背景:WHO中枢神经系统肿瘤分类(第5版)对星形细胞瘤进行了分类,IDH-突变体伴随CDKN2A/B纯合缺失为WHO4级。甲硫腺苷磷酸化酶(MTAP)的免疫组织化学(IHC)染色缺失被开发为CDKN2A-HD的替代标记。CDKN2A状态的成像生物标志物的鉴定具有巨大的临床相关性。在这项研究中,我们探索了非增强型星形细胞瘤的放射学特征之间的关联,IDH-突变至CDKN2A/B状态。
方法:星形细胞瘤31例,本研究包括通过IHC得到的具有MTAP结果的IDH突变体。CDKN2A的状态在所有病例中通过MTAP的IHC染色诊断,12例病例的综合基因组分析进一步证实了这一点。T2-FLAIR不匹配信号,囊性成分,钙化,和肿瘤内微出血进行评估。分析影像学特征与分子病理诊断的关系。
结果:26例CDKN2A完整,5例CDKN2A-HD。在23例(74.2%)和14例(45.2%)中观察到>33%和>50%T2-FLAIR不匹配的存在,分别,与CDKN2A完整星形细胞瘤相关(p=0.0001,0.0482)。没有星形细胞瘤,具有CDKN2A-HD的IDH-突变体显示T2-FLAIR错配征。囊性成分,钙化,肿瘤内微出血与CDKN2A状态无关.
结论:在非增强型星形细胞瘤患者中,IDH-突变体,T2-FLAIR错配征是CDKN2A完整亚型的潜在成像生物标志物.这种成像生物标志物可以使术前预测星形细胞瘤中的CDKN2A状态,IDH-突变体.
BACKGROUND: The WHO classification of central nervous system tumors (5th edition) classified astrocytoma, IDH-mutant accompanied with CDKN2A/B homozygous deletion as WHO grade 4. Loss of immunohistochemical (IHC) staining for methylthioadenosine phosphorylase (MTAP) was developed as a surrogate marker for CDKN2A-HD. Identification of imaging biomarkers for CDKN2A status is of immense clinical relevance. In this study, we explored the association between radiological characteristics of non-enhancing astrocytoma, IDH-mutant to the CDKN2A/B status.
METHODS: Thirty-one cases of astrocytoma, IDH-mutant with MTAP results by IHC were included in this study. The status of CDKN2A was diagnosed by IHC staining for MTAP in all cases, which was further confirmed by comprehensive genomic analysis in 12 cases. The T2-FLAIR mismatch sign, cystic component, calcification, and intratumoral microbleeding were evaluated. The relationship between the radiological features and molecular pathological diagnosis was analyzed.
RESULTS: Twenty-six cases were identified as CDKN2A-intact while 5 cases were CDKN2A-HD. The presence of > 33% and > 50% T2-FLAIR mismatch was observed in 23 cases (74.2%) and 14 cases (45.2%), respectively, and was associated with CDKN2A-intact astrocytoma (p = 0.0001, 0.0482). None of the astrocytoma, IDH-mutant with CDKN2A-HD showed T2-FLAIR mismatch sign. Cystic component, calcification, and intratumoral microbleeding were not associated with CDKN2A status.
CONCLUSIONS: In patients with non-enhancing astrocytoma, IDH-mutant, the T2-FLAIR mismatch sign is a potential imaging biomarker for the CDKN2A-intact subtype. This imaging biomarker may enable preoperative prediction of CDKN2A status among astrocytoma, IDH-mutant.