Tumor Margin Detection Using Quantitative NIRF Molecular Imaging Targeting EpCAM Validated by Far Red Gene Reporter iRFP

Wide-field surgical excision reduces the chance of residual disease, but can also lead to disfigurement and devastating morbidities when resection is close to critical structures. We hypothesize that near-infrared fluorescence (NIRF) imaging can enable accurate detection of tumor margins for image-guided resection. An orthotopic model of human prostate cancer (PCa) was used to assess primary tumor margins using a NIRF-labeled antibody against epithelial cell adhesion molecule (EpCAM). PCa cells stably expressing far red fluorescent gene reporter, iRFP, enabled colocalization with NIRF signals for direct assessment of tumor margins. Using receiver operating characteristic analysis, far red fluorescence was validated against standard pathology of primary and metastatic lesions with > 96 % accuracy. Primary tumor margins were more accurately detected by quantitative NIRF imaging using the EpCAM-targeting antibody as compared to a NIRF-labeled isotype control antibody. NIRF molecular imaging may enable real-time and accurate assessment of tumor margins.