In vivo Quantitative Three-Dimensional Localization of Tumor Labeled with Exogenous Specific Fluorescence Markers

We introduce a diffused optical detection system based on the administration of a fluorophore-antibody conjugate to diseased tissue. The conjugate interacts with the antigens expressed by the diseased tissue, resulting in fluorescent labeling of the antigen. By combining an optical detection system with a reconstruction algorithm developed on the basis of the random-walk model, we were able to determine the position of the fluorophore (and, thus, of the diseased cells) in the tissue. We present threedimensional reconstructions of the location of a fluorophore (FITC-fluorescein isothiocyanate) in the tongues of mice. Measurements were performed with the fluorophore embedded at various simulated depths. The simulations were performed with agarose-based gel slabs applied to the tongue as tissuelike phantoms. Reconstructed fluorophore locations agree well with the actual values.