^18F-FDG PET／CT显像监测胃癌术后复发转移的价值

目的评价^18F-脱氧葡萄糖（FDG）PET／CT监测胃癌术后复发及转移的临床价值。方法回顾性分析胃癌术后临床疑复发或转移而行^18F-FDG PET／CT检查的45例患者临床资料，根据细胞学、病理或随访结果分析PET／CT检查结果，计算残胃及转移灶最大标准摄取值（SUVmax）。采用SPSS11．5软件进行数据处理，SUVmax两样本均数比较采用t检验。结果（1）45例中22例临床疑残胃复发，12例患者最终确定残胃复发，^18F-FDG PET／CT诊断残胃复发的灵敏度、特异性及准确性分别为100．0％（12／12）、70．0％（7／10）和86．4％（19／22），12例复发病灶SUVmax为6．27±3．42（其中2例低分化腺癌的SUVmax较低，分别为2．5和3．3），另10例无复发的残胃SUVmax为3．92±2．24（其中3例吻合口炎性病灶局部SUVmax较高，分别为8．3，5．2和6．3），差异无统计学意义（t=1．862，P〉0．05）。（2）对残胃以外转移灶的检出：PET／CT灵敏度、特异性、准确性在区域淋巴结转移中分别为78．9％（15／19）、92．3％（24／26）和86．7％（39／45），在腹膜转移中分别为6／9、97．2％（35／36）和91．1％（41／45），在远处转移中分别为86．7％（13／15）、93．3％（28／30）和91．1％（41／45）。（3）PET／CT假阳性8处为炎性或肠管摄取，假阴性9处多为直径〈1．0cm的转移灶和低分化腺癌及印戒细胞癌的转移灶。结论^18F-FDG PET／CT虽然检测胃癌术后区域淋巴结和腹膜转移的灵敏度较低，但仍是监测其术后复发转移的有效手段。

Value of 18F-FDG PET/CT in detecting recurrence and metastasis in gastric carcinoma

Objective PET with 18F-fluorodeoxyglucose (FDG) has been used to beth detect and stage a variety of malignancies. The aim of this retrospective study was to evaluate the clinical value of 18F-FDG PET/CT for recurrence and metastasis in gastric carcinoma patients after total gastrectomy. Methods A total of 45 gastric carcinoma patients who underwent total gastrectomy were included. PET/CT scans were obtained for restaging. The " gold standard" of 18F-FDG PET/CT diagnostic accuracy was based on either histopathology or clinical follow-up. By using the t-test from SPSS 11.5, the cut-off of maximum standard-ized uptake values (SUVmax) from 18F-FDG to differentiate benign from malignant lesion at stomach were determined and calculated. Results (1) Of the 45 patients, 22 were suspicion recurrent lesion at stomach. Of the 22 patients, 12 were confirmed to have recurrent lesions. The diagnostic accuracy were 100.0% (12/ 12) for sensitivity, 70.0% (7/10) for specificity, and 86.4% (19/22) for accuracy, respectively. A higher SUVmax in malignant than benign lesion was noted (6.27 ± 3.42 vs 3.92 ± 2.24), though not reached to the significance (t = 1. 862, P > 0.05). (2) For extra-gastric lesion detection, the sensitivity, specificity, and accuracy for region lymph nodes were 78.9% (15/19), 92.3% (24/26), and 86.7% (39/ 45), for peritoneal spreading were 6/9, 97.2% (35/36), 91. 1% (41/45), and for distant sites were 86.7%(13/15), 93.3% (28/30), 91.1% (41/45). (3) False positive were found in eight sites. All were either inflammatory or physiological uptake at intestine. False negative were found in nine sites. Either due to small in size (less than 1.0 cm in diameter), well differentiation of the tumor cell or with a nature of signet ring. Conclusion 18F-FDG PET/CT had a potential to detect local, regional, and distant metastasis in gastric cancer.