title: [Prediction of lateral lymph node metastasis by magnetic resonance imaging].
abstract: OBJECTIVE
  Considering the advantages and disadvantages of lateral lymph node dissection in patients with advanced lower rectal cancer, it would be ideal to select candidates for lateral lymph node dissection by preoperative imaging study including magnetic resonance imaging(MRI). We have reported that the cut-off value of minimal diameter of lateral lymph node could be set at 6 mm for indication of lateral lymph node dissection. In the present study, we evaluated whether it would be appropriate to apply the cut-off value of minimal diameter of lateral lymph node in MRI.
  
  
  METHODS
  Forty-four patients with advanced lower rectal cancer underwent a curative surgery with lateral lymph node dissection or sampling from 1997 to 2009 in our institute. Among them, 25 patients received MRI preoperatively and analyzed. The images were obtained by a sagittal method that was diagonal along sacro-iliac joint with 5 mm thick sections.
  
  
  RESULTS
  Lateral lymph node metastasis was detected in 5 cases, one side in 4 cases and both sides in 1 case. The sensitivity, specificity, positive predict value, and accuracy for predicting metastasis was 50%, 90%, 42.9% and 84.8% respectively, when the cut-off value of the minimal diameter was set at 6 mm in MRI.
  
  
  CONCLUSIONS
  Our results indicated that a 6 mm set as the cut-off value of minimal diameter of lateral lymph node was suitable for the prediction of lateral lymph node metastasis since the accuracy was relatively high (84.8%), though it was hardly to detect metastatic lymph node less than 6 mm.
authors.affiliation: Dept. of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hatano
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kumamoto
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Toru
authors.initials: T
authors.lastname: Ishiguro
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ohsawa
authors.forename: Norimichi
authors.initials: N
authors.lastname: Okada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakata
authors.forename: Masaru
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Norihiro
authors.initials: N
authors.lastname: Haga
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ishida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000473:pathology*; D012680:Sensitivity and Specificity