[Detection of lateral lymph node metastasis by PET/CT].
OBJECTIVE
There appears to be no gold standard concerning preoperative imaging studies in patients with locally advanced lower rectal cancer. In the present study, we evaluated whether it would be appropriate to diagnose metastases of the lateral lymph node by positron emission tomography/computed tomography (PET/CT).


METHODS
From 1997 to 2014, 45 patients with locally advanced lower rectal cancer underwent curative surgery and lateral lymph node dissection without neoadjuvant chemotherapy in our institute. Preoperative PET/CT analysis was performed; a total of 180 regions (45 lt. internal iliac, 45 rt. Internal iliac, 45 lt. obturator, 45 rt. obturator)were evaluated.


RESULTS
Lateral lymph node metastasis was detected in ten cases, present in thirteen regions overall. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of predicting metastasis were 23.1%, 98.8%, 60.0%, 94.3%, and 93.3%, respectively, upon PET/CT.


CONCLUSIONS
Our results indicate that PET/CT diagnosis alone was not suitable for detecting lateral lymph node metastasis, since the sensitivity was low when compared with the high rate of accuracy.
Dept. of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University.
Yuichiro
Y
Watanabe
Keiichiro
K
Ishibashi
Satoshi
S
Hatano
Takeaki
T
Matsuzawa
Minoru
M
Fukuchi
Yoichi
Y
Kumagai
Erito
E
Mochiki
Hideyuki
H
Ishida
D000368:Aged; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed