Comparison of separation methods for 47Ca/47Sc radionuclide generator

Production of scandium radionuclides for theranostic applications: towards standardization of quality requirements

“…Those with atomic mass smaller than 45 decay by emission of positrons, while those with atomic mass greater than 45 emit electrons. Characteristics of Sc radioisotopes with longer half-lives are given in Table 1 (adapted from Pawlak et al 2019). Among them, 43 Sc, 44,44m Sc and 47 Sc are suitable for medical applications.…”

“…Nontheless, to obtain significant activity of 47 Ca the target enriched in 46 Ca must be used (presently 46 Ca is available with a maximum 30% enrichment) which is rather expensive (Chakravarty et al 2017) but recycling would allow to drastically reduce the cost. For comparison, when 0,97 mg of 46 Ca (48.5 mg of 5% enriched [ 46 Ca]CaCO 3 ) was irradiated in a thermal neutron flux 1.2 × 10 14 ns − 1 cm − 2 for 6 days, around 700 MBq of 47 Ca and 350 MBq of 47 Sc were produced at EOB (Pawlak et al 2019). The produced 47 Ca decays to 47 Sc with a half-life of 4.5 days, which is longer than the half-life of 47 Sc, enabling multiple separations of in-grown 47 Sc in the generator-like system.…”

“…The optimized chemical isolation of 47 Sc from the target material allowed the formulation of up to 1.5 GBq 47 Sc with high radionuclidic purity (> 99.99%) in a small volume (∼700 μL), which was useful for labeling purposes. Three consecutive separations within 1 week were possible by isolating the in-grown 47 Sc (Domnanich et al 2017a;Pawlak et al 2019).…”

“…The half-lives of 43 Sc, 44 Sc or 47 Sc are compatible with the pharmacokinetics of a fairly wide range of targeting vectors. Several somatostatin analogs, either DOTA-derivatized (DOTATOC, DOTATATE, DOTANOC) or with NODAGA as a chelator, have been labeled with scandium radionuclides to prove the suitability of the obtained radionuclide solution for radiolabeling (Pawlak et al 2019;Loveless et al 2019a) or to compare under the same conditions the in vitro/in vivo imaging/therapeutic potential of scandium radiolabeled peptides to their 68 Ga-or 177 Lu ( 90 Y)radiolabeled counterparts (Walczak et al 2015;Loveless et al 2019a;Singh et al 2017;Pruszynski et al 2012). The scandium radionuclides labeled bombesin analogs (Koumarianou et al 2012), RGD peptides (Domnanich et al 2017c), folate derivatives (Muller et al 2018;Muller et al 2014;Siwowska et al 2019) and PSMA ligands (Umbricht et al 2017) have been evaluated pre-clinically.…”

PSMA-D4 Radioligand for Targeted Therapy of Prostate Cancer: Synthesis, Characteristics and Preliminary Assessment of Biological Properties

“…Lutetium-177 (LutaPol) as lutetium chloride of SA higher than 555 MBq mg −1 Lu in 0.04 N HCl and yttrium-90 (ItraPol) as a yttrium chloride in a 0.04-0.05 N HCl of 0.925-37 GBq in a volume 0.010-2 mL were produced at Radioisotope Centre POLATOM, (Otwock, Poland). Scandium-47 was produced via the nuclear reaction 46 Ca(n,γ) 47 Ca→ 47 Sc, by irradiation of enriched 46 Ca target at the Institute Laue-Langevin (Grenoble, France) or Maria research reactor (Otwock, Poland), and 47 Sc was separated from the irradiated target by extraction chromatography on DGA resin [42]. Actinium-225 as actinium nitrate was purchased from the Institute of Physics and Power Engineering (Obninsk, Russia).…”