title: Tc-99m diphosphonate as a potential radiotracer to detect sentinel lymph nodes in patients with breast cancer.
abstract: OBJECTIVE
  To evaluate the potential of Tc-99m diphosphonate as a tracer for sentinel lymph node biopsy in breast cancer.
  
  
  METHODS
  Lymphoscintigraphs of 35 patients (50.9 ± 10.2 years) with breast cancer were acquired after administering a subareolar intradermal injection of Tc-99m diphosphonate 18 h before surgery. Static images were taken within 15 min (early phase) and 15 h after injection (delayed phase). The lymphoscintigraphic identification rate was defined as the percentage of subjects studied with visible foci at axillae. Sentinel lymph node biopsies were performed using a gamma probe and by blue dye injection. Any node that was radioactive or stained with blue dye was labeled as a sentinel lymph node. Lymph nodes without radioactivity or blue dye staining were defined as non-sentinel lymph nodes. The intraoperative identification rate was defined as the percentage of patients with a radioactive sentinel lymph node. Percentages of lymphoid cells expressing S-100, CD83, and CD1a were compared.
  
  
  RESULTS
  The lymphoscintigraphic identification rate was 94.3% (33/35) during the early phase and 96.9% (31/32) during the delayed phase, whereas the intraoperative identification rate was 94.3% (33/35). The mean percentages of lymphoid cells that stained positively for S-100 or CD83 were lower in sentinel lymph nodes than in non-sentinel lymph nodes (1.5% vs. 9.0% for S-100, and 4.5% vs. 9.3% for CD83, respectively, p = 0.0286). The mean percentages of lymphoid cells in sentinel lymph nodes and non- sentinel lymph nodes expressing CD1a were 3.3% and 7.0%, respectively (p = ns).
  
  
  CONCLUSIONS
  Tc-99m diphosphonate can reliably detect regional lymph nodes in breast cancer.
authors.affiliation: Department of Nuclear Medicine, Medical College of Kyung Hee University, 149 Sang-Il-dong, Kangdong-gu, Seoul, 134-727 South Korea.
authors.forename: You-Jung
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: Department of Pathology, Medical College of Kyung Hee University, Seoul, Korea.
authors.forename: Sung-Jig
authors.initials: SJ
authors.lastname: Lim
authors.affiliation: Department of Surgery, Medical College of Kyung Hee University, Seoul, Korea.
authors.forename: Jeong-Yoon
authors.initials: JY
authors.lastname: Song
keywords: Breast cancer; Sentinel node; Tc-99m diphosphonate