正位移植的脑胶质母细胞瘤异种移植模型对于评估创新抗癌治疗的效果至关重要。在纵向研究中，只能通过非侵入性成像监测脑胶质母细胞瘤的肿瘤生长（或逆转）。因此，生物发光成像（BLI）因其低成本和易于使用而变得流行。在针对治疗脑胶质母细胞瘤的新型纳米医药的开发过程中，我们正在使用表达荧光素酶的GL261细胞系。碰巧，在一种特定的GL261脑胶质母细胞瘤模型中，该模型具有表达荧光素酶和绿色荧光蛋白（GL261-luc-GFP）的细胞，我们观察到表面上的自发逆转。但是，磁共振成像（MRI）分析显示，这些肿瘤实际上随着时间的推移而增长。对于其他模型（GL261仅表达荧光素酶和U87同时表达荧光素酶和GFP），从BLI和MRI得到的数据相关性很好。我们发现，不同成像模式所产生的结果分歧并非由于肿瘤定位或光穿透深度所致，而是由于用于GL261-luc-GFP模型的病毒载体中荧光素酶表达的不稳定性所导致的。因此，使用多模式成像可避免肿瘤生长评估中的可能误差，并且在仅使用BLI作为成像模式时，必须检查荧光素酶表达的稳定性。

Orthotopic glioblastoma xenografts are paramount for evaluating the effect of innovative anti-cancer treatments. In longitudinal studies, tumor growth (or regression) of glioblastoma can only be monitored by noninvasive imaging. For this purpose, bioluminescence imaging (BLI) has gained popularity because of its low cost and easy access. In the context of the development of new nanomedicines for treating glioblastoma, we were using luciferase-expressing GL261 cell lines. Incidentally, using BLI in a specific GL261 glioblastoma model with cells expressing both luciferase and the green fluorescent protein (GL261-luc-GFP), we observed an apparent spontaneous regression. By contrast, the magnetic resonance imaging (MRI) analysis revealed that the tumors were actually growing over time. For other models (GL261 expressing only luciferase and U87 expressing both luciferase and GFP), data from BLI and MRI correlated well. We found that the divergence in results coming from different imaging modalities was not due to the tumor localization nor the penetration depth of light but was rather linked to the instability in luciferase expression in the viral construct used for the GL261-luc-GFP model. In conclusion, the use of multi-modality imaging prevents possible errors in tumor growth evaluation, and checking the stability of luciferase expression is mandatory when using BLI as the sole imaging modality.