Radionuclide impurities in proton-irradiated [18O]H2O for the production of 18F−: Activities and distribution in the [18F]FDG synthesis process

Distribution and separation of metallic and radionuclidic impurities in the production of 18F-fluorodeoxyglucose

“…These results confirm the hypothesis that Havar is a major source of radionuclidic contamination [7][8][9][11][12][13][14][15][16]. Other identified isotopes are 48 V and 7 Be.…”

“…51 C was determined both in the recovery water and the QMA column, since chromium can exist both as a Cr(III) cation travelling with H 2 18 O water and a Cr(VI) anion retained in the QMA column. This promotes the diversity in distribution observed in [9] where the 51 Cr activity was highest in the QMA column, which meant that the predominant form was Cr(VI); in [14,15] it was roughly balanced but in [15] significant activity was found in the waste, which has not been confirmed by other studies. 52 Mn was observed in all elements.…”

“…This distribution is confirmed by other cited papers. 56,57,58 Co isotopes make the greatest contribution to the activity due to radionuclidic impurities [7][8][9][11][12][13][14][15]. 56 Co and 57 Co radionuclides were approx.…”

Dependence of 18F Production Yield and Radioactive Impurities on Proton Irradiation Dose

“…Thus the number of secondary neutrons produced in this process is not directly proportional to the number of the incoming protons. As discussed in previous studies [14,16], 56 Co is generated from 56 Fe(p,n) 56 Co nuclear reaction whereas 110m Ag is produced via 109 Ag(n, ) 110m Ag nuclear reaction. As a result, the number of 110m Ag radioisotopes is much less than that of 56 Co radionuclides.…”

“…As indicated in Figure 2, two radioisotopes are captured by the gamma ray spectroscopy system, namely, 56 Co and 110m Ag. The two impurities have been previously discussed in the production of 18 F radionuclide [16], despite no further discussion on the radioactivity dependence on the proton beam dose. The identified gamma rays for 56 Co are at = 0.847 and 1.238 MeV, whereas, for 110m Ag, the strong peaks are recorded at = 0.658, 0.885, and 1.4 MeV.…”