title: The role of multidetector CT in local staging and evaluation of retroperitoneal surgical margin involvement in colon cancer.
abstract: OBJECTIVE
  We aimed to evaluate preoperative T and N staging and retroperitoneal surgical margin (RSM) involvement in colon cancer using multidetector computed tomography (MDCT).
  
  
  METHODS
  In this retrospective study, preoperative MDCTs of 141 patients with colon adenocarcinoma were evaluated in terms of T and N staging and retroperitoneal surgical margin involvement by two observers. Results were compared with histopathology.
  
  
  RESULTS
  In determining extramural invasion, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MDCT were 81%, 50%, 95%, 26%, and 81% for observer 1 and 87%, 75%, 97%, 27%, and 84% for observer 2, respectively. Moderate interobserver agreement was observed (ĸ=0.425). In determining T stage of the tumor, accuracy of MDCT was 55% for observer 1 and 51% for observer 2. In the detection of lymph node metastasis, sensitivity, specificity, PPV, NPV, and accuracy of MDCT were 84%, 46%, 60%, 74% and 64% for observer 1 and 84%, 56%, 65%, 78%, and 70% for observer 2, respectively. Interobserver agreement was substantial (ĸ=0.650). RSM was involved in six cases (4.7%). When only retroperitoneal colon segments were considered, 1.6% of subjects demonstrated RSM involvement. Four of the six RSM-positive tumors were located on sigmoid colon and one tumor was on transverse colon and caecum. Considering all colon tumors, in the detection of RSM involvement, sensitivity and specificity of MDCT were 33% and 81% for observer 1 and 50% and 80% for observer 2. Interobserver agreement was moderate (ĸ=0.518).
  
  
  CONCLUSIONS
  MDCT is a promising technique with moderate interobserver agreement in detection of extramural invasion, lymph node metastases, and RSM involvement in colon carcinomas.
authors.affiliation: Department of Radiology Dokuz Eylül University School of Medicine, İzmir, Turkey. fundadi@yahoo.com.
authors.forename: Funda Dinç
authors.initials: FD
authors.lastname: Elibol
authors.forename: Funda
authors.initials: F
authors.lastname: Obuz
authors.forename: Selman
authors.initials: S
authors.lastname: Sökmen
authors.forename: Cem
authors.initials: C
authors.lastname: Terzi
authors.forename: Aras Emre
authors.initials: AE
authors.lastname: Canda
authors.forename: Özgül
authors.initials: Ö
authors.lastname: Sağol
authors.forename: Sülen
authors.initials: S
authors.lastname: Sarıoğlu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D015588:Observer Variation; D011237:Predictive Value of Tests; D012187:Retroperitoneal Space / Q000000981:diagnostic imaging / Q000473:pathology; D012189:Retrospective Studies; D055815:Young Adult