Pharmacokinetics of ICG and HPPH-car for the detection of normal and tumor tissue using fluorescence, near-infrared reflectance imaging: a case study.
We present in vivo fluorescent, near-infrared (NIR), reflectance images of indocyanine green (ICG) and carotene-conjugated 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide (HPPH-car) to discriminate spontaneous canine adenocarcinoma from normal mammary tissue. Following intravenous administration of 1.0 mg kg-1 ICG or 0.3 mg kg-1 HPPH-car into the canine, a 25 mW, 778 nm or 70 mW, 660 nm laser diode beam, expanded by a diverging lens to approximately 4 cm in diameter, illuminated the surface of the mammary tissue. Successfully propagating to the tissue surface, ICG or HPPH-car fluorescence generated from within the tissue was collected by an image-intensified, charge-coupled device camera fitted with an 830 or 710 nm bandpass interference filter. Upon collecting time-dependent fluorescence images at the tissue surface overlying both normal and diseased tissue volumes, and fitting these images to a pharmacokinetic model describing the uptake (wash-in) and release (wash-out) of fluorescent dye, the pharmacokinetics of fluorescent dye was spatially determined. Mapping the fluorescence intensity owing to ICG indicates that the dye acts as a blood pool or blood persistent agent, for the model parameters show no difference in the ICG uptake rates between normal and diseased tissue regions. The wash-out of ICG was delayed for up to 72 h after intravenous injection in tissue volumes associated with disease, because ICG fluorescence was still detected in the diseased tissue 72 h after injection. In contrast, HPPH-car pharmacokinetics illustrated active uptake into diseased tissues, perhaps owing to the overexpression of LDL receptors associated with the malignant cells. HPPH-car fluorescence was not discernable after 24 h. This work illustrates the ability to monitor the pharmacokinetic delivery of NIR fluorescent dyes within tissue volumes as great as 0.5-1 cm from the tissue surface in order to differentiate normal from diseased tissue volumes on the basis of parameters obtained from the pharmacokinetic models.
Gurfinkel
M
M
School of Chemical Engineering, Purdue University, West Lafayette, IN, USA.
Thompson
A B
AB
Ralston
W
W
Troy
T L
TL
Moore
A L
AL
Moore
T A
TA
Gust
J D
JD
Tatman
D
D
Reynolds
J S
JS
Muggenburg
B
B
Nikula
K
K
Pandey
R
R
Mayer
R H
RH
Hawrysz
D J
DJ
Sevick-Muraca
E M
EM
D000230:Adenocarcinoma / Q000175:diagnosis; D000818:Animals; D002338:Carotenoids / Q000493:pharmacokinetics; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004283:Dog Diseases / Q000175:diagnosis; D004285:Dogs; D005260:Female; D007208:Indocyanine Green / Q000493:pharmacokinetics*; D015674:Mammary Neoplasms, Animal / Q000175:diagnosis*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D013050:Spectrometry, Fluorescence; D019265:Spectroscopy, Near-Infrared
D017319:Photosensitizing Agents; D002734:Chlorophyll; C083998:2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a; D002338:Carotenoids; D007208:Indocyanine Green