System could boost production of cancer-killing isotopes

Scientists at the UK-supported Institut Laue-Langevin (ILL) in France, one of the world’s leading neutron research centres, are seeking funding for a €2m (£1.7m) automated system that would upscale production of material used in targeted radiotherapy.

The system, which would use a small nuclear reactor and a hydraulic production line, could enable scientists to manufacture new radioactive isotopes that are better at killing cancer cells and do less damage to healthy tissue.

‘The proposed irradiation system is outside of ILL’s normal sphere of activity, but we have a moral imperative to do this work’

Prof Andrew Harrison, science director of ILL

Radioisotope therapy (RIT) involves inserting radioactive isotopes of metals such as yttrium and lutetium into the body by injection or ingestion in order to target and kill tumours.

This method of radiotherapy can be more effective and has fewer side effects than chemotherapy because the isotopes are attached to protein molecules (antibodies or peptides) that seek out and bind with the cancer cells, although they can still damage healthy tissue.

The radioisotopes, which are also used for medical imaging, are produced in nuclear research reactors. Shortages can occur when the machines shut down for maintenance because the short half-life of the materials makes them impossible to stockpile.

Using a high-flux reactor — which emits a continuous and more intense beam of neutrons — such as that at ILL, allows scientists to produce higher-quality radioisotope samples.

This means new materials that cause less damage to healthy tissue and emit less gamma radiation — so patients do not have to be isolated after treatment — could be manufactured on an industrial scale.

The researchers at ILL hope their proposed production system would allow them to introduce one such material, the 161TB isotope of terbium, to the medical market.

‘We can produce more in the next 10 years than we believe there will be demand for. We could produce for thousands of patients a week,’ said ILL physicist, Dr Ulli Köster.

The system could also help avoid shortages of other isotopes by creating redundancy in global production, he added.

The current method for producing isotopes from a high-flux reactor is labour intensive, as a human operator has to unload the material in a separate shielded room using long manipulator arms to avoid radiation exposure.

The reactor itself is kept below a deep pool of water to contain the radiation and samples have to be lowered into the reactor’s neutron beam.

ILL’s design draws on a method first used at Oak Ridge National Laboratory in the US. Samples of material are placed inside a shuttle and sent down for irradiation and then drawn back up from the reactor using a hydraulic pipe.

The proposed system uses a carousel that automatically unloads finished material from the shuttle once they have returned from the reactor, and loads new samples for the next round or sends back samples that need further irradiation.

ILL would be able to build the €2m system alongside its existing reactor without impacting its research programme and hopes to also build a chemical laboratory on site to prepare the radioisotopes for patient treatment.

The institute has submitted an application to authorities in Paris for safety approval, which it hopes to receive within a year.

During that time, it will also seek investment from pharmaceutical companies and from the member governments that fund the centre, primarily the UK, France and Germany, as well as 11 other European countries and India.

Prof Andrew Harrison, science director of ILL, said: ‘The proposed irradiation system is outside of ILL’s normal sphere of activity, but we have a moral imperative to do this work.

‘It’s a great example of how a publicly funded facility can have a totally unexpected and unpredictable pay-off for society.’