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

Abstract

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. 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. 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. 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.