Molecular Imaging and Biology

, Volume 14, Issue 2, pp 156–162

In Vivo Photoactivation Without “Light”: Use of Cherenkov Radiation to Overcome the Penetration Limit of Light

Authors

  • Chongzhao Ran
    • Molecular Imaging Laboratory, Department of RadiologyMassachusetts General Hospital/Harvard Medical School
    • Department of Radiology, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical ImagingMassachusetts General Hospital/Harvard Medical School
  • Zhaoda Zhang
    • Department of Radiology, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical ImagingMassachusetts General Hospital/Harvard Medical School
  • Jacob Hooker
    • Department of Radiology, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical ImagingMassachusetts General Hospital/Harvard Medical School
    • Molecular Imaging Laboratory, Department of RadiologyMassachusetts General Hospital/Harvard Medical School
    • Department of Radiology, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical ImagingMassachusetts General Hospital/Harvard Medical School
Research Article

DOI: 10.1007/s11307-011-0489-z

Cite this article as:
Ran, C., Zhang, Z., Hooker, J. et al. Mol Imaging Biol (2012) 14: 156. doi:10.1007/s11307-011-0489-z

Abstract

Purpose

The poor tissue penetration of visible light has been a major barrier for optical imaging, photoactivatable conversions, and photodynamic therapy for in vivo targets with depths beyond 10 mm. In this report, as a proof-of-concept, we demonstrated that a positron emission tomography (PET) radiotracer, 2-deoxy-2-[18F]fluoro-d-glucose (18FDG), could be used as an alternative light source for photoactivation.

Procedures

We utilized 18FDG, which is a metabolic activity-based PET probe, as a source of light to photoactivate caged luciferin in a breast cancer animal model expressing luciferase.

Results

Bioluminescence produced from luciferin allowed for the real-time monitoring of Cherenkov radiation-promoted uncaging of the substrate.

Conclusion

The proposed method may provide a very important option for in vivo photoactivation, in particular for activation of photosensitizers for photodynamic therapy and eventually for combining radioisotope therapy and photodynamic therapy.

Key words

Cherenkov radiationBioluminescencePhotoactivationCaged luciferin

Supplementary material

11307_2011_489_MOESM1_ESM.pdf (27 kb)
SI Fig. 1The LC–MS spectra of a water solution of DMNP-luciferin irradiated with UV 365 nm light for 5 min. Insert mass spectra of the released luciferin (left) and the unreacted DMNP-luciferin (right). (PDF 27 kb)
11307_2011_489_MOESM2_ESM.pdf (602 kb)
SI Fig. 2a Bioluminescence images of mice bearing luciferase-expressing tumors injected with luciferin. b Quantitative analysis of the images in (a). (PDF 602 kb)
11307_2011_489_MOESM3_ESM.pdf (59 kb)
SI Fig. 3Full-time course optical signal from tumor sites of control mice injected with 18FDG only. (PDF 58 kb)

Copyright information

© Academy of Molecular Imaging and Society for Molecular Imaging 2011