Sm-153 is a radiolanthanide, usually in trivalent state. It can be radiolabelled with macrocyclic chelators, in particular DOTA. The ionic radius is 95.8 pm.
Sm-153 decays by beta-minus emission with a half-life of 1.9285(2) days to stable Eu-153. It emits a low to medium energy beta spectrum with 225 keV average energy and 808 keV maximum energy. In addition to beta-minus emission it shows ample emission of low energy conversion and Auger electrons , thus emitting in total about 2.34 electrons (with energies above 4 keV) per decay.
Moreover, Sm-153 emits gamma-rays at 103.2 keV (29.14%) suitable for SPECT imaging.
Sm-153 is produced by thermal neutron irradiation of enriched Sm-152 oxide targets in the BR2 reactor at SCK CEN. The produced carrier-added Sm-153 is then mass separated at the MEDICIS facility at CERN. Thus, Sm-153 with high specific activity is obtained .
A final radiochemical separation is performed at SCK CEN (Mol, Belgium). Activity will be shipped from there to the users in form of SmCl3 solution, ready for labelling of e.g. DOTA-compounds.
Examples of use
|Branching Ratio/Decay||100% β-|
|Purification||Mass separation (CERN-MEDICIS) + 3-step column separation|
|Chemical Form||In 0.05 M HCl (evaporation to dryness is also possible)|
|Specific Activity||1.87 TBq/mg (at time of mass separation)|
|Radiochemical Purity||Labelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE|
|Identification||69.7 keV, 97.4 keV and 103.2 keV gamma lines present|
|Appearance||Clear and colourless solution|
|Activity available||Up to 150 MBq|
|Availability||On demand (availability CERN-MEDICIS + BR2 reactor cycle)|
|Other information||With/without analysis certificate|