Positron emission tomography (PET)

A Positron Emission Tomography (PET) scan produces images of how organs or tissues inside the body work.

Find information for health professionals

Information for Patients

It provides information that is not available from using other scans. This information can be used to decide the best treatment for managing your cancer. PET scanning can also be used to monitor the effectiveness of treatment and to help plan for surgery and radiation therapy. The scanner looks very similar to a CT scanner and is open at both ends.

What will the procedure involve?

  • A small amount of radioactive solution (radiotracer) will be injected into a vein in your hand or arm. The most common radiotracer is 18F-FDG (FDG), which is a sugar compound.
  • After this injection, you will need to rest quietly in a bed or recliner chair for at least 60 minutes, while the radiotracer travels through the body. It is important that you lie still during the resting period to prevent muscles from taking up the radiotracer. You can watch TV or listen to music whilst you rest, but you cannot read a magazine or book.
  • Following the resting period, the PET scan will begin. You will lie on the scanning bed, which moves slowly through the scanner. The PET scanner will detect the radiation released from the injection and will use this to create pictures of the inside of your body. The scan will take around 25-30 minutes, depending on the area of the body being scanned. You will need to lie as still as possible, to help the technologist obtain good quality images.
  • If you usually experience pain when lying down for similar periods, we ask that you bring your pain-relief medication with you.
  • Most patients spend approximately 2 to 3 hours at the PET Centre. Please consider this when parking your car.

What preparation is required for an FDG PET scan?

  • Generally, you will need to fast for several hours before the PET scan. This means no eating any food or drinking any liquids containing sugars. It is ok to drink plain water during this time and we recommend you drink at least 500mls of water before you arrive for your appointment. Your appointment letter will give specific instructions about when to begin your fast.
  • If you have diabetes, please call and inform the PET Centre as some diabetic medications may affect the PET scan.
  • Dress in warm, comfortable clothing, preferably without metal items like zips or studs.

Do you have claustrophobia?

Most patients with claustrophobia find this test quite easy. However if you think you may need any medication to help you go through the scanner, please call to discuss your requirements prior to your appointment. If medication is used, then you will need someone to accompany you home after the scan.

Will there be any side effects?

There are no side effects associated with a PET scan. You will be able to eat and resume normal activities as soon as the scan is complete.

Are there any radiation risks?

The PET scan is a very safe and routine procedure. Millions of PET scans have been done around the world without complications. The amount of radiation that is administered is a small amount and will be passed out of the body in urine. By the end of the day almost all of the radioactive sugar will be out of your body. There is no need to distance or isolate yourself from other people.

Are you pregnant or breast feeding?

All PET scans use a small amount of radioactivity, so try to avoid bringing young children or pregnant women with you to this appointment. If you are breast feeding or think you may be pregnant, please contact our department to discuss your situation.

When will the results be available?

PET scan results will be provided to your referring doctor within 1 or 2 working days. You will need to make an appointment with your referring doctor to discuss the results of your scan.

Are all PET scans funded by Medicare?

Unfortunately not all PET scans are funded through Medicare. If your PET scan is not covered by Medicare, we will advise you of any costs at the time of booking your scan. Please call us if you have any questions about the cost of your scan.

Other PET radiotracers

In our department, there are a number of other PET radiotracers available.

68Ga-tate (Gatate)is a radioactive tracer used to detect some Neuroendocrine tumours (NETs). You are not required to fast for this test but you need to be well hydrated. If you having Octreotide or Somatostatic injections, please let our staff know when booking your appointment. Patients should expect to be in the department for 2 to 3 hours.

68Ga-PSMA (Prostate-Specific Membrane Antigen) or 18F-PSRare radiotracers used to look at Prostate Cancer. Patients do not need to fast for this scan but do need to be well hydrated prior to the scan. You should plan on being at the PET centre for 2 to 4 hours.

18F-FETis useful for looking at primary brain tumours or metastases. Patients are not required to fast for this test and are advised to be well hydrated.


Cancer Imaging

Location: Level 5 (5C), 305 Grattan Street, Melbourne 3000.

Phone: 8559 5510

Fax: 8559 5519

Email: [email protected]

information For health professionals

A positron emission tomography (PET) scan is an imaging procedure showing the chemical function of an organ or tissue, rather than its structure.

Peter Mac was an early adopter of the PET technology in 1996 and installed Australia’s first PET/CT scanner in 2002. Peter Mac has four state-of-the-art PET/CT scanners, including one that is used for radiotherapy planning and our department performs more than 8000 PET/CT scans per year.

PET is extremely sensitive for detecting the early stages of disease and can detect abnormalities even in the absence of structural changes. Small amounts of tumour may be found using PET, even if they are undetectable by other imaging procedures, which can have an important impact on choosing the best treatment option.

PET information can be used to determine what combination of surgery, radiation therapy and chemotherapy is most likely to be successful in managing a patient’s cancer. PET can also help to monitor the effectiveness of therapy and assist in planning for surgery and radiation therapy.

Types of PET scans

Name of test/radiotracerPurpose of test
Fluorodeoxyglucose (FDG) PET                             The vast majority of scans are done with this sugar-like tracer. As tumours use sugars to grow, it is useful for imaging a wide range of different tumours but can also be useful for imaging inflammation, infection and brain function
DOTA-TATE (GaTate) and DOTA-NOC PETMainly used to image neuroendocrine tumours, phaechromocytoma, paraganglioma and neuroblastoma
Ga-68 Prostate specific membrane antigen (PSMA) or F-18 PSRImaging of prostate cancer
Fluoroethyltyrosine (FET) PETMainly used for imaging brain tumours
Ga-68 Exendin-4 (GLP1R) PETLocalisation of insulinoma

How to order a PET scan?

Specialist consultants may order a PET scan using our 2 page request form and email it to [email protected] or fax it to 8559 5519. Please ensure all areas of the form are complete.


Cancer Imaging

Location: Level 5 (5C), 305 Grattan Street, Melbourne VIC 3000.

Phone: (03) 8559 5510

Fax: (03) 8559 5529

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