['Evaluate if vascular normalization with an antiangiogenic monoclonal antibody improves detection of melanoma using fluorescently labeled antibody-based imaging.', 'Preclinical.', 'Panitumumab and control IgG were covalently linked to a near-infrared fluorescent probe (IRDye800CW). Immunodeficient mice with ear xenografts of melanoma cell lines (A375 and SKMEL5) were systemically injected (200 μg, tail vein) with either IgG-IRDye800CW, panitumumab-IRDye800CW, or a combination (bevacizumab [5mg/kg], administered 72 hours prepanitumumab-IRDye800CW) (n = 5). Primary tumors were imaged with open-field (LUNA, Novadaq, Toronto, Ontario, Canada) and closed-field (Pearl, LI-COR Biosciences, Lincoln, NB) imaging devices. Postresection, the concentration of labeled antibody within the tumor (μg/g) was calculated using normalized standards.', 'The mean fluorescence within the melanoma tumors was greater for the combination group compared to panitumumab alone for both cell lines (P < 0.001). The tumor-to-background ratio (TBR) for the A375 tumors was greater for the combination (3.4-7.1) compared to the panitumumab alone (3.2-5.0) (P = 0.04). The TBR for SKMEL5 tumors was greater for the combination (2.4-6.0) compared to the panitumumab alone (2.2-3.9) (P = 0.02). Within A375 tumors, the concentration was lower for panitumumab (0.51 μg/g) compared to combination group (0.68 μg/g) (P = 0.036). Within SKMEL5 tumors, the concentration was lower for panitumumab (0.0.17 μg/g) compared to combination group (0.35 μg/g) (P = 0.048). Residual tumor (1.0-0.2 mg) could be differentiated from background in both panitumumab and combination groups. For both cell lines, panitumumab and combination groups had greater mean fluorescence of the tumor compared to control IgG.'] Does antiangiogenic antibody improve melanoma detection by fluorescently labeled therapeutic antibodies?