Assessment of radionuclide impurities in [18F]fluoromethylcholine ([18F]FMCH)

Recovered water - H218O from the 18F[FDG] production as liquid radioactive waste

In this study, ten recovered water samples were analysed using gamma spectrometry and Liquid Scintillation Counting techniques for identification of radioactive impurities (quality and quantity) and for radioactive waste qualifications. The presence of several radioactive isotopes of 3H, 56,57Co 52Mn in the recovered [18O] water irradiated with 11 MeV protons used to produce [18F] fluoride by the 18O(p,n)18F reaction has been confirmed. Radioactive impurities were generated directly in enriched water or washed out from activated Havar foil, or tantalum body target material. The highest impact on the qualification of the recovered water remains after the production as a radioactive waste has 56Co. The highest activity concentration of about 0.1 GBq/ml has been detected in the case of tritium 3H. All ten samples were qualified as transitional, low-level radioactive wastes.

PET Radiotracers in Atherosclerosis: A Review

Traditional atherosclerosis imaging modalities are limited to late stages of disease, prior to which patients are frequently asymptomatic. Positron emission tomography (PET) imaging allows for the visualization of metabolic processes underscoring disease progression via radioactive tracer, allowing earlier-stage disease to be identified. 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) uptake largely reflects the metabolic activity of macrophages, but is unspecific and limited in its utility. By detecting areas of microcalcification, 18F-Sodium Fluoride (18F-NaF) uptake also provides insight into atherosclerosis pathogenesis. Gallium-68 DOTA-0-Tyr3-Octreotate (68Ga-DOTATATE) PET has also shown potential in identifying vulnerable atherosclerotic plaques with high somatostatin receptor expression. Finally, 11-carbon (11C)-choline and 18F-fluoromethylcholine (FMCH) tracers may identify high-risk atherosclerotic plaques by detecting increased choline metabolism. Together, these radiotracers quantify disease burden, assess treatment efficacy, and stratify risk for adverse cardiac events.