The nuclear medicine community is catching its breath after a one-week strike at a Canadian nuclear reactor caused a brief cutoff of the supply of molybdenum-99, the raw material for the commonly used radiotracer technetium-99m. While the strike was
The nuclear medicine community is catching its breath after a one-week strike at a Canadian nuclear reactor caused a brief cutoff of the supply of molybdenum-99, the raw material for the commonly used radiotracer technetium-99m. While the strike was short-lived, it had a major impact on nuclear medicine physicians and companies that supply technetium-based radiopharmaceuticals.
The crisis began when a group of unions went on strike June 19 at the Chalk River Laboratories reactor, which is operated by Atomic Energy of Canada, Ltd. (AECL), a corporation owned by the Canadian government (SCAN 6/25/97). The strike, which involved support personnel at the reactor rather than the operators of the facility, underscored the vulnerability of the nuclear imaging community. Chalk River supplies 80% of the world's molybdenum, which serves as a generator of technetium-99, and virtually all of the moly used by nuclear medicine customers in the U.S. These supplies are routed through MDS Nordion, a Canadian processor and distributor of the radioisotope.
"The strike brought to everyone's attention just how critical the product is and how an interruption in supply is intolerable and challenging," said Ian Mumford, a spokesperson for Nordion, of Kanata, Ontario.
The short half-life of molybdenumæ66 hoursæexplains why even a short interruption presents such a challenge. The strike, which forced the reactor to shut down on June 19, was resolved five days later, and the reactor was immediately restarted. But Nordion's supply of the technetium generator had been exhausted several days earlier.
"Certainly, having the strike settled quickly minimized the interruption," Mumford said. "But it was a tough time."
Among the hardest hit was Syncor International of Chatsworth, CA, a major operator of radiopharmacies in the U.S., which derives some 60% of sales from technetium-based products. In an effort to mitigate the impact of the disruption, Syncor used non-technetium radiopharmaceuticals and worked with customers to reschedule elective and other noncritical imaging procedures. Those moves helped customers, but not Syncor, which lost about $1.4 million in net sales and about $500,000 in pharmacy profits as a result of the temporary interruption.
Jean-Pierre Labrie, general manager of AECL's isotope business, is hopeful that no further hitches will affect the supply of molybdenum in the near future. Labrie noted, however, that several unions operate at the Chalk River facilities, any one of which could cause another reactor shutdown. AECL, located in Mississauga, Ontario, must negotiate more than one contract with labor unions at Chalk River in the next 12 months, he said.
The nuclear medicine community in the U.S. has long worried about what would happen if the supply of technetium were interrupted. But years of searching for solutions have been fruitless. At least two reactors in Europe and another in South Africa are capable of producing molybdenum-99, but these reactors cannot ramp up fast enough to provide the quantity of molybdenum needed in the U.S. to offset a break in the Canadian connection.
"When that reactor shuts down, virtually everything involving technetium in the Western Hemisphere is going down with it," said Dr. William Strauss, president of the Society of Nuclear Medicine and section chief of nuclear medicine at Stanford University.
There is also a regulatory question. Until the day before the strike, only one distributor, Nordion, had clearance from the Food and Drug Administration to sell molybdenum in the U.S. But, coincidentally, at the same time the labor dispute at Chalk River was threatening to shut down the reactor so important to U.S. medical interests, the FDA was opening another channel for the sale of molybdenum. On June 18, the FDA cleared Mallinckrodt to begin selling the isotope in the U.S. from its facility in Petten, the Netherlands. Limited production has already begun at the Petten facility. The operation will be scaled up over the coming several months, according to Dave Morra, president of Mallinckrodt's nuclear medicine division.
"We hope some day to be in a position to alleviate a shortage," Morra said. "This time there was a substantial shortfall, and we were not able to do anything to make up that gap."
The immediate priority of the St. Louis-based company will be to supply molybdenum to its own customers through the 35 Mallinckrodt radiopharmacies in the U.S.
"If a situation arose in the future and we needed to step in to help the industry, we would do that," Morra said.
If possible, Mallinckrodt would likely send molybdenum to competitors, such as Syncor, he added.
In time, the nuclear medicine community will see the molybdenum supply stabilize as other reactors capable of producing the radioisotope come online, such as two reactors MDS Nordion is building, and an effort by the Department of Energy to ramp up a reactor at Sandia National Laboratories in Albuquerque (see story, page 2). The first of the MDS Nordion reactors is not scheduled for completion until 1999, however, and the DOE's effort has been slowed by lack of funds. Nuclear medicine physicians will have to wait several years before they can be assured that a crisis like the one that occurred last month will not happen again.