Discriminating healthy from tumor and necrosis tissue in rat brain tissue samples by Raman spectral imaging

Abstract

The purpose of this study was to investigate molecular changes associated with glioma tissues by Raman microspectroscopy in order to develop its use in clinical practice. Spectroscopic markers obtained from C6 glioma tissues were compared to conventional histological and histochemical techniques. Cholesterol and phospholipid contents were highest in corpus callosum and decreased gradually towards the cortex surface as well as in the tumor. Two different necrotic areas have been identified: a fully necrotic zone characterized by the presence of plasma proteins and a peri-necrotic area with a high lipid content. This result was confirmed by Nile Red staining. Additionally, one structure was detected in the periphery of the tumor. Invisible with histopathological hematoxylin and eosin staining, it was revealed by immunohistochemical Ki-67 and MT1-MMP staining used to visualize the proliferative and invasive activities of glioma, respectively. Hierarchical cluster analysis on the only cluster averaged spectra showed a clear distinction between normal, tumoral, necrotic and edematous tissues. Raman microspectroscopy can discriminate between healthy and tumoral brain tissue and yield spectroscopic markers associated with the proliferative and invasive properties of glioblastoma. Development of in vivo Raman spectroscopy could thus accurately define tumor margins, identify tumor remnants, and help in the development of novel therapies for glioblastoma.

Fourier Transform Infrared Microspectroscopy for Cancer Diagnostic of C6 Glioma on Animal Model

“…These clusters were associated to the proliferative and invasive character of glioma tumors. In fact, in our previous study, immunohistochemical Ki-67 and MT1-MMP staining were used to visualize the proliferative and invasive activities of glioma and were clearly correlated with the cluster that encoded the surrounding tumor area (Amharref et al, 2007). Histopathological staining confirms this FTIR result ( fig.…”

Raman spectroscopy as a promising noninvasive tool in brain cancer detection

“…15 These early studies provided the impetus for further research on human biopsy samples which are described in the next section. Animal models were also used to study normal and necrotic brain tissues by Amharref et al 17 Raman microspectroscopy of 15-m-thick brain sections followed by pseudo color maps were compared with histopathology and biomarkers for Ki-67 and MT1-MMP.…”

Review of the potential of optical technologies for cancer diagnosis in neurosurgery: a step toward intraoperative neurophotonics

“…The rat glioma model has similar morphology to glioblastoma multiforme. 49 This study showed that Raman spectral features could be used to differentiate tumor, edema, necrotic, and healthy brain tissue. Specific spectral bands associated with proteins and lipids are the main Raman spectral features used for differentiation.…”