title: Precise localization of sentinel lymph nodes and estimation of their depth using a prototype intraoperative mini gamma-camera in patients with breast cancer.
abstract: The aim of this study was to evaluate the ability of a prototype intraoperative mini gamma-camera, the CarolIReS, with a 50 x 50 mm field of view, to precisely localize sentinel lymph nodes (SLNs) and to determine their depth in a series of patients with infiltrative breast cancer requiring SLN excision.
  
  
  METHODS
  With the use of phantoms, the broadness of the signal of an acquired projection was shown to linearly depend on its distance from the collimator. A preclinical ex vivo study of 25 excised SLNs demonstrated that SLN size did not influence depth estimation. The minimum activity threshold for successful use of the proposed method was determined. After a preoperative radioisotope injection and lymphoscintigraphy, the SLN was localized in a series of 11 patients using both the mini gamma-camera and a gamma-probe. During surgery, a ruler was used to measure the depth of all SLNs before their excision.
  
  
  RESULTS
  Using the measured linear dependence of image broadness, we found that the expected SLN anatomic depth was compatible with its measured depth during surgery.
  
  
  CONCLUSIONS
  This study showed that the mini gamma-camera efficiently estimated the location of SLNs in 3 dimensions.
authors.affiliation: Service de Gynécologie-Obstétrique, Hôpital Civil, CHRU, Strasbourg, France. carole.mathelin@chru-strasbourg.fr
authors.forename: Carole
authors.initials: C
authors.lastname: Mathelin
authors.forename: Samuel
authors.initials: S
authors.lastname: Salvador
authors.forename: Daniel
authors.initials: D
authors.lastname: Huss
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Guyonnet
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D019047:Phantoms, Imaging; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D021701:Sentinel Lymph Node Biopsy
chemical_list: D019275:Radiopharmaceuticals