Resources for Patients

What is a PET scan?

A PET scan is a tool that can be used to diagnose and stage many life-threatening diseases. PET stands for positron emission tomography.

PET scans are a type of nuclear medicine scan; nuclear medicine is a specialization within radiology which uses small amounts of radioactive materials (called radiopharmaceuticals or radiotracers) to diagnose and treat disease.

Doctors use nuclear medicine to see how different parts of the body are functioning. For example, it can show how well a patient’s heart is pumping blood or how their kidneys are filtering waste. The radiotracer is usually injected, and then travels through the body and collects in the organ or area of the body being studied. Here, it gives off energy and a special camera, used to detect these signals, creates detailed images.

Why are PET scans useful?

Across the world, PET scans are considered the gold standard of care for imaging, diagnosing and staging many diseases. They can detect diseases earlier, more accurately, and in a less invasive manner than other tests.

For example, the use of PET/CT in cancer care assists physicians in answering clinical questions such as:

  • How advanced is the cancer?

  • Has the cancer spread? 

  • What course of treatment should be utilized based on patients’ individual needs?

  • Is the chosen treatment working? 

PET scans are often used in combination with CTs (these tests are called PET-CT). In many cases, PET scans can detect diseases earlier and more accurately than other tools such as conventional CT scans and MRIs. 

PET scans can also be used in place of more invasive tests such as biopsies.

Nuclear medicine has been in use for over 60 years, making it older than tests such as MRI, CT, and ultrasound.

How do I get a PET scan in Ontario?

Talk to your doctor about whether a PET scan is right for you.

In most cases, a specialist such as an oncologist or cardiologist will order a PET scan if it is right for the patient. But the process hasn’t always been easy, and many specialists and physicians may not be aware of significant improvements that have made access to these important scans much easier for the patients who need them.

Currently in Ontario, PET scans can be easily ordered for a variety of OHIP-approved cases (called “indications”) covering a wide variety of diseases. PET for these indications have been shown to significantly alter patient management to more appropriate treatment in approximately 30% of patients. That’s 3 out of 10 patients that could be receiving more appropriate therapy.

Patients living with any of the conditions above should speak with their care team about whether a PET scan may help in the management and treatment of their condition. Details on these indications and the ordering process are clearly laid out in the Coalition’s Resources for Doctors. We encourage patients to talk with their doctors about these resources.

PET scans are available in Ontario for additional use cases beyond those listed above. Talk to your doctor about whether a PET scan is right for you, and visit Cancer Care Ontario for more information.

View Resources for Doctors


Where are PET scans available in Ontario?

PET scans are already available at the following 16 locations in Ontario, and are expected to become available in more Ontario communities in the coming years:

*Note: This chart is based on the latest information available from Cancer Care Ontario as of August 2024. Please visit Cancer Care Ontario for the more up-to-date information.

More Resources

If you’re a patient interested in learning more about nuclear medicine and PET scans, here are some helpful resources to help you understand the science behind PET technology, nuclear medicine! 

**Please note that most resources are from outside of Ontario. Details such as clinical guidelines, insurance, and requisition process will differ across jurisdictions.

From the Society of Nuclear Medicine and Molecular Imaging (SNMMI):

From the Canadian Association of Nuclear Medicine: