18F-FDGPET／CT显像鉴别腹腔积液性质的价值

Value of 18F-FDG PET/CT in differentiating the character of ascites

目的探讨18F—FDGPET／CT显像在不明原因腹腔积液患者积液性质鉴别诊断中的作用。方法回顾性分析因不明原因腹腔积液入院的初诊患者70例，所有患者均行18F—FDGPET／CT显像、同机CT平扫和腹腔积液细胞学检查，PET／CT显像计算病灶SUV。结果经组织病理学、腹腔镜、胃镜、肠镜等检查及临床随访确定，随访时间均大于6个月。对疑有胃肠道病变患者行PET／CT延迟显像以明确诊断。有无腹膜转移组间SUV。。差异行两样本t检验；PET／CT、同机CT平扫及腹腔积液细胞学检查对腹膜转移诊断效能比较用McNemar检验；三者与最终结果吻合度检验用Kappa检验。结果腹腔积液患者70例，经手术、腹膜活组织检查或腹腔积液细胞学检查证实48例为腹膜转移癌引起的恶性积液，22例为良性积液。2组腹膜的SUV…分别为6．08±3．92和2．66±1．74，差异有统计学意义（t=一5．063，P〈0．001）。PET／CT诊断45例为恶性积液，其中2例为假阳性，另有5例恶性积液被误诊为良性积液，PET／CT诊断腹膜转移的灵敏度、特异性和准确性分别为89．6％（43／48）、90．9％（20／22）和90．0％（63／70）。定位CT诊断27例为腹膜转移，其中4例为假阳性，CT准确诊断良性腹腔积液18例，另有25例假阴性；定位CT诊断腹膜转移的灵敏度、特异性和准确性分别为47．9％（23／48）、81．8％（18／22）和58．6％（41／70）。PET／CT与定位CT诊断腹膜转移的灵敏度差异有统计学意义（r=14．286，P〈0．001）。70例腹腔积液患者中仅2l例腹腔积液中见癌细胞，其余患者细胞学检查均为阴性，腹腔积液细胞学对腹膜转移诊断的灵敏度、特异性和准确性分别为43．8％（21／48）、100％（22／22）和61．4％（43／70）；PET／CT与细胞学检查对腹膜转移诊断的灵敏度差异有统计学意义（z2=13．885，P〈0．001）。PET／CT检查结果与最后诊断结果吻合度较强（Kappa=0．776，P〈0．001），定位CT、腹腔积液细胞学检查结果与最后诊断结果吻合度均较弱（Kappa值分别为0．236和0．328，P均〈0．05）。结论”F—FDGPET／CT显像对不明原因腹腔积液患者腹膜转移诊断有重要临床价值，可用于不明原因腹腔积液的良恶性鉴别诊断。

Objective To assess the value of PET/CT in differentiating the character of ascites in patients with ascites of undetermined origin. Methods A total of 70 patients with aseites of undetermined origin were analyzed retrospectively. Each patient underwent a whole body mSF-FDG PET/CT scan, serum tumor marker examination and cytological examination of ascites. The diagnosis of peritoneal careinomatosis was established based on the results of histopathology examination, multimodality imaging and clinical follow-up after more than 6 months. T-test, McNemar test and Kappa test were used to analyze the data. Resuits Forty-eight patients were proven to have malignant ascites caused by peritoneal carcinomatosis accoming to histopathology examination, and the rest were proven to have benign aseites. The SUVmaX of peri- toneal lesions in the malignant ascites group and benign ascites group were 6.08±3.92 and 2.66±1.74, respectively （t = - 5. 063, P 〈 0. 001 ）. PET/CT lead to accurate diagnosis in 43 patients with malignant ascites and in 20 patients with benign ascites. False-positive and false-negative results were found in 2 and 5 patients, respectively. The sensitivity, specificity and accuracy of PET/CT for diagnosing peritoneal carci- nomatosis were 89.6% （43/48）, 90.9% （20/22） and 90.0% （63/70）, respectively. Located CT analysis accurately diagnosed 23 patients with malignant ascites and 18 patients with benign ascites. False-positive and false-negative diagnosis occurred in 4 and 25 patients, respectively. The sensitivity, specificity and ac- curacy of located CT for diagnosing peritoneal carcinomatosis were 47.9% （23/48）, 81.8% （18/22） and 58.6% （41/70）, respectively. The diagnostic sensitivities between PET/CT and located CT were signifi- cantly different （X2 = 14. 286, P 〈 0.001 ）. The cytological examination results were positive in 21 patients with malignant ascites. The diagnostic sensitivity, specificity and accuracy of cytological examination were 43.8 % （21/48 ）, 100% （22/22） and 61.4% （43/70）, respectively. The diagnostic sensitivity of PET/CT was higher than that of cytological examination （X2 = 13. 885, P 〈 0.001 ）. There was good agreement be- tween the diagnosis using PET/CT and the final diagnosis （Kappa =0.776, P 〈0. 001 ）. However, the agreements between the diagnosis using located CT or cytological examination and the final diagnosis were poor （Kappa = 0. 236 and 0. 328, both P 〈 0.05 ）. Conclusion is F-FDG PET/CT may help in diagnosing peritoneal carcinomatosis in patients with ascites of undetermined origin, and it can be used to differentiate the character of ascites.