Integrating Confocal Laser Endomicroscopy and Label-Free Nanoplasmonic Biosensing for Intraoperative Glioblastoma Tissue Discrimination - A hypothesis generating study.

OBJECTIVE: Accurate intraoperative discrimination between glioblastoma and infiltrated peritumoral brain tissue remains challenging and limits maximal safe resection. Label-free nanoplasmonic biosensing provides quantitative tissue characterization based on refractive index (RI), whereas confocal laser endomicroscopy (CLE) enables high-resolution morphological assessment. This study explored the integration of both technologies for glioblastoma tissue discrimination. METHODS: In this prospective exploratory study, 45 paired tumor and peritumoral samples were obtained intraoperatively from patients with histologically confirmed WHO grade 4 glioblastoma. RI measurements were acquired using a label-free nanoplasmonic biosensor. In a subgroup of 14 paired samples, ex vivo CLE analysis was performed on the same specimens. Histopathology served as the reference standard. RI differences were assessed using the Wilcoxon signed-rank test, and ROC analysis evaluated biosensor performance. An exploratory analysis assessed the complementary behavior of both modalities. RESULTS: Tumor tissue showed significantly higher RI values than peritumoral tissue (median 1.350 vs 1.345; p = 0.004). The biosensor achieved an ROC area of 0.71. Using an RI threshold of 1.342, sensitivity, specificity, and accuracy were 88%, 41%, and 68%, respectively. In the CLE subgroup, classification was concordant with histopathology in 86% of paired samples. Exploratory analysis suggested complementary performance, with CLE showing greater concordance for negative discrimination and the biosensor for positive discrimination. CONCLUSIONS: Integrating label-free nanoplasmonic biosensing and CLE may provide complementary quantitative and morphological information for intraoperative glioblastoma margin assessment. These preliminary findings support further investigation of multimodal intraoperative strategies.