Department of Nuclear Medicine, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
German Cancer Consortium (DKTK), partner site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany.
Eur J Nucl Med Mol Imaging. 2017 Dec;44(13):2230-2238. doi: 10.1007/s00259-017-3799-9. Epub 2017 Aug 19.
The 18-kDa mitochondrial translocator protein (TSPO) was reported to be upregulated in gliomas. F-GE-180 is a novel 3rd generation TSPO receptor ligand with improved target-to-background contrast compared to previous tracers. In this pilot study, we compared PET imaging with F-GE-180 and MRI of patients with untreated and recurrent pretreated glioblastoma.
Eleven patients with histologically confirmed IDH wildtype gliomas (10 glioblastomas, 1 anaplastic astrocytoma) underwent F-GE-180 PET at initial diagnosis or recurrence. The PET parameters mean background uptake (SUV), maximal tumour-to-background ratio (TBR) and PET volume using different thresholds (SUV × 1.6, 1.8 and 2.0) were evaluated in the 60-80 min p.i. summation images. The different PET volumes were compared to the contrast-enhancing tumour volume on MRI.
All gliomas were positive on F-GE-180 PET and were depicted with extraordinarily high tumour-to-background contrast (median SUV 0.47 (0.37-0.93), TBR 6.61 (3.88-9.07)). F-GE-180 uptake could be found even in areas without contrast enhancement on MRI, leading to significantly larger PET volumes than MRI-based volumes (median 90.5, 74.5, and 63.8 mL vs. 31.0 mL; p = 0.003, 0.004, 0.013). In percentage difference, the PET volumes were on average 179%, 135%, and 90% larger than the respective MRI volumes. The median spatial volumetric correlation (Sørensen-Dice coefficient) of PET volumes and MRI volumes prior to radiotherapy was 0.48, 0.54, and 0.58.
F-GE-180 PET provides a remarkably high tumour-to-background contrast in untreated and pretreated glioblastoma and shows tracer uptake even beyond contrast enhancement on MRI. To what extent F-GE-180 uptake reflects the tumour extent of human gliomas and inflammatory cells remains to be evaluated in future prospective studies with guided stereotactic biopsies and correlation of histopathological results.
18kDa 线粒体转位蛋白（TSPO）在神经胶质瘤中被报道上调。F-GE-180 是一种新型第三代 TSPO 受体配体，与之前的示踪剂相比，具有改善的靶背对比。在这项初步研究中，我们比较了未经治疗和复发性预处理胶质母细胞瘤患者的 F-GE-180 PET 成像和 MRI。
11 例经组织学证实 IDH 野生型神经胶质瘤（10 例胶质母细胞瘤，1 例间变性星形细胞瘤）患者在初始诊断或复发时接受 F-GE-180 PET 检查。在 60-80 分钟的累积图像中，评估了不同阈值（SUV×1.6、1.8 和 2.0）下的平均背景摄取（SUV）、最大肿瘤-背景比（TBR）和 PET 体积。将不同的 PET 体积与 MRI 上的增强肿瘤体积进行比较。
所有神经胶质瘤在 F-GE-180 PET 上均呈阳性，表现出极高的肿瘤-背景对比度（中位数 SUV 0.47（0.37-0.93），TBR 6.61（3.88-9.07））。即使在 MRI 上没有增强的区域也可以检测到 F-GE-180 的摄取，导致 PET 体积明显大于 MRI 体积（中位数 90.5、74.5 和 63.8ml 与 31.0ml；p=0.003，0.004，0.013）。按百分比计算，PET 体积平均比各自的 MRI 体积大 179%、135%和 90%。放疗前 PET 体积和 MRI 体积的中位数空间体积相关性（Sørensen-Dice 系数）为 0.48、0.54 和 0.58。
F-GE-180 PET 在未经治疗和预处理的胶质母细胞瘤中提供了极高的肿瘤-背景对比度，并显示出即使在 MRI 增强之外也有示踪剂摄取。F-GE-180 摄取在多大程度上反映人类胶质母细胞瘤和炎症细胞的肿瘤范围，有待于未来进行前瞻性研究，通过引导性立体定向活检和组织病理学结果的相关性进行评估。
