论文部分内容阅读
目的 探讨18F-FDG PET/CT同机序贯CECT(PET/CT+CECT)在胃癌治疗前分期中的价值,并分析影响胃癌原发灶18F-FDG摄取的相关因素.方法 前瞻性地选择经胃镜活组织检查病理证实为胃癌的未治患者28例[男23例,女5例,年龄(62.0±11.3)岁],常规18F-FDG PET/CT显像后,患者原位行腹盆部CECT.比较常规18F-FDG PET/CT与CECT在诊断胃癌原发灶、胃周淋巴结转移、腹盆腔脏器转移上的差异.数据分析采用Pearson相关分析、Kappa检验、Mann-Whitey u检验、Kruskal-Wallis H检验、配对x2检验.结果 28例患者中,12例为临床Ⅳ期,其中2例患者18F-FDGPET/CT发现CECT未显示的3枚较小肝转移灶.CECT发现了全部16例根治术患者的原发灶,其中15例胃癌原发灶放射性摄取明显增高,SUVmax3.15～ 19.99.16例胃癌患者原发灶体积与SUVmax有中度相关性(r=0.573,95％ CI:0.108～ 0.832,P＜0.05).CECT判断16例胃癌患者原发灶浆膜有无浸润与术后病理对比的一致性较低(κ=0.143,95％ CI:-0.338～0.624).有无原发灶脉管和(或)神经浸润者,不同T分期,不同组织学分级的原发灶SUVmax差异均无统计学意义(u=27.00,H=4.79和1.99,均P＞0.05);16例胃癌根治术患者共清扫淋巴结399枚,发现转移淋巴结81枚.CECT所示淋巴结转移与常规PET/CT所示转移淋巴结判断结果并不完全相符,两者之间有互补性.CECT判断胃周转移淋巴结的灵敏度、特异性、准确性、PPV和NPV分别为10/10、1/6、11/16、10/15和1/1;PET/CT的相应值分别为6/10、6/6、12/16、6/6和6/10;PET/CT+CECT的相应值分别为10/10、4/6、14/16、10/12和4/4.结论 常规18F-FDG PET/CT能够弥补CECT在较小肝癌转移灶诊断上的不足,18F-FDG PET/CT+CECT有助于提高胃癌治疗前分期的准确性.“,”Objective To evaluate the value of sequential 18F-FDG PET/CT and CECT (PET/CT+ CECT) in the pretreatment staging of gastric cancer,and to analyze the factors affecting the uptake of 18F-FDG in gastric cancer.Methods A total of 28 untreated gastric cancer patients (23 males,5 females,age (62.0± 11.3) years) confirmed by endoscopy biopsy were selected for this prospectively study.18F-FDG PET/CT was performed first,followed by 3-phase abdominopelvic CECT in the same position.They were compared in terms of their efficacy in primary gastric tumor detection,and accuracy in finding peri-gastric lymph node and abdominopelvic organ metastasis.Pearson correlation analysis,Kappa test,Mann-Whitney u test,Kruskal-Wallis H test,paired x2 test were used.Results Of 12 stage Ⅳ inoperable patients,18F-FDG PET/CT revealed 3 more small liver metastases in 2 patients which were negative on CECT.In 16 patients who underwent gastrectomy and lymph node dissection,all primary tumors were positive on CECT while 15/16 were positive on PET (SUVmax 3.15-19.99).The remaining case was a poorly differentiated signet-ring gastric adenocarcinoma with mild uptake (SUVmax 1.62).In all 16 patients,there was moderate correlation between primary tumor volume and SUVmean (r =0.573,95％ CI:0.108-0.832,P＜ 0.05).The consistency of serosal infiltration evaluated by CECT was low as compared with post-operative pathology (κ=0.143,95％ CI:-0.338-0.624).There was no significant statistical correlation between SUVmax of primary tumors with presence/absence of vascular or perineural infiltration,different T staging and histological grades (u=27.00,H=4.79 and 1.99,all P＞0.05).A total of 399 lymph nodes were dissected from the 16 patients;81 were confirmed metastatic.The evaluation of lymph node metastasis by PET/CT and CECT was not consistent but complementary.The sensitivity,specificity,accuracy,PPV and NPV for the detection of lymph node metastasis were 10/10,1/6,11/16,10/15 and 1/1 for CECT;6/10,6/6,12/16,6/6 and 6/10 for PET/CT;and 10/10,4/6,14/16,10/12 and 4/4 for PET/CT+CECT.Conclusions 18F-FDG PET/CT is superior to CECT for detection of small liver metastasis.18F-FDG PET/CT+CECT can improve the accuracy of pretreatment staging of gastric cancer.