higher concentration of glucose. The higher levels of concentration correlate to increased activity in cells and can help your physician to determine if a cancer is present or has spread to other parts of the body.

FDG leaves your body very quickly, so by the time you leave, more than 90% of the FDG has left your body. After your test, a Guthrie radiologist will read your PET scan and review the results with your physician to assist in your treatment planning. Your physician will share the results with you.

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PET is most typically used in oncology, cardiology and neurology to identify diseases such as cancer, Alzheimer’s, Parkinson’s, Huntington’s, epilepsy and others. A large portion of patients who have PET are radiation therapy/oncology patients receiving pre- or post-procedure assessments. PET is able to detect extremely small cancerous tumors and very subtle changes of function in the brain and heart. This allows physicians to treat these diseases at earlier stages.

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Who can I call if I have questions before the scan?

You may contact Robert Packer Hospital’s Nuclear Medicine Department from 8 AM to 5 PM Monday through Friday at (570) 882-4040.

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• On the day of your procedure, you will need to register at the Outpatient Registration Desk on the third level of the main hospital building in the Radiology Department. Please bring your doctor’s written request with you. After registering, you will be directed to the PET unit.
• Wear loose, comfortable clothing, such as sweatpants and a t-shirt.
• The scan itself takes about an hour, but you should plan to be at the hospital for about two hours.
• Do not eat or drink for eight hours prior to your scan. You may drink water, but no other liquids. Please refrain from having caffeine or sugar and from chewing gum for 12 hours prior to the scan.
• Take your regular medications if they can be taken without food.
• Please do not engage in exercise or any other vigorous activity for 24 hours prior to the scan.
• If resting in a recliner or lying on a scanning table for the exam will be uncomfortable for you, ask your physician if it is acceptable for you to take over-the-counter pain medication about 30 minutes before you arrive for your scan.
• If you have diabetes and have been scheduled for a PET scan, take your regular medications the day of the scan, as well as your insulin if you are insulin-dependent. Do not eat or drink for six hours prior to your scan. (However, if your scan is scheduled for an afternoon, you may have a light breakfast.) You may drink water, but no other liquids. Please refrain from having caffeine or sugar and from chewing gum for 12 hours prior to the scan.

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A Guthrie radiologist will review the results of the test and will communicate these results to your physician. (This process may take up to three days.) Your doctor will then review the results with you.

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