title: In vivo identification of sentinel lymph nodes for clinical stage I non-small cell lung cancer for abbreviation of mediastinal lymph node dissection.
abstract: BACKGROUND
  We previously reported that an identification of sentinel lymph node (SN) with a techenetium-99m (99mTc) tin colloid by ex vivo counting, i.e. the radio-activity of dissected lymph nodes, was a reliable method of establishing the first site of nodal metastasis in non-small cell lung cancer [J. Thorac. Cardiovasc. Surg. 124(2002)486]. However, for SN navigation surgery, SN should be identified before lymph node dissection (in vivo) but not after that (ex vivo). In order to reduce mediastinal lymph node dissection for clinical stage I non-small cell lung cancer (NSCLC) by SN navigation surgery, the SN identifications for hilar lymph nodes by ex vivo counting, and for mediastinal lymph nodes by in vivo, were evaluated.
  
  
  METHODS
  Intra-operative SN identification using 99mTc tin colloid was conducted on 104 patients with clinical stage I NSCLC who had had major lung resections with mediastinal lymph node dissections. The hilar SNs were identified by ex vivo counting (after lung resection) and the mediastinal SNs were identified by in vivo counting (before lymph node dissection). To evaluate the accuracy of mediastinal SN identification by in vivo counting, it was compared with the data by ex vivo counting.
  
  
  RESULTS
  SNs were identified in 84 patients (81%). SNs were identified at the hilum by ex vivo counting in 78 patients (93%) and at the mediastinum by in vivo counting in 40 patients (48%). While 15 patients had lymph node metastases, i.e. N1 in six and N2 in nine, the SNs could be found to have metastases during operation in 13 of the 15 patients (87%). The in vivo counting of the mediastinum missed out the mediastinal SNs identified by ex vivo counting in four of the 84 patients (5%).
  
  
  CONCLUSIONS
  If the hilar SNs identified by ex vivo counting and the mediastinal SNs identified by in vivo counting had no metastases, then mediastinal lymph node dissection could be abbreviated for patients with clinical stage I NSCLC.
authors.affiliation: Department of Thoracic Surgery, Saiseikai Central Hospital, 1-4-17 Mita, Minato-ku, Tokyo 108-0073, Japan. hnomori@qk9.so-net.ne.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nomori
authors.forename: Kenichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Tsuguo
authors.initials: T
authors.lastname: Naruke
authors.forename: Keiichi
authors.initials: K
authors.lastname: Suemasu
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008175:Lung Neoplasms / Q000473:pathology*; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D017556:Technetium Compounds; D017971:Tin Compounds
chemical_list: D017556:Technetium Compounds; D017971:Tin Compounds; C033493:technetium Tc 99m tin colloid