As of the latest update, Google Chrome and Microsoft Edge have made a breaking change to how file uploads are handled. Once your system installs this update, you will not be able to upload new images. Please use another browser until we can get it fixed.


Samarium-153 (Sm-153) is a radioisotope used in metabolic radiotherapy for the treatment of pain from bone metastases. It is produced in nuclear reactors, by neutron irradiation of samarium-152 (Sm-152 Sm2O3).

Samarium-153 decays by emitting both beta minus particles and gamma photons with a characteristic gamma peak of 103.2 KeV; it has a physical half-life time of 1.93 days. The carrier molecule used is the ethylene diamine tetramethylene phosphonate acid (EDTMP), a chelator osteotropic tetraphosphonate. The radiopharmaceutical Sm-153 EDTMP (dose: 37 MBq/Kg) shows a biodistribution similar to that of technetium-99m methylene diphosphonate (Tc-99m MDP). The gamma (photons) component also allows the use of the radiotracer for nuclear medical imaging (follow-up).

Imaging technology
Share article

Article information

rID: 74414
System: Oncology
Synonyms or Alternate Spellings:
  • Sm-153
  • Sm-153 EDTMP
  • Samarium-153 EDTMP

Support Radiopaedia and see fewer ads

Cases and figures

  • Skeletal metastases
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.