INVIVO COMPARISON OF 16-ALPHA-[BR-77]BROMOESTRADIOL-17-BETA AND 16-ALPHA-[I-125]IODOESTRADIOL-17-BETA

  • 1 January 1982
    • journal article
    • research article
    • Vol. 23  (5) , 420-424
Abstract
Estrogen-receptor-binding radiopharmaceuticals of high specific activity, 16.alpha.-[77Br]bromoestradiol-17.beta. and 16.alpha.[125I]iodoestradiol-17.beta., were compared in immature female rats. The iodoestradiol has slightly higher uterine uptake at 1 h after injection, whereas the brominated analog has significanlty enhanced uptake at later times. The similar behavior of the 2 compounds in vivo suggests that estradiol labeled with 123I, 77Br on 75Br could be used interchangeably for the imaging of breast tumors containing estrogen receptors. Coinjection of 16.alpha.-[125I]iodoestradiol as an internal standard may be useful for comparison of different radiohalogenated estrogens.