Background: Gliomas have a heterogeneous nature, and identifying the most aggressive parts of the tumor and defining tumor borders are important for histomolecular diagnosis, surgical resection, and radiation therapy planning. This study evaluated [18F]-FACBC PET for glioma tissue classification. Methods: Pre-surgical [18F]-FACBC PET/MR images were used during surgery and image-localized biopsy sampling in patients with high- and low-grade glioma. TBR was compared to histomolecular results to determine optimal threshold values, sensitivity, specificity, and AUC values for the classification of tumor tissue. Additionally, PET volumes were determined in patients with glioblastoma based on the optimal threshold. [18F]-FACBC PET volumes and diagnostic accuracy were compared to ce-T1 MRI. In total, 48 biopsies from 17 patients were analyzed. Results: [18F]-FACBC had low uptake in non-glioblastoma tumors, but overall higher sensitivity and specificity for the classification of tumor tissue (0.63 and 0.57) than ce-T1 MRI (0.24 and 0.43). Additionally, [18F]-FACBC TBR was an excellent classifier for IDH1-wildtype tumor tissue (AUC: 0.83, 95% CI: 0.71–0.96). In glioblastoma patients, PET tumor volumes were on average eight times larger than ce-T1 MRI volumes and included 87.5% of tumor-positive biopsies compared to 31.5% for ce-T1 MRI. Conclusion: The addition of [18F]-FACBC PET to conventional MRI could improve tumor classification and volume delineation.
背景：胶质瘤具有异质性，识别肿瘤最具侵袭性的区域并界定肿瘤边界对于组织分子诊断、手术切除及放疗计划制定至关重要。本研究评估了[18F]-FACBC PET在胶质瘤组织分类中的应用价值。方法：在高、低级别胶质瘤患者手术过程中，采用术前[18F]-FACBC PET/MR影像进行图像引导活检取样。通过比较肿瘤背景比值与组织分子检测结果，确定肿瘤组织分类的最佳阈值、敏感性、特异性及曲线下面积值。此外，基于最佳阈值测定胶质母细胞瘤患者的PET肿瘤体积，并将[18F]-FACBC PET体积及诊断准确性与增强T1加权磁共振成像进行对比分析。研究共纳入17例患者的48份活检样本。结果：[18F]-FACBC在非胶质母细胞瘤中摄取较低，但对肿瘤组织分类的整体敏感性（0.63）和特异性（0.57）均优于增强T1加权磁共振成像（0.24和0.43）。同时，[18F]-FACBC肿瘤背景比值对IDH1野生型肿瘤组织具有优异分类效能（曲线下面积：0.83，95%置信区间：0.71-0.96）。在胶质母细胞瘤患者中，PET测定的肿瘤体积平均为增强T1加权磁共振成像的8倍，且能覆盖87.5%的肿瘤阳性活检区域，而增强T1加权磁共振成像仅覆盖31.5%。结论：在传统磁共振成像基础上联合应用[18F]-FACBC PET可提升肿瘤分类准确性与体积勾画精度。
Histomolecular Validation of [18F]-FACBC in Gliomas Using Image-Localized Biopsies
肿瘤(癌症)患者之家