The McMaster Nuclear Reactor has been supplying the world with Iodine-125 for more than 20 years. Using a process designed, developed, and commercialized at McMaster, NOF staff expose enriched xenon-124 to neutrons in the reactor core, converting it first to xenon-125, and then iodine-125, which they chemically separate from the xenon.

Iodine Production Team Preparing to Extract Iodine-125 from Xenon-125

At the end of 2016, NOF faced a major challenge, as one of the world’s three major I-125 suppliers chose to exit the market abruptly, and another halted production unexpectedly, leaving McMaster as the sole active supplier of this essential medical isotope. As global supplies of I-125 dwindled, seed manufacturers shut down production lines, while oncologists’ prescriptions for I-125 went unfilled. Nuclear Operations and Facilities responded to this crisis by implementing round-the-clock operation of the McMaster Nuclear Reactor.

For six weeks, NOF staff volunteered to work overnight shifts to increase the amount of Iodine-125 available from MNR to treat prostate cancer patients both in Canada and abroad. Their volunteerism saved an estimated 20,000 lives.In parallel, NOF staff designed, validated, and implemented a fully qualified process that enables staff to receive and purify crude I-125 that is generated at a partner irradiation facility. A new glovebox facility for this work was quickly installed, and in January 2017, NOF began distributing I-125 from this secondary supply to medical device manufacturers around the world, alleviating the global shortage of this isotope.

MNR continued to serve as the sole global source of Iodine-125 through April of 2017, when a European supplier returned to the market. During this time, MNR cemented its reputation as a reliable supplier of high quality medical isotopes, and increased its I-125 market share significantly. By the end of 2017, the McMaster Nuclear Reactor had firmly established itself as the world’s preeminent supplier of I-125, and now provides cancer treatments for “400 dads a day”.