Institute of Neuroscience and Medicine (INM-3, -4), Forschungszentrum Jülich, D-52425, Jülich, Germany.
Department of Nuclear Medicine & Nancyclotep Imaging Platform, CHRU Nancy, Lorraine University, Nancy, France.
Eur J Nucl Med Mol Imaging. 2017 Dec;44(13):2257-2265. doi: 10.1007/s00259-017-3812-3. Epub 2017 Aug 22.
Both perfusion-weighted MR imaging (PWI) and O-(2-F-fluoroethyl)-L-tyrosine PET (F-FET) provide grading information in cerebral gliomas. The aim of this study was to compare the diagnostic value of F-FET PET and PWI for tumor grading in a series of patients with newly diagnosed, untreated gliomas using an integrated PET/MR scanner.
Seventy-two patients with untreated gliomas [22 low-grade gliomas (LGG), and 50 high-grade gliomas (HGG)] were investigated with F-FET PET and PWI using a hybrid PET/MR scanner. After visual inspection of PET and PWI maps (rCBV, rCBF, MTT), volumes of interest (VOIs) with a diameter of 16 mm were centered upon the maximum of abnormality in the tumor area in each modality and the contralateral unaffected hemisphere. Mean and maximum tumor-to-brain ratios (TBR, TBR) were calculated. In addition, Time-to-Peak (TTP) and slopes of time-activity curves were calculated for F-FET PET. Diagnostic accuracies of F-FET PET and PWI for differentiating low-grade glioma (LGG) from high-grade glioma (HGG) were evaluated by receiver operating characteristic analyses (area under the curve; AUC).
The diagnostic accuracy of F-FET PET and PWI to discriminate LGG from HGG was similar with highest AUC values for TBR and TBR of F-FET PET uptake (0.80, 0.83) and for TBR and TBR of rCBV (0.80, 0.81). In case of increased signal in the tumor area with both methods (n = 32), local hot-spots were incongruent in 25 patients (78%) with a mean distance of 10.6 ± 9.5 mm. Dynamic FET PET and combination of different parameters did not further improve diagnostic accuracy.
Both F-FET PET and PWI discriminate LGG from HGG with similar diagnostic performance. Regional abnormalities in the tumor area are usually not congruent indicating that tumor grading by F-FET PET and PWI is based on different pathophysiological phenomena.
灌注加权磁共振成像（PWI）和 O-(2-氟乙基)-L-酪氨酸 PET（F-FET）均可提供脑胶质瘤的分级信息。本研究旨在使用集成的 PET/MR 扫描仪，比较 F-FET PET 和 PWI 在一组未经治疗的新诊断脑胶质瘤患者中的肿瘤分级诊断价值。
72 例未经治疗的脑胶质瘤患者[22 例低级别胶质瘤（LGG）和 50 例高级别胶质瘤（HGG）]使用混合 PET/MR 扫描仪进行 F-FET PET 和 PWI 检查。在视觉检查 PET 和 PWI 图（rCBV、rCBF、MTT）后，在每种模式的肿瘤区域最大异常处和对侧无病变半球的中心位置，放置直径为 16mm 的感兴趣区（VOI）。计算平均和最大肿瘤与脑比值（TBR、TBR）。此外，还计算了 F-FET PET 时间-活性曲线的达峰时间（TTP）和斜率。通过受试者工作特征分析（曲线下面积；AUC）评估 F-FET PET 和 PWI 区分低级别胶质瘤（LGG）和高级别胶质瘤（HGG）的诊断准确性。
F-FET PET 和 PWI 区分 LGG 和 HGG 的诊断准确性相似，F-FET PET 摄取的 TBR 和 TBR 以及 rCBV 的 TBR 和 TBR 的 AUC 值最高（0.80、0.83）（0.80、0.81）。在两种方法均显示肿瘤区域信号增加的情况下（n=32），25 例患者（78%）的局部热点不一致，平均距离为 10.6±9.5mm。动态 FET PET 和不同参数的组合并未进一步提高诊断准确性。
F-FET PET 和 PWI 均可区分 LGG 和 HGG，具有相似的诊断性能。肿瘤区域的局部异常通常不一致，表明 F-FET PET 和 PWI 的肿瘤分级基于不同的病理生理现象。
