212 Intra-Operative Near Real-Time Detection of Tumor Infiltration in IDH-Mutant Gliomas Using Desorption Electrospray Ionization-Mass Spectrometry (DESI-MS). (April 2023)

• Record Type: Journal Article
• Authors: Garcia, Diogo P.; Brown, Hannah; Chen, Rong; Jentoft, Mark E.; Middlebrooks, Erik; Chaichana, Kaisorn L.; Cooks, Graham; Quinones-Hinojosa, Alfredo
• Is Part Of: Neurosurgery. Volume 69(2023)Supplement 1
• Page Start: 37
• Page End: 38
• Publication Date: 2023-04
• Subjects: Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1227/neu.0000000000002375_212
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract : INTRODUCTION: Surgery remains the mainstay of treatment in gliomas. However, distinction between tumor infiltrated and non-infiltrated tissues remains a challenge with current surgical adjuncts, particularly at the margin. Isocitrate dehydrogenase (IDH) mutation is unique to IDH mutant glioma cells and can be used as a potential surrogate for tumor infiltration. METHODS: We conducted a prospective study, using intraoperative DESI-MS analysis on freshly obtained tissue samples to evaluate the presence of 2-hydroxyglutarate (2HG) by relative quantitation in comparison with an internal control (glutamate), with subsequent review of each smear by board-certified neuropathologist. RESULTS: Earlier iterations of our DESI-MS allowed for genotyping of the tumor with a total of 247 biopsies from a 49-patient study yielding sensitivity, specificity, and accuracy values of 89, 100, and 94% for core biopsies (n = 71). Subsequent improvement of DESI-MS, from absolute quantitation to relative measurement in comparison to glutamate (GLU) allowed for detection of IDH-mut infiltration at the margin. We have collected 183 biopsies (116 core and 67 margin) from 23 patients. Preliminary results of IDH mutation assessments of core biopsies indicate 93% sensitivity, 100% specificity, and 98% accuracy and margin biopsies indicate 88% sensitivity, 100% specificity, 94% accuracy, with turnover times averaging 3 minutes per patient. Tumor infiltration at the margin after surgical resection was detected in 88% of margin biopsies from IDH mutant tumors (30 of 34 biopsies). CONCLUSIONS: We present a novel system to allow intraoperative evaluation of tumor infiltration at the margin in IDH-mutant gliomas. Our method and its validation identified tumor infiltration beyond the surgical margins and serves as a foundation for future uses employing DESI-MS to allow for molecularly guided surgery in IDH-mut gliomas.