Optical imaging of metastatic tumors using a folate-targeted fluorescent probe

J Biomed Opt. 2003 Oct;8(4):636-41. doi: 10.1117/1.1609453.


We describe the use of a tumor targeting ligand, the vitamin folic acid, to deliver an attached fluorescent probe to both primary and metastatic tumors overexpressing the folate receptor. Upon laser excitation, derived images of normal tissues generally show little or no fluorescence, whereas images of folate receptor-expressing tumors display bright fluorescence that can be easily distinguished from adjacent normal tissue. Furthermore, metastatic tumor loci of submillimeter size can also be visualized without the aid of image processing or enhancement. The sharp distinction between tumor and normal tissues provided by this technique could find application in the localization and resection of tumor tissue during surgery or in the enhanced endoscopic detection and staging of cancers.

Publication types

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

MeSH terms

  • Animals
  • Biomarkers, Tumor / metabolism
  • Carrier Proteins / metabolism
  • Cell Line, Tumor
  • Fluorescent Dyes
  • Folate Receptors, GPI-Anchored
  • Folic Acid / pharmacokinetics*
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Fluorescence / methods*
  • Neoplasm Metastasis / pathology
  • Neoplasms / metabolism
  • Neoplasms / pathology*
  • Neoplasms, Unknown Primary / metabolism
  • Neoplasms, Unknown Primary / pathology*
  • Peritoneal Neoplasms / metabolism
  • Peritoneal Neoplasms / pathology
  • Peritoneal Neoplasms / secondary
  • Receptors, Cell Surface*
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology
  • Skin Neoplasms / secondary


  • Biomarkers, Tumor
  • Carrier Proteins
  • Fluorescent Dyes
  • Folate Receptors, GPI-Anchored
  • Receptors, Cell Surface
  • Folic Acid