Kosaka Nobuyuki, Tsuchida Tatsuro, Uematsu Hidemasa, Kimura Hirohiko, Okazawa Hidehiko, Itoh Harumi
Department of Radiology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.
AJR Am J Roentgenol. 2008 Jun;190(6):W365-9. doi: 10.2214/AJR.07.2660.
The purpose of our study was to determine whether (18)F-FDG PET can be used to differentiate among common enhancing brain tumors such as lymphoma, high-grade glioma, and metastatic brain tumor.
We evaluated 34 patients with an enhancing brain tumor on MRI, including seven lymphomas, nine high-grade gliomas, and 18 metastatic tumors. All patients also underwent FDG PET. For PET image analysis, regions of interest were placed over the tumor (T), contralateral cortex (C), and white matter (WM). Average and maximum pixel values were determined at each site. On the basis of these measurements, average and maximum standard uptake values (SUV(avg) and SUV(max)) were calculated, along with activity ratios (T/C(avg), T/WM(avg), T/WM(max), and T/C(max)), and comparisons among lesions were then made.
All parameters were significantly higher for lymphoma than for other tumors (p < 0.01). High-grade gliomas showed significantly higher SUV(avg) and SUV(max) than metastatic tumors (p < 0.05). Other parameters did not differ between lesion types. SUV(max) was the most accurate parameter for distinguishing lymphomas. Using an SUV(max) of 15.0 as a cutoff for diagnosing CNS lymphoma, only one high-grade glioma was found as a false-positive (SUV(max), 18.8).
FDG PET may be useful for differentiating common enhancing malignant brain tumors, particularly lymphoma versus high-grade glioma and metastatic tumor. FDG PET can provide useful information for distinguishing between lymphoma and other malignant enhancing brain tumors and is recommended when differential diagnoses are difficult to narrow using MRI alone.
我们研究的目的是确定¹⁸F - FDG PET是否可用于鉴别常见的强化脑肿瘤，如淋巴瘤、高级别胶质瘤和脑转移瘤。
我们评估了34例MRI显示有强化脑肿瘤的患者，其中包括7例淋巴瘤、9例高级别胶质瘤和18例转移瘤。所有患者均接受了FDG PET检查。对于PET图像分析，在肿瘤（T）、对侧皮质（C）和白质（WM）上放置感兴趣区。测定每个部位的平均像素值和最大像素值。基于这些测量结果，计算平均标准摄取值和最大标准摄取值（SUV(avg)和SUV(max)）以及活性比值（T/C(avg)、T/WM(avg)、T/WM(max)和T/C(max)），然后对病变进行比较。
淋巴瘤的所有参数均显著高于其他肿瘤（p < 0.01）。高级别胶质瘤的SUV(avg)和SUV(max)显著高于转移瘤（p < 0.05）。其他参数在病变类型之间无差异。SUV(max)是区分淋巴瘤最准确的参数。以SUV(max) 15.0作为诊断中枢神经系统淋巴瘤的临界值，仅发现1例高级别胶质瘤为假阳性（SUV(max)，18.8）。
FDG PET可能有助于鉴别常见的强化恶性脑肿瘤，特别是淋巴瘤与高级别胶质瘤和转移瘤。FDG PET可为区分淋巴瘤和其他恶性强化脑肿瘤提供有用信息，当仅使用MRI难以缩小鉴别诊断范围时推荐使用。
