5-氨基乙酰丙酸（5-ALA）荧光引导切除增加了完全中枢神经系统肿瘤切除的比例，提高了IDH野生型胶质母细胞瘤患者的无进展生存率。IDH野生型胶质母细胞瘤的一个小的子集不显示5-ALA荧光。对于这些病例的解释尚缺失。在本研究中，我们使用DNA甲基化谱分析进一步表征非荧光胶质母细胞瘤。分析了新诊断和复发的IDH野生型胶质母细胞瘤的手术患者。术中5-ALA荧光的强度被归为不可见或可见两类。从肿瘤中提取DNA，并使用Illumina EPIC（850k）芯片分析全基因组DNA甲基化模式。此外，通过流式细胞术在人类胶质瘤球系（BT112和BT145）上测量了5-ALA的强度。在74名被纳入的患者中，12名（16.2％）患者患有非荧光胶质母细胞瘤，与62例表现为5-ALA荧光的胶质母细胞瘤进行了比较。两组之间的临床特征分布均匀。我们在DNA甲基化亚型和5-ALA荧光之间未发现显著差异（P = .24）。肿瘤微环境细胞的分布在非荧光和荧光肿瘤之间没有显著差异。EGFR的拷贝数变异和同时EGFRvIII的表达与5-ALA荧光密切相关，因为所有非荧光胶质母细胞瘤都存在EGFR扩增（P < .01）。这一发现在复发肿瘤中也得到了证实。同样，EGFR扩增的胶质母细胞瘤细胞系在培养24小时后没有5-ALA荧光。我们的研究证明了非荧光IDH野生型胶质母细胞瘤与EGFR基因扩增之间的关联，这应该在复发手术和未来研究中考虑到EGFR扩增的胶质母细胞瘤。© 2023作者。由牛津大学出版社代表神经肿瘤学会和欧洲神经肿瘤学会发表。版权所有。有关权限，请发送电子邮件至journals.permissions@oup.com。

5-aminolevulinic acid (5-ALA) fluorescence-guided resection increases the percentage of complete CNS tumor resections and improves the progression-free survival of IDH-wildtype glioblastoma patients. A small subset of IDH-wildtype glioblastoma shows no 5-ALA fluorescence. An explanation for these cases is missing. In this study, we used DNA methylation profiling to further characterize non-fluorescent glioblastomas.Patients with newly diagnosed and recurrent IDH-wildtype glioblastoma that underwent surgery were analyzed. The intensity of intraoperative 5-ALA fluorescence was categorized as non-visible or visible. DNA was extracted from tumors and genome-wide DNA methylation patterns were analyzed using Illumina EPIC (850k) arrays. Furthermore, 5-ALA intensity was measured by flow cytometry on human gliomasphere lines (BT112 and BT145).Of 74 included patients, 12 (16.2%) patients had a non-fluorescent glioblastoma, which were compared to 62 glioblastomas with 5-ALA fluorescence. Clinical characteristics were equally distributed between both groups. We did not find significant differences between DNA methylation subclasses and 5-ALA fluorescence (P = .24). The distribution of cells of the tumor microenvironment was not significantly different between the non-fluorescent and fluorescent tumors. Copy number variations in EGFR and simultaneous EGFRvIII expression were strongly associated with 5-ALA fluorescence since all non-fluorescent glioblastomas were EGFR-amplified (P < .01). This finding was also demonstrated in recurrent tumors. Similarly, EGFR-amplified glioblastoma cell lines showed no 5-ALA fluorescence after 24 h of incubation.Our study demonstrates an association between non-fluorescent IDH-wildtype glioblastomas and EGFR gene amplification which should be taken into consideration for recurrent surgery and future studies investigating EGFR-amplified gliomas.© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology and the European Association of Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.