PURPOSE Heterogeneity within GBMs and variability of visualized fluorescence combine to confer practical limitations to the technique of optical imaging. A biometric analysis was planned to objectively ascertain and analyse this phenomenon METHODS: 25 adult glioblastoma subjects undergoing resection were prospectively accrued. Biopsies were taken from various parts of the tumor and safe peritumoral zones. White light (WL) and visualized fluorescence was subjectively recorded. Corresponding histopathology [coalescent (C) or infiltrating (I) tumor] and protoporphyrin-IX (PPIX) levels were assayed. RESULTS WL was very sensitive for detecting tumor. SF was more specific and had high positive predictive value for detecting tumor. WF on the other hand had a poor discriminatory efficacy. Mean PPIX levels were 3.0, 2.01 and 0.16 for SF, WF, and NF respectively. WF had a wide variable range of PPIX levels. Within the coalescent tumor areas, there was a variable distribution of fluorescence (both subjective as well as objective PPIX levels) with only 54% samples showing SF and high PPIX. In seven cases this discordance was noted within the same tumor (biological heterogeneity). CONCLUSIONS Fluorescence may miss important tumor areas even if objective assessment is used. Histologically similar tumor areas may exhibit contrasting fluorescence properties, a phenomenon which needs further investigation and elucidation of underlying mechanisms which could potentially be manipulated to optimize the utility of fluorescence guidance.

中文翻译：

---

术中肿瘤荧光的客观评估揭示了胶质母细胞瘤内的生物学异质性：一项生物统计学研究。

用途GBM中的异质性和可视化荧光的可变性相结合，给光学成像技术带来了实际限制。计划进行生物特征分析，以客观地确定和分析此现象。方法：前瞻性收集了25名接受切除的成年胶质母细胞瘤受试者。活检取自肿瘤的各个部位和安全的肿瘤周围区域。主观记录白光（WL）和可视化荧光。测定了相应的组织病理学[结缔（C）或浸润（I）肿瘤]和原卟啉-IX（PPIX）水平。结果WL对检测肿瘤非常敏感。SF更特异性，对检测肿瘤具有较高的阳性预测价值。另一方面，WF的辨别力较差。SF，WF，PP和PP的平均PPIX水平分别为3.0、2.01和0.16，和NF。WF的PPIX级别变化范围很大。在合并的肿瘤区域内，荧光分布可变（主观和客观PPIX水平），只有54％的样本显示SF和高PPIX。在七个案例中，在同一肿瘤中发现了这种不一致（生物学异质性）。结论即使使用客观评估，荧光也可能错过重要的肿瘤区域。组织学上相似的肿瘤区域可能表现出不同的荧光特性，这一现象需要进一步研究和阐明潜在的机制，这些机制可能会被操纵以优化荧光指导的实用性。荧光的分布是可变的（主观和客观PPIX水平），只有54％的样品显示SF和高PPIX。在七个案例中，在同一肿瘤中发现了这种不一致（生物学异质性）。结论即使使用客观评估，荧光也可能错过重要的肿瘤区域。组织学上相似的肿瘤区域可能表现出不同的荧光特性，这一现象需要进一步研究和阐明潜在的机制，这些机制可能会被操纵以优化荧光指导的实用性。荧光的分布是可变的（主观和客观PPIX水平），只有54％的样品显示SF和高PPIX。在七个案例中，在同一肿瘤中发现了这种不一致（生物学异质性）。结论即使使用客观评估，荧光也可能错过重要的肿瘤区域。组织学上相似的肿瘤区域可能表现出不同的荧光特性，这种现象需要进一步研究和阐明潜在的机制，可以潜在地对其进行操纵以优化荧光指导的实用性。