Sm 153
1.93 d
β- 0.7, 0.8
γ 103, 70,,,

Chemical properties

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.

Nuclear properties

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.

The mean electron energy emitted per decay is 265 keV, the mean photon energy per decay is 62 keV .

Production

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 .

Distribution

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

  • c.a. Sm-153 with limited specific activity is mainly used for bone pain palliation, commercially available under the brand name Quadramet®.
  • The high-specific activity variant described here enables applications for receptor-targeted radionuclide therapy.
  • Sm-153 is also suited as source for Mößbauer spectroscopy , a highly sensitive technique to characterize the chemical state and chemical environment of samarium bound in solids or frozen ex vivo samples.

Purity grades available

preclinical

No carrier added (n.c.a.)

Available in n.c.a form (but not in theoretical specific activity)
ParameterSpecifications
Half-life1.93 d
DaughterStable Eu-153
Branching Ratio/Decay100% β-
ProductionSm-152(n,γ)Sm-153
PurificationMass separation (CERN-MEDICIS) + 3-step column separation
Chemical FormIn 0.05 M HCl (evaporation to dryness is also possible)
Specific Activity1.87 TBq/mg (at time of mass separation)
Radionuclidic Purity>99.99%
Radiochemical PurityLabelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE
Identification69.7 keV, 97.4 keV and 103.2 keV gamma lines present
AppearanceClear and colourless solution
pH1-2
Activity availableUp to 150 MBq
AvailabilityOn demand (availability CERN-MEDICIS + BR2 reactor cycle)
GradePreclinical grade
Other informationWith/without analysis certificate

Applications

  • β-therapy
  • SPECT

Point of supply

  • Mol, Belgium

Involved production facilities

SCK CEN, Belgium
CERN, International