Development of Radioiodinated Nonsteroidal Androgen Receptor Ligands for SPECT Imaging of Prostate Cancer

In 2001, researchers at the University of Michigan Medical School developed radioiodinated nonsteroidal androgen receptor ligands for SPECT imaging of prostate cancer. The study was based on the observation that most prostate tumors and metastases express androgen receptors (AR). The researchers focused on the antiandrogens RU 59063 and RU 58841, nonsteroidal AR ligands that display high AR affinity and selectivity. They synthesized a series of iodinated analogs of these compounds for investigation as in vivo AR radioligands. The radioiodinated ligands were synthesized with a chemical purity and specific activity of >95% and >155 Ci/mmole, respectively. The study concluded with the successful synthesis of these [¹²5]]-labeled nonsteroidal AR radioligands, and biological studies were underway to evaluate their utility as in vivo radioligands for AR imaging.