PURPOSE To explore the relationship between [18F]fluorodeoxyglucose (18F-FDG uptake) and PD-L1 expression and determine the usefulness of 18F-FDG PET/CT for evaluating the PD-L1 status in tumour cells (TCs) and tumour-infiltrating immune cells (TIICs) in patients with nasopharyngeal carcinoma (NPC). METHODS We retrospectively evaluated the records of 84 eligible patients who received an initial histopathological diagnosis of NPC between December 2016 and March 2019. All tissue specimens and PET/CT images were collected prior to treatment. High PD-L1 expression in TCs and TIICs was defined as ≥ 50% of stained cells. RESULTS There was a significant difference in 18F-FDG uptake according to the PD-L1 status in TCs and TIICs. Univariate analysis showed that PD-L1 expression in TCs was associated with tumour maximum standardized uptake value (SUVmax) (P < 0.001), primary tumour total lesion glycolysis (TLG; P < 0.001), and T stage (P = 0.044), but not with plasma Epstein-Barr virus (EBV) load (P = 0.816), whereas PD-L1 expression in TIICs was related to SUVmax (P = 0.011), TLG (P = 0.001), T stage (P = 0.028), and plasma EBV load (P = 0.003). In multivariate logistic regression, PD-L1 expression in TCs was positively associated with SUVmax (P = 0.003) and TLG (P = 0.001), and in TIICs, negatively associated with SUVmax (P = 0.038) and plasma EBV load (P = 0.025). CONCLUSIONS 18F-FDG uptake in NPC lesions was positively correlated with PD-L1 expression in TCs and negatively correlated with PD-L1 expression in TIICs. Thus, 18F-FDG PET/CT may be useful for evaluating the PD-L1 status in patients with NPC.

中文翻译：

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[18F]氟脱氧葡萄糖PET / CT在评估鼻咽癌PD-L1状态中的有用性。

目的探讨[18F]氟脱氧葡萄糖（摄取18F-FDG）与PD-L1表达之间的关系，并确定18F-FDG PET / CT对评估肿瘤细胞（TCs）中PD-L1状态和肿瘤浸润免疫的有效性鼻咽癌（NPC）患者的细胞（TIIC）。方法我们回顾性评估了2016年12月至2019年3月之间接受NPC初始组织病理学诊断的84例合格患者的记录。在治疗前收集了所有组织标本和PET / CT图像。TC和TIIC中高PD-L1表达被定义为染色细胞的≥50％。结果根据TC和TIIC中PD-L1的状态，18F-FDG摄取存在显着差异。单因素分析显示TCs中PD-L1的表达与肿瘤最大标准化摄取值（SUVmax）（P <0.001），原发肿瘤总病变糖酵解（TLG; P <0.001）和T期（P = 0.044）相关，但与血浆爱泼斯坦-巴尔病毒（EBV）负载无关（P = 0.816），而TIICs中PD-L1的表达与SUVmax（P = 0.011），TLG（P = 0.001），T期（P = 0.028）和血浆EBV负荷（P = 0.003）。在多元逻辑回归中，TCs中的PD-L1表达与SUVmax（P = 0.003）和TLG（P = 0.001）正相关，而TIICs与SUVmax（P = 0.038）和血浆EBV负荷负相关）。结论NPC病变中18F-FDG的摄取与TCs中PD-L1表达呈正相关，与TIICs中PD-L1表达呈负相关。从而，