Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai cho, Shouwa ku, Nagoya, 466-8550, Japan.
Clin Nucl Med. 2012 Sep;37(9):843-9. doi: 10.1097/RLU.0b013e318262af48.
The aim of our study was to examine the usefulness of PET with C-methionine (MET) and F-fluorodeoxyglucose (FDG) in the differentiation of glioblastoma multiforme (GBM) and intracranial diffuse large B-cell lymphoma (DLBCL).
We evaluated 22 patients retrospectively with an enhancing brain tumor on MRI, including 15 GBM and 7 DLBCL, which was confirmed by histopathology. Dynamic PET scans with MET and FDG were performed for preoperative differential diagnosis. We assessed the images qualitatively and quantitatively. In quantitative assessment, the SUVmax was used on FDG PET and both late and early phases on MET PET. In addition, the ratio of SUVmax in the late and early phases on MET-PET was evaluated (ΔSUVmax).
SUVmax on FDG PET of DLBCL was significantly higher than that of GBM. Setting an SUVmax of 12.0 as the cutoff for differentiating DLBCL from GBM, 1 GBM and 1 DLBCL were found to be false-positive and false-negative, respectively.SUVmax in the late and early phases of MET-PET was not significantly different between DLBCL and GBM; however, we also found significant differences in ΔSUVmax on MET-PET. Using ΔSUVmax 1.17 as the cutoff, we could differentiate DLBCL from GBM completely. In the present study, ΔSUVmax on MET-PET was slightly superior to SUVmax on FDG PET.
Both SUVmax on FDG PET and ΔSUVmax on MET-PET were considered to be good diagnostic tests when encountering difficulties in this differential diagnosis.
本研究旨在探讨 C-蛋氨酸（MET）和 F-氟代脱氧葡萄糖（FDG）正电子发射断层扫描（PET）在鉴别多形性胶质母细胞瘤（GBM）和颅内弥漫性大 B 细胞淋巴瘤（DLBCL）中的作用。
我们回顾性评估了 22 例 MRI 增强脑肿瘤患者，包括 15 例 GBM 和 7 例 DLBCL，这些患者均经组织病理学证实。对术前鉴别诊断进行了 MET 和 FDG 动态 PET 扫描。我们对图像进行了定性和定量评估。在定量评估中，使用 FDG PET 的 SUVmax 和 MET PET 的晚期和早期相。此外，还评估了 MET-PET 晚期和早期相的 SUVmax 比值（ΔSUVmax）。
DLBCL 的 FDG PET SUVmax 明显高于 GBM。当以 SUVmax 12.0 作为区分 DLBCL 和 GBM 的截止值时，1 例 GBM 和 1 例 DLBCL 分别被误诊为阳性和阴性。MET-PET 晚期和早期相的 SUVmax 在 DLBCL 和 GBM 之间无显著差异；然而，我们也发现 MET-PET 上的ΔSUVmax 存在显著差异。使用 MET-PET 的ΔSUVmax 1.17 作为截止值，我们可以完全区分 DLBCL 和 GBM。在本研究中，MET-PET 上的ΔSUVmax 略优于 FDG PET 上的 SUVmax。
在遇到这种鉴别诊断困难时，FDG PET 上的 SUVmax 和 MET-PET 上的ΔSUVmax 均被认为是很好的诊断试验。
