Abstract
PURPOSE: This study aimed to investigate the uptake characteristics of (18)F-fluoromisonidazole (FMISO), in mutant-type isocitrate dehydrogenase (IDH-mutant, grade 3 and 4) and wild-type IDH (IDH-wildtype, grade 4) 2021 WHO classification adult-type diffuse gliomas. MATERIALS AND METHODS: Patients with grade 3 and 4 adult-type diffuse gliomas (n = 35) were included in this prospective study. After registering (18)F-FMISO PET and MR images, standardized uptake value (SUV) and apparent diffusion coefficient (ADC) were evaluated in hyperintense areas on fluid-attenuated inversion recovery (FLAIR) imaging (HIA), and in contrast-enhanced tumors (CET) by manually placing 3D volumes of interest. Relative SUV(max) (rSUV(max)) and SUV(mean) (rSUV(mean)), 10th percentile of ADC (ADC(10pct)), mean ADC (ADC(mean)) were measured in HIA and CET, respectively. RESULTS: rSUV(mean) in HIA and rSUV(mean) in CET were significantly higher in IDH-wildtype than in IDH-mutant (P = 0.0496 and 0.03, respectively). The combination of FMISO rSUV(mean) in HIA and ADC(10pct) in CET, that of rSUV(max) and ADC(10pct) in CET, that of rSUV(mean) in HIA and ADC(mean) in CET, were able to differentiate IDH-mutant from IDH-wildtype (AUC 0.80). When confined to astrocytic tumors except for oligodendroglioma, rSUV(max), rSUV(mean) in HIA and rSUV(mean) in CET were higher for IDH-wildtype than for IDH-mutant, but not significantly (P = 0.23, 0.13 and 0.14, respectively). The combination of FMISO rSUV(mean) in HIA and ADC(10pct) in CET was able to differentiate IDH-mutant (AUC 0.81). CONCLUSION: PET using (18)F-FMISO and ADC might provide a valuable tool for differentiating between IDH mutation status of 2021 WHO classification grade 3 and 4 adult-type diffuse gliomas.