Positron Emission Tomography (PET)

 

How it works

The Positron Emission Tomography (PET) scanner is a powerful, non-invasive, nuclear imaging technology that allows detailed diagnostic measurements of physiological and biochemical processes within the body. Since changes in biological function precede structural or anatomic changes in a variety of disease conditions, PET is uniquely capable of detecting cancer before it is evident through other diagnostic imaging tests such as CT (computed tomography) or MRI (magnetic-resonance imaging). In cancer care, early detection prompts earlier treatment, thereby improving the probability of a successful outcome.

Virtually all new PET scanners are bundled with a CT scanner and this hybrid device, known as a PET/CT scanner, is one of the most sophisticated scanning technologies available today. It allows for the simultaneous detection of functional (physiological) anatomic (structural) changes via CT technology.


Diagnostic role in Cancer

Cancer is the leading cause of premature death in Canadians and the number of cancer cases increases with each year. As Canada’s population grows and ages, cancer incidence and mortality rates will continue to rise and place growing pressure on the Canadian healthcare system to provide new technologies and therapeutics that will provide better, more efficient and cost-effective care for cancer patients.

The statistics below present the harsh realities of cancer in Canada (Canadian Cancer Statistics, 2011):

  1. One out of every four Canadians will die from cancer
  2. Cancer is the cause of almost one-third (30%) of all premature deaths (National Post, 2011)
  3. 40% of Canadian women and 45% of Canadian men will develop cancer during their lifetimes
  4. 177,800 new cases of cancer and 75,000 deaths from cancer will occur in Canada in 2011
  5. Every hour, an average of 20 Canadians will be diagnosed with some type of cancer and another eight will die from cancer
  6. 42% of new cancer cases and 59% of cancer deaths will occur among Canadians 70 years of age and older


It has long been known that early detection of cancer and selecting the most appropriate treatment strategy will enhance a patient’s chance of survival. New technology exists that is uniquely capable of detecting the source and full extent of cancer before it is evident through other widely-used diagnostic imaging tests such as CT (computed tomography) and MRI (magnetic resonance imaging).

The positron emission tomography (PET) scanner is a powerful, non-invasive, nuclear imaging technology that allows detailed diagnostic measurements of physiological and biochemical processes within the body prior to changes in anatomy. Since changes in biological function precede structural or anatomic changes in conditions such as cancer, PET is capable of detecting cancerous cells at an early stage, before they congregate to form a mass. This early detection is critical to cancer care as it prompts more timely treatment and greatly improves the probability of a successful outcome.

Cost savings can also be realized by using PET to ensure the most appropriate management of cancer patients. PET imaging at early stages in therapy can reveal when treatments are ineffective; thereby allowing doctors to quickly change to a more effective treatment strategy and reducing healthcare expenditures on ineffective therapies.

Since PET scans typically find that the cancer has spread beyond that demonstrated by conventional imaging, they often provide doctors with an opportunity to avoid futile, costly and invasive interventions such as surgery or radical chemotherapy/radiotherapy. This does not always improve the survival of the patient, but it does improve the patient’s quality of life through the use of more appropriate palliative measures. It also ensures the most appropriate use of scarce healthcare resources.


PET use in Canada

PET imaging technology is increasingly well established in the Canadian health-research community. However, Canada lags far behind the United States and Europe in its adoption of PET and other diagnostic technologies. Canada currently has only 43 publically-funded PET scanners in comparison to, for example, over 2000 in the United States.

The availability and utilization of PET infrastructure varies widely, province by province. The cost of a PET scan varies from a low of $956 in Quebec to a high of $1,800 in Manitoba and Nova Scotia. The average cost of a scan in Canada is $1,506.20.

Quebec leads Canada with a well-established and expanding PET infrastructure that offers broad access to PET imaging for cancer. In sharp contrast to Quebec, the province of Ontario has restricted patient access to PET over the past decade. This has resulted in underutilization of its present PET network and a provincial medical community that appears to be divided in its perception of the usefulness of PET imaging.


Further Reading

The Use of PET for Cancer Care Across Canada
PET scans: underused, underfunded, everywhere except Quebec
Publicly Funded Uses of PET Scans in Canada

This webpage contains excerpts from "Positron Emission Tomography (PET) for Cancer Care Across Canada: Time for a National Strategy", Susan D. Martinuk (2011). © 2011 AAPS, Inc. and TRIUMF. Reproduced with permission.

Watch videos about how a PET scan works

By the Numbers

How does Canada measure up to the rest of the world?

PET scanners in the United States.

PET scanners in all of Europe.

PET scanners in Canada.