gms | German Medical Science

Joint-Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN) and the Scandinavian Neuropathological Society (SNS)

Deutsche Gesellschaft für Neuropathologie und Neuroanatomie

22.09.-24.09.2016, Hamburg

Multiphoton microscopy: a new technique for label-free imaging of brain tumors

Meeting Abstract

  • presenting/speaker Roberta Galli - Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Dresden, Germany
  • Ortrud Uckermann - Universitätsklinikum Carl Gustav Carus, Neurochirurgie, Dresden, Germany
  • Matthias Meinhardt - Universitätsklinikum Carl Gustav Carus, Neuropathologie, Dresden, Germany
  • Gabriele Schackert - Universitätsklinikum Carl Gustav Carus, Neurochirurgie, Dresden, Germany
  • Edmund Koch - Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Dresden, Germany
  • Matthias Kirsch - Universitätsklinikum Carl Gustav Carus, Neurochirurgie, Dresden, Germany
  • Gerald Steiner - Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Dresden, Germany

Deutsche Gesellschaft für Neuropathologie und Neuroanatomie. Scandinavian Neuropathological Society. Joint-Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN) and the Scandinavian Neuropathological Society (SNS). Hamburg, 22.-24.09.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. Doc16dgnnNO4

doi: 10.3205/16dgnn02, urn:nbn:de:0183-16dgnn020

Veröffentlicht: 14. September 2016

© 2016 Galli et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Question: Histopathological evaluation of suspicious tissue biopsies is the gold standard for intra-operative tumor margin detection. However, this method is of retrospective nature. On the other hand, neurosurgery directly targets the tumor and opens the possibility of in situ diagnosis with non-invasive optical analyses. Therefore, label-free multiphoton microscopy was assessed for visualization of tissue structures and recognition of neoplastic tissue as well as its correlate with histopathology.

Methods: Using multiphoton microscopy optical contrast can be generated without further labels: Coherent anti-Stokes Raman scattering (CARS) is used for imaging of lipids. Endogenous two-photon fluorescence (TPF) is correlated with inflammatory cells, subcellular organelles or elastin. Second harmonic generation (SHG) allows visualization of fibrillar collagen. By using a combination of CARS, TPEF and SHG microscopy, we analyzed cryosections and fresh tissue biopsies from 60 patients (GBM, astrocytoma, oligodendroglioma, meningioma, brain metastases of melanoma, mamma, lung, colon, kidney carcinoma), as well as experimental orthotopic tumors in mouse models.

Results: GBM was found to express fibrillar collagen in the extracellular matrix and in the altered blood vessel network, which was imaged by SHG. Diffuse TPEF was assigned to areas of necrosis. Cells displaying strong TPEF signal were observed in the normal tissue. Axonal bundles were identified by CARS, while tumors were characterized by decreased CARS signal intensity, reflecting lower tumor lipid content. CARS indicated that lipid droplets are characteristic of necrosis. Additionally, the ability of CARS microscopy to identify infiltrating glioblastoma cells was proven on fresh tissue specimens and in vivo by imaging of experimental brain tumors in mice.

Conclusions: We demonstrated the ability of label-free multiphoton to visualize tumor structures and discern between normal and neoplastic tissue of different tumor types, on cryosections as well as on fresh samples and in vivo. This technology has the potential to be used in adjunct to frozen section histopathology since it is label and marker free, non-destructive, image-based and, therefore, amendable to pathological diagnosis in situ.