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Medical isotopes

Medical isotopes are the cornerstone of nuclear medicine. This branch of medical science uses radioactive sources, atoms and molecules to diagnose, characterize and treat disease.

Canada has consistently led the world in producing radioisotopes for medical use. Canadian medical isotopes are used by doctors in diagnostic procedures to determine what is ailing patients and in therapeutic procedures to treat those diseases.

Cobalt-60 is the most common isotope used in radiation therapy. Hospitals also use colbalt-60 to sterilize medical equipment, including gowns, gloves, masks, syringes and implants.

Injecting isotopes does increase radiation levels in the body for a short time, but it also saves lives through screening, diagnosis and therapy. With the development of Canadian radioisotopes, the cure rate for cervical cancer increased from 25 per cent to 75 per cent. About 1.5 million nuclear diagnostic scans are performed each year in Canada. Canada’s medical isotopes have saved lives in both diagnostic and therapeutic procedures around the world.

What is a half-life?

Each isotope has a unique half-life: the time it takes for half of the atoms to undergo radioactive decay. The shorter the half-life, the faster the isotope decays and the more radioactive it is. A radioactive half-life can range from nanoseconds to hundreds of thousands of years.

Isotopes that are commonly used in medicine include colbalt-60, which has a half-life of 5.27 years, and technetium-99, which has a half-life of six hours. Fluorodeoxyglucose (FDG), which is used in positron emission tomography (PET) scans, has a half-life of about 110 minutes.

Radiologists select isotopes that exit the body quickly through excretion or that naturally decay quickly to non-radioactive isotopes.

The Canadian situation

Canada’s nuclear isotope program pioneered a new era in cancer-fighting treatments and in research and development around health care.

The National Research Universal reactor was taken out of service in 2018 after six decades of supplying medical isotopes to the world’s health-care community. It was the end of an era for medical isotope production in Canada. This happened as new advances are quickly being made in the field of targeted therapeutics for the treatment of cancer.

The landscape of medical isotope production in Canada is diverse, due in part to the long-standing and world-class research into reactor and accelerator technologies.

Canada is a leader in the development and production of medical isotopes that have been used globally for the past several decades. Canada relies on both domestic production and the global supply chain to provide medical isotopes to our hospitals.

Medical isotopes support about 8,500 jobs in the nuclear industry across Canada.

Quick facts about isotopes

  • Worldwide there are more than 40 million medical procedures performed each year using isotopes, with about 36 million for diagnostic nuclear medicine and four million for radiation therapy.
  • Canada has 45 approved radiopharmaceuticals and 23 approved radioisotopes.
  • In developed countries (a quarter of the world’s population), about one person in 50 has a nuclear diagnostic procedure each year. In Canada, this means about 760,000 diagnostic procedures and 76,000 radiation therapy procedures each year.
  • More than 40 per cent of all single-use medical devices produced globally are sterilized with cobalt-60.
  • More than 70 per cent of the world’s supply of cobalt-60 is produced at Canadian nuclear power plants.
  • Canada refines more than 90 per cent of the cobalt-60 market globally.
  • About 60 per cent of the world’s market of iodine-125 is produced at the McMaster Nuclear Reactor.

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