Improved disease-free survival and overall survival after fluorescence-guided surgery of liver metastasis in an orthotopic nude mouse model

Background In the present study, we sought to determine if fluorescence-guided surgery (FGS) would improve survival compared to standard bright light surgery (BLS) in an experimental colorectal liver metastasis nude mouse model. Methods Orthotopic nude-mouse models of human HT-29-GFP colon cancer liver metastasis were established in the left lobe of the liver of mice. Fourteen mice with a single liver metastasis were randomized into FGS or BLS groups of seven each. FGS of liver metastasis was performed using a hand-held portable fluorescence imaging system (Dino-Lite) to visualize the GFP fluorescence of the metastasis. The BLS- and FGS-treated mice were followed by weekly fluorescence imaging in order to detect recurrence. Results The bright fluorescence of GFP provided sufficient illumination to accurately distinguish the margins of the metastasis within the liver. Recurrence occurred in multiple sites including the liver, lung, and other organs in the BLS-treated mice but was significantly reduced in FGS-treated mice. The FGS-treated mice had significantly prolonged disease-free survival (P=0.001) and overall survival (P=0.027) compared to BLS-treated mice. Conclusion The results of the present report demonstrate the feasibility and efficacy of FGS for liver metastasis and suggest its important clinical potential. J. Surg. Oncol. 2015 111:119-124.