Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
Diagnostics (Basel). 2015;5(3):318-32. doi: 10.3390/diagnostics5030318.
Magnetic resonance imaging (MRI) of glioblastoma multiforme (GBM) with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T 1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA)3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T 1-weighted imaging techniques. In this study, we used a dynamic quantitative T 1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA)3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA)3 agent, a scrambled-Tris-(Gd-DOTA)3 control agent, and the non-specific clinical contrast agent Optimark(™) all enhanced flank tumors of human glioma cells with similar maximal changes on T 1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T 1 while the specific agent SBK2-Tris-(Gd-DOTA)3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T 1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T 1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA)3 agent over time compared to the non-specific contrast agent currently in clinical use.
磁共振成像（MRI）与分子成像剂联合应用于多形性胶质母细胞瘤（GBM），可以实现脑肿瘤的特异性定位。先前的研究表明，与传统 T1 加权成像技术相比，使用 T1 加权 MR 成像，SBK2-Tris-（Gd-DOTA）3 分子成像剂可以更强烈地标记脑肿瘤的异位异种移植模型。在这项研究中，我们使用动态定量 T1 映射策略，更客观地比较了 SBK2-Tris-（Gd-DOTA）3 与非靶向对照剂随时间在肿瘤内的保留情况。我们的研究结果表明，靶向 SBK2-Tris-（Gd-DOTA）3 剂、无靶向的 Tr is-（Gd-DOTA）3 对照剂和非特异性临床造影剂 Optimark（™）均能增强人胶质细胞瘤细胞的侧腹肿瘤，在 T1 映射上的最大变化相似。然而，这些药物的保留情况有所不同。非特异性药物在 20 分钟内通过 T1 的增加而显著恢复，而特异性药物 SBK2-Tris-（Gd-DOTA）3 则保留在肿瘤中，在 60 分钟内几乎没有恢复。T1 值百分比变化、斜率计算以及肿瘤与肌肉之间的钆浓度计算均表明了保留效果。定量 T1 映射表明，与目前临床应用的非特异性造影剂相比，SBK2-Tris-（Gd-DOTA）3 剂在肿瘤中的结合和保留效果随时间的推移更为优越。
