The Dutch medical device company Quirem Medical recently started using the BR2 research reactor at the SCK CEN nuclear research centre for the production of QuiremSpheres, SCK CEN said on 15 June. QuiremSpheres are used for treating liver cancer and consist of small radioactive spheres loaded with holmium-166. In 2020, more than 905,000 people across the world were diagnosed with primary liver cancer, and 830,180 liver cancer patients died. A promising treatment is the use of a therapeutic radioisotope: holmium-166. This radioisotope is injected into the hepatic artery in the form of millions of tiny spheres – each one smaller than a human hair. The holmium spheres, called holmium microspheres, accumulate in the tiniest capillaries of the liver tumours and locally emit their radiation there. The tumours shrink or disappear, while the surrounding healthy liver tissue is spared. Patients with liver cancer for whom surgery is not an option are eligible for this treatment, also known as selective internal radiotherapy (SIRT).

Quirem Medical’s QuiremSpheres are the only commercially available SIRT product based on holmium-166. The microspheres are produced in Deventer, where the company is located. At the time of production, they contain the stable isotope holmium-165. To achieve a therapeutic effect, they must then be activated. “We activate the microspheres in the BR2 research reactor by bombarding them with neutrons”, explained Bernard Ponsard, BR2 stakeholder manager for radioisotope and doped silicon production. “SCK CEN has been working for years with players in the nuclear medicine field to secure the worldwide supply of medical radioisotopes. We are pleased that we can now also support the production of holmium-166 microspheres and, in doing so, help to step up the fight against liver cancer.”