NIMG-84. PREDICTION OF RESPONSE TO LOMUSTINE-BASED CHEMOTHERAPY IN GLIOMA PATIENTS AT RECURRENCE USING MRI AND FET PET. (14th November 2022)

• Record Type: Journal Article
• Authors: Wollring, Michael M; Werner, Jan-Michael; Bauer, Elena; Tscherpel, Caroline; Lohmann, Philipp; Stoffels, Gabriele; Kabbasch, Christoph; Goldbrunner, Roland; Fink, Gereon; Langen, Karl-Josef; Galldiks, Norbert
• Is Part Of: Neuro-oncology. Volume 24(2022)Supplement 7
• Page Start: vii184
• Page End: vii185
• Publication Date: 2022-11-14
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noac209.702
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: BACKGROUND: This study evaluates O-(2-[ 18 F]fluoroethyl)-L-tyrosine (FET) PET and contrast-enhanced MRI for early response assessment in glioma patients at recurrence treated with lomustine-based chemotherapy. METHODS: Thirty-six adult patients with WHO CNS Grade 3 or 4 gliomas (glioblastoma, 69%) at recurrence (median number of recurrences, 1; range, 1-3) were retrospectively identified. Besides MRI, serial FET PET scans were performed at baseline and early after chemotherapy initiation (median number of cycles, 2). Mean and maximum tumor-to-brain ratios (TBR), metabolic tumor volumes (MTV), the occurrence of new distant hotspots with a mean TBR > 1.6 at follow-up, and the dynamic parameter time-to-peak were derived from all FET PET scans. Threshold values of PET parameters were defined using receiver operating characteristic analyses to predict progression-free survival (PFS) of ≥ 6 months and overall survival (OS) of ≥ 12 months. MRI response assessment was based on RANO criteria. Using univariate and multivariate survival estimates, the predictive value of FET PET parameters and RANO criteria were subsequently evaluated. RESULTS: After treatment initiation, the median follow-up time was 11 months (range, 3-71 months). Relative changes of the mean and maximum TBR, MTV, and RANO criteria predicted a significantly longer PFS (all P< 0.003) and OS (all P< 0.05). At follow-up, the occurrence of new distant hotspots (n≥ 1) predicted a worse outcome, with significantly shorter PFS (P=0.001) and OS (P< 0.001). Changes of the dynamic parameter time-to-peak did not predict a significantly longer PFS or OS (P > 0.05). Multivariate survival analyses revealed that new distant hotspots at follow-up had the highest significance level to predict non-response (P< 0.001; hazard ratio, 8.578), independent of RANO criteria, IDH mutation status, and O 6 -methylguanine-DNA-methyltransferase promoter methylation. CONCLUSIONS: FET PET seems to be a powerful tool for identifying responders to lomustine-based chemotherapy early after treatment initiation.