title: Near-infrared fluorescence (NIRF) imaging in breast-conserving surgery: assessing intraoperative techniques in tissue-simulating breast phantoms.
abstract: OBJECTIVE
  Breast-conserving surgery (BCS) results in tumour-positive surgical margins in up to 40% of the patients. Therefore, new imaging techniques are needed that support the surgeon with real-time feedback on tumour location and margin status. In this study, the potential of near-infrared fluorescence (NIRF) imaging in BCS for pre- and intraoperative tumour localization, margin status assessment and detection of residual disease was assessed in tissue-simulating breast phantoms.
  
  
  METHODS
  Breast-shaped phantoms were produced with optical properties that closely match those of normal breast tissue. Fluorescent tumour-like inclusions containing indocyanine green (ICG) were positioned at predefined locations in the phantoms to allow for simulation of (i) preoperative tumour localization, (ii) real-time NIRF-guided tumour resection, and (iii) intraoperative margin assessment. Optical imaging was performed using a custom-made clinical prototype NIRF intraoperative camera.
  
  
  RESULTS
  Tumour-like inclusions in breast phantoms could be detected up to a depth of 21 mm using a NIRF intraoperative camera system. Real-time NIRF-guided resection of tumour-like inclusions proved feasible. Moreover, intraoperative NIRF imaging reliably detected residual disease in case of inadequate resection.
  
  
  CONCLUSIONS
  We evaluated the potential of NIRF imaging applications for BCS. The clinical setting was simulated by exploiting tissue-like breast phantoms with fluorescent tumour-like agarose inclusions. From this evaluation, we conclude that intraoperative NIRF imaging is feasible and may improve BCS by providing the surgeon with imaging information on tumour location, margin status, and presence of residual disease in real-time. Clinical studies are needed to further validate these results.
authors.affiliation: Department of Surgery, University Medical Center Groningen, Hanzeplein 1, Groningen, The Netherlands.
authors.forename: R G
authors.initials: RG
authors.lastname: Pleijhuis
authors.forename: G C
authors.initials: GC
authors.lastname: Langhout
authors.forename: W
authors.initials: W
authors.lastname: Helfrich
authors.forename: G
authors.initials: G
authors.lastname: Themelis
authors.forename: A
authors.initials: A
authors.lastname: Sarantopoulos
authors.forename: L M A
authors.initials: LM
authors.lastname: Crane
authors.forename: N J
authors.initials: NJ
authors.lastname: Harlaar
authors.forename: J S
authors.initials: JS
authors.lastname: de Jong
authors.forename: V
authors.initials: V
authors.lastname: Ntziachristos
authors.forename: G M
authors.initials: GM
authors.lastname: van Dam
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D005260:Female; D005453:Fluorescence; D006801:Humans; D007259:Infrared Rays; D007432:Intraoperative Period; D015412:Mastectomy, Segmental; D008953:Models, Anatomic; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D019047:Phantoms, Imaging; D011859:Radiography; D018714:Radiotherapy, Adjuvant