18氟-脱氧葡萄糖正电子发射计算机断层成像联合同机增强CT对结直肠癌肝转移的诊断价值

Diagnostic value of 18F-fluorodexyglucose positron emission tomography combined with contrast enhanced computed tomography in colorectal cancer liver metastasis

目的：探讨18氟-脱氧葡萄糖正电子发射计算机断层成像（18F-FDG PET-CT）联合同机增强CT技术（PET-增强CT）对结直肠癌肝转移中的诊断价值。方法回顾性分析2010年4月至2013年3月中山大学附属第六医院接受PET-增强CT检查可疑存在肝转移的58例结直肠癌患者的临床和影像资料。以最终确定诊断为标准，计算常规PET-CT、同机增强CT和PET-增强CT对结直肠癌肝转移诊断的灵敏度、特异度、准确性及其与最终诊断的一致性。结果58例结直肠癌患者通过影像学检查共发现147个可疑肝转移灶，最后证实恶性病灶125个，其中直径小于或等于1．0 cm者58个（46．4％）；良性病灶22个，其中直径小于或等于1．0 cm者17（77．3％）个。常规18F-FDG PET-CT、增强CT和18F-FDG PET-增强CT对直径大于1．0 cm病灶的诊断准确性分别为100％、93．1％和100％，与最终诊断的一致性分别为优、中等和优（Kappa值分别为1．000、0．408和1．000）；对直径小于或等于1．0 cm病灶诊断的准确性分别为42．7％、78．7％和94．7％，与最终诊断的一致性分别为无意义、一般和优（Kappa值分别为－0．005、0．305和0．848）。常规PET-CT、增强CT和PET-增强CT诊断直径小于或等于1．0 cm肝转移灶的曲线下面积（AUC）分别为0．525（95％ CI：0．407～0．462）、0．651（95％ CI：0．532～0．757）和0．924（95％ CI：0．839～0．972）；PET-增强CT的AUC明显大于常规PET-CT（Z＝5．559， P＜0．05）和增强CT（Z＝4．183， P＜0．05）。结论 PET-增强CT可以明显提高结直肠癌患者肝内小转移灶的诊断准确性。

Objective To explore the preoperative diagnostic value of 18F-fluorodexyglucose positron emission tomography combined with contrast enhanced computed tomography （18F-FDG PET-ceCT） in patients with colorectal cancer liver metastasis. Methods Clinical and imaging data of 58 patients with suspicious colorectal cancer liver metastasis between April 2010 and March 2013 were retrospectively evaluated. All the patients underwent 18F-FDG PET-ceCT. On the basis of definitive diagnosis, the sensitivity, specificity, accuracy and consistency of routine PET-CT, ceCT and 18F-FDG PET-ceCT were calculated. Results A total of 147 suspicious lesions of colorectal cancer liver metastasis were found in 58 patients. Finally, 125 lesions were confinmed as malignant, of which 58 （46.4%） lesions were less than 1.0 cm. The other 22 lesions were confinmed as benign , of which 17 （77.3%） lesions were less than 1.0 cm. The diagnostic accuracy of routine PET-CT , ceCT and 18F-FDG PET-ceCT in colorectal cancer liver metastasis for the lesions more than 1.0 cm was 100%, 93.1%,100% respectively, and the consistency with final diagnosis was perfect, moderate, and perfect respectively （Κappa value 01.00, 0.408, 1.00）. For the lesions less than 1.0 cm, the accuracy was 42.7%, 78.7%, 94.7% respectively, and the consistency with definitive diagnosis was insignificance, fair, and almost perfect respectively （Κappa value -0.005, 0.305, 0.848）. The area under curve （AUC） was 0.525 （95% CI： 0.407-0.462） for routine PET-CT, 0.651 （95% CI：0.532-0.757） for ceCT, and 0.924 （95% CI：0.839-0.972） for 18F-FDG PET-ceCT respectively. The AUC of 18F-FDG PET-ceCT was significantly larger than that of routine PET-CT （Z=5.559, P〈0.05） or ceCT （Z=4.183, P〈0.05）. Conclusion 18F-FDG PET-ceCT can improve the diagnostic accuracy for smaller lesions of colorectal cancer liver metastasis.