title: Clinically useful detection criteria for sentinel nodes in patients with breast cancer using a radioisotope technique.
abstract: BACKGROUND
  The radioisotope technique has been used to identify sentinel nodes in patients with breast cancer. However, quantitative analysis of the radioactivity for detecting the sentinel nodes was not previously examined. In this study, we considered a clinically useful criterion for detecting sentinel nodes by a detailed analysis of 312 sentinel nodes using the radioisotope technique.
  
  
  METHODS
  Patients with T1-2, N0 breast cancer were eligible for this study. The nodes with the highest radioactivity after injection of technetium-labeled tin colloids were identified as hot nodes. The radioactivities of the hot nodes and the background counts of the axillary basin were examined in order to establish new criteria for detecting the sentinel nodes.
  
  
  RESULTS
  Between May 1997 and December 2001, 312 hot nodes were detected in 183 of 186 patients (98.4%). Since the false-negative rate for metastasis in hot nodes was only 2.1% (1/48), they could serve as sentinel nodes to predict the nodal status. However, there was a wide distribution of the hot nodes and the background in terms of absolute counts and a criterion for the sentinel nodes could not be established in terms of the absolute counts. When we adopted the criterion of sentinel nodes with a >/=100 count ratio in relation to the background, only 169 hot nodes (54.3%) met our definition. When the criterion of a >or=10 count ratio was adopted, all hot nodes met our definition and all other nodes remained non-sentinel nodes.
  
  
  CONCLUSIONS
  The criterion for defining sentinel nodes in our method is a node with a >or=10 count ratio with respect to the background. It is recommended that an analysis based on such objective data should be investigated in order to provide surgeons with more accurate and clinically useful criteria for detecting sentinel nodes.
authors.affiliation: Department of Surgery I, National Defense Medical College, Tokorozawa, Saitama, Japan. sato-k-a@mtg.biglobe.ne.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sato
authors.forename: Kuniyoshi
authors.initials: K
authors.lastname: Tamaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Shigekawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuda
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kosuda
authors.forename: Shoichi
authors.initials: S
authors.lastname: Kusano
authors.forename: Hoshio
authors.initials: H
authors.lastname: Hiraide
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Mochizuki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001417:Background Radiation; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011851:Radioactivity; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid