Stereotactic needle biopsy is a time-consuming and invasive procedure that often cannot accurately distinguish recurrent tumors from treatment effect in gliomas. We report an intraoperative multispectral fluorescence lifetime imaging (FLIm) system coupled with a custom-made fiber optic probe integrated with the stealth biopsy needle as an optical biopsy tool. FLIm parameters collected from 3 suspected recurrent glioma patients changed over the biopsy trajectory as the needle passed different brain areas. An SVM classifier validated using a leave-one-patient-out validation scheme could identify the lesions from the normal surrounding tissue with sensitivity=0.99, specificity=0.91, and accuracy=0.95.
Accurate detection of brain tumor boundaries is crucial for successful tumor removal and better patient outcomes. A novel method using label-free Fluorescence Lifetime Imaging (iFLIm) is presented in this study. The approach involved developing an optimized classification model based on tumor enhancement status, utilizing multispectral FLIm. The method was evaluated on 52 patients with adult-type diffuse glioma, demonstrating promising results with 87% sensitivity, 92% specificity, and an AUC of 0.90. This FLIm-based model has the potential to offer a non-invasive and real-time technique to assist neurosurgeons in accurately identifying tumor infiltrates, potentially improving tumor resection and patient outcomes.
In-situ identification of glioma subtype can enable modifications of clinical and surgical strategies. Particularly, astrocytoma benefit from more aggressive resection than oligodendroglioma, which have a more favorable response to post-surgical chemotherapy. Preoperative MRI and intraoperative histology cannot accurately determine glioma subtype. There is a need for real-time identification of adult-type diffuse glioma subtypes to aid the neurosurgeon’s decision-making during resection surgery. Fluorescence lifetime imaging (FLIm) where tissue autofluorescence can be used as an indicator to distinguish among brain tumor tissue types in real-time could aid this process. Here, we report the use of label-free FLIm in distinguishing IDH-mutant glioma subtypes (astrocytoma and oligodendroglioma). The FLIm system (excitation: 355 nm; emission bands: 390/40 nm, 470/28 nm, 542/50 nm) was used to scan brain tissue from the resection margins of glioma patients during tumor resection. Fluorescence lifetimes were extracted and analyzed by constrained least-squares deconvolution with the Laguerre expansion method. FLIm data was validated with histopathology of collected biopsies. Current results show that FLIm provides optical contrast between tumor and healthy white matter, and between IDH-mutant astrocytoma (N=7 patients) and oligodendroglioma (N=5 patients). Tumors showed shorter lifetime values (470-nm: 3.6±0.6ns; 542-nm: 3.3±0.7ns) than healthy white matter (470-nm: 4.6±0.4ns; 542-nm: 4.3±0.5ns, p<0.01). Oligodendroglioma had shorter lifetimes in the 470-nm (3.3±0.1ns) and 542-nm (2.8±0.2ns) channels, which are associated with NAD(P)H and FAD fluorescence respectively, when compared with IDH-mutant astrocytoma (470-nm: 4.1±0.1ns; 542-nm: 3.9±0.2ns, p<0.01). Together, these results demonstrate the feasibility of using FLIm as an intraoperative tool in glioma diagnosis.
The standard treatment for infiltrative gliomas is surgery to remove as much tumor tissue as possible without compromising neurological functions. Thus, real-time identification of infiltrative tumor tissue is necessary. Here a fluorescence lifetime imaging (FLIm) was used to distinguish between healthy brain and areas with different degrees of tumor cellularity as defined by histopathology. We conducted FLIm measurements and collected microbiopsies from tumor resection margins to identify the FLIm characteristics of tumor edges in cortex and white matter of low- and high-grade gliomas. Results from a 13-patient cohort indicate that FLIm identifies infiltrations of up to moderate tumor cellularity.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.