NIMG-41. NON-INVASIVE DETECTION OF IDH-WILDTYPE GENOTYPE IN GLIOMAS USING DYNAMIC 18F-FET-PET. (5th November 2018)

• Record Type: Journal Article
• Authors: Suchorska, Bogdana; Vettermann, Franziska; Unterrainer, Marcus; Nelwan, Debie; Forbrig, Robert; Dorostkar, Mario; Kreth, Friedrich-Wilhelm; Bartenstein, Peter; Tonn, Jörg-Christian; Lisa Albert, Nathalie
• Is Part Of: Neuro-oncology. Volume 20(2018)Supplement 6
• Page Start: vi185
• Page End: vi185
• Publication Date: 2018-11-05
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noy148.767
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: PURPOSE: Gliomas with an isocitarate dehydrogenase (IDH) wildtype (wt) status have a dismal prognosis comparable to glioblastoma as reflected by the 2016 WHO classification of gliomas. In order to ensure timely adjustment of surgical and adjuvant treatment strategy, demand for non-invasive imaging methods is high. 18F-FET-PET has been shown to be an important diagnostic tool for glioma management, delivering information on prognosis and therapy response. Aim of this study was to evaluate dynamic 18F-FET-PET for non-invasive evaluation of IDH wt status prior to therapy. METHODS: 341 patients with WHO II-IV glioma were included, in whom IDH mutation status, MRI and dynamic 18F-FET-PET scans were available at initial diagnosis. We assessed sensitivity, specificity, accuracy and positive as well as negative predictive values for maximal tumour-to-background ratio (TBRmax) and minimal time-to-peak (TTPmin) for prediction of IDH wt status in the entire group as well as in the subgroup of non-contrast enhancing (non-CE) tumors. RESULTS: Molecular analyses revealed 178 IDH mutant and 163 IDH wt tumors; 270 patients were classified as FET-positive, in these cases, TTP analysis was performed. Median TBRmax in IDH wt gliomas was 3.1 compared to 2.8 in IDH mutant tumors (p=<0.01). ROC-analyses revealed no reliable cut-off using TBRmax, due to high overlap of the two groups. In contrast, searching for a threshold in dynamic analysis, TTPmin 12.5 minutes identified IDH wt gliomas with a high positive predictive value (accuracy: 79%, PPV: 87%; NPV: 72%). In the subgroup of non-CE glioma in MRI (n=161), IDH wt genotype was identified with an accuracy of 84% (PPV: 83%, NPV: 84 %). CONCLUSION: Dynamic 18F-FET PET using TTPmin analysis provides a reliable non-invasive method for detection of IDH wt genotype especially in tumors without CE on MRI and can help to identify high-risk patients prior to treatment initiation.