title: Use of radiotracer for sentinel lymph node mapping in breast cancer optimizes staging independent of site of administration.
abstract: OBJECTIVE
  In an effort to optimize sentinel lymph node (SLN) mapping for breast cancer, sites of mapping agent administration and types of mapping agents used continue to be evaluated. This study compares SLN mapping using peritumoral (PT) or subareolar (SA) injection of radiolabeled colloid and examines the relative contributions of radiotracer and blue dye to SLN identification.
  
  
  METHODS
  A retrospective review was performed of 456 patients with breast cancer and clinically negative axillae who underwent SLN mapping. Sequential groups of patients were injected with filtered Tc-99m SC, 326 peritumorally (group 1) and 130 subareolarly (group 2). All patients had intraoperative SA injection of 1% isosulfan blue dye.
  
  
  RESULTS
  The SLN identification and isotope success rates were 97% and 96% in group 1 and 98% and 98% in group 2, respectively. Eighty-one patients (25%) in group 1 and 44 patients (34%) in group 2 had positive SLNs. Of these patients, 15% from group 1 and 14% from group 2 had only positive nodes detected by radiotracer, and 9 of these patients (6 from group 1 and 3 from group 2) had other nodes identified by both radiotracer and blue dye that were negative for metastases. Six percent of patients with positive SLNs were upstaged because of use of radiotracer.
  
  
  CONCLUSIONS
  PT and SA injection of radiotracer have comparable success rates for axillary SLN identification. Given that 15% of patients in group 1 and 14% in group 2 had only positive SLNs detected by radiotracer, independent of site of administration, radiotracer remains essential for optimizing breast SLN mapping.
authors.affiliation: Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, 19104, USA.
authors.forename: Susan B
authors.initials: SB
authors.lastname: Kesmodel
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Canter
authors.forename: Kyla P
authors.initials: KP
authors.lastname: Terhune
authors.forename: Todd W
authors.initials: TW
authors.lastname: Bauer
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Mick
authors.forename: Ernest F
authors.initials: EF
authors.lastname: Rosato
authors.forename: Francis R
authors.initials: FR
authors.lastname: Spitz
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.forename: Abass
authors.initials: A
authors.lastname: Alavi
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Czerniecki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid