Assessment of a Liposomal CT/Optical Contrast Agent for Image-Guided Head and Neck Surgery.

BACKGROUND: This study evaluates a long-acting liposomal fluorescence / CT dual-modality contrast agent (CF800) in head and neck cancer to enhance intraoperative tumor demarcation with fluorescence imaging and cone-beam computed tomography (CBCT).

METHODS: CF800 was administered to 12 buccal cancer-bearing rabbits. Imaging was acquired at regular timepoints to quantify time-dependent contrast enhancement. Surgery was performed 5-7days after, with intraoperative near-infrared fluorescence endoscopy and CBCT, followed by histological and ex-vivo fluorescence assessment.

RESULTS: Tumor enhancement on CT was significant at 24, 96 and 120hours. Volumetric analysis of tumor segmentation showed high correlation between CBCT and micro-CT. Fluorescence signal was apparent in both ex-vivo and in-vivo imaging. Histological correlation showed [100%] specificity for primary tumor. Sensitivity and specificity of CF800 in detecting nodal involvement require further investigation.

CONCLUSION: CF800 is long acting and has dual function for CT and fluorescence contrast, making it an excellent candidate for image-guided surgery.