title: Sentinel node mapping for colorectal cancer with radioactive tracer.
abstract: OBJECTIVE
  The aim of this study was to test the feasibility and accuracy of radioactivity-guided mapping of the first lymph nodes found in draining the primary tumor site for colorectal cancer.
  
  
  METHODS
  We enrolled 56 consecutive patients with preoperative diagnosis of curatively resectable colorectal cancer. Endoscopic injection of technetium Tc 99m-labeled tin colloid (15 MBq) was performed preoperatively, and radioactive sentinel nodes were identified intraoperatively with a gamma probe. Standard radical resection with lymph node dissection was performed in all patients, and all resected nodes were evaluated by routine histopathologic examination.
  
  
  RESULTS
  Radioactivity-guided methods were used to detect sentinel nodes in 51 (91 percent) of 56 patients. The number of lymph nodes resected was 23.9 +/- 15.2 per case. The number of sentinel nodes was 3.5 +/- 2.1 (range, 0-8) per case. In 18 of 22 patients with lymph node metastasis, the sentinel node was positive. The incidence of metastasis in the sentinel node (22 percent) was significantly higher than that in nonsentinel nodes (3 percent, P < 0.01). Diagnostic accuracy according to sentinel node status was 92 percent (47/51). Four false-negative cases in this study were advanced cases with T3 primary tumors. The detection rate and diagnostic accuracy for patients with T1 or T2 primary tumors (29 cases) were 100 percent each.
  
  
  CONCLUSIONS
  Intraoperative radioactivity-guided sentinel node mapping was accurate for patients with colorectal cancer with T1 or T2 tumors. The results suggest that sentinel node mapping and intraoperative biopsy may be a sensitive and specific diagnostic method for detecting metastasis in regional lymph nodes in patients with colorectal cancer.
authors.affiliation: Departments of Surgery, School of Medicine, Keio University, 55 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Fujii
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Matsuda
authors.forename: Makio
authors.initials: M
authors.lastname: Mukai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kubo
authors.forename: Masaki
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011877:Radionuclide Imaging; D017556:Technetium Compounds; D017971:Tin Compounds
chemical_list: D017556:Technetium Compounds; D017971:Tin Compounds; C033493:technetium Tc 99m tin colloid