Kato T, Shinoda J, Oka N, Miwa K, Nakayama N, Yano H, Maruyama T, Muragaki Y, Iwama T
Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Kizawa Memorial Hospital, Minokamo City, Gifu, Japan.
AJNR Am J Neuroradiol. 2008 Nov;29(10):1867-71. doi: 10.3174/ajnr.A1242. Epub 2008 Aug 7.
The relationship of (11)C-methionine (MET) uptake and tumor activity in low-grade gliomas (those meeting the criteria for World Health Organization [WHO] grade II gliomas) remains uncertain. The aim of this study was to compare MET uptake in low-grade gliomas and to analyze whether MET positron-emission tomography (PET) can estimate tumor viability and provide evidence of malignant transformation.
We studied glioma metabolic activity in 49 consecutive patients with newly diagnosed grade II gliomas by using MET PET before surgical resection. On MET PET, we measured tumor/normal brain uptake ratio (T/N ratio) in 21 diffuse astrocytomas (DAs), 12 oligodendrogliomas (ODs), and 16 oligoastrocytomas (OAs). We compared MET T/N ratio among these 3 tumors and investigated possible correlation with proliferative activity, as measured by Mib-1 labeling index (LI).
MET T/N ratios of DA, OD, and OA were 2.11 +/- 0.87, 3.75 +/- 1.43, and 2.76 +/- 1.27, respectively. The MET T/N ratio of OD was significantly higher than that of DA (P < .005). In comparison of MET T/N ratios with the Mib-1 LI, a significant correlation was shown in DA (r = 0.63; P < .005) but not in OD and OA.
MET uptake in DAs may be closely associated with tumor viability, which depends on increased amino acid transport by an activated carrier-mediated system. DAs with lower MET uptake were considered more quiescent lesions, whereas DA with higher MET uptake may act more aggressively.
在低级别胶质瘤（符合世界卫生组织[WHO]II级胶质瘤标准者）中，（11）C-蛋氨酸（MET）摄取与肿瘤活性之间的关系仍不明确。本研究旨在比较低级别胶质瘤中的MET摄取情况，并分析MET正电子发射断层扫描（PET）是否能够评估肿瘤的生存能力并提供恶性转化的证据。
我们在手术切除前，通过MET PET对49例新诊断的II级胶质瘤患者的胶质瘤代谢活性进行了研究。在MET PET上，我们测量了21例弥漫性星形细胞瘤（DA）、12例少突胶质细胞瘤（OD）和16例少突星形细胞瘤（OA）的肿瘤/正常脑摄取比值（T/N比值）。我们比较了这3种肿瘤之间的MET T/N比值，并研究其与通过Mib-1标记指数（LI）测量的增殖活性之间可能存在的相关性。
DA、OD和OA的MET T/N比值分别为2.11±0.87、3.75±1.43和2.76±1.27。OD的MET T/N比值显著高于DA（P<.005）。在将MET T/N比值与Mib-1 LI进行比较时，DA显示出显著相关性（r=0.63；P<.005），而OD和OA则未显示出相关性。
DA中的MET摄取可能与肿瘤的生存能力密切相关，这取决于由激活的载体介导系统增加的氨基酸转运。MET摄取较低的DA被认为是更静止的病变，而MET摄取较高的DA可能具有更强的侵袭性。
