Paraaortic lymph node metastasis in patients with intra-abdominal malignancies: CT vs PET.
OBJECTIVE
To compare the diagnostic accuracy of computed tomography (CT) and positron emission tomography (PET) for the preoperative detection of paraaortic lymph node (PAN) metastasis in patients with intra-abdominal malignancies.


METHODS
Sixty-six patients with intra-abdominal malignancies who underwent both CT and PET before lymphadenectomy were included in this study. Histopathologically, 13 patients had metastatic PAN, while 53 had non-metastatic PAN. The CT criteria for metastasis were: short diameter of > 8 mm, lobular or irregular shape, and/or combined ancillary findings, including necrosis, conglomeration, vessel encasement, and infiltration. The PET criterion was positive fluorodeoxyglucose (FDG) uptake. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of both modalities were compared with the pathologic findings, and the false positive and false negative cases with both CT and PET were analyzed.


RESULTS
The sensitivity, specificity, PPV, NPV, and accuracy of CT were 61.5%, 84.9%, 50%, 90% and 80.3%, respectively. For PET, the percentages were 46.2%, 100%, 100%, 88.3%, and 89.4%. Additionally, there were 8 false positive CT cases (8/53, 15.1%) and zero false positive PET cases. Of the 13 metastatic PANs, there were 5 false negative CT scans (38.5%) and 7 (53.9%) false negative PET scans.


CONCLUSIONS
For detecting PAN metastasis, CT is more sensitive than PET, while PET is more specific.
Lee
Mi-Jung
MJ
Department of Diagnostic Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, Seodaemun-Gu, Seoul 120-752, South Korea.
Yun
Mi Jin
MJ
Park
Mi-Suk
MS
Cha
Seung Hwan
SH
Kim
Myeong-Jin
MJ
Lee
Jong Doo
JD
Kim
Ki Whang
KW
D000008:Abdominal Neoplasms / Q000175:diagnosis* / Q000556:secondary; D000328:Adult; D000368:Aged; D001011:Aorta / Q000000981:diagnostic imaging; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18