A new internal pair production branching ratio of 90Y: the development of a non-destructive assay for 90Y and 90Sr

Appl Radiat Isot. 2007 Mar;65(3):318-27. doi: 10.1016/j.apradiso.2006.08.009. Epub 2006 Oct 11.


(90)Y is utilized as a therapeutic radioisotope in radiolabeled monoclonal antibodies and in microspheres for targeted radiation therapy of the liver. Currently, the widely used dose calibrator assay of (90)Y can have uncertainties exceeding +/-10%. A non-destructive assay using spectroscopy is possible by reducing the currently published uncertainty (+/-12%) in the internal pair production branching ratio for the 0(+)-0(+) transition of (90)Zr. A high-purity germanium detector was used to determine the branching ratio to be (31.86+/-0.47) x 10(-6).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Calibration
  • Radiation Monitoring / methods*
  • Strontium Radioisotopes / analysis*
  • Yttrium Radioisotopes / analysis*


  • Strontium Radioisotopes
  • Yttrium Radioisotopes