Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, Japan.
Ann Nucl Med. 2011 Jul;25(6):432-8. doi: 10.1007/s12149-011-0483-1. Epub 2011 Mar 16.
It is sometimes difficult to distinguish between primary central nervous system lymphomas (PCNSL) and glioblastoma multiforme (GBM). The aim of this study was to investigate whether the addition of (18)F-2-fluoro-2-deoxy-D: -glucose positron emission tomography ([(18)F]FDG-PET) and apparent diffusion coefficients (ADC) to conventional MRI improves diagnostic accuracy for distinguishing between PCNSL and GBM with similar MRI findings.
We used conventional- and diffusion-weighted MRI and FDG-PET scans of 21 patients with histologically confirmed brain tumors exhibiting similar MRI findings (PCNSL, n = 14, GBM, n = 7) in our observer performance study that consisted of 3 interpretation sessions. ADC and maximum standard uptake values (SUV(max)) of the tumors were calculated. Three radiologists first interpreted conventional MRI (1st session), then they read images to which the ADC value had been added (2nd session), and finally they interpreted images supplemented with SUV(max) (3rd session). Observer performance was evaluated using κ statistic and receiver operating characteristics analyses.
The addition of ADC values to conventional MRI failed to improve the differentiation between PCNSL and GBM. The addition of SUV(max) at the third session improved the diagnostic accuracy of all 3 readers and resulted in higher interobserver agreement; mean accuracy was 95% (range 93-100%). In one observer the accuracy of tumor differentiation was significantly improved at the third compared to the second session (p = 0.017).
In a selected group of PCNSL and GBM with similar MRI findings, the addition of quantitative FDG-PET to MRI may improve their differentiation. ADC measurement did not allow further discrimination.
原发性中枢神经系统淋巴瘤（PCNSL）和多形性胶质母细胞瘤（GBM）有时难以区分。本研究旨在探讨在常规 MRI 的基础上增加（18）F-2-氟-2-脱氧-D：-葡萄糖正电子发射断层扫描（[(18)F]FDG-PET）和表观扩散系数（ADC）是否可以提高诊断 PCNSL 和 GBM 的准确性，这些肿瘤具有相似的 MRI 表现。
我们在一项观察者效能研究中使用了常规和弥散加权 MRI 以及 FDG-PET 扫描，该研究纳入了 21 例组织学证实的脑肿瘤患者，这些患者的肿瘤具有相似的 MRI 表现（PCNSL，n=14；GBM，n=7）。在该研究中，我们进行了 3 次解释会议，计算了肿瘤的 ADC 值和最大标准摄取值（SUV(max)）。3 位放射科医生首先解释常规 MRI（第 1 次会议），然后他们阅读添加了 ADC 值的图像（第 2 次会议），最后他们解释补充了 SUV(max)的图像（第 3 次会议）。使用κ统计和受试者工作特征分析评估观察者的表现。
在常规 MRI 的基础上增加 ADC 值并不能改善 PCNSL 和 GBM 的区分。在第 3 次会议中添加 SUV(max)提高了所有 3 位读者的诊断准确性，并提高了观察者间的一致性；平均准确率为 95%（范围 93%-100%）。在 1 位观察者中，与第 2 次会议相比，第 3 次会议时肿瘤分化的准确性显著提高（p=0.017）。
在具有相似 MRI 表现的选定的 PCNSL 和 GBM 患者中，在 MRI 的基础上增加定量 FDG-PET 可能会改善它们的区分。ADC 测量并不能进一步区分。
