title: Fluorescence-guided resection of experimental malignant glioma using cetuximab-IRDye 800CW.
abstract: The standard treatment for glioblastoma multiforme (GBM) remains maximal safe surgical resection. Here, we evaluated the ability of a systemically administered antibody-dye probe conjugate (cetuximab-IRDye 800CW) to provide sufficient fluorescent contrast for surgical resection of disease in both subcutaneous and orthotopic animal models of GBM. Multiple luciferase-positive GBM cell lines (D-54MG, U-87MG, and U-251MG; n = 5) were implanted in mouse flank and tumors were fluorescently imaged daily using a closed-field near-infrared (NIR) system after cetuximab-IRDye 800CW systemic administration. Orthotopic models were also generated (n = 5), and tumor resection was performed under white light and fluorescence guidance using an FDA-approved wide-field NIR imaging system. Residual tumor was monitored using luciferase imaging. Immunohistochemistry was performed to characterize tumor fluorescence, epidermal growth factor receptor (EGFR) expression, and vessel density. Daily imaging of tumors revealed an average tumor-to-background (TBR) of 4.5 for U-87MG, 4.1 for D-54MG, and 3.7 for U-251MG. Fluorescence intensity within the tumors peaked on day-1 after cetuximab-IRDye 800CW administration, however the TBR increased over time in two of the three cell lines. For the orthotopic model, TBR on surgery day ranged from 19 to 23 during wide-field, intraoperative imaging. Surgical resection under white light on day 3 after cetuximab-IRDye 800CW resulted in an average 41% reduction in luciferase signal while fluorescence-guided resection using wide-field NIR imaging resulted in a significantly (P = 0.001) greater reduction in luciferase signal (87%). Reduction of luciferase signal was found to correlate (R (2) = 0.99) with reduction in fluorescence intensity. Fluorescence intensity was found to correlate (P < 0.05) with EGFR expression in D-54MG and U-251MG tumor types but not U-87MG. However, tumor fluorescence was found to correlate with vessel density for the U-87MG tumors. Here we show systemic administration of cetuximab-IRDye 800CW in combination with wide-field NIR imaging provided robust and specific fluorescence contrast for successful localization of disease in subcutaneous and orthotopic animal models of GBM.
authors.affiliation: a Department of Surgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Warram
authors.affiliation: a Department of Surgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.|d Department of Surgery , University Medical Center Groningen, University of Groningen , the Netherlands.
authors.forename: Esther
authors.initials: E
authors.lastname: de Boer
authors.affiliation: a Department of Surgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Korb
authors.affiliation: a Department of Surgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Hartman
authors.affiliation: c LI-COR Biosciences , Lincoln, Nebraska , USA.
authors.forename: Joy
authors.initials: J
authors.lastname: Kovar
authors.affiliation: b Department of Neurosurgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Markert
authors.affiliation: b Department of Neurosurgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: G Yancey
authors.initials: GY
authors.lastname: Gillespie
authors.affiliation: a Department of Surgery , University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors.forename: Eben L
authors.initials: EL
authors.lastname: Rosenthal
mesh_terms: D000818:Animals; D001557:Benzenesulfonates; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D045744:Cell Line, Tumor; D000068818:Cetuximab; D066246:ErbB Receptors; D005260:Female; D005456:Fluorescent Dyes; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007211:Indoles; D007259:Infrared Rays; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D019635:Neurosurgical Procedures / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*
chemical_list: D001557:Benzenesulfonates; D005456:Fluorescent Dyes; C562366:IRDye 800CW; D007211:Indoles; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D000068818:Cetuximab
keywords: IRDye 800CW; antibody imaging; cetuximab; fluorescence-guided surgery