Abdo Redha-Alla, Lamare Frédéric, Fernandez Philippe, Bentourkia M'hamed
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, QC J1H5N4, Canada.
Service de Médecine Nucléaire, Université de Bordeaux-II, EPHE, Bordeaux 33076, France.
Cancer Drug Resist. 2019 Mar 19;2(1):131-140. doi: 10.20517/cdr.2018.21. eCollection 2019.
The purpose of this study was to locate the levels of hypoxia in glioblastoma PET images measured with 18F-fluoromisonidazole in human subjects. It is recognized that tumors with hypoxia are resistant to treatment by radiotherapy and chemotherapy. The images were acquired in dynamic mode for 15 min or 30 min and in static mode for two single scans at 2 h and 3 h to allow the accumulation of the radiotracer in the tumor. The images were analyzed at the voxel basis with compartmental analysis (CA) and with the usual tumor-to-blood uptake ratio (TBR). Kmeans algorithm was applied to cluster the levels of hypoxia in the images. TBR at a threshold of 1.2 at imaging times of 15 min, 2 h and 3 h produced images with different clusters. Also, the comparison of TBR with the distribution volume obtained with CA had a similarity index of 0.61 ± 0.05. We found some differences in defining the hypoxic volume within a tumor using TBR. The compartmental analysis allowed discrimination of the tumor hypoxic sub-volumes which can be useful for a better treatment with radiotherapy.
本研究的目的是在人体受试者中，利用18F-氟米索硝唑测量胶质母细胞瘤PET图像中的缺氧水平。众所周知，存在缺氧情况的肿瘤对放疗和化疗具有抗性。图像以动态模式采集15分钟或30分钟，并在静态模式下于2小时和3小时进行两次单次扫描，以使放射性示踪剂在肿瘤中蓄积。采用房室分析（CA）和常用的肿瘤与血液摄取比（TBR）在体素基础上对图像进行分析。应用Kmeans算法对图像中的缺氧水平进行聚类。在15分钟、2小时和3小时的成像时间，TBR阈值为1.2时生成了具有不同聚类的图像。此外，TBR与通过CA获得的分布容积的比较得出相似性指数为0.61±0.05。我们发现在使用TBR定义肿瘤内的缺氧体积方面存在一些差异。房室分析能够区分肿瘤的缺氧亚体积，这对于放疗的更好治疗可能有用。
