18F-FLT和18F-FDG PET/CT对胸段食管癌淋巴结分期诊断的对比研究

目的 评价18F-脱氧胸苷（FLT）PET/CT对未经治疗的胸段食管癌淋巴结分期诊断的价值,并与18F-脱氧葡萄糖（FDG）PET/CT进行比较.方法 选择22例拟行手术治疗的胸段食管癌患者,术前行双显像剂PET/CT检查及淋巴结分期诊断,术后以病理学诊断为＂金标准＂,比较18F-FLT和18F-FDG PET/CT对胸段食管癌淋巴结分期的灵敏度、特异性、准确性、阳性预测值和阴性预测值.应用SPSS 13.0软件进行x2检验.结果 患者均行食管癌切除和淋巴结清扫术,病理检查结果显示16例患者存在淋巴结转移,N0期7例,N1期15例,M1a期6例（其中1例为N0M1a,另外5例为N1M1a）,全组均无M1b期.共检出424枚淋巴结,其中47枚为转移淋巴结.18F-FDG PET/CT诊断呈假阳性的淋巴结14枚,而18F-FLT诊断呈假阳性的淋巴结为3枚;18F-FDG假阴性的淋巴结8枚,18F-FLT假阴性的淋巴结12枚.18F-FLT PET/CT的诊断灵敏度、特异性、准确性、阴性预测值和阳性预测值分别为74.47%（35/47）、99.20%（374/377）、96.46%（409/424）、96.89%（374/386）和92.11%（35/38）,18F-FDG分别为82.98%（39/47）、96.29%（363/377）、94.81%（402/424）、97.84%（363/371）和73.58%（39/53）;两者比较的x2值分别为0.572,6.018,1.017,0.348,3.852,P值分别＞0.05,＜0.05、＞0.05、＞0.05和＞0.05.结论 18F-FLT对食管癌区域淋巴结的诊断灵敏度与18F-FDG显像接近,特异性高于18F-FDG,但仍存在一定的局限性.

Comparison of 18F-FLT and 18F-FDG PET/CT for lymph node staging in thoracic esophageal carcinoma

Objective To compare the diagnostic value 18F-fluorothymidine (FLT) and 18F-fluorodeoxyglucose (FDG) PET/CT in detecting lymph node metastases of untreated thoracic esophageal carcinoma. Methods Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent both 18F-FLT and 18F-FDG PET/CT before surgery. The imaging results of the two modalities in detecting regional lymph node metastases were compared prospectively with the pathologic findings. The X2-test was used with SPS S 13.0. Results All patients underwent esophagectomy and lymphadenectomy. The metastatic lymph nodes were found in 16 patients, from which 47 of 424 excised nodes were positive by pathologic examination. False positive results were 14 while false negative 8 on 18F-FDG PET/CT. In contrast, false positive results were only 3 but false negative were 12 on 18 F-FLT PET/CT. The sensitivity, specificity, accuracy,negative predictive value, and positive predictive value were 74.47% ( 35/47 ), 99.20% ( 374/377 ),96.46% (409/424), 96.89% ( 374/386 ) and 92.11% ( 35/38 ) respectively for 18 F-FLT PET/CT, whereas the corresponding values were 82.98% (39/47), 96.29% (363/377), 94.81% (402/424), 97.84%(363/371 ) and 73.58% (39/53) respectively for 18 F-FDG PET/CT (X2 = 0.572, 6.018, 1.017, 0.348,3.852, P＞0. 05, ＜0.05, ＞0.05, ＞0.05 and ＞0.05). Conclusions Compared with 18F-FDG PET/CT, 18F-FLT PET/CT may be less sensitive but more specific for the detection of lymph node metastases of thoracic esophageal carcinoma.