RT Journal Article SR Electronic T1 Diagnostic Performance of 18F Fibroblast Activation Protein Inhibitor (FAPI)-42 PET Compared with Multiparametric MRI for Glioma Grading JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 3109 OP 3109 VO 63 IS supplement 2 A1 Jie Lv A1 Tao Lin A1 Peng Hou A1 Shaoyu Liu A1 Xin Wen A1 Hainan Li A1 Xubiao Zhang A1 Yongqin Zeng A1 Lina Zhang A1 Linbo Cai A1 Xinlu Wang YR 2022 UL http://jnm.snmjournals.org/content/63/supplement_2/3109.abstract AB 3109 Introduction: Both diffuse-weighted MR imaging (DWI) and 18F-fibroblast activation protein inhibitor (FAPI)-42 provide grading information in cerebral gliomas. This study aimed to compare the diagnostic value of 18F–FAPI-42 PET and DWI for tumor grading in patients with gliomas. Methods: Twenty-two patients (9 newly diagnosed and 13 recurrence patients) with pathologically confirmed gliomas [7 low-grade gliomas (LGGs), and 15 high-grade gliomas (HGGs)] were investigated with 18F–FAPI PET and DWI study. The minimum apparent diffusion coefficient (ADCmin) in DWI, tumor-to-brain ratios of mean and maximum standard uptake value (TBRmean, TBRmax) in18F- FAPI-42 PET were recorded. The nomogram was constructed using multivariate logistic regression combined with ADCmin, TBRmax, and TBRmean. The sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and diagnostic accuracies of ADCmin, TBRmax, TBRmean, and nomogram for differentiating LGGs from HGGs were compared. The diagnostic accuracies were evaluated by receiver operating characteristic (ROC) analyses and the value of area under the curve (AUC).Results: Twenty-two patients (median age,39.5 years; interquartile range, 32–50 years) were included, of which 73% (16 of 22) underwent open resection. There were significant differences in all parameters, including ADCmin, TBRmax, TBRmean between LGGs and HGGs (P=0.013 vs. P=0.020 vs. P=0.014, respectively). The specificities of ADCmin, TBRmean, and nomogram were similar(all 85.7%) and higher than that of TBRmax (71.4%). The sensitivities of ADCmin, TBRmax, and nomogram were similar (all 93.3%) and higher than that of TBRmean (73.3%). The diagnostic accuracies of 18F–FAPI-42 and DWI to discriminate LGGs from HGGs were similar with the highest AUC values for TBRmax and TBRmean of 18F–FAPI PET [85.7(95% CI: 68.8,100) vs. 82.4(95% CI: 64.6,100), respectively] and for ADCmin of DWI [87.6 (95% CI: 65.1,100)]. The nomogram model with an AUC of 90.5% (95% CI: 73.3,100) could further improve diagnostic accuracy. Conclusions: Both 18F–FAPI-42 PET and DWI discriminated LGGs from HGGs with similar diagnostic performance. The nomogram model based on 18F-FAPI-42 PET and DWI might be clinically useful in non-invasive grade classification for glioma patients.