title: Magnetic sentinel lymph node biopsy in a murine tumour model.
abstract: The magnetic technique for sentinel node biopsy provides a radioisotope-free alternative for staging breast cancer. It requires refinement to reduce "residual iron content" at injection sites by maximising lymphatic uptake to prevent "void artefacts" on magnetic resonance imaging (MRI), which could adversely affect clinical use. The site and timing of injection of magnetic tracer was evaluated in a murine tumour model (right hind limb) in 24 wild type mice. Right-sided intratumoural and left sided subcutaneous injection of magnetic tracer and assessment of nodal iron uptake on MRI, surgical excision and histopathological grading at time frames up to 24 hours were performed. Rapid iron uptake on MRI, smaller "void artefacts"(P<0.001) and a significant increase in iron content with time were identified in the subcutaneous injection group (r=0.937; P<0.001).Subcutaneous injection and increasing delay between tracer injection and surgery is beneficial for lymphatic iron uptake.
  
  
  BACKGROUND
  Sentinel lymph node biopsy (SLNB) has been the standard of care in breast cancer management for some time. Recent development has seen the introduction of magnetic tracer for SLNB. In this article, the authors investigated the refined use of magnetic tracer in determining the optimal timing of administration and the location of injection. The findings should provide more data on the future use of this new technique.
authors.affiliation: Research Oncology, Division of Cancer Studies, King's College London, Guy's Hospital Campus, Great Maze Pond, London, UK. Electronic address: muneer.ahmed@kcl.ac.uk.
authors.forename: Muneer
authors.initials: M
authors.lastname: Ahmed
authors.affiliation: Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Taeseong
authors.initials: T
authors.lastname: Woo
authors.affiliation: Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Kaichi
authors.initials: K
authors.lastname: Ohashi
authors.affiliation: Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kaneko
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Atushi
authors.initials: A
authors.lastname: Hoshino
authors.affiliation: Research Oncology, Division of Cancer Studies, King's College London, Guy's Hospital Campus, Great Maze Pond, London, UK.
authors.forename: Ali
authors.initials: A
authors.lastname: Zada
authors.affiliation: Department of Statistics, School of Business 612, Maxwell Building, University of Salford, Salford, UK.
authors.forename: Rose
authors.initials: R
authors.lastname: Baker
authors.affiliation: Research Oncology, Division of Cancer Studies, King's College London, Guy's Hospital Campus, Great Maze Pond, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Douek
authors.affiliation: Advanced Technology Research Laboratory, Research Centre for Food Safety, Graduate School of Agriculture and Life Sciences, University of Tokyo, Tokyo, Japan.
authors.forename: Moriaki
authors.initials: M
authors.lastname: Kusakabe
authors.affiliation: Department of Electrical Engineering and Information Systems, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Sekino
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000009:adverse effects*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000009:adverse effects*; D051379:Mice; D000071036:Sentinel Lymph Node / Q000187:drug effects / Q000473:pathology; D021701:Sentinel Lymph Node Biopsy
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles
keywords: Magnetic technique; Magnetic tracer; Murine tumour model; Sentinel lymph node biopsy; Superparamagnetic iron oxide (SPIO)