Background: During transoral robotic surgery (TORS), the surgeon is reliant primarily on visualization for detection of residual tumor, in the absence of traditional tactile feedback. In an effort to improve overall survival and recurrence rates for head and neck squamous cell carcinoma (HNSCC), cetuximab-IRDye800CW is being trialed for the detection of microscopic disease. This is the first report of using the Firefly fluorescence-imaging device in conjunction with the robot for real-time intraoperative detection of HNSCC.
Objective: Evaluate currently available image guidance technology for detection of cetuximab-IRDye800CW labeled HNSCC intraoperatively during TORS.
Methods: A prospective piolet study of patients with HNSCC undergoing TORS was conducted (n=3; 2 oropharynx, 1 hypopharynx). This series was included as part of a clinical trial (Clinicaltrials.gov Identifier: NCT01987375) evaluating the safety and tumor-specificity of systemically injected cetuximab-IRDye800CW. Five days following systemic infusion with cetuximab-IRDye800CW (50mg), intraoperative fluorescence imaging was performed using the Firefly (Novadaq) during TORS procedures.
Results: Fluorescence contrast was observed at the site of the primary lesion during intraoperative imaging. There was an average tumor-to-background ratio (TBR) of 2.9 using the Firefly fluorescence-imaging device. Following resection, the wound bed was visualized with traditional bright light followed by fluorescence imaging. The fluorescence imaging was able to detect residual disease which was not visualized on bright light imaging alone. When compared to normal tissues, unresected residual tumor within the primary wound bed had an average TBR of 2.6. Post resection imaging of the tumor specimens were compared to control fluorescence imaging using the Luna imaging system (Novadaq) and confirmed high levels of fluorescence intensity within pathology-positive tissue with a TBR range of 3.0-4.6. Areas of increased fluorescence were confirmed to correlate with HNSCC cells on final histopathology.
Conclusion: This series demonstrated a novel approach with the potential for improving HNSCC detection during TORS. It utilizes the Firefly for real-time intraoperative imaging of HNSCC.