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. 2004 Aug 17;101(33):12294-9.
doi: 10.1073/pnas.0401137101. Epub 2004 Aug 10.

Visualization of antitumor treatment by means of fluorescence molecular tomography with an annexin V-Cy5.5 conjugate

Vasilis Ntziachristos  1 , Eyk A Schellenberger, Jorge Ripoll, Doreen Yessayan, Edward Graves, Alexei Bogdanov Jr, Lee Josephson, Ralph Weissleder
Affiliations

Visualization of antitumor treatment by means of fluorescence molecular tomography with an annexin V-Cy5.5 conjugate

Vasilis Ntziachristos et al. Proc Natl Acad Sci U S A. .

Abstract

In vivo imaging of treatment responses at the molecular level could have a significant impact on the speed of drug discovery and ultimately lead to personalized medicine. Strong interest has been shown in developing quantitative fluorescence-based technologies with good molecular specificity and sensitivity for noninvasive 3D imaging through tissues and whole animals. We show herein that tumor response to chemotherapy can be accurately resolved by fluorescence molecular tomography (FMT) with a phosphatidylserine-sensing fluorescent probe based on modified annexins. We observed at least a 10-fold increase of fluorochrome concentration in cyclophosphamide-sensitive tumors and a 7-fold increase of resistant tumors compared with control studies. FMT is an optical imaging technique developed to overcome limitations of commonly used planar illumination methods and demonstrates higher quantification accuracy validated by histology. It is further shown that a 3-fold variation in background absorption heterogeneity may yield 100% errors in planar imaging but only 20% error in FMT, thus confirming tomographic imaging as a preferred tool for quantitative investigations of fluorescent probes in tissues. Tomographic approaches are found essential for small-animal optical imaging and are potentially well suited for clinical drug development and monitoring.

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Figures

Fig. 1.
Fig. 1.
The combined planar imaging/FMT system. (a) A schematic of the major components of the system is shown, with details given in the text. (b) Details of the imaging chamber that was used for planar, transillumination, and tomographic acquisitions of small animals. AR-coated, antireflection-coated. (c) Experimental protocol followed for the animal studies performed.
Fig. 2.
Fig. 2.
Phantom study examining the relative appearance of planar and FMT images as a function of increasing absorption in the left of the two tubes shown. Experimental details are described in the text.
Fig. 3.
Fig. 3.
Imaging apoptotic response in vivo. (a) Planar fluorescence image. (b) Four consecutive FMT slices (in color) superimposed on the planar image of the mouse obtained at the excitation wavelength. The bottom right slice is the one closer to the surface of the animal as seen in a, and successive slices are reconstructed from deeper in the animal. (c and d) TUNEL-stained histological slices from the sensitive LLC and resistant CR-LLC tumors.
Fig. 4.
Fig. 4.
Second imaging example, showcasing advantages of FMT imaging compared with planar imaging. (a) Planar fluorescence image. (b) Four consecutive FMT slices (in color) superimposed on the planar image of the mouse obtained at the excitation wavelength. The bottom right slice is the one closer to the surface of the animal as seen in a, and successive slices are reconstructed from deeper in the animal. (c and d) TUNEL-stained histological slices from the sensitive LLC and resistant CR-LLC tumors.
Fig. 5.
Fig. 5.
Control studies. (a–d) Imaging results from a treated animal injected with the nonbinding annexin V2.4-Cy5.5 probe. (a and e) Excitation light images. (b and f) Fluorescence images. (c and g) FMT slices, z = 1.22 cm. (d and h) FMT slices, z = 1.30 cm. Very little background fluorescence is shown in either planar (b) or FMT images (c and d) serving as a positive control for nonspecific accumulation. (f–h) Planar (f) and FMT (g and h) results from an untreated animal injected with the annexin V1.1-Cy5.5 probe. Slightly higher fluorescence is resolved than in b and c, especially for the CR-LLC tumor, as seen in the FMT images indicative of background apoptosis. Overall, the fluorescence activity resolved in control studies is 10-fold less than when imaging chemo-induced apoptosis.
Fig. 6.
Fig. 6.
Summary of results. (a) Mean concentration values (Upper) calculated for the LLC and CR-LLC tumors for the animals studied and corresponding volumes reconstructed (Lower). (b) Summary of apoptotic index ratio between LLC and CR-LLC calculated from volumetric TUNEL histological analysis from excised tumors (left column) and corresponding in vivo calculation of fluorescence ratios obtained with FMT (center column) and planar imaging (right column).
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References

    1. Herschman, H. R. (2003) Science 302, 605–608. - PubMed
    1. Massoud, T. F. & Gambhir, S. S. (2003) Genes Dev. 17, 545–580. - PubMed
    1. Blankenberg, F. G., Naumovski, L., Tait, J. F., Post, A. M. & Strauss, H. W. (2001) J. Nucl. Med. 42, 309–316. - PubMed
    1. Thompson, C. B. (1995) Science 267, 1456–1462. - PubMed
    1. Brooks, P. C., Montgomery, A. M., Rosenfeld, M., Reisfeld, R. A., Hu, T., Klier, G. & Cheresh, D. A. (1994) Cell 79, 1157–1164. - PubMed

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