Assessment of indocyanine green-labeled cetuximab to detect xenografted head and neck cancer cell lines.

OBJECTIVE

The aim of this study is to determine the efficacy of indocyanine green (ICG) conjugated to antiepidermal growth factor receptor antibody (cetuximab) to image head and neck cancer.

STUDY DESIGN

Mice (n = 3) were injected with unconjugated ICG and imaged at 100-second intervals for a total of 1000 seconds to assess imaging characteristics. Mice (n = 10) xenografted with SCC-1 cells were then systemically injected with cetuximab conjugated to indocyanine green and imaged over a 72-hour period. To assess the sensitivity and specificity, xenografted tumors underwent subtotal resections and then were assessed for residual disease by fluorescence stereomicroscopy and confirmed by histology.

RESULTS

Tumors demonstrated excellent fluorescence 24 hours after injection of cetuximab-ICG. There was a direct relationship between fluorescence and the given dose of cetuximab-ICG. Following subtotal resection, we found fluorescence correlated with a sensitivity of 78.4% and specificity of 96%.

CONCLUSIONS

This study provides evidence that supports further preclinical investigation of cetuximab in the evaluation of surgical margins, but linkage to ICG lacks the sensitivity for use in a clinical setting.