Folic acid conjugates for nuclear imaging of folate receptor-positive cancer.

The folate receptor (FR) is overexpressed on a variety of tumor types, whereas its distribution in normal tissues and organs is highly limited. Exploration of the utility of the FR revealed its promising potential for targeting with folate-based radiopharmaceuticals. Herein, we report the principle of the FR-targeting strategy and summarize the development of several folic acid radioconjugates useful for SPECT and PET of cancer diseases. The potential applicability of folate radiopharmaceuticals for FR-targeted radionuclide therapy is also discussed.