Medical radioisotope supply options for Australia

Jim Green

National nuclear campaigner – Friends of the Earth, Australia

January 2012

jim.green@foe.org.au

Does Australia need a new nuclear reactor to produce medical isotopes? The short answer is ‘no’. A better strategy would be to close the existing HIFAR reactor at Lucas Heights in southern Sydney combined with:

1. Greater reliance on imported radioisotopes;

2. Ongoing use of the existing cyclotrons in Sydney, Melbourne and Perth and others that are likely to be built in Australia;

3. Further research into advanced, non-reactor radioisotope sources such as cyclotrons, with the aim of sharply reducing demand for imported, reactor-produced radioisotopes (so other countries don’t have to deal with the adverse impacts of reactors such as intractable radioactive waste management problems); and

4. Greater use of alternative clinical modalities such as MRI, and Computerised Tomography.

None of these four strategies alone will suffice, but combined, they are more than adequate.

The above strategies are tried and tested. Over 250 cyclotrons are operating around the world. Many countries – including Australia – import isotopes. Alternative clinical modalities are well advanced – in fact they are used far more frequently than nuclear medicine! So there’s no risk involved in closing the existing reactor without replacement.

IMPORTATION

You might hear the argument that radioisotopes with short half-lives cannot be imported. True, but almost all of the short-lived radioisotopes used in nuclear medicine are produced in cyclotrons, not research reactors. With no research reactor in Australia, over 99% of nuclear medicine procedures would be unaffected, using either cyclotron-produced radioisotopes or imported radioisotopes. As for the small number of rarely-used radioisotopes that would not be available, alternative clinical technologies can easily fill this gap.

The Lucas Heights reactor was closed for three months from February-May 2000 and many doctors – including the President of the Association of Physicians in Nuclear Medicine – did not even know about the closure of the reactor! ANSTO staff members wrote to Sutherland Shire Council during the three-month reactor shutdown noting: “ANSTO’s radioisotope production has suffered no dislocation as a result of the shutdown, since bulk supplies of radioisotopes are purchased from the big international players in Canada and South Africa.”

Properly funded research into alternative radioisotope production technologies and alternative clinical technologies will enable reduced reliance on imported reactor-produced radioisotopes. To the extent that there is still a requirement for reactor-produced radioisotopes, the fewer reactors the better.

The major global radioisotope suppliers have the capacity to supply world demand several times over. More than three-quarters of all nuclear medicine procedures carried out around the world use imported radioisotopes. Countries largely reliant on imported radioisotopes include advanced industrial countries such as the United States, Britain, and Japan; in these countries nuclear medicine is widely practised and technically sophisticated despite the heavy reliance on imported radioisotopes.

CYCLOTRONS

Most nuclear medicine procedures are diagnostic (90-99% depending on the country): radioisotopes are administered to the patient (usually by injection) and as the radioisotopes ‘decay’ they emit radiation which is captured by a camera and used to generate an image. Only a small minority (1-10%) of nuclear medicine procedures are palliative (pain-relieving) or therapeutic.

About 75% of all nuclear medicine procedures use the radioisotope technetium-99m. There are several non-reactor methods of producing this, but none of these techniques is in routine use. ANSTO operates the National Medical Cyclotron but has not used it to pursue this important line of research.

Cyclotrons beyond to a class of machines called particle accelerators – electromagnetic devices that accelerate charged particles to enormous velocities. The particles can then be directed to hit a target and thus produce radioisotopes.

Because they are powered by electricity rather than the uranium fission reaction of a nuclear reactor, cyclotrons have important advantages:

– they generate only a tiny fraction of the waste of research reactors (typically less than 10%, and none of the spent fuel containing fission products and transuranics)

– they pose no risk in relation to nuclear weapons proliferation; and

– cyclotrons are much safer (for comparison, there have been five fatal research reactor accidents according to the International Atomic Energy Agency).

OTHER ALTERNATIVES

The alternative clinical technologies that compete with nuclear medicine include magnetic resonance imaging, X-radiology, computerised tomography and ultrasound. Moreover, the competition is not only between imaging techniques; there are also many chemical and biological alternatives to radioisotopes for in vitro studies and research.

In 2000, the President of the Royal Australian and New Zealand College of Radiologists told a Senate inquiry that the potential to reduce demand for reactor produced isotopes through greater reliance on cyclotron-produced isotopes is constrained by the current Commonwealth Government policy “specifically barring” the use of cyclotron-based Positron Emission Tomography (PET) as a substitute for conventional nuclear medicine.

Professor Hicks from the Peter MacCallum Cancer Institute said that PET had proved more accurate than any other diagnostic technology in diagnosing tumors, and that it had saved hundreds of lives and thousands of dollars and had the potential to revolutionise cancer treatment. (Sydney Morning Herald 12/3/01; The Age 28/1/01).

At the moment, there are only two hospitals in Australia with PET facilities. This compares starkly with the hundreds of millions of dollars spent on a new reactor at Lucas Heights.

QUOTABLE QUOTES

Former ANSTO scientist Murray Scott says: “The most publicly appealing rationale for a replacement reactor is the provision of medical radioisotopes. … But of all the programs associated with the replacement reactor this operation also carries the greatest risk, the greatest potential for massive contamination release and the most significant future weapons proliferation potential.”

Dr. Geoff Bower, then President of the Association of Physicians in Nuclear Medicine, was asked if it would be a life threatening situation if Australia did not produce medical isotopes locally on ABC radio in late 1998. ABC-JJJ radio. “Probably not life threatening. I think that’s over-dramatising it and that’s what people have done to win an argument. I resist that.”

Professor Barry Allen, former chief research scientist at ANSTO, says, “It’s reported that if we don’t have the reactor people will die because they won’t be getting their nuclear medicine radioisotopes. I think that’s rather unlikely. Most of the isotopes can be imported into Australia. Some are being generated on the cyclotron. But on the other hand a lot of people are dying of cancer and we’re trying to develop new cancer therapies which use radioisotopes which emit alpha particles which you cannot get from reactors. And if it comes down to cost-benefit, I think a lot more people will be saved if we can proceed with targeted alpha cancer therapy than being stuck with the reactor when we could in fact have imported those isotopes. … The question is really what the taxpayer of Australia wants. Do they want new therapies or do they want the reactor to be the centre of all research?”

MORE INFORMATION:


Australian Labor Party position

4/11/01 Joint Media Release by:
Martyn Evans (Shadow Minister for Science and Resources)
Jenny Macklin (Shadow Minister for Health)
Nick Bolkus (Shadow Minister for the Environment).

Howard Wrong on Medical Isotopes

Australia will have a secure supply of medical isotopes for cancer treatment, medical research and other applications under Labor’s policy of not building a nuclear reactor at Lucas Heights.

John Howard is living in the past – the Lucas Heights reactor is not significant to Australia’s security and it is not the only source of medical isotopes.
The principle isotope from the Lucas Heights reactor used in medical treatment is Molybdenum. This is in turn used to produce Technetium on site at hospitals. Bulk supplies of Molybdenum can be readily imported and made up into ‘Technetium generators’ in Australia.

Other countries, including the United States and Japan do not produce their own medical Molybdenum. In fact, the great bulk of this material is currently produced in Canada and shipped around the world.

Australia already imports this material on a regular basis when the existing reactor is shut down for up to three months every year for maintenance.

The Senate Inquiry into Lucas Heights examined this issue in detail and was not convinced that logistical difficulties constitute a serious obstacle to the successful importation of radioisotopes.

In addition, other nuclear materials are already produced in Australia using the National Medical Cyclotron. The future direction of nuclear medicine lies with cyclotron produced products and accelerators.

Labor remains unconvinced of the arguments for the need for a new reactor and believes it is completely inappropriate for a reactor in suburban Sydney at Lucas Heights.

The Howard Government has committed more than $300 million for the new Argentinian designed reactor. This is not the best investment of that money. It is the wrong way forward for Australian nuclear science.

Labor supports the continuation of the other activities at Lucas Heights campus as a centre for medical, environmental, industrial and scientific applications on nuclear technologies under ANSTO.