Department of Nuclear Medicine, Ludwig-Maximilians-University Munich, Marchioninistr 15, 81377 Munich, Germany.
Eur J Nucl Med Mol Imaging. 2012 Jun;39(6):1021-9. doi: 10.1007/s00259-012-2109-9. Epub 2012 Apr 11.
Since differentiation between low-grade glioma (LGG) and high-grade glioma (HGG) remains challenging according to MRI criteria alone, we investigated the discriminative value of additional dynamic FET PET in patients with MRI-suspected LGG.
Included in this retrospective study were 127 patients with newly diagnosed MRI-suspected LGG and dynamic FET PET prior to histopathological assessment. FET PET lesions were visually classified as having reduced, normal, or increased tracer uptake. Maximal tumour uptake scaled to the mean background uptake (SUV(max)/BG), mean tumour uptake (SUV(mean)/BG), biological tumour volume and kinetics were evaluated and correlated with individual histopathological findings.
Histopathological analysis revealed 71 patients with LGG, 47 patients with HGG (including 5 glioblastoma multiforme), 2 patients with low-grade ganglioglioma and 7 patients with non-neoplastic lesions. Of the 127 patients, 97 had lesions with increased FET uptake, of which 93 were neoplastic. Increased uptake was found in 49/71 LGG (69 %) and 42/47 HGG (89 %). None of the conventional uptake parameters differed significantly between the HGG and LGG groups. Kinetic analysis reliably identified HGG (sensitivity 95 %, specificity 72 %, PPV 74 %, NPV 95 %). Normal tracer uptake was observed in 19 patients (15 with LGG, 1 with HGG and 3 with non-neoplastic lesions) and reduced uptake in 11 patients (7 with LGG and 4 with HGG).
Among the MRI-suspected LGG, kinetic but not conventional analysis of FET uptake enabled remarkably high sensitivity for detection of HGG. This held true even for lesions with low or diffuse tracer uptake. Lesions with reduced tracer uptake must be interpreted with caution, as they can also harbour HGG tissue.
由于单凭 MRI 标准，低级别胶质瘤（LGG）和高级别胶质瘤（HGG）的区分仍然具有挑战性，因此我们研究了在 MRI 疑似 LGG 患者中，额外的动态 FET PET 对其的鉴别价值。
本回顾性研究纳入了 127 例新诊断的 MRI 疑似 LGG 患者和动态 FET PET 检查，这些患者在进行组织病理学评估前均进行了检查。FET PET 病变通过目测分为摄取减少、正常或增加。对最大肿瘤摄取与平均背景摄取（SUV(max)/BG）、平均肿瘤摄取（SUV(mean)/BG）、肿瘤生物体积和动力学进行了评估，并与个别组织病理学发现进行了相关性分析。
组织病理学分析显示，71 例患者为 LGG，47 例患者为 HGG（包括 5 例多形性胶质母细胞瘤），2 例患者为低级别神经节细胞瘤，7 例患者为非肿瘤性病变。在 127 例患者中，97 例患者的 FET 摄取增加，其中 93 例为肿瘤。在 71 例 LGG 中，49 例（69%）和 47 例 HGG 中（89%）发现摄取增加。在 HGG 和 LGG 组之间，常规摄取参数均无显著差异。动力学分析可可靠地识别 HGG（灵敏度 95%，特异性 72%，PPV 74%，NPV 95%）。在 19 例患者中观察到正常的示踪剂摄取（15 例为 LGG，1 例为 HGG，3 例为非肿瘤性病变），11 例患者的摄取减少（7 例为 LGG，4 例为 HGG）。
在 MRI 疑似 LGG 中，FET 摄取的动力学而非常规分析对于检测 HGG 的敏感性非常高。即使对于摄取减少或弥漫性摄取的病变也是如此。摄取减少的病变必须谨慎解释，因为它们也可能含有 HGG 组织。
