The development of estrogen and progestin radiopharmaceuticals for imaging breast cancer

Anticancer Res. May-Jun 1997;17(3B):1573-6.


Background: The presence of receptors for estrogens and progestins in many breast tumors provides a means for imaging these tumors using positron emission tomography (PET) with appropriate fluorine-18 labeled estrogen and progestin radiopharmaceuticals. In this context, the estrogen analog 16 alpha-[18F]fluoroestradiol (FES) has already proven to be an effective imaging agent for estrogen receptor-positive tumors.

Methods: Clinical studies comparing FES images with those based on the metabolic probe 2-[18F]fluoro-2-deoxyglucose (FDG) in patients before and after tamoxifen hormone therapy are underway. Several fluorine-18 labeled progestins have been prepared, and efforts are underway to develop methods for labeling steroid receptor imaging agents with the widely available radionuclide technetium-99m, using both pendant and integrated approaches.

Results and conclusion: Breast tumor imaging with FES and FDG shows an interesting relationship between tumor metabolic response (assessed with FDG) and tumor estrogen receptor levels (assessed with FES). The fluorine-18 labeled progestins show excellent target tissue selective distribution in experimental animals and are ready for imaging studies in humans. The development of steroids labeled with technetium-99m poses special challenges because of the metallic nature of this radioisotope.

Publication types

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

MeSH terms

  • Animals
  • Antineoplastic Agents, Hormonal / therapeutic use
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / drug therapy
  • Deoxyglucose / analogs & derivatives*
  • Deoxyglucose / pharmacokinetics
  • Estradiol / analogs & derivatives*
  • Estradiol / pharmacokinetics
  • Female
  • Fluorine Radioisotopes / pharmacokinetics*
  • Fluorodeoxyglucose F18
  • Humans
  • Rats
  • Receptors, Estrogen / analysis*
  • Receptors, Progesterone / analysis*
  • Tamoxifen / therapeutic use
  • Tissue Distribution
  • Tomography, Emission-Computed


  • Antineoplastic Agents, Hormonal
  • Fluorine Radioisotopes
  • Receptors, Estrogen
  • Receptors, Progesterone
  • Tamoxifen
  • Fluorodeoxyglucose F18
  • 4-fluoroestradiol
  • Estradiol
  • 16-fluoroestradiol
  • Deoxyglucose