Imaging a photodynamic therapy photosensitizer in vivo with a time-gated fluorescence tomography system.
We report the tomographic imaging of a photodynamic therapy (PDT) photosensitizer, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) in vivo with time-domain fluorescence diffuse optical tomography (TD-FDOT). Simultaneous reconstruction of fluorescence yield and lifetime of HPPH was performed before and after PDT. The methodology was validated in phantom experiments, and depth-resolved in vivo imaging was achieved through simultaneous three-dimensional (3-D) mappings of fluorescence yield and lifetime contrasts. The tomographic images of a human head-and-neck xenograft in a mouse confirmed the preferential uptake and retention of HPPH by the tumor 24-h post-injection. HPPH-mediated PDT induced significant changes in fluorescence yield and lifetime. This pilot study demonstrates that TD-FDOT may be a good imaging modality for assessing photosensitizer distributions in deep tissue during PDT monitoring.
Roswell Park Cancer Institute, Department of Cell Stress Biology and PDT Center, Elm and Carlton Streets, Buffalo, New York, 14263, USA.
Weirong
W
Mo
Daniel
D
Rohrbach
Ulas
U
Sunar
D045744:Cell Line, Tumor; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics / Q000627:therapeutic use; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D008657:Metabolic Clearance Rate; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D057054:Molecular Imaging / Q000379:methods; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D010778:Photochemotherapy / Q000295:instrumentation*; D017319:Photosensitizing Agents / Q000032:analysis / Q000493:pharmacokinetics / Q000627:therapeutic use; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041622:Tomography, Optical / Q000295:instrumentation*; D016896:Treatment Outcome
D017319:Photosensitizing Agents; D002734:Chlorophyll; C083998:2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a