Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Minokamo, Japan.
Department of Neurosurgery, Gifu University Graduate School of Medicine, Gifu, Japan.
J Neuroimaging. 2023 Jul-Aug;33(4):652-660. doi: 10.1111/jon.13114. Epub 2023 May 9.
C-methionine (MET)-PET is a useful tool in neuro-oncology. The T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign on MRI is a characteristic finding in lower grade gliomas with isocitrate dehydrogenase (IDH) mutations and the absence of the 1p/19q codeletion; however, the T2-FLAIR mismatch sign has low sensitivity in differentiating gliomas and does not aid in identifying glioblastomas with IDH mutations. We therefore investigated the efficacy of the combination of the T2-FLAIR mismatch sign and MET-PET for accurately determining the molecular subtype of gliomas of all grades.
The present study comprised 208 adult patients diagnosed with supratentorial glioma confirmed by molecular genetics and histopathology. The ratio of the maximum lesion MET accumulation to the mean normal frontal cortex MET accumulation (T/N) was measured. The presence or absence of the T2-FLAIR mismatch sign was determined. The presence or absence of the T2-FLAIR mismatch sign and the MET T/N ratio were compared between glioma subtypes to evaluate individual and combined utility in identifying gliomas with IDH mutations and no 1p/19q codeletion (IDHmut-Noncodel) or gliomas with IDH mutations (IDHmut).
The addition of MET-PET to MRI for the presence of the T2-FLAIR mismatch sign improved diagnostic accuracy, with the area under the curve values increasing from .852 to .871 for IDHmut-Noncodel and from .688 to .808 for IDHmut.
The combination of the T2-FLAIR mismatch sign and MET-PET may provide improved diagnostic utility in differentiating gliomas according to molecular subtype, particularly in determining IDH mutation status.
C-蛋氨酸（MET）-PET 是神经肿瘤学中的一种有用工具。MRI 上 T2 液体衰减反转恢复（FLAIR）不匹配征象是异柠檬酸脱氢酶（IDH）突变且无 1p/19q 缺失的低级别胶质瘤的特征性表现；然而，T2-FLAIR 不匹配征象在鉴别胶质瘤方面的敏感性较低，并且不能帮助识别 IDH 突变的胶质母细胞瘤。因此，我们研究了 T2-FLAIR 不匹配征象与 MET-PET 相结合对准确确定所有级别胶质瘤的分子亚型的效果。
本研究纳入了 208 名经分子遗传学和组织病理学证实为幕上胶质瘤的成年患者。测量最大病变 MET 摄取与平均正常额叶皮质 MET 摄取的比值（T/N）。确定是否存在 T2-FLAIR 不匹配征象。比较不同胶质瘤亚型中 T2-FLAIR 不匹配征象和 MET T/N 比值的存在情况，以评估其在识别 IDHmut-Noncodel 或 IDHmut 胶质瘤中的个体和联合应用价值。
将 MET-PET 添加到 MRI 中以确定 T2-FLAIR 不匹配征象的存在可提高诊断准确性，IDHmut-Noncodel 的曲线下面积值从 0.852 增加到 0.871，IDHmut 从 0.688 增加到 0.808。
T2-FLAIR 不匹配征象和 MET-PET 的结合可能会提高根据分子亚型区分胶质瘤的诊断实用性，特别是在确定 IDH 突变状态方面。
