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Yttrium-90 (90Y) is a radioisotope; derived from the decay of 90Sr.

Yttrium-90 decays due to the emission of β- particles, with a half-life of 2.67 days. It can be used for metabolic radiopharmaceutical therapy, for example: non-Hodgkin’s B-cell lymphomas radioimmunotherapy (radiopharmaceutical therapy and immunotherapy). The radiopharmaceutical used is 90Y-ibritumomab tiuxetan; it is a murine monoclonal antibody (mAb) directed at human CD20. Radio-yttrium is bound to the mAb through the tiuxetan chelator.

Chemical-physical characteristics

Yttrium belongs to the group of transition metals; it has atomic number (Z) 39 and atomic weight 88.90585

Its electronic configuration is: [Kr] 4d1 5s2

The maximum energy of the emitted particles is 2.28 MeV with an average path in the human tissuses of approximately 5.8 mm. It decays in the non-radioactive isotope 90Zr.

History and etymology

Yttrium was discovered in 1794 by Johan Gadolin, a Finnish chemist, in a sample of mineral originating from Ytterby (Sweden).

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Article information

rID: 73201
System: Oncology
Synonyms or Alternate Spellings:
  • 90Y

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