title: Superparamagnetic iron oxide as a tracer for sentinel node biopsy in breast cancer: A comparative non-inferiority study.
abstract: OBJECTIVE
  The gold standard for detection of Sentinel Lymph Nodes (SLN) is a combined radioisotope and blue dye breast injection, using a gamma probe (GP). A new, non-radioactive method was developed, using a tracer (Sienna+(®)) of superparamagnetic iron oxide (SPIO) nanoparticles and a manual magnetometer (SentiMag(®)) (SM). The IMAGINE study was designed to show the non-inferiority of SM compared to GP, for the detection of SLN in breast cancer patients with SLN biopsy indication.
  
  
  METHODS
  From November 2013 to June 2014, 181 patients were recruited, and 321 nodes were excised and assessed ex-vivo. Readings from both SM and GP devices were recorded during transcutaneous, intraoperative, and ex-vivo detection attempts.
  
  
  RESULTS
  At the patient level, ex-vivo detection rates (primary variable) with SM and GP were 97.8% and 98.3% (concordance rate 99.4%). Transcutaneous and intraoperative detection rates were 95.5% vs 97.2%, and 97.2% vs 97.8% for SM and GP respectively (concordance rates > 97%). At the node level, intraoperative and ex-vivo detection rates were 92.5% vs 89.3% and 91.0% vs 86.3% for SM and GP respectively. In all cases the non-inferiority of SM compared to SM was shown by ruling out a predefined non-inferiority margin of 5%.
  
  
  CONCLUSIONS
  Our study showed the non-inferiority of SM as compared to GP. Moreover, the ex-vivo and intraoperative detection rates at the node level were slightly higher with SM.
authors.affiliation: Department of Surgery, "Virgen de la Arrixaca" University Hospital, 30120 Murcia, Spain. Electronic address: pineromadrona@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Piñero-Madrona
authors.affiliation: Department of Surgery, "Lluís Alcanyís" Hospital, Xàtiva, Valencia, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Torró-Richart
authors.affiliation: Breast Unit, "Virgen del Rocío" University Hospital, Sevilla, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: de León-Carrillo
authors.affiliation: Breast Unit, University Hospital Complex of Vigo, Vigo, Spain.
authors.forename: G
authors.initials: G
authors.lastname: de Castro-Parga
authors.affiliation: Breast Pathology Unit, Hospital Complex of Jaén, Jaén, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Navarro-Cecilia
authors.affiliation: Department of Surgery, Hospital Complex of Navarra, Pamplona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Domínguez-Cunchillos
authors.affiliation: Breast Unit, University Clinic Hospital "San Carlos", Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Román-Santamaría
authors.affiliation: Breast Unit, University General Hospital, Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Fuster-Diana
authors.affiliation: Breast Unit, Department of Surgery, University Hospital of Ciudad Real, Ciudad Real, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Pardo-García
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D005260:Female; D052203:Ferrosoferric Oxide / Q000493:pharmacokinetics; D006801:Humans; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*
chemical_list: C427127:superparamagnetic blood pool agent; D052203:Ferrosoferric Oxide
keywords: Invasive breast cancer; SentiMag(®); Sentinel lymph node biopsy; Sienna+(®); Superparamagnetic iron oxide (SPIO)