title: Fourier transform infrared spectromicroscopy and hierarchical cluster analysis of human meningiomas.
abstract: Limitations of conventional light microscopy in pathological diagnosis of brain tumors include subjective bias in interpretation and discordance of nomenclature. A study using mid-infrared (IR) spectromicroscopy was undertaken to determine whether meningiomas, a group of brain tumors prone to recurrence, could be identified by the unique spectral 'fingerprints' of their chemical composition. Paired, thin (5-microm) cryosections of snap-frozen human meningioma tumor samples removed at elective surgery were mounted on glass (hematoxylin and eosin-stained tissue section) and infrared (unstained tissue section) reflectance slides, respectively. Concordance of the tumor-bearing areas identified in the stained section by a pathologist with the unstained IR tissue section was ensured using a novel digital grid and tumor-mapping system developed in our laboratory. Compared with the normal control, tumor samples from four meningioma patients revealed a marked decrease in bands associated with unsaturated fatty acids, particularly in the bands at 3010, 2920, 2850, and 1735 cm(-1). Spectral datasets were subjected to hierarchical cluster analyses (HCA) using Ward's algorithm for comparison and grouping of similar data groups, and were converted into color-coded digital maps for matching spectra with their respective clusters. False color images of 5 and 6 clusters obtained by HCA identified dominant clusters corresponding to tumor tissue. Corroboration of these findings in a larger number of meningiomas may allow for more precise identification of these and other types of brain tumors.
authors.affiliation: Saskatoon Cancer Centre, Cancer Research Unit, Saskatchewan Cancer Agency, University of Saskatchewan, 20 Campus Drive, Saskatoon S7N 4H4, Canada. kaiser@scf.sk.ca
authors.forename: Kaiser
authors.initials: K
authors.lastname: Ali
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Lu
authors.forename: Colleen
authors.initials: C
authors.lastname: Christensen
authors.forename: Tim
authors.initials: T
authors.lastname: May
authors.forename: Craig
authors.initials: C
authors.lastname: Hyett
authors.forename: Robert
authors.initials: R
authors.lastname: Griebel
authors.forename: Daryl
authors.initials: D
authors.lastname: Fourney
authors.forename: Kotoo
authors.initials: K
authors.lastname: Meguro
authors.forename: Lothar
authors.initials: L
authors.lastname: Resch
authors.forename: Rajendra K
authors.initials: RK
authors.lastname: Sharma
mesh_terms: D000368:Aged; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008579:Meningioma / Q000175:diagnosis* / Q000473:pathology*; D008875:Middle Aged; D017550:Spectroscopy, Fourier Transform Infrared