title: Auxiliary diagnosis of lymph node metastasis in early gastric cancer using quantitative evaluation of sentinel node radioactivity.
abstract: BACKGROUND
  Sentinel node (SN) mapping using dye and radioisotope (RI) tracer has been reported to be feasible in cases of early gastric cancer. Because accurate diagnosis of micrometastasis is sometimes difficult in the limited time available during surgery, a faster and simpler method of improving the intraoperative diagnostic precision of lymph node metastasis is needed. The amount of tracer deposited in an SN can be determined from its radioactivity; however, the significance of the RI count has not been fully discussed. We investigated the clinical impact of the RI count when used as an adjunct to conventional lymph node dissection when diagnosing lymphatic metastasis in cases of early gastric cancer.
  
  
  METHODS
  From 2008 to 2009, patients with clinically diagnosed T1N0M0 gastric cancers who underwent gastrectomy and SN mapping were enrolled. SNs were examined by intraoperative and postoperative pathology. The RI count was measured for each SN with a handheld gamma probe; the correlation between nodal metastasis and the RI count was assessed.
  
  
  RESULTS
  A total of 308 SNs were harvested from 72 patients. Patients with SN metastasis had significantly higher total RI counts than those without SN metastasis (p = 0.007). Among cases with SN metastasis, RI counts were also significantly elevated in metastasis-positive nodes, stations, and basins. In these cases, the most of SNs having the highest RI count in each case had metastasis including isolated tumor cells.
  
  
  CONCLUSIONS
  In early gastric cancer patients, a high RI count from an SN was correlated with lymph node metastasis. Therefore, RI counting may aid efficient pathological diagnosis and focused lymph node dissection.
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kamiya
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. htakeuchi@a6.keio.jp.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Tadaki
authors.initials: T
authors.lastname: Nakahara
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Niihara
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Wada
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kawakubo
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Saikawa
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Tai
authors.initials: T
authors.lastname: Omori
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Murakami
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D019275:Radiopharmaceuticals; D000071036:Sentinel Lymph Node / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D021701:Sentinel Lymph Node Biopsy; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery
chemical_list: D019275:Radiopharmaceuticals
keywords: Gastric cancer; Radioactivity; Sentinel lymph node biopsy