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 β- decay with a half-life of 1.9285(2) days to stable Eu-153. It emits a low to medium energy β- spectrum with 225 keV average energy and 808 keV maximum energy. In addition to β- 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 γ-rays at 103 keV (29.14%) suitable for SPECT imaging.
The mean electron energy emitted per decay is 265 keV, the mean photon energy per decay is 62 keV .
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
|Daughter||Decays to stable Eu-153: 100% β-|
|Processing||Off-line mass separation (CERN-MEDICIS) + 3-step column separation|
|Primary Container||2.5 mL borosilicate glass V-vial with silicon rubber screw cap|
|Product Grade||n.c.a. (but not in theoretical molar activity)|
|Physical Form||Liquid or solid deposit|
|Chemical Form||In 0.05 M HCl (evaporation to dryness is also possible)|
|Radioactive Concentration (gamma spectrometry)||> 50 MBq/ml|
|Appearance||Clear colourless solution|
|Radionuclide identification (gamma spectrometry)||70 keV, 97 keV and 103 keV gamma lines present|
|Radionuclidic Purity (gamma spectrometry)||>99.99%|
|Chemical purity (ICP-OES)||n.a.|
|Molar activity (ICP-OES)||280 GBq/µmol Sm at time of mass separation (>11% of theoretical maximum)|
|Apparent Molar Activity||Labelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE|
|pH (pH strips)||1-2|
|Activity available||Up to 150 MBq on demand (availability CERN-MEDICIS + BR2 reactor cycle)|
|Activity limit for UN2910 (excepted package) shipment||0.6 GBq in dry state or 60 MBq in liquid form|
|Other information||Labelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE|