18F-FDG PET/CT在胃癌中的临床应用进展

胃癌是全球范围内最常见的恶性肿瘤之一。18F-氟脱氧葡萄糖（FDG）PET/CT在胃癌中的应用既有优点又有局限性。胃癌原发灶对18F-FDG的摄取与癌症分期、组织学分型和肿瘤大小密切相关。早期胃癌18F-FDG摄取阳性预示着内镜黏膜下剥离术的不可治愈性。进展期胃癌的最大标准化摄取值（SUV_max）在肠型与印戒细胞癌（SRC）或弥漫型胃癌间的差异显著，SRC的SUV_max与患者的总生存时间和无病生存时间呈负相关。18F-FDG PET/CT对区域淋巴结转移的诊断灵敏度较低，但其特异度很高，区域淋巴结对18F-FDG摄取呈阳性是预后不良的指征。18F-FDG PET/CT可检出隐匿的远处转移（7.2%~10.0%），其中大部分（4.7%~8.8%）使用腹腔镜也不能检出。常规性应用18F-FDG PET/CT并联合腹腔镜检查对明确胃癌分期的意义重大。因此，笔者就18F-FDG PET/CT在胃癌中的临床应用进展进行综述。

Research progress in the clinical application of 18F-FDG PET/CT in gastric cancer

Gastric cancer is one of the commonest malignant tumors in the world. The application of 18F-fluorodeoxyglucose (FDG) PET/CT in gastric cancer has both advantages and limitations. 18F-FDG uptake in primary gastric cancer is closely related to cancer staging, histological classification and tumor size. Positive 18F-FDG uptake in early gastric cancer often indicates the incurability of endoscopic submucosal dissection. Maximum standardized uptake value (SUV_max) of advanced gastric cancer is significantly different between intestinal type and signet ring cell carcinoma (SRC) or diffuse type gastric cancer; SUV_max of SRC is negatively correlated with the overall survival time and disease-free survival time of patients. The sensitivity of 18F-FDG PET/CT for regional lymph node metastasis is low, but the specificity is high. Regional lymph nodes with positive 18F-FDG uptake indicate poor prognosis. 18F-FDG PET/CT can detect occult distant metastases (7.2%~10.0%), most of which (4.7%~8.8%) cannot be detected by laparoscopy. Routine application of 18F-FDG PET/CT combined with laparoscopy is of great significance in determining the staging of gastric cancer.