Determination of Tumor Margins with Surgical Specimen Mapping Using Near-Infrared Fluorescence

Abstract

For many solid tumors, surgical resection remains the gold standard and tumor-involved margins are associated with poor clinical outcomes. Near-infrared (NIR) fluorescence imaging using molecular agents has shown promise for in situ imaging during resection. However, for cancers with difficult imaging conditions, surgical value may lie in tumor-mapping of surgical specimens. We thus evaluated a novel approach for real-time, intraoperative tumor margin assessment. 21 adult patients with biopsy-confirmed squamous cell carcinoma arising from the head and neck (HNSCC) scheduled for standard-of-care surgery were enrolled. Cohort 1 (n=3) received panitumumab-IRDye800CW at an intravenous microdose of 0.06 mg/kg, cohort 2A (n=5) received 0.5mg/kg, cohort 2B (n=7) received 1mg/kg, and cohort 3 (n=6) received 50 mg. Patients were followed 30 days post-infusion and adverse events were recorded. Imaging was performed using several closed- and wide-field devices. Fluorescence was histologically correlated to determine sensitivity and specificity. In situ imaging demonstrated tumor-to-background ratio (TBR) of 2-3, compared to ex vivo specimen imaging TBR of 5-6. We obtained clear differentiation between tumor and normal tissue, with a three-fold signal difference between positive and negative specimens (p89%; fluorescence predicted distance of tumor tissue to the cut surface of the specimen. This novel method of detecting tumor-involved margins in surgical specimens using a cancer-specific agent provides highly sensitive and specific, real-time, intraoperative surgical navigation in resections with complex anatomy which are otherwise less amenable to image guidance.