By Kurt Woock
With a half-life of 66 hours, molybdenum-99 (Mo-99) makes getting from point A to point B quickly a matter of survival. Mo-99 is the parent of the isotope technetium-99m (Tc-99m), which is used in the detection of heart disease, detection and staging of cancer, and the study of brain and kidney function, among other things. The narrow window of opportunity during which the isotope is useful leads to a supply chain that is perpetually stretched thin—it’s impossible to stockpile a reserve to use when manufacturing or shipping problems occur. Making conditions more precarious, every molecule of Mo-99 in the United States is currently imported. A bill recently passed by Congress and signed into law by the president lays the groundwork for bringing production—and with it, added reliability—into the United States.
There’s not one particular reason Mo-99 is not produced in the United States, according to the president of the Society of Nuclear Medicine and Molecular Imaging, Frederic Fahey, DSc. “I don’t think there was a perceived necessity to provide this until it became clear that it wasn’t as reliable as we had hoped.”
The United States, which consumes half of the world’s output of Mo-99, has relied largely on Canadian and Dutch sources. Those companies import highly enriched uranium from the United States, manufacture the Mo-99, and sell it back to the United States. “There has been talk for 10 or more years about finding a new source,” Fahey said. “Push came to shove in 2009 when the reactor in Canada was down for a year. At the time, we were getting about 50% of Mo-99 from Canada.” At the same time the Canada plant went down, the volcanic eruption in Iceland further interrupted the shipments from European plants. The shutdown of a Netherlands facility made problems worse.
A confluence of events such as those might be chalked up to extremely bad luck—not something to change policy over. But a host of other factors indicate that the time for change is here: The eight reactors used to manufacture Mo-99 worldwide are aging—many are upwards of 40 years old. The Canadian NRU reactor is scheduled to cease isotope production in 2016; and increased global demand provides ample motivation for the United States to have its own supply. The US government also has an interest in limiting the availability and use of highly enriched uranium. In fact, the law, which passed as part of the Conference Agreement for the National Defense Authorization Act for fiscal year 2013, calls for exports of highly enriched uranium to cease in 7 years. New manufacturing methods allow Mo-99 to be produced using low enriched uranium.
The law ensures Mo-99 production in the United States keeps rolling forward. It outlines how resources will be used and the fundamentals of cost sharing among constituents. However, the law does not come with funding. Fahey said passing a bill with dollars attached would have been difficult in this political climate, but the importance of getting the ball rolling on what is a multiyear project is important. “I think what this does is send a message to those who might fund the research [universities and private companies alike] that the government now understands this, that they are in the game. I think this will spur some of these people to get ready.”
Since 2009, the Global Threat Reduction Initiative, part of the Department of Energy’s National Nuclear Security Administration (NNSA), has formed four partnerships with organizations intent on manufacturing Mo-99 domestically without the use of highly enriched uranium. The NNSA provides support, including 50-50 cost-sharing of up to $25 million per project. The funding is intended to accelerate the various plants’ entry to market and is not meant to be a long-term subsidy. The goal is to be up and running as rapidly as possible. The new law reinforces the sense of urgency surrounding these projects.
What the new law means for those who use imaging agents based on Mo-99 is still unclear. If these programs develop as planned, reliability ought to rise. So, too, might the price for Mo-99, according to Fahey. “That may be the price we pay for having a reliable, consistent source.” How might a more expensive Mo-99 affect products farther down the production stream? Too early to tell: “There’s a bunch of people between the reactor and the patient.”
Fahey says that the net effect of this law will be improved care. “In the end, this has an impact on patients,” he said. “In order to do the right test for the right patient at the right time, this is critical. We appreciate the fact that the US government understands the importance of nuclear medicine and is willing to provide for that success in the long term.”
