Australian news, and some related international items

Why medical isotopes produced in cyclotrons are so much better than those produced in a nuclear reactor.

This is probably the best explanation of the difference between the use of nuclear reactor produced isotopes in nuclear medicine, and cyclotron produced isotopes in nuclear medicine. It is a quote from TRIUMF Canada – an internationally recognised establishment which has celebrated 50 years in the world as a leading authority on subatomic physics.

This definition was released by them in 2011… “The field of nuclear medicine has evolved into what can be considered its third generation. Generation-I originated in the 1950s, with several reactors producing large enough quantities of simple radioisotope formulations that could be distributed for use globally. This allowed for the launch of the era of modern nuclear medicine, and for the next thirty years the medical community developed and implemented dedicated cameras needed to image patients injected with gamma-emitting isotopes. Generation-I radiopharmaceuticals were simple, perfusion-based compounds that distributed within the body based on simple properties such as molecular shape, size, and charge; and the isotopes injected were typically single photon emitters. The world came to adopt nuclear medicine as a cheap, yet powerful tool for the non-invasive diagnosis of disease.”

Generation-1 radiopharmaceuticals – That’s your nuclear reactor generated nuclear medicine isotopes – predominately the Technitium-99m (Tc-99m) used in diagnostic imaging. This is what the reactor in ANSTO Lucas Heights is predominately used to produce – the Molybednum-99 (Mo-99) which then decays to Tc-99m.

“Generation-II radiopharmaceuticals evolved during the 1980s and involved the development of compounds targeted to specific cellular biomarkers. With a rapid growth in understanding of the molecular basis of physiology and disease, and the expansion of a global cyclotron infrastructure, new and powerful positron-emitting compounds such as [18F]fluorodeoxyglucose, or FDG for short, were discovered and widely implemented for the safe and accurate diagnosis and evaluation of diseases affecting millions of patients. Over the next thirty years, the radiopharmaceutical research community spent an enormous amount of time and effort developing a myriad of targeted radiopharmaceuticals that have continued to feed our understanding of biology and medicine at the molecular level.”

Generation II radiopharmaceuticals – that’s your cyclotron generated nuclear medicine isotopes – predominately FDG amongst many others now – MET, FET, FLT, FCH, FMISO, FDOPA, Ga isotopes, Oxygen isotopes…the list goes on. There are currently 18 cyclotrons in Australia – this current list is from IAEA: They are normally associated with diagnostic imaging partnerships on site.

“Today we are witnessing the evolution of Generation-III compounds, which have come to include both imaging and therapeutic isotopes. In a nearly synonymous way to which we came to appreciate the power and utility of imaging isotopes, therapeutic isotopes are now entering the active conscience of the medical community.”

This was remember published in 2011. The problem with radioisotopes is that you cannot control their emissions. You can certainly use low energy emitters, but regardless the ultimate aim of medicine now in 2022 is to have as little damage done to normal cells as is possible. That is why immunotherapy and nanotechnology are the foregrounds for cancer treatment now.–


April 11, 2022 - Posted by | AUSTRALIA - NATIONAL, health

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