(ANSTO) in Camperdown, Sydney, the Cyclotron has experienced continuously increasing demand for the radiopharmaceuticals it produces since it was officially opened by Governor General, Bill Hayden in 1992. Cyclotrons belong to a class of machine called particle accelerators. Most homes have at least one particle accelerator in them as part of a television picture tube or computer monitor.
The large majority of radiopharmaceuticals in Australia continue to be produced by the HIFAR research reactor at Lucas Heights, however demand for both reactor and cyclotron produced radiopharmaceuticals is increasing.
Nuclear reactors produce radioisotopes by adding an extra neutron into the atoms of the respective elements - that is, they are neutron-rich isotopes, and it is the excess of neutrons that makes the isotopes radioactive. On the other hand, cyclotrons bombard atoms with different particles (for example protons or deuterons) to produce isotopes that are deficient in the number of their neutrons.
In this case it is the neutron deficiency that makes the isotopes radioactive. This is why reactor radioisotopes cannot generally be made by a cyclotron, and cyclotron-produced radioisotopes cannot generally be made in a reactor. Reactor produced and cyclotron produced radioisotopes are complementary in nature and both are required to provide the range of diagnostic medical products needed to service Australias health needs.
The NMC supplies a high portion of Australia's needs for diagnostic medical radioisotopes such as gallium-67, thallium-201 and iodine-123. Gallium-67 detects soft tissue tumours and hidden infections, and is injected intravenously to assess cancers in the bronchi, lymph nodes, spleen (Hodgkin's Disease) and malignant melanoma. It is also used to track certain solid tumours in children and to assess the effectiveness of treatments.
Thallium-201 is used in the diagnosis of coronary artery disease, diagnosis of tissue viability (which helps the cardiologist judge the most appropriate course of therapy) and is the most powerful indicator of prospects for patient management over a broad range of coronary diseases.
Iodine-123 is used in SPECT applications to monitor thyroid function and detect adrenal dysfunction. Another cyclotron-produced radiopharmaceutical experiencing increasing demand is Fluorine-18 deoxyglucose (FDG), a radioisotope with a 110-minute half life.
ANSTO is one of only a small number of manufacturing sites around the world with approval to produce FDG, which is the subject of some intensive medical studies into better imaging methods.
Operations Manager at the NMC, Doug Arnott said there have been considerable improvements made to the Cyclotrons facilities over the last decade.
"This is a considerable achievement, given that were one of very few facilities in the world producing the range and quantity of products we produce, with a single cyclotron, operating more than 100 hours per week," he said. "The Cyclotron Engineering, Production and Quality Control teams have worked hard over theyears to hone their skills and do it better.
"Weve been able to keep up with a steadily increasing demand for our main products. As an example, in 1993 our production of thallium-201, which is usedfor heart scans, was at the level of 60 GBq a week, today we supply around 250 GBq. In general, we produce more material, process it more efficiently, perform quality control faster and deliver more efficiently!"