Radioisotope production and radiotracer research at the Reactor Institute Delft, the Netherlands

by Dr Robin de Kruijff (TU Delft)

Monday 12 Jun 2023, 14:30 → 15:30 Europe/Berlin

PH HS 3 (Physics Department)

In recent years, the world has seen a turnaround in the use of medical radioisotopes for diagnostic, but even more so for therapeutic purposes. While ^99mTc is still the workhorse of nuclear medicine, many other radioisotopes are finding their place in the medical landscape, including diagnostic agents such as ⁶⁸Ga as well as beta- and alpha-emitting radiotherapeutics including ¹⁷⁷Lu and ²²⁵Ac. With radioisotopes thus fulfilling essential roles both in the diagnosis and treatment of diseases such as (metastasized) cancer, and because as radiotracers they can give us valuable insights into the uptake and distribution of essential minerals, we need to ensure they will be abundantly available. In this talk I will provide an overview of our recent research efforts at Delft University of Technology, the Netherlands, in radionuclide production and separation as well as radiotracer research, including:

 

1.The synthesis of nanomaterial-based target materials for the development of a novel type of ⁹⁹Mo/^99mTc radionuclide generator. ⁹⁹Mo, the mother radioisotope of ^99mTc, is currently produced though fission of ²³⁵U, resulting in long-lived nuclear waste associated with fission-based production. While ⁹⁹Mo can also be produced through direct activation of stable molybdenum isotopes, this production route results in very low specific activity ⁹⁹Mo necessitating a new type of generator. We investigate molybdenum-based nanomaterials to replace current low-capacity aluminum oxide adsorbers, allowing for selective ^99mTc extraction.

 

2.The design of a fast radionuclide separation method for the cyclotron-based production of ⁶⁸Ga. Given the generally short half-lives and high activities associated with radionuclide production, fast, automatable separation strategies are warranted. To this end, we are working on an alternative to current lengthy separation strategies. Using solvent extraction we have been able to extract up to 99.6% ± 0.3% ⁶⁸Ga from zinc nitrate solutions within 10 minutes, with back-extraction efficiencies of up to 94.5% ± 0.6% within 1 minute. Microfluidic solvent extraction can allow for direct recycling of the target solutions after the extraction process, making it a suitable method to create an irradiation loop that enables a continuous supply of ⁶⁸Ga to be generated in an automated set-up.

 

3.The use of radiotracers to investigate the bioaccessibility of different minerals and mineral supplements. Globally, it is estimated that more than two billion people suffer from micronutrient deficiencies. Nutrient-rich foods are at the center of creating healthy and sustainable diets, but supplementation approaches fail to consider the uptake potential of these nutrients. We have taken the first steps to develop radiotracers approaches for the investigation of nutrient bioaccessibility in nutrient-rich foods. A detailed understanding of food-matrix interactions is essential to predict, and subsequently improve, digestibility and uptake.