Accelerator-Based Production of Scandium Radioisotopes for Applications in Prostate Cancer: Toward Building a Pipeline for Rapid Development of Novel Theranostics

Positronium image of the human brain in vivo

Positronium is abundantly produced within the molecular voids of a patient's body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.

Nuclear Cross-Section of Proton-Induced Reactions on Enriched 48Ti Targets for the Production of Theranostic 47Sc Radionuclide, 46cSc, 44mSc, 44gSc, 43Sc, and 48V

The cross-sections of the 48Ti(p,x)47Sc, 46cSc, 44mSc, 44gSc, 43Sc, and 48V nuclear reactions were measured from 18 to 70 MeV, with particular attention to 47Sc production. Enriched 48Ti powder was deposited on an aluminum backing and the obtained targets were characterized via elastic backscattering spectroscopy at the INFN-LNL. Targets were exposed to low-intensity proton irradiation using the stacked-foils technique at the ARRONAX facility. Activated samples were measured using γ-spectrometry; the results were compared with the data int he literature and the theoretical TALYS-based values. A regular trend in the new values obtained from the different irradiation runs was noted, as well as a good agreement with the literature data, for all the radionuclides of interest: 47Sc, 46cSc, 44mSc, 44gSc, 43Sc, and 48V. 47Sc production was also discussed, considering yield and radionuclidic purity, for different 47Sc production scenarios.