Medical Isotopes

A pioneer in nuclear medicine, NRU continues to make an important contribution to the world’s medical isotopes used in both the diagnosis and treatment of life-threatening diseases. Isotopes from NRU benefit thousands of people each day, millions of people internationally each year – an amazing contribution to world health. 

One of the NRU reactor's most important contributions to health is without a doubt the cobalt-60 it produces. Cobalt-60 accounts for 10 million cancer therapy treatments each year and was originally produced in the NRX reactor through which Canada launched the modern field of nuclear medicine. The first cancer treatments using cobalt-60 were delivered at hospitals in Ontario and Saskatchewan in 1951. Today, cobalt-60 from NRU treats cancer patients in countries around the world.

Canada has made impressive contributions to world health care, and Canadian scientists continue to research nuclear medicine techniques and explore the vastly refined techniques of medical science.

Isotopes produced at CNL’s Chalk River Laboratories include:

Molybdenum-99: Used for medical diagnosis (imaging) of the brain, thyroid, parathyroid, heart, lungs, liver, kidney, spleen and bone marrow.

Iodine-131: An isotope used mainly in therapy, imaging and diagnosis.

Iodine-125: Used in prostate cancer treatment (brachytherapy), in-vitro diagnostic kits (radio immunoassays), bone densitometry devices, protein iodination.

Xenon-133: A medical diagnosis tool, especially for scanning lungs.

High Specific Activity (SA) Cobalt-60: Nickel-plated cobalt-59 pellets are irradiated in NRU for two to four years, becoming High SA Co-60. The High SA Co-60 produced in NRU is primarily used in cancer treatment applications.

Iridium-192: Used as intense source of radiation for industrial imaging, including radiography and weld-inspection. Also used in portable units for cancer therapy and radiography.