肝癌是我国死亡率位居第二的恶性肿瘤，每年死亡人数占全球肝癌死亡病例数的51%，给我国的社会和医疗带来了沉重的负担。早期诊断是预防肝癌、提高肝癌患者生存率最重要的措施之一，也是目前肿瘤分子影像研究的努力方向。针对目前18FDG PET/CT肝细胞癌显像存在诊断率较低的不足，本研究拟以肝癌细胞高表达的磷脂酰肌醇蛋白聚糖-3受体（GPC3）为靶点，构建一种99mTc标记的基于纳米抗体（Nanobody，VHH）的核医学显像分子探针，通过选择不同药代动力学修饰分子（PKM）并优化制备工艺，评价其在肝细胞癌动物模型上进行肿瘤早期核医学诊断的可行性，为肝癌的的早期显像诊断、疗效监测及指导个体化治疗提供方法和手段。

Hepatocellular carcinoma ( HCC) is a malignant tumor with the second highest mortality rate in China，and annual deaths account for 51% of all deaths in the world. This has brought a heavy burden on our society and medical care. Early diagnosis not only be one of the most important methods for preventing HCC and improving survival rate, but also be an important research direction of tumor molecular imaging. In this proposal, GPC3-targeted SPECT imaging of HCC will be performed. A series of molecular imaging probes will be designed, synthesized, and optimized by selecting different pharmacokinetic modifying (PKM) linkers. The possibility of using these molecular probes for early SPECT diagnostic imaging HCC will be investigated. The standard rule for designing 99mTc labelled nanobody will also be explored. This study would provide important information for the development of other nanobody-based imaging probes.