[ RadSafe ] shortage of tech 99
conradsherman at gmail.com
Fri Jul 24 12:34:40 CDT 2009
from NY times just now
Radioactive Drug for Tests Is in Short Supply
By MATTHEW L. WALD
WASHINGTON — A global shortage of a radioactive drug crucial to tests
for cardiac disease, cancer
and kidney function in children is emerging because two aging nuclear
reactors that provide most of the world’s supply are shut for repairs.
The 51-year-old reactor in Ontario, Canada
that produces most of this drug, a radioisotope, has been shut since May
14 because of safety problems, and it will stay shut through the end of
the year, at least.
Some experts fear it will never reopen. The isotope, technetium-99m, is
used in more than 40,000 medical procedures a day in the United States.
Loss of the Ontario reactor created a shortage over the last few weeks.
But last Saturday a Dutch reactor that is the other major supplier also
closed for a month.
The last of the material it produced is now reaching hospitals
and doctors’ offices. The Dutch reactor, at Petten
<http://www.nrg-nl.com/public/medical/valley/node2.html>, is 47 years
old, and even if it reopens on schedule, it will have to be shut for
several months in 2010 for repairs, its operators say.
“This is a huge hit,” said Dr. Michael M. Graham, president of the
Society of Nuclear Medicine <http://www.snm.org/> and a professor of
radiology at the University of Iowa
There are substitute techniques and materials for some procedures that
use the isotope, Dr. Graham and others said, but they are generally less
effective, more dangerous or more expensive. With the loss of diagnostic
capability, “some people will be operated on that don’t need to be, and
vice versa,” he said.
Dr. Andrew J. Einstein, an assistant professor of clinical medicine at
the Columbia University
College of Physicians and Surgeons, said the isotope was used to
determine if a patient had a coronary blockage that required an
Without the test, Dr. Einstein said, those invasive procedures would be
performed on some who did not need them. His hospital is already
sometimes using smaller doses of the radioactive drug than guidelines
specify, he said.
In patients with a known cancer, the drug pinpoints additional tumors
in bone. At a tumor
site, new bone will develop, and new bone growth absorbs the radioactive
In breast cancer
surgery, the radioisotope is injected to find the lymph node
nearest the tumor, so it can be biopsied for signs of cancer, to
determine whether more extensive surgery is needed.
The alternative is to inject a dye, which sometimes does not let the
surgeon find the node.
Without the tool, Dr. Graham said, the quality of medical care is
“dropping back into the 1960s.”
On Tuesday, Representative Edward J. Markey
a Massachusetts Democrat who is one of the House’s fiercest critics of
the nuclear industry, declared that the United States was facing “a
crisis in nuclear medicine.”
Mr. Markey, chairman of the House Energy and Commerce subcommittee on
energy, called for establishing new production facilities in the United
States. He joined the ranking Republican on the subcommittee,
Representative Fred Upton of Michigan, to introduce a bill to authorize
$163 million over five years to assure new production.
The White House is coordinating an interagency effort to find new
sources of supply, involving the Nuclear Regulatory Commission
the Food and Drug Administration
and the Energy Department, but officials said the process would take months.
The reactors are typically small — sometimes no larger than a
homeowner’s trash barrel — but a complete setup costs tens of millions
Tech-99m, as it is abbreviated, emits a gamma ray that makes its
presence obvious. It has a half-life of six hours, meaning that it loses
half its strength in that period. Thus it does its job quickly, without
lingering to give the patient a big dose. But it also means the isotope
must be produced and used faster than most other drugs.
Tech-99m is the product of another isotope, molybdenum-99, which also
has a short half-life, 66 hours. Thus a week after it is made, less than
a quarter of the molybdenum-99 remains. Stockpiling is not practical.
“You lose about 1 percent an hour,” said another expert, Kevin D.
Crowley, director of the Nuclear and Radiation Studies Board at the
National Research Council
“So time is of the essence.”
Molybdenum-99 is made when uranium-235 is split, but only about 6
percent of the fission fragments are molybdenum. Purification has to be
done in a heavily shielded “hot cell.”
The common method is to put a uranium target into the stream of neutrons
produced in the reactor as uranium is split. But the preferred material
is a high-purity uranium-235, which is also bomb fuel.
Mr. Markey and others are trying to have the industry switch to
low-enriched — nonweapons-grade — uranium.
Dr. Crowley said that could be done, although the industry has resisted.
The reactors’ poor condition has been obvious for a while. In 2007,
Canadian safety regulators said the Ontario reactor should not restart,
but the Canadian Parliament overruled them.
In 1996, the company that purifies the molybdenum from the Ontario
reactor, MDS Nordion, contracted with Atomic Energy of Canada Ltd.
<http://www.aecl.ca/site3.aspx>, which owns the reactor, to build two
new ones. MDS Nordion paid more than $350 million for them.
But when the new reactors were started up, both showed a problem: as the
power level increased, the reactors had a tendency to run faster and
faster, a condition called positive coefficient of reactivity. That is a
highly undesirable characteristic in a reactor, one that contributed
heavily to the Chernobyl disaster in 1986. So Atomic Energy of Canada
Ltd., which is owned by the Canadian government, said it would not open
For all the years that the Ontario plant was running or the replacements
were under construction, other potential manufacturers believed they
could not compete, Dr. Klein said. And the business has always been
small, he said, adding that a big pharmaceutical company “can make more
in two days than on tech-99m in a year.”
Several long-term alternatives are available. Babcock & Wilcox, a
reactor manufacturer, has proposed a new kind of reactor that would
manufacture molybdenum that could be siphoned off continuously.
In a few weeks, a company in Kennewick, Wash., Advanced Medical
Isotopes, plans to test a new system, using a linear accelerator, a
machine that shoots subatomic particles at high speeds.
Reactors in Belgium, France, South Africa and Argentina could also be
used to make small amounts.
The High Flux Reactor at the Oak Ridge National Laboratory in Tennessee,
owned by the federal government, and a research reactor at the
University of Missouri
could do the work, but neither has the equipment in place to extract the
molybdenum from the targets.
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