Clin Nucl Med. 2021 Dec 1;46(12):952-957. doi: 10.1097/RLU.0000000000003914.
The aim of this study was to evaluate the distribution of hypoxia using 18F-EF5 as a hypoxia tracer in cervical cancer patients with PET/MRI. We investigated the association between this 18F-EF5-PET tracer and the immunohistochemical expression of endogenous hypoxia markers: HIF1α, CAIX, and GLUT1.
Nine patients with biopsy-proven primary squamous cell cervix carcinoma (FIGO 2018 radiological stages IB1-IIIC2r) were imaged with dual tracers 18F-EF5 and 18F-FDG using PET/MRI (Int J Gynaecol Obstet. 2019;145:129-135). 18F-EF5 images were analyzed by calculating the tumor-to-muscle ratio to determine the hypoxic tissue (T/M ratio >1.5) and further hypoxic subvolume (HSV) and percentage hypoxic area. These 18F-EF5 hypoxic parameters were correlated with the size and localization of tumors in 18F-FDG PET/MRI and the results of hypoxia immunohistochemistry.
All primary tumors were clearly 18F-FDG and 18F-EF5 PET positive and heterogeneously hypoxic with multiple 18F-EF5-avid areas in locally advanced cancer and single areas in clinically stage I tumors. The location of hypoxia was detected mainly in the periphery of tumor. Hypoxia parameters 18F-EF5 max T/M ratio and HSV in primary tumors correlated independently with the advanced stage (P = 0.036 and P = 0.040, respectively), and HSV correlated with the tumor size (P = 0.027). The location of hypoxia in 18F-EF5 imaging was confirmed with a higher hypoxic marker expression HIF1α and CAIX in tumor fresh biopsies.
The 18F-EF5 imaging has promising potential in detecting areas of tumor hypoxia in cervical cancer.
本研究旨在使用 18F-EF5 作为缺氧示踪剂评估宫颈癌患者的 PET/MRI 中的缺氧分布。我们研究了 18F-EF5-PET 示踪剂与内源性缺氧标志物：HIF1α、CAIX 和 GLUT1 的免疫组化表达之间的关联。
对 9 例经活检证实的原发性宫颈鳞状细胞癌（FIGO 2018 影像学分期 IB1-IIIC2r）患者进行了双重示踪剂 18F-EF5 和 18F-FDG 的 PET/MRI 成像（Int J Gynaecol Obstet. 2019;145:129-135）。通过计算肿瘤与肌肉的比值来分析 18F-EF5 图像，以确定缺氧组织（T/M 比值>1.5）和进一步的缺氧亚体积（HSV）和缺氧面积百分比。这些 18F-EF5 缺氧参数与 18F-FDG PET/MRI 中的肿瘤大小和定位以及缺氧免疫组化的结果相关。
所有原发性肿瘤均为 18F-FDG 和 18F-EF5 PET 阳性，局部晚期肿瘤呈异质性缺氧，存在多个 18F-EF5 阳性区域，临床 I 期肿瘤呈单个区域。缺氧的位置主要在肿瘤的外围检测到。原发性肿瘤的缺氧参数 18F-EF5 max T/M 比值和 HSV 与晚期阶段独立相关（分别为 P=0.036 和 P=0.040），HSV 与肿瘤大小相关（P=0.027）。在 18F-EF5 成像中缺氧的位置与肿瘤新鲜活检中更高的缺氧标志物表达 HIF1α 和 CAIX 相吻合。
18F-EF5 成像在检测宫颈癌肿瘤缺氧区域方面具有很大的潜力。
