Proof of concept study on differentiating metastatic brain samples by their originating organ using multimodal autofluorescence spectroscopy.

Brain metastasis are the most frequent central nervous system tumors that usually occur during systemic malignancy. However, they can be diagnosed before the primary cancer site. The number of brain and systemic metastases and the identification of the primary cancer can favor specific treatments and impacts survival estimates. During surgery, intraoperative identification of metastatic tissue may help the surgical strategy and postoperative adjuvant treatment. The study of endogenous fluorescence of the brain tissue has already demonstrated its capability to differentiate metastasis tissue from control and identify specific optical signatures. In this study, based on deep ultraviolet and near-infrared excitation, we investigated for the first time the potentiality of the endogenous fluorescence analysis to characterize brain metastasis origin and to highlight the heterogeneity of molecular components and properties according to the metastasis sub-types, This study gives thus a glimpse of the possibility to find the primary cancer site from the secondary tumor.