Abstract: A composition comprises an antigen-specific antibody or antigen-binding fragment thereof labeled with Iodine-124 at a site other than, and which does not significantly interfere with, the antibody-antigen binding site. An in vivo method of radiotherapy directed to an antigenic site comprises administering to a subject in need of the therapy an amount of the antigen-specific composition described above effective to attain a reduction of the size of a tumor associated with the antigen. An in vivo method for detecting and localizing an antigenic site in a subject in need of such detection comprises administering to the subject an amount of the antigen-specific composition of the invention effective to localize the antigen-antibody binding site and scanning the subject's body with a positron-emitter detector to attain the localization of the site.

Abstract: Fluorinated derivatives 3,14-dihydroxy-4,5.alpha.-epoxy-6.beta.-fluoro-17-methylmorphinan ("fluorooxymorphone"; FOXY, compound 10) and 17-cyclopropylmethyl-3,14-dihydroxy-4,5.alpha.-epoxy-6.beta.-fluoromorphin an (CYCLOFOXY, compound 18) are prepared based upon the structures of the potent opioid agonist oxymorphone 4 and the antagonist naltrexone 11, respectively. Fluorine was introduced in the final stages of synthesis by a facile nucleophilic displacement with fluoride ion of the 6.alpha.-triflate functions in 8 and 16. The synthetic procedures were suitable for the production of the corresponding positron emitting .sup.18 F-labeled analogs .sup.18 F-FOXY and .sup.18 F-CYCLOFOXY, which are useful for in vivo studies of the opioid receptor system using positron emission transaxial tomography. In addition, the tritiation of FOXY (10) to high specific activity is noted.