title: Positron emission tomography for preoperative staging in patients with locally advanced or metastatic colorectal adenocarcinoma in lymph node metastasis.
abstract: OBJECTIVE
  The impact of positron emission tomography was prospectively evaluated using 18 (F)-fluoro-deoxyglucose (FDG-PET) for the detection of lymph node (LN) metastasis in preoperative locally advanced colorectal adenocarcinoma, compared with computed tomography (CT) and pathologic findings.
  
  
  METHODS
  Fifty-three patients who were suspected of LN involvement by CT were staged preoperatively for LN metastasis using FDG-PET and CT. Regional LNs were classified into 3 groups, N1, N2-3, and N4, according to the Japanese General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (6th Edition). A comparison of pathologic findings with CT and FDG-PET findings was used to calculate sensitivity, specificity, and accuracy.
  
  
  RESULTS
  The sensitivity, specificity and accuracy of CT/FDG-PET were 91.3%/52.2%, 91.7%/75.0% and 65.9%/72.3%, respectively, for N1, 91.7%/75.0%, 72.2%/94.4% and 77.1%/89.6%, respectively, for N2-3, and 100%/100%, 17.6%/100% and 41.7%/100%, respectively, for N4. The detection rate of the num ber of metastatic N1 LNs by CT was significantly higher than by FDG-PET, and not significantly in the N2-4 area. LNs hidden by strong halation of the primary tumor were not detected by FDG-PET.
  
  
  CONCLUSIONS
  While FDG-PET is markedly more sensitive than CT for detection of N4 LN involve. ment, the number of metastatic LNs is difficult to determine.
authors.affiliation: Division of Colorectal Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. ckosugi0126@yahoo.co.jp
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kosugi
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.forename: Koji
authors.initials: K
authors.lastname: Murakami
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
authors.forename: Keiji
authors.initials: K
authors.lastname: Koda
authors.forename: Masato
authors.initials: M
authors.lastname: Ono
authors.forename: Masanori
authors.initials: M
authors.lastname: Sugito
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ito
authors.forename: Kenji
authors.initials: K
authors.lastname: Oda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Seike
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000556:secondary; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011446:Prospective Studies