title: The impact of nonvisualization of sentinel nodes on lymphoscintigraphy in breast cancer.
abstract: BACKGROUND
  This study aimed at evaluating the relationship between the nonvisualization of sentinel nodes (SNs) at lymphoscintigraphy and the intraoperative detection rate, radioactive counts in vivo, and histological status of SNs.
  
  
  METHODS
  Two hundred eighty patients with infiltrating breast carcinoma (T0, T(1)/T(2)) underwent preoperative lymphoscintigraphy before gamma probe-guided SN biopsy.
  
  
  RESULTS
  The surgical identification rate with a gamma probe was 84.6% (56 of 280) in lymphoscintigraphy-negative patients and 93.2% (224 of 280) in lymphoscintigraphy-positive patients (P < .05) after two subdermal periareolar injections. The average number of SNs per patient was 1.7 in lymphoscintigraphy-negative patients and 2.2 in lymphoscintigraphy-positive patients (P < .01), as assessed by gamma detection. The mean age of lymphoscintigraphy-negative patients was 62 +/- 10 years, versus 55 +/- 13 years for lymphoscintigraphy-positive patients (P < .001). The median radioactive count in dissected SNs identified by gamma detection was 204 cps (range, 4-618 cps) in lymphoscintigraphy-negative patients, versus 606 cps (range, 43-16,928 cps) in lymphoscintigraphy-positive patients (P < .001). The rate of macrometastatic SNs was 40% in lymphoscintigraphy-negative patients, versus 30% in lymphoscintigraphy-positive patients (not significant), whereas the size of involved SNs was 16.6 mm in lymphoscintigraphy-negative patients, versus 13.1 in lymphoscintigraphy-positive patients (P < .05). The micrometastasis detection rate in SNs from lymphoscintigraphy-negative patients was 6.25%, versus 23.3% in lymphoscintigraphy-positive patients (P < .01).
  
  
  CONCLUSIONS
  Negative lymphoscintigraphy was observed in 20% of patients and was more frequent in elderly patients. Negative lymphoscintigraphy was predictive of a lower surgical identification rate and fewer detected SNs. These SNs had fewer micrometastases, were fairly large, and tended to harbor metastases.
authors.affiliation: Service of Nuclear Medicine, René Gauducheau Cancer Center Nantes-Saint Herblain, Boulevard Monod, 44805 Saint Herblain Cedex, France. c-rousseau@nantes.fnclcc.fr
authors.forename: C
authors.initials: C
authors.lastname: Rousseau
authors.forename: J M
authors.initials: JM
authors.lastname: Classe
authors.forename: L
authors.initials: L
authors.lastname: Campion
authors.forename: C
authors.initials: C
authors.lastname: Curtet
authors.forename: F
authors.initials: F
authors.lastname: Dravet
authors.forename: R
authors.initials: R
authors.lastname: Pioud
authors.forename: C
authors.initials: C
authors.lastname: Sagan
authors.forename: B
authors.initials: B
authors.lastname: Bridji
authors.forename: I
authors.initials: I
authors.lastname: Resche
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000473:pathology*; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy; D008875:Middle Aged; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011877:Radionuclide Imaging / Q000379:methods*; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*