Latest development of α emitter imaging and quantification on a large Field Of View

International audienceCurrently, the characterization of the nature and spatial distribution of radionuclides in a sample is time consuming and fastidious. Indeed, it necessarily requires the use of two distinct analytical techniques and detectors of a different nature. Moreover, the resolutions of the two methods are often different from each other because they also depend on the nature of the detector used, which makes it difficult to integrate and interpret these two types of measurements together.To overcome these limitations and to simplify and accelerate the measurement process, it is now possible to use a digital autoradiograph capable of combining the measurement of the spatial distribution with the ability to separate and quantify each radionuclide.For this purpose, a set of temporal and energy spectrometry techniques had to be specifically developed. On the one hand, the use of instruments capable of recording the location of each decay product allows measuring the evolution of the activity of the sample and thus, to deduce the contributions of several radionuclides. On the other hand, the development of an innovative method of autoradiography spectroscopy in particle energy also allows separating them by measuring their initial energy. Even if the efficiency of energy spectrum reconstruction is low (4.4%) compared to the efficiency of a simple autoradiograph (50%), this novel measurement approach offers the opportunity to select areas on an autoradiograph to perform an energy spectrum analysis within that area.From an application point of view, this opens up possibilities for theragnostic applications that typically use two radionuclides. Further upstream, it can optimize the production and distribution challenge of α radionuclides by allowing the identification and characterization of individual radionuclides in radionuclide chains such as 225Ac