gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Methodology for fiber-optic Raman mapping and FTIR imaging of metastases in mouse brains

Meeting Abstract

  • M. Kirsch - Klinik für Neurochirurgie, Carl Gustav Carus Universitätsklinikum Dresden
  • S. Sobottka - Klinik für Neurochirurgie, Carl Gustav Carus Universitätsklinikum Dresden
  • C. Beleites - Institut für Analytische Chemie, Technische Universität Dresden
  • R. Salzer - Institut für Analytische Chemie, Technische Universität Dresden
  • G. Schackert - Klinik für Neurochirurgie, Carl Gustav Carus Universitätsklinikum Dresden
  • C. Krafft - Institut für Analytische Chemie, Technische Universität Dresden

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMI.06-09

DOI: 10.3205/09dgnc210, URN: urn:nbn:de:0183-09dgnc2109

Published: May 20, 2009

© 2009 Kirsch et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Optical spectroscopic imaging has the potential to be introduced into the surgical microscope. These methods, namely Raman spectroscopy and Fourier-transformed infrared spectroscopy (FTIR), analyse the complete biochemical information at any given pixel within the visual field. The objectives of this study were to 1) evaluate preclinical models, namely murine brain slices containing experimental tumors, 2) optimize the preparation of pristine brain tissue to obtain reference information, to 3) optimize the conditions for introducing a fiber-optic probe to acquire Raman maps, and 4) to transfer results obtained from human brain tumors to an animal model.

Methods: Disseminated brain metastases of malignant melanomas were induced by injecting tumor cells into the carotid artery of mice. The procedure mimicked hematogenous tumor spread in one brain hemisphere while the other hemisphere remained tumor free. Three series of sections were prepared consecutively from whole mouse brains: dried, thin sections for FTIR imaging, hematoxylin and eosin-stained thin sections for histopathological assessment, and pristine, 2-mm thick sections for Raman mapping. FTIR images were recorded using a spectrometer with a multi-channel detector. Raman maps were collected serially using a spectrometer coupled to a fiber-optic probe. The FTIR images and the Raman maps were segmented by cluster analysis.

Results: The color-coded cluster memberships coincided well with the morphologyof mouse brains in stained tissue sections. More details in less time were resolved in FTIR images with a nominal resolution of 25 μm than in Raman maps collected with a laser focus 60 μm in diameter. The spectral contributions of melanin in tumor cells were resonance enhanced in Raman spectra on excitation at 785 nm which enabled their sensitive detection in Raman maps.

Conclusions: Possible reasons why metastatic cells of malignant melanomas were not identified in FTIR images are discussed.