TY - JOUR
T1 - Multiphoton excitation fluorescence microscopy of 5-aminolevulinic acid induced fluorescence in experimental gliomas
AU - Kantelhardt, Sven Rainer
AU - Diddens, Heike
AU - Leppert, Jan
AU - Rohde, Veit
AU - Hüttmann, Gereon
AU - Giese, Alf
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/4
Y1 - 2008/4
N2 - Background and Objective: The clinical usefulness of 5-ALA guided detection of tumor tissue has been demonstrated for a number of malignancies. However, current techniques of intraoperative detection of protoporphyrin IX fluorescence in situ do not offer subcellular resolution. Therefore, discrimination of non-specific 5-ALA induced fluorescence remains difficult. Materials and Methods: In this study we have used an orthotopic glioma model to analyze PpIX fluorescence in tumor tissue and normal brain by multiphoton excitation microscopy after intraperitoneal administration of 5-ALA. A DermaInspect in vivo imaging system was used for autofluorescence measurements at 750 nm excitation and detection in the green channel of a standard photomultiplier module. For detection of PpIX fluorescence at different excitation wavelengths a red sensitive version of the photomultiplier and a filter combination of short pass filters and a color glass long pass filter was used restricting the sensitivity in the red channel to a range of 580-700 nm. Results: Multiphoton microscopy allowed a higher structural definition of tumor tissue based on the excitation of 5-ALA induced PpIX fluorescence compared to autofluorescence imaging. The high resolution of multiphoton microscopy allowed discrimination of fluorescence from the cytoplasm of tumor cells and 5-ALA induced PpIX fluorescence of normal brain parenchyma adjacent to tumor. Fluorescence lifetime imaging showed significantly longer fluorescence lifetimes of 5-ALA induced PpIX fluorescence in tumor tissue compared to normal brain. This allowed definition and visualization of the tumor/brain interface based on this parameter alone. Conclusion: Multiphoton microscopy of 5-ALA induced PpIX fluorescence in brain tumor tissue conceptually provides a high resolution diagnostic tool, which in addition to structural information may also provide photochemical/functional information.
AB - Background and Objective: The clinical usefulness of 5-ALA guided detection of tumor tissue has been demonstrated for a number of malignancies. However, current techniques of intraoperative detection of protoporphyrin IX fluorescence in situ do not offer subcellular resolution. Therefore, discrimination of non-specific 5-ALA induced fluorescence remains difficult. Materials and Methods: In this study we have used an orthotopic glioma model to analyze PpIX fluorescence in tumor tissue and normal brain by multiphoton excitation microscopy after intraperitoneal administration of 5-ALA. A DermaInspect in vivo imaging system was used for autofluorescence measurements at 750 nm excitation and detection in the green channel of a standard photomultiplier module. For detection of PpIX fluorescence at different excitation wavelengths a red sensitive version of the photomultiplier and a filter combination of short pass filters and a color glass long pass filter was used restricting the sensitivity in the red channel to a range of 580-700 nm. Results: Multiphoton microscopy allowed a higher structural definition of tumor tissue based on the excitation of 5-ALA induced PpIX fluorescence compared to autofluorescence imaging. The high resolution of multiphoton microscopy allowed discrimination of fluorescence from the cytoplasm of tumor cells and 5-ALA induced PpIX fluorescence of normal brain parenchyma adjacent to tumor. Fluorescence lifetime imaging showed significantly longer fluorescence lifetimes of 5-ALA induced PpIX fluorescence in tumor tissue compared to normal brain. This allowed definition and visualization of the tumor/brain interface based on this parameter alone. Conclusion: Multiphoton microscopy of 5-ALA induced PpIX fluorescence in brain tumor tissue conceptually provides a high resolution diagnostic tool, which in addition to structural information may also provide photochemical/functional information.
UR - http://www.scopus.com/inward/record.url?scp=43049151449&partnerID=8YFLogxK
U2 - 10.1002/lsm.20623
DO - 10.1002/lsm.20623
M3 - Journal articles
C2 - 18412229
AN - SCOPUS:43049151449
SN - 0196-8092
VL - 40
SP - 273
EP - 281
JO - Lasers in Surgery and Medicine
JF - Lasers in Surgery and Medicine
IS - 4
ER -