Department of Neurosurgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo- ku, Tokyo, 113-8519, Japan.
Research Team of Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
J Neurooncol. 2023 Aug;164(1):257-265. doi: 10.1007/s11060-023-04417-0. Epub 2023 Aug 17.
The T2-FLAIR mismatch sign is recognized as an imaging finding highly suggestive of IDH-mutant astrocytomas. This study was designed to determine whether the T2-FLAIR mismatch sign correlates with uptake of C-methionine in lower-grade gliomas.
We included 78 histopathologically verified lower-grade gliomas (grade 2: 31 cases, grade 3: 47 cases) in this study. 78 patients underwent C-methionine positron emission tomography (MET-PET) scans and magnetic resonance (MR) imaging scans prior to histological diagnosis. The tumor-to-normal ratio (T/N) of C-methionine uptake was calculated by dividing the maximum standardized uptake value (SUV) for the tumor by the mean SUV of the normal brain. MR imaging scans were evaluated for the presence of the T2-FLAIR mismatch sign by three independent reviewers. We compared molecular status, the T2-FLAIR mismatch sign and C-methionine uptake among patients with different lower-grade glioma molecular types.
The 78 lower-grade gliomas were assigned to one of three molecular groups: Group A (IDH-mutant and 1p/19q non-codeleted, n = 22), Group O (IDH-mutant and 1p/19q codeleted, n = 20), and Group W (IDH wildtype, n = 36). T2-FLAIR mismatch was found in 16 cases (20.5%) that were comprised of 8 (36.4%), 0 (0%), 8 (22.2%) cases in the molecular group A, O and W, respectively. The median T/N ratio of MET-PET in tumors with T2-FLAIR mismatch was 1.50, which was significantly lower than that of tumors without T2-FLAIR mismatch (1.83, p < 0.001, Mann-Whitney U test). In the Groups A and W (excluding Group O), the median T/N ratio on MET-PET in groups A and W (but not group O) with T2-FLAIR mismatch was 1.50, which was significantly lower than that of tumors without T2-FLAIR mismatch (1.81, p = 0.002, Mann-Whitney U test).
The T2-FLAIR mismatch sign correlated with lower C-methionine uptake in lower grade gliomas.
T2-FLAIR 不匹配征象被认为是 IDH 突变型星形细胞瘤的高度提示性影像学表现。本研究旨在确定 T2-FLAIR 不匹配征象是否与低级别胶质瘤中 C-蛋氨酸摄取有关。
本研究纳入了 78 例经组织病理学证实的低级别胶质瘤（2 级：31 例，3 级：47 例）。78 例患者在组织学诊断前接受了 C-蛋氨酸正电子发射断层扫描（MET-PET）和磁共振（MR）成像扫描。通过将肿瘤的最大标准化摄取值（SUV）除以正常脑的平均 SUV，计算 C-蛋氨酸摄取的肿瘤与正常比值（T/N）。由三位独立的审查员评估 MR 成像扫描中是否存在 T2-FLAIR 不匹配征象。我们比较了不同低级别胶质瘤分子类型患者的分子状态、T2-FLAIR 不匹配征象和 C-蛋氨酸摄取。
78 例低级别胶质瘤分为三个分子组之一：A 组（IDH 突变且 1p/19q 非缺失，n=22）、O 组（IDH 突变且 1p/19q 缺失，n=20）和 W 组（IDH 野生型，n=36）。T2-FLAIR 不匹配见于 16 例（20.5%），其中 A、O 和 W 组分别为 8 例（36.4%）、0 例（0%）和 8 例（22.2%）。T2-FLAIR 不匹配肿瘤的 MET-PET 中位 T/N 比值为 1.50，明显低于无 T2-FLAIR 不匹配肿瘤的 T/N 比值（1.83，p<0.001，Mann-Whitney U 检验）。在 A 组和 W 组（不包括 O 组）中，T2-FLAIR 不匹配的 A 组和 W 组（而非 O 组）的 MET-PET 中位 T/N 比值为 1.50，明显低于无 T2-FLAIR 不匹配肿瘤的 T/N 比值（1.81，p=0.002，Mann-Whitney U 检验）。
T2-FLAIR 不匹配征象与低级胶质瘤中 C-蛋氨酸摄取较低有关。
