title: Breast cancer: variables affecting sentinel lymph node visualization at preoperative lymphoscintigraphy.
abstract: OBJECTIVE
  To compare patients with visualized sentinel lymph nodes (SLNs) and patients with nonvisualized SLNs, with a focus on variables affecting SLN visualization at preoperative lymphoscintigraphy and on nodal drainage basins as related to tumor location.
  
  
  METHODS
  One hundred thirty-six patients who had breast cancer underwent preoperative lymphoscintigraphy before SLN biopsy. Patients with visualized and nonvisualized SLNs were compared for age; tumor site, size, and histologic findings; injection guidance method; diagnostic biopsy type; interval between biopsy and lymphoscintigraphy; intraoperative identification method; and surgical identification rate. Visualized SLN drainage basins were noted.
  
  
  RESULTS
  Ninety-nine patients had visualized and 37 had nonvisualized SLNs, without statistically significant differences in tumor site, size, and histologic findings; injection guidance method; diagnostic biopsy type; and interval between biopsy and lymphoscintigraphy. Ninety-nine (73%) of the 136 SLNs were visualized at lymphoscintigraphy; 30 (81%) of the 37 nonvisualized SLNS were identified at surgery. Of the seven SLNs not identified at surgery, five were mapped with radiocolloid only. Patients with nonvisualized SLNs were older than those with visualized SLNs. Eleven (46%) of 24 tumors with internal mammary drainage were in the outer part of the breast.
  
  
  CONCLUSIONS
  Patients with and those without visualization differed in age, SLN identification at surgery, and surgical identification method. Nonvisualized status does not preclude axillary metastasis. In older patients with nonvisualized SLNs, blue dye may aid in SLN detection, as compared with isotope-only localization.
authors: Department of Radiology, Stanford University Medical Center, 300 Pasteur Dr, H-1307, Stanford, CA 94305-5105, USA. birdwell@stanford.edu
authors: R L
authors: RL
authors: Birdwell
authors: K L
authors: KL
authors: Smith
authors: B J
authors: BJ
authors: Betts
authors: D M
authors: DM
authors: Ikeda
authors: H W
authors: HW
authors: Strauss
authors: S S
authors: SS
authors: Jeffrey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D011877:Radionuclide Imaging; D012016:Reference Values; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*