a Central Institute of Isotope Science, Hokkaido University , Sapporo , Japan.
b Radiation Oncology Branch , Center for Cancer Research, National Cancer Institute, National Health Institutes , Bethesda , MD , USA.
Free Radic Res. 2017 Oct;51(9-10):861-871. doi: 10.1080/10715762.2017.1388506.
Hypoxia is considered one of the microenvironmental factors associated with the malignant nature of glioblastoma. Thus, evaluating intratumoural distribution of hypoxia would be useful for therapeutic planning as well as assessment of its effectiveness during the therapy. Electron paramagnetic resonance imaging (EPRI) is an imaging technique which can generate quantitative maps of oxygen in vivo using the exogenous paramagnetic compound, triarylmethyl and monitoring its line broadening caused by oxygen. In this study, the feasibility of EPRI for assessment of oxygen distribution in the glioblastoma using orthotopic U87 and U251 xenograft model is examined. Heterogeneous distribution of pO between 0 and 50 mmHg was observed throughout the tumours except for the normal brain tissue. U251 glioblastoma was more likely to exhibit hypoxia than U87 for comparable tumour size (median pO; 29.7 and 18.2 mmHg, p = .028, in U87 and U251, respectively). The area with pO under 10 mmHg on the EPR oximetry (HF10) showed a good correlation with pimonidazole staining among tumours with evaluated size. In subcutaneous xenograft model, irradiation was relatively less effective for U251 compared with U87. In conclusion, EPRI is a feasible method to evaluate oxygen distribution in the brain tumour.
缺氧被认为是与胶质母细胞瘤恶性性质相关的微环境因素之一。因此，评估肿瘤内缺氧的分布情况对于治疗计划以及评估治疗过程中的疗效都很有用。电子顺磁共振成像（EPRI）是一种成像技术，它可以使用外源性顺磁化合物三芳基甲基生成体内氧的定量图谱，并监测其由氧引起的线宽变宽。在这项研究中，使用原位 U87 和 U251 异种移植模型，研究了 EPRI 评估胶质母细胞瘤中氧分布的可行性。除了正常脑组织外，整个肿瘤中都观察到了 pO 在 0 到 50mmHg 之间的不均匀分布。对于可比的肿瘤大小，U251 胶质母细胞瘤比 U87 更有可能出现缺氧（中位数 pO；在 U87 和 U251 中分别为 29.7 和 18.2mmHg，p=0.028）。在 EPR 血氧测定中，pO 值低于 10mmHg 的区域（HF10）与评估大小的肿瘤中的咪达唑仑染色具有良好的相关性。在皮下异种移植模型中，与 U87 相比，U251 的放疗效果相对较差。总之，EPRI 是一种评估脑肿瘤中氧分布的可行方法。
