Comparison of PET/CT and PET/MRI hybrid systems using a 68Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience
Comparison of PET/CT and PET/MRI hybrid systems using a 68Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience
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DOI：
10.1007/s00259-013-2660-z
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发表时间：
2014-05-01
影响因子：
9.1
通讯作者：
Roethke, M.
中科院分区：
文献类型：
--
作者：
Afshar-Oromieh, A.;Haberkorn, U.;Roethke, M.
Ga-68标记的HBED-CC-PSMA是用于成像复发性前列腺癌（PCa）的非常有前途的示踪剂。本研究的目的是评估PET/MRI与这种示踪剂的可行性。20例患者在注射Ga-68-PSMA配体后1 h进行PET/CT，然后在注射后3 h进行PET/MRI。首先对两项研究的数据进行单独分析，然后比较肿瘤检出率和各种组织中放射性示踪剂的摄取。为了评价PET/MRI系统的定量准确性，将PET/CT和相应PET/MRI之间的SUV差异与另一患者队列中注射后1小时和3小时PET/CT之间的SUV差异进行比较。该队列研究使用相同的PET/CT系统，使用PET/MRI，不同的诊断序列，更高的病灶对比度和更高的MRI分辨率使图像的主观评价更容易。此外，PET/CT上的4个不明确结果可通过PET/MRI澄清为PCa转移的特征。然而，在PET/MRI的PET图像中，在肾脏水平（11例患者）和膀胱周围（15例患者）观察到信号降低。这导致6处病变的SUV减少。PET/MRI系统提供的SUV平均值在肌肉、血池、肝脏和脾脏中存在差异，Ga-PSMA PET/MRI比PET/CT更容易、更准确地检测到PCa，且辐射暴露量更低。因此，这项新技术可以澄清PET/CT上不明确的发现。然而，当使用特异性Ga-68-PSMA配体时，散射校正具有挑战性。此外，需要仔细进行PET/CT和PET/MR SUV的直接比较。
Ga-68-labelled HBED-CC-PSMA is a highly promising tracer for imaging recurrent prostate cancer (PCa). The intention of this study was to evaluate the feasibility of PET/MRI with this tracer.Twenty patients underwent PET/CT 1 h after injection of the Ga-68-PSMA ligand followed by PET/MRI 3 h after injection. Data from the two investigations were first analysed separately and then compared with respect to tumour detection rate and radiotracer uptake in various tissues. To evaluate the quantification accuracy of the PET/MRI system, differences in SUVs between PET/CT and corresponding PET/MRI were compared with differences in SUVs between PET/CT 1 h and 3 h after injection in another patient cohort. This cohort was investigated using the same PET/CT system.With PET/MRI, different diagnostic sequences, higher contrast of lesions and higher resolution of MRI enabled a subjectively easier evaluation of the images. In addition, four unclear findings on PET/CT could be clarified as characteristic of PCa metastases by PET/MRI. However, in PET images of the PET/MRI, a reduced signal was observed at the level of the kidneys (in 11 patients) and around the urinary bladder (in 15 patients). This led to reduced SUVs in six lesions. SUVmean values provided by the PET/MRI system were different in muscles, blood pool, liver and spleen.PCa was detected more easily and more accurately with Ga-PSMA PET/MRI than with PET/CT and with lower radiation exposure. Consequently, this new technique could clarify unclear findings on PET/CT. However, scatter correction was challenging when the specific Ga-68-PSMA ligand was used. Moreover, direct comparison of SUVs from PET/CT and PET/MR needs to be conducted carefully.