Tateishi Ukihide, Maeda Tetsuo, Morimoto Tsuyoshi, Miyake Mototaka, Arai Yasuaki, Kim E Edmund
Division of Diagnostic Radiology, National Cancer Center Hospital, Tokyo, Japan.
Eur J Nucl Med Mol Imaging. 2007 Oct;34(10):1627-34. doi: 10.1007/s00259-007-0455-9. Epub 2007 May 26.
The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer.
Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([(18)F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities.
Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p = 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001).
Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer.
本研究旨在确定在PET/CT一体化检查中，非增强CT和增强CT对直肠癌术前淋巴结分期的诊断准确性。
对53例经病理证实的直肠癌患者进行回顾性分析，这些患者均因术前分期而接受检查。所有患者均接受了PET/CT一体化检查，包括非增强CT、增强CT及随后的全身氟-18-氟脱氧葡萄糖（[18F]FDG）PET检查。非增强和增强PET/CT图像由两名观察者分别进行一致性评估。参考标准为组织病理学结果。对于直肠癌的淋巴结分期，我们在两种检查方式之间比较了每位患者的诊断准确性。
37例患者（70%）通过非增强检查正确确定了淋巴结分期，42例患者（79%）通过增强检查正确确定了淋巴结分期。就每位患者而言，增强检查的区域淋巴结分期的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为85%、68%、83%、72%和79%，非增强检查分别为85%、42%、73%、62%和70%。两种检查方式在淋巴结分期准确性上的差异无统计学意义（p = 0.063）。与非增强检查相比，增强检查能更准确地确定直肠旁淋巴结（p = 0.002）、髂内淋巴结（p = 0.004）和闭孔淋巴结（p < 0.0001）的状态。
在精确界定直肠癌区域淋巴结状态方面，增强PET/CT优于非增强PET/CT。
