New paths in medical X-ray Fluorescence Imaging

There are still grand challenges in medical imaging, such as localising very small tumors and/or metastases, as well as in-vivo tracking of medical drugs or e.g. immune cells. A promising imaging candidate for such studies is X-ray Fluorescence Imaging (XFI), where typically gold-nanoparticles (GNPs) are functionalised with antibodies or drug molecules. These GNPs can be tracked in-vivo as they emit X-ray fluorescence photons when excited by a scanning X-ray pencil beam. While this concept is more than three decades old, until recently the expectation was that XFI cannot be applied to human-sized objects due to a huge background-level from Compton-scattering. Our team, however, has solved this background-problem, which now opens the doors towards advanced XFI-studies. We will also report on first experimental results from the DESY-synchrotron, such as an in-vitro measurement on the uptake of antibody-loaded GNPs into prostate tumor cells. In close collaboration with DESY-teams we have already measured first XFI-signals from a phantom using a laser-driven X-ray Thomson source. Such as source would allow the translation of XFI-studies from synchrotrons to hospitals.