Background: Indocyanine green (ICG) fluorescent image (FI)-guided surgery has demonstrated success in improving intraoperative visualization and tumor resections. The objectives were to evaluate the use of IGC in FI-guided transoral robotic surgery (TORS) and the underlying molecular mechanism.Methods: HPV+ oropharyngeal squamous cell carcinoma (OPSCCa) patient (n = 10) undergoing TORS were enrolled in this prospective study. Participants received intravenous ICG. Excised tissues were evaluated for ICG accumulation, tumor demarcation, and pathological characteristics using In-vivo imaging system (IVIS), histology, and RNA sequencing. Results: ICG accumulation was significantly increased in primary tumor and pathological lymph nodes compared with normal tissues (p < 0.001). IVIS was 91.3% accurate in identifying OPSCCa in excised tissues; the correlation between IVIS-and histologically determined tumor tissues was significant (R 2 = 0.8301; p = 0.001). Genes associated with vascular and angiogenic signaling pathways were significantly upregulated in OPSCCa tissues.
Conclusion:ICG effectively demarcates tumor margins in OPSCCa, due to the increased upregulation of genes associated with vascular permeability.