POTENTIAL CYCLOTRON NETWORK / RéSEAU POTENTIEL DE CYCLOTRONS
DISTRIBUTION / RéPARTITION
Car/ Truck – 4 Hour /
Automobile/Camion – 4 heures
Plane – 2 Hour /
Avion – 2 heures
Each node represents an exisiting or planned
cyclotron facility, ringed by the size of area
it could serve, by road and air.
Chaque point représente une installation de
cyclotron existante ou prévue, entourée
d’un cercle représentant la région desservie
en voiture ou en avion.
Source: Advanced Cyclotron Systems Inc.
to meet short-term demand as well as a new system to provide a continu-
ous, reliable supply of isotopes in the future. That’s why, early last year,
Natural Resources Canada formally announced the participants in its
Non-reactor Isotope Supply Contribution Program, dubbed NISP. The
list makes for a who’s who of medical isotope users across the country.
They are pursuing the four major projects that could lead to new ways of
supplying medical isotopes. The perceived urgency of the isotopes crisis
prompted a tight, 15-month deadline: final reports are due in March of
The four projects represent an extraordinary collaboration among
Canadian researchers from hospitals, universities and private firms. Two
separate projects led by TRIUMF and by ACSI are looking at ways of tap-
ping into cyclotrons that are already installed at hospitals across the
country. The other two projects are led by Canadian Light Source Inc. at
the University of Saskatchewan and by a Winnipeg consortium called
Prairie Isotope Production Enterprise. These last two are exploring the
potential of systems called linear accelerators that send charged particles
in a straight line (rather than circles as in the cyclotron), dramatically
simplifying the process.
Paul Schaffer, deputy head of nuclear medicine for TRIUMF, says,
“Networking was absolutely crucial. There is no single group that can
tackle a project of this magnitude.” TRIUMF, for example, is aligned with
Most of the researchers who responded to the call from government
after the isotope crisis already had some connection with one another,
says Dr. Schaffer. “The relationships were primed, and then this situation
just kicked in.”
The focus, in each project, is to come up with a cost-effective, safe
and reliable way of domestically supplying isotopes without the cost of
building nuclear reactors or the need to use weapons-grade uranium and
produce nuclear waste. The technology exists, but implementing it would
be a major departure from clinical practices used for decades. The result
would be a revolution in the field of medical imaging – yet an invisible
one to most Canadians who need this important service. The same ma-
chinery would be in place at hospitals and clinics, using the same key
The importance of Technetium-99m in modern nuclear medicine
cannot be overstated. Technetium-99m’s isotopes emit large amounts of
electromagnetic energy, known as gamma rays, primarily during a short
half-life of about six hours. This brief exposure minimizes any risk to the
human body, but for the few hours it remains active it offers an unrivaled
opportunity to look around. Even dynamic activities, like blood flow or
drug interactions, are visible with Single Photon Emission Computed
Tomography (SPECT) cameras.
Throughout the 1980s and 1990s, SPECT became a workhorse tech-
nology in labs and clinics around the world. And Canada’s MDS Nordion,
by offering a steady and reasonably priced supply of much longer-lived
isotopes to clinicians (who used a chemical kit to convert them to Tech-
netium-99m), dominated both the domestic and global market. The long-
lived, reactor-produced isotopes remain viable for several days and thus
have been crucial to Nordion’s ability to ship to destinations across North
America and beyond.
Soon after the isotope crisis, members of TRIUMF began discussing
the virtue of producing Technetium-99m with cyclotrons that are already
in use at Canadian hospitals and clinics, instead of at a nuclear reactor.
The feasibility of that idea is what is being formally assessed through the
$35 million in government funding.
Among the organizations involved with TRIUMF is the Lawson Health
Research Institute in London, Ontario, which manages its own cyclotron
facility. Lawson staff were already well-practised in producing isotopes
for another type of medical scanning instrument, known as Positron
Emission Tomography (PET). But this process is more onerous for clinics