Sc-47 is a rare earth, usually in trivalent state. It can be radiolabelled with macrocyclic chelators, in particular DOTA.The ionic radius is 74.5 pm.
Sc-47 decays by beta-minus emission with a half-life of 3.3492(6) days to stable Ti-47. It emits a low energy beta spectrum with 162 keV average energy and 600 keV maximum energy. Emission of conversion and Auger electrons is negligible (<1%).
Moreover, Sc-47 emits gamma-rays at 159.4 keV (68.3%) suitable for SPECT-imaging.
Sc-47 is produced indirectly by thermal neutron irradiation of enriched Ca-46 oxide or carbonate targets in the research reactors of the PRISMAP network: RHF at ILL, BR2 at SCK CEN and MARIA at NCBJ. The Ca-47 (T1/2=4.54 d) produced upon neutron capture decays to Sc-47 via beta-minus decay and serves as a generator, allowing several subsequent elutions of Sc-47 . With respect to other production pathways of Sc-47, this production scheme provides optimum radionuclidic purity .
The radiochemical separations are performed at POLATOM (NCBJ, Otwock-Swierk, Poland). Activity will be shipped from there to the users in form of ScCl3 solution, ready for labelling of e.g. DOTA-compounds.
Examples of use
|Branching Ratio/Decay||100% β-|
|Purification||2 steps column separation|
|Chemical Form||In 0.05 M HCl or 4.85 M NaCl /0.13 M HCl|
|Specific Activity||1 GBq/mg|
|Radionuclidic Purity||> 99.95% (< 0.005% Sc-46)|
|Radiochemical Purity||Labelling up to 10-25 MBq/nmol DOTANOC (>96%) or ≈10 MBq/nmol DOTATATE (>95%)|
|Identification||159.4 keV gamma line present|
|Appearance||Clear and colourless solution|
|Activity available||Up to 500 MBq|
|Availability||few times per year (planning in advance), depends on reactor schedules|
|Grade||Preclinical grade, n.c.a.|