Nuclear Propulsion Neg

Download 0.87 Mb.
Size0.87 Mb.
1   ...   57   58   59   60   61   62   63   64   ...   78

HEU – Uq

Medical isotope supply is dwindling – stable supply key to diagnostic medicine

Ruth 9 (Thomas J. – senior research scientist @ TRIUMF and senior scientist @ British Columbia Cancer Research Centre, Oct. 2009, JPG

With the most recent shut down of the NRU reactor in Chalk River, Canada, the supply of medical isotopes has dwindled to the point that it is impacting medical diagnoses worldwide. How did we reach a situation with supply so fragile and prospects for solutions so bleak? As with most stories the answer is complex and convoluted. In some respects the medical isotopes community is a victim of its own success. Technetium-99m is the most widely used radionuclide in diagnostic medicine. Its use for imaging human disease has its roots in the US Atomic Energy Commission, the predecessor of today’s Department of Energy. Research at Brookhaven National Laboratory in the early 1960s resulted in the development of the generator for producing Tc-99m. The parent element, molybdenum-99, can be produced through a number of nuclear reactions, but the fission of 235U with thermal neutrons provides for the most efficient, high-yield product with very high specific activity. Six per cent of the fission process results in the production of Mo-99. After it is produced, Mo-99 is sequestered on an inert column matrix to which the decay product, Tc-99m, is loosely bound and can be washed off with saline. With half-lives of 66 hours and 6 hours, respectively, the 99Mo/99mTc pair can be separated repeatedly over a week, with the Tc-99m fraction growing due to radioactive decay of the parent after each separation. Tc-99m is subsequently used for imaging studies such as bone scans or cardiac profusion. These scans are made possible by bonding the Tc-99m to an appropriate radiopharmaceutical that has the in vivo biological activity to be monitored. The gamma camera found in nearly every nuclear medicine department around the world has been designed for high efficiency for the 140 keV gamma ray emissions from the decay of Tc-99m to its ground state. Thus for more than 40 years Tc-99m has been the primary radionuclide used in nuclear medicine. Figure 1 shows a whole-body Tc-99m-based bone scan.

Medical isotope supplies are dwindling – causes procedures to be cancelled – alternatives fail

Ruth 9 (Thomas J. – senior research scientist @ TRIUMF and senior scientist @ British Columbia Cancer Research Centre, Oct. 2009, JPG

With the NRU shut down that left the remaining reactors to try and fill the gap; however the capacity is not there and thus the patient community has been severely affected by these shortages. Many procedures have been delayed or cancelled. While there are some alternatives such as using PET scanning or CT scanning with contrast agents, these measures cannot match the demand. To compound the situation further, the HFR will be off line for at least a month during the August/September 2009 period. In addition, the HFR is due for a major maintenance period lasting six months in early 2010.
Supplies of medical isotopes are finite – its used in 30 million medical imaging procedures

Johnston 10 (Hamish, editor @, 12/3/10, JPG

Supply shortages of molybdenum-99 could become commonplace over the next decade unless longer-term actions are taken. That is the main conclusion of a report from the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development. Published by the NEA's High-level Group on the Security of Supply of Medical Radioisotopes (HLG-MR), the report points out that more than 90% of the world's molybdenum-99 is produced by just five research reactors. These facilities are all 43–50 years old and two – NRU in Canada and OSIRIS in France – are expected to stop production by 2016. Molybdenum-99 is used to produce technetium-99m, which is used in 30 million medical imaging procedures every year. Technetium-99m is bound into radiopharmaceuticals, which are injected into the body and target specific tissues or biological processes. Technetium-99m decays producing just a gamma ray, which can easily leave the body and be detected. The isotope is well suited for this application because it does not emit harmful charged particles and has a relatively long half-life (6 h) for a gamma emitter. The HLG-MR was set up in April 2009 in the wake of short-term isotope shortages caused by scheduled and unscheduled shutdowns of several reactors worldwide. The most significant disruption occurred in 2009–2010 when a leak put the NRU reactor in Canada out of commission for more than 13 months.

HEU – Uq

Were on the brink – the only isotope supplier in north America is inconsistent

Austen 9 (Ian, writer @ NYT, 7/9/9, JPG

A leaky Canadian reactor which supplies the United States with about half of its medical isotopes will be shut for much longer than first anticipated. Atomic Energy of Canada, a government-owned reactor maker and operator, said on Wednesday that it will likely take until late this year to repair the device in Chalk River, Ontario. Speaking on a conference call with reporters, Hugh MacDiarmid, the company’s president, did not rule out longer delays. The 52-year-old reactor, which has been plagued with problems in recent years, closed on May 15 after a leak of heavy water, which it uses as a moderator, was discovered. At the time, Atomic Energy estimated that repairs would take three months. The reactor is the only one in North America that produces isotopes used medical imaging and treatments. Sourcing isotopes from other reactors is difficult because Chalk River is the world’s largest isotope maker. Medical isotopes also have a relatively short shelf life, making it impossible to build up stockpiles to cover periods when the reactor is out of order. Some medical imaging and nuclear physics experts have speculated that Chalk River may never reopen, a possibility that Mr. MacDiarmid rejected. In a joint statement, Leona Aglukkaq, Canada’s health minister, and Lisa Raitt, the natural resources minister, said the continued reactor shutdown “will result in a significant shortage of medical isotopes in Canada and in the world this summer.”
Shutdowns of that reactor create critical shortages – cuts off 16 million people in the US alone

USA Today 9 (8/14/9, JPG

The shutdown of a nuclear reactor in Canada has caused a shortage of a radioactive isotope used to detect cancers and heart disease, forcing doctors into costlier procedures that can be less effective and expose patients to more radioactivity. Some 16 million people in the United States — 40,000 patients each day — undergo medical imaging procedures using the isotope, technetium-99. Eighty percent of nuclear medicine scans use it. Ninety-one percent of hospitals, pharmacies and commercial imaging groups that answered a June survey by the Society of Nuclear Medicine said the shortage had affected them. "You already have a vulnerable population with cancer, so it's not trivial," said Dr. Jeffrey Norenberg, who heads the National Association of Nuclear Pharmacies and directs radiopharmaceutical sciences at the University of New Mexico. Technetium-99 is processed from molybdenum-99 and used in body scans for cancer, heart disease or kidney illness. It's combined with a substance to target a specific organ or tumor, then that tracer is injected and a gamma camera looks at the distribution of radioactivity to spot problems. The shortage began with the shutdown of a Canadian nuclear reactor in Chalk River, Ontario, that produces half the U.S. supply of molydenum-99. Technetium-99 must be made daily because it lasts just six to 12 hours. The Canadian reactor and another in the Netherlands produce most of the U.S. and European supply. The Dutch reactor is down for maintenance for several weeks, then will be offline for up to six months next year. "With both of them offline, it's very perilous," Norenberg said. In the meantime, the U.S. is getting a smaller supply from South Africa. Past shutdowns have left similar problems; a month-long shutdown of the Canadian reactor in 2007 created a critical shortage.
Effects the entire globe – its used for 80 % of medical procedures

Zakzouk 9 (Mohamed, Analyst in Industry, Infrastructure and Resources Division in Canadian Govt, 9/1/9, JPG

The shutdown of the NRU reactor has triggered a global shortage in nuclear medical isotopes (mainly molybdenum-99 or Mo-99), which has made the situation particularly problematic from a medical standpoint. Technetium-99m (Tc-99m), which is derived from Mo-99, is used for the vast majority of nuclear medical procedures – primarily cardiac imaging, bone scans to detect cancers, and general organ scans.(13) Introducing radioisotopes into the body (as opposed to external imaging) allows an earlier and more complete diagnosis by tracking the location and movement of the isotopes into diseased tissues. In the case of cancer, radioisotopes can also be used for treatment by emitting energy that kills diseased cells.(14)

Share with your friends:
1   ...   57   58   59   60   61   62   63   64   ...   78

The database is protected by copyright © 2019
send message

    Main page