PET组合融合成像在分化型甲状腺癌复发和转移中的应用进展

甲状腺癌是最常见的内分泌系统恶性肿瘤之一，其中分化型甲状腺癌约占甲状腺癌发病率的90%以上，预后良好。但中国甲状腺癌患者5年相对生存率与一些发达国家差距较大。早期、准确地发现复发性疾病并应用适当的治疗策略，可改善复发性疾病患者的预后。因此，早期发现这些病人的复发和转移是至关重要的。随着诊断技术从系统向分子水平的过渡，多模态分子成像的作用越来越重要。PET能提供肿瘤细胞的功能学信息，而CT、MRI则能提供肿瘤的解剖学信息。功能成像技术和解剖学成像技术相结合能够实现优势互补，对于疾病复发和转移的诊断意义重大。随着近年来PET-CT在分化型甲状腺癌诊断、分期、疗效及预后评估上都较常规影像学检查更具优势，而PET-MRI是继PET-CT之后又一项优秀的多模态成像技术，因其软组织高分辨率和多序列多参数成像特性，所发挥的作用也愈发重要。因此，本文就PET-CT和PET-MRI在分化型甲状腺癌术后复发/转移中临床应用及未来前景进行综述。 

Application progress of PET combined fusion imaging in the recurrence and metastasis of differentiated thyroid cancer

Thyroid cancer is one of the most common endocrine system malignancies, in which differentiated thyroid cancer accounts for more than 90% of the incidence of thyroid cancer, with a good prognosis. However, the 5-year relative survival rate of thyroid cancer patients in China is far from that in some developed countries. Early and accurate detection of recurrent disease and appropriate treatment strategies can improve the prognosis of patients with recurrent disease. Therefore, early detection of recurrence and metastasis of these patients is essential. With the transition of diagnostic technology from system to molecular level, multi-modal molecular imaging is increasingly important. PET can provide functional information of tumor cells, while CT and MRI can provide anatomical information of tumors.The combination of functional imaging technology and anatomical imaging technology can achieve complementary advantages and is of great significance for the diagnosis of disease recurrence and metastasis. Two major directions of combined PET fusion imaging are PET-CT and PET-MRI. In recent years,PET-CT has more advantages than conventional imaging in the efficacy and prognosis evaluation of DTC diagnosis staging,and PET-MRI is another excellent multi-mode imaging technology after PET-CT. Due to its high-resolution soft tissue and multi-sequence and multi-parameter imaging characteristics, PET-MRI is increasingly important. Therefore, the clinical application and future prospect of PET-CT and PET-MRI in postoperative recurrence/metastasis of differentiated thyroid cancer is reviewed.