脑干胶质瘤模型的建立及其MRI特征

Establishment of Brainstem Glioma Models and Their Characteristics in MRI

[目的]探索稳定建立脑干胶质瘤模型的方法,探讨1.5TMRI观察脑干胶质瘤模型的可行性。[方法]将F98鼠胶质瘤细胞系、U87MG和U251MG人胶质瘤细胞分别种植于Fischer344大鼠和裸小鼠脑干,1.5TMRI观察肿瘤在脑干的生长情况,比较MRI影像及病理肿瘤体积的相关性,及肿瘤病理切片与MRI图像的依从性。采用生存分析研究三种胶质瘤细胞致瘤的稳定性。[结果]18/20只种植F98胶质瘤细胞的大鼠形成脑干胶质瘤,U87MG和U251MG在裸鼠脑干形成肿瘤的效率分别12/15和3/15,MRI影像学表现与病理学表现一致。大鼠MRI肿瘤体积(95.9±17.8mm3)比病理肿瘤体积(81.8±20.5mm3)增加约14.7%(t=4.78,P<0.01);裸鼠MRI肿瘤体积(9.49±0.91mm3)比病理肿瘤体积(8.79±1.15mm3)增加约8.0%(t=3.04,P=0.01)。相关性分析发现两者呈线性相关,在大鼠脑干胶质瘤模型中相关系数为0.631(P=0.005),在裸鼠脑干胶质瘤模型中为0.526(P<0.001)。F98脑干胶质瘤模型中Fischer344大鼠生存期10～19天,约有50%(9/18)的Fischer344大鼠在第13～15天时死亡。而U87MG脑干胶质瘤模型中裸小鼠的生存期在21～41天,其中75%(9/12)的裸小鼠生存期为24～31天。[结论]F98鼠胶质瘤细胞系和U87MG人胶质瘤细胞可建立稳定的脑干胶质瘤模型。1.5TMRI可用于监测肿瘤生长的动态特征。

[Purpose] To establish the models of brainstem glioma in rats and nude mice, and to investigate the feasibility of monitoring the brainstem glioma with 1.ST MRI system. [Methods ] Fischer344 rats and nude mice were inoculated with rat glioma cell line F98, human glioma cell lines U251MG and U87MG into brainstem, respectively. Brainstem gliomas were followed up with a 1.ST MRI scanner. Volumes of tumor in MRI were compared with that in pathology to assess the coherence between MRI section and pathological section. The repeatability of brainstem glioma models was explored by survival analysis. [Results] Of 20 Fischer344 rats implanted with F98 glioma, brainstem glioma was formed in 18 rats, and U251MG, U87MG resulted in brainstem gliomas in 3 of 15 and 12 of 15 nude mice respectively. MRI of glioma models was consistent with the features in pathology. Volume of tumor in MRI （95.9±17.8mm3）in rats was 14.7% larger than that in pathology（81.8±20.Smm3） （t=-4.78, P〈0.01 ）. Volume of tumor in MRI （9.49±0.91mm3）in nude mice was 8.0% larger than that in pathology（8.79±l.15mm3） （t=3.04, P=0.01）. Volume of tumor in MRI and in pathology was highly correlated （r=-0.631 in rats and r=-0.526 in nude mice）. F98 burdened Fiscsher344 rats survived for 10 to 19 days, and 50% died in 13 to 15 days. However, survival of U87MG burdened mice ranged 21 to 41 days, and 75% survived for 24 to 31 days. [Conclusion] F98 and U87MG are suitable to establish brainstem glioma models. It is feasible to monitor the development of brainstem glioma with 1.ST MRI scanner.