Significance: Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. With a worldwide incidence rate of 2 to 3 per 100,000 people, it accounts for more than 60% of all brain cancers; currently, its 5-year survival rate is <5 % . GBM treatment relies mainly on surgical resection. In this framework, multimodal optical spectroscopy could provide a fast and label-free tool for improving tumor detection and guiding the removal of diseased tissues. Aim: Discriminating healthy brain from GBM tissues in an animal model through the combination of Raman and reflectance spectroscopies. Approach: EGFP-GL261 cells were injected into the brains of eight laboratory mice for inducing murine GBM in these animals. A multimodal optical fiber probe combining fluorescence, Raman, and reflectance spectroscopy was used to localize in vivo healthy and tumor brain areas and to collect their spectral information. Results: Tumor areas were localized through the detection of EGFP fluorescence emission. Then, Raman and reflectance spectra were collected from healthy and tumor tissues, and later analyzed through principal component analysis and linear discriminant analysis in order to develop a classification algorithm. Raman and reflectance spectra resulted in 92% and 93% classification accuracy, respectively. Combining together these techniques allowed improving the discrimination between healthy and tumor tissues up to 97%. Conclusions: These preliminary results demonstrate the potential of multimodal fiber-probe spectroscopy for in vivo label-free detection and delineation of brain tumors, and thus represent an additional, encouraging step toward clinical translation and deployment of fiber-probe spectroscopy.

中文翻译：

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拉曼和反射纤维探针光谱法在体内检测鼠胶质母细胞瘤

启示：胶质母细胞瘤（GBM）是成人中最常见和侵袭性的恶性脑肿瘤。在全世界，每10万人中有2-3例发病率，它占所有脑癌的60％以上；目前，其5年生存率低于5％。GBM的治疗主要依靠手术切除。在这种框架下，多峰光谱技术可以提供一种快速且无标签的工具，以改善肿瘤的检测并指导病变组织的去除。目的：通过拉曼光谱和反射光谱法的组合，从动物模型中的GBM组织中区分出健康的大脑。方法：将EGFP-GL261细胞注射到八只实验小鼠的大脑中，以诱导这些动物的鼠GBM。一种多模态光纤探头，结合了荧光，拉曼，反射光谱法用于定位体内健康和肿瘤脑区域并收集其光谱信息。结果：通过检测EGFP荧光发射来定位肿瘤区域。然后，从健康和肿瘤组织中收集拉曼光谱和反射光谱，然后通过主成分分析和线性判别分析进行分析，以开发分类算法。拉曼光谱和反射光谱分别导致92％和93％的分类精度。将这些技术结合在一起，可以将健康组织与肿瘤组织之间的区分度提高多达97％。结论：这些初步结果证明了多峰光纤探针光谱技术在体内无标记物检测和描述脑肿瘤方面的潜力，因此代表了另外一种