Folate-receptor-targeted radionuclide imaging agents

The cell-membrane folate receptor is a potential molecular target for tumor-selective drug delivery, including delivery of radiolabeled folate-chelate conjugates for diagnostic imaging. This review surveys the growing literature on tumor imaging with radionuclide agents targeted to the folate receptor. Successful folate-receptor targeting has been reported, both in vitro and in vivo. using a variety of radionuclides that are suitable for clinical diagnostic imaging (Ga-67, In-111, Tc-99m, Ga-66, and Cu-64). While none of these agents has, to date, been demonstrated to have clinical efficacy as a diagnostic tool, existing data indicates that it is feasible to noninvasively assess (at least qualitatively) tissue folate receptor levels by external radionuclide imaging. (C) 2004 Elsevier B.V. All rights reserved.