RT Journal Article SR Electronic T1 Correlation between metabolic parameters on dual-time-point FDG PET and tumor immune microenvironment marker in non-small cell lung cancer JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 86 OP 86 VO 60 IS supplement 1 A1 Jianyuan Zhou A1 Sijuan Zou A1 Dong Kuang A1 Siyuan Cheng A1 Dan Li A1 Lixing Chen A1 Xiaohua Zhu YR 2019 UL http://jnm.snmjournals.org/content/60/supplement_1/86.abstract AB 86Purpose: Tumor immune microenvironment (TIME) is associated with response to immunotherapy and outcome of patient with non-small cell lung cancer (NSCLC). Dual-time-point (DTP) 18F-FDG PET reflects the dynamics of glucose metabolism. The objective of this study was to investigate the correlation of metabolic parameters (MP) on DTP 18F-FDG PET with tumor expression of immune checkpoints and CD8 (+) tumor-infiltrating lymphocytes (TILs) in NSCLC patients. Methods: Seventy-five patients with NSCLC confirmed by surgical pathology who underwent preoperative DTP 18F-FDG PET/CT scans were enrolled in the study. Tumor specimens were analyzed by immunohistochemistry (IHC) for PD-L1, PD-1 expression and CD8 (+) TILs. DTP FDG-PET images were analyzed to define metabolic parameters, including early SUVmax and SUVmean (eSUVmax, eSUVmean), delayed SUVmax and SUVmean (dSUVmax, dSUVmean), early and delayed metabolic tumor volume (eMTV, dMTV), early and delayed total lesion glycolysis (eTLG, dTLG), change in SUVmax, SUVmean, MTV and TLG (ΔSUVmax, ΔSUVmean, ΔMTV and ΔTLG). Metabolic parameters were correlated with tissue markers expression, using a Mann-Whitney U, Spearman's correlation coefficient test and multivariate analyses. The cut-off value of dSUVmax to predict tumor PD-L1 expression was determined by receiver operating characteristic curve analyses. Results: Seventy-five patients with NSCLC (56 with adenocarcinoma and 19 with squamous cell carcinoma) were analyzed. We found a statistically significant correlation between eSUVmax, eSUVmean, dSUVmax, dSUVmean, ΔSUVmax, ΔSUVmean and ΔTLG with the expression of PD-L1 (P= 0.004, 0.003, 0.001, 0.001, 0.001, 0.001, 0.012) and CD8 (+) TILs (r=0.239; p =0.042). Multivariate analysis revealed that dSUVmax (P = 0.012) was an independent predictor of PD-L1 expression in pretreated NSCLC. With AUC value of 0.740, dSUVmax was the preferred metabolic parameter for assessment of PD-L1 positive expression. Meanwhile, the expression of PD-1 was associated with ΔTLG, eSUVmax, eSUVmean, dSUVmax and dSUVmean (P = 0.037, 0.036, 0.022, 0.027, 0.023, respectively). Conclusions: Hypermetabolic changes on DTP 18F-FDG PET showed good correlation with tumor positive expression of PD-L1 and high density of CD8 TILs and PD-1 in tumor immune microenvironment. Furthermore, dSUVmax was an independent predictor of PD-L1 expression in pretreated NSCLC.