title: Lymphatic mapping and sentinel node biopsy using 99mTc tin colloid in gastric cancer.
abstract: OBJECTIVE
  The aim of this study was to determine the feasibility of sentinel lymph node (SLN) biopsy in patients with gastric cancer for the assessment of regional lymph node status.
  
  
  BACKGROUND
  SLN is the first draining node from the primary lesion, and it is the first site of lymph node metastasis in malignancy. SLN mapping and biopsy are of great significance in the determination of the extent of lymphadenectomy, allowing patients with gastric cancer to have a better quality of life without jeopardizing survival.
  
  
  METHODS
  The SLN biopsy was performed in 46 consecutive patients having gastric cancer with a preoperative imaging stage of T1/T2, N0, or M0. Three hours prior to each operation, Tc tin colloid (2.0 mL, 1.0 mCi) was endoscopically injected into the gastric submucosa around the primary tumor. Subsequently, serial lymphoscintigraphy was performed using a dual-head gamma camera. After the SLN biopsy had been performed using a gamma probe, all patients underwent radical gastrectomy (D2 or D2+alpha). The SLN was cut and immediately frozen-sectioned. A paraffin block was then produced for permanent hematoxylin-eosin staining and immunohistochemistry (IHC).
  
  
  RESULTS
  SLNs were successfully identified in 43 of 46 patients (success rate, 93.5%). On average, 2 (range, 1-8) SLNs were identified per patient. The positive predictive value, negative predictive value, sensitivity, and specificity of SLN biopsy were 100% (11 of 11), 93.8% (30 of 32), 84.6% (11 of 13), and 100% (30 of 30), respectively. SLNs were located at the level I lymph nodes in 38 (88.4%), the level I+II nodes in 2 (4.7%), and the level II nodes in 3 (7.0%). No micrometastases of SLNs was found on IHC for cytokeratin.
  
  
  CONCLUSIONS
  SLN biopsy using a radioisotope in patients with gastric cancer is a technically feasible and accurate technique, and it is a minimally invasive approach in the assessment of patient nodal status.
authors.affiliation: Department of Surgery, Dong-A University College of Medicine, Busan, South Korea.
authors.forename: Min-Chan
authors.initials: MC
authors.lastname: Kim
authors.forename: Hyung-Ho
authors.initials: HH
authors.lastname: Kim
authors.forename: Ghap-Joong
authors.initials: GJ
authors.lastname: Jung
authors.forename: Jong-Hun
authors.initials: JH
authors.lastname: Lee
authors.forename: Seok-Ryeol
authors.initials: SR
authors.lastname: Choi
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Kang
authors.forename: Mee-Sook
authors.initials: MS
authors.lastname: Roh
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Jeong
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D005240:Feasibility Studies; D006801:Humans; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D017556:Technetium Compounds; D017971:Tin Compounds
chemical_list: D019275:Radiopharmaceuticals; D017556:Technetium Compounds; D017971:Tin Compounds; C033493:technetium Tc 99m tin colloid