title: Does the preparation and utilization of 99mTc-sulfur colloid affect the outcomes of breast lymphoscintigraphy?
abstract: The purpose of this study was to determine whether certain factors in the preparation and use of (99m)Tc-sulfur colloid affected the number of sentinel lymph nodes (SLNs) detected during SLN mapping and during intraoperative SLN identification. The factors that were investigated included the use of a dry heat block versus a hot water bath to heat the (99m)Tc-sulfur colloid bulk vial, amount of (99m)TcOH4(-) added to form the sulfur colloid particles, time between the unit dose calibration and the injection of the dose, and breast quadrant in which the injection occurred.
  
  
  METHODS
  Data were collected retrospectively and quantitatively analyzed from images and reports of 488 patients with breast cancer who had undergone SLN mapping and intraoperative SLN identification from January 1, 2008, to June 30, 2011, inclusive. The dependent variables assessed were the number of SLNs visualized during lymphoscintigraphy, number of radioactive SLNs removed during surgery, and total number of lymph nodes removed intraoperatively.
  
  
  RESULTS
  There was no significant difference in outcomes when comparing the amount of (99m)TcOH4(-) added during the preparation process to form the sulfur colloid particles, time between the unit dose calibration time and the time that the unit doses were injected, or location in the breast tissue in which the unit dose was administered. Initially, there were observed significant differences in outcomes when the heating methods used to prepare the (99m)Tc-sulfur colloid were compared. When the increased number of patients who were administered a calibrated unit dose activity of 74 MBq in the group using a dry heat block preparation method was taken into account, however, the findings were not significant.
  
  
  CONCLUSIONS
  The use of a dry heat block versus a hot water bath to heat the (99m)Tc-sulfur colloid bulk vial, amount of (99m)TcOH4(-) added to form sulfur colloid particles, time between the unit dose calibration and the injection of the dose, and breast quadrant in which the injection occurred do not affect the number of SLNs detected during SLN mapping and during intraoperative SLN identification.
authors.affiliation: Department of Nuclear Medicine, Duke University Medical Center, Durham, NC 27710, USA. kasey.powell@dm.duke.edu
authors.forename: Kasey P
authors.initials: KP
authors.lastname: Nelson
authors.forename: Kingshuk Roy
authors.initials: KR
authors.lastname: Choudhury
authors.forename: R Edward
authors.initials: RE
authors.lastname: Coleman
authors.forename: Steven W
authors.initials: SW
authors.lastname: Shipes
authors.forename: William L
authors.initials: WL
authors.lastname: Siler
authors.forename: William L
authors.initials: WL
authors.lastname: Hubble
authors.forename: Terence Z
authors.initials: TZ
authors.lastname: Wong
mesh_terms: D001940:Breast / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy / Q000379:methods*; D011829:Radiation Dosage; D012189:Retrospective Studies; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D013671:Technetium Tc 99m Sulfur Colloid
keywords: 99mTc-sulfur colloid; breast cancer; lymphoscintigraphy; sentinel lymph node