Mari Aparici Carina, Behr Spencer C, Seo Youngho, Kelley R Kate, Corvera Carlos, Gao Kenneth T, Aggarwal Rahul, Evans Michael J
1 Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
2 Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA.
Mol Imaging. 2017 Jan-Dec;16:1536012117723256. doi: 10.1177/1536012117723256.
While cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging is the primary method for diagnosing hepatocellular carcinoma (HCC), they provide little biological insight into this molecularly heterogeneous disease. Nuclear imaging tools that can detect molecular subsets of tumors could greatly improve diagnosis and management of HCC. To this end, we conducted a patient study to determine whether HCC can be resolved using Ga-citrate positron emission tomography (PET). One patient with recurrent HCC was injected with 300 MBq of Ga-citrate and imaged with PET/CT 249 minutes post injection. Four (28%) of 14 hepatic lesions were avid for Ga-citrate. One extrahepatic lesion was not PET avid. The average maximum standardized uptake value (SUV) for the lesions was 7.2 (range: 6.2-8.4), while the SUV of the normal liver parenchyma was 4.7 and blood pool was 5.7. The avid lesions were not significantly larger than the quiescent lesions, and a prior contrast CT showed uniform enhancement among the lesions, suggesting that tumor signals are due to specific binding of the radiotracer to the transferrin receptor, rather than enhanced vascularity in the tumor microenvironment. Further studies are required in a larger patient cohort to verify the molecular basis of radiotracer uptake and the clinical utility of this tool.
虽然计算机断层扫描（CT）和磁共振成像的横断面成像技术是诊断肝细胞癌（HCC）的主要方法，但它们对这种分子异质性疾病的生物学特性了解甚少。能够检测肿瘤分子亚群的核成像工具可极大地改善HCC的诊断和管理。为此，我们开展了一项患者研究，以确定是否可用镓柠檬酸盐正电子发射断层扫描（PET）来分辨HCC。一名复发性HCC患者注射了300MBq的镓柠檬酸盐，并在注射后249分钟进行PET/CT成像。14个肝脏病灶中有4个（28%）对镓柠檬酸盐摄取活跃。一个肝外病灶PET未摄取活跃。病灶的平均最大标准化摄取值（SUV）为7.2（范围：6.2 - 8.4），而正常肝实质的SUV为4.7，血池为5.7。摄取活跃的病灶并不比静止的病灶大很多，之前的增强CT显示病灶间强化均匀，这表明肿瘤信号是由于放射性示踪剂与转铁蛋白受体的特异性结合，而非肿瘤微环境中血管增多所致。需要在更大的患者队列中进行进一步研究，以验证放射性示踪剂摄取的分子基础及该工具的临床实用性。
