Nuclear physicist Phumzile Tshelane highlights how life-saving radio-isotopes manufactured in South Africa are benefiting scores of people in the country and beyond borders

More than 40-million people globally receive life-saving medical diagnosis or treatment using nuclear medicine every year, and up to one-quarter of the medical radio- isotopes used in these procedures come from just one nuclear reactor in South Africa, Safari-1, which is owned and operated by the South African Nuclear Energy Corporation (Necsa).

These radioisotopes have extremely short half-lives, and have to be used within a matter of hours. Several of the radioisotopes produced by the Safari-1 reactor have commercial value – they are used either for medical or industrial applications. The most important radio- isotope or radiochemical produced at Necsa is called Molybdenum-99, or Mo-99, and is the parent of the most widely used medical radioisotope, Technetium-99m (Tc-99m).

Tc-99m has a half-life of just six hours, which is one of the reasons why it is suitable for medical use on humans. Tc-99m emits gamma radiation, which can be detected using special gamma cameras or imaging technology that is able to detect radiation, such as those found in positron emission tomography, or PET, scans.

Necsa produces several other reactor- based medical radioisotopes, including Iodine-131, which is used to diagnose and treat thyroid cancers. It also manufactures cyclotron-based isotopes and radiopharmaceuticals in an on-site cyclotron – a type of particle accelerator – that is operated in partnership with the National Research Foundation’s iThemba LABS. Cyclotron-based medical radioisotopes include Gallium-68 and Gluscan F-18 FDG.

Total production is equivalent to 20% of world demand for key medical radioisotope Mo-99, and Necsa supplies up to one-third of total demand through partnership agreements. It is also the third-largest global supplier of API bulk iodine-131. Necsa/NTP holds 15% of the global neutron transmutation doping, or NTD, market share and also provides high-quality irradiation services and industrial isotopes for nondestructive testing and process control applications.

Nuclear medicine uses radio- pharmaceuticals to target specific systems or organs in the human body, mostly for medical imaging procedures. When Tc-99m or any other medical radioisotope is paired with a special pharmaceutical compound, allowing it to be injected or ingested (or sometimes inhaled), this compound is known as a radiopharmaceutical. The pharmaceutical part acts as a carrier and decides where in the body the radioisotope will go and how it will be distributed. The radioisotope part is what allows the dose to be seen.

Unlike X-rays and other radiological imaging, nuclear medicine scans make it possible for physicians to observe both the structures and functioning of the human body, right down to molecular level. As a result, imaging obtained from nuclear medicine scans often allows a disease to be identified at a much earlier stage, before anatomical changes become visible.

Nuclear medicine has been used for well over 70 years, predominantly for the diagnostic imaging of various cancers, cardiovascular disease and neuroendocrine tumours. The same technology also allows physicians to target and treat certain conditions using medical radioisotopes. Over the past decade, therapeutic applications of nuclear medicine have become increasingly important, boosted by the discovery of new applications for existing isotopes.

Improved imaging technology and growing access to nuclear medicine facilities in South Africa could also have important implications for the role nuclear medicine is able to play in managing or the staging of both communicable and noncommunicable diseases.

Necsa works with the Department of Health to provide medical isotopes and equipment used in nuclear medicine procedures to 12 tertiary and quaternary hospitals around South Africa that have nuclear medicine departments, as well as various private nuclear medicine practices around the country. Every year, thousands of South Africans are able to receive life-saving diagnosis and effective treatment using nuclear medicine techniques. They join up to ten-million patients around the world who are assisted by other nuclear medicine physicians, on every continent, using a truly remarkable nuclear technology, and life-saving radioactive isotopes manufactured right here in South Africa.

The story of Necsa/NTP is one of constant innovation and adaptation. For more than 50 years, South Africa has been at the forefront of nuclear and radiation-based technology, growing from a research facility and local radioisotope manufacturer to a leading global radiation-based products and services provider.

Tshelane is Necsa group CEO - communications@necsa.co.za