Tumor-Specific Imaging with Angiostamp800 or Bevacizumab-IRDye 800CW Improves Fluorescence-Guided Surgery over Indocyanine Green in Peritoneal Carcinomatosis

Complete surgical removal of lesions improves survival of peritoneal carcinomatosis and can be enhanced by intraoperative near-infrared fluorescence imaging. Indocyanine green (ICG) is the only near-infrared fluorescent dye approved for clinical use, but it lacks specificity for tumor cells, highlighting the need for tumor-selective targeting agents. We compared the tumor-specific near-infrared fluorescent probes Bevacizumab-IRDye 800CW and Angiostamp800, which target tumor angiogenesis and cancer cells, to ICG for fluorescence-guided surgery in peritoneal carcinomatosis of ovarian origin. The probes were administered to mice with orthotopic peritoneal carcinomatosis prior to conventional and fluorescence-guided surgery. The influence of neoadjuvant chemotherapy was also assessed. Conventional surgery removed 88.0 +/- 1.2% of the total tumor load in mice. Fluorescence-guided surgery allowed the resection of additional nodules, enhancing the total tumor burden resection by 9.8 +/- 0.7%, 8.5 +/- 0.8%, and 3.9 +/- 1.2% with Angiostamp800, Bevacizumab-IRDye 800CW and ICG, respectively. Interestingly, among the resected nodules, 15% were false-positive with ICG, compared to only 1.4% with Angiostamp800 and 3.5% with Bevacizumab-IRDye 800CW. Furthermore, conventional surgery removed only 69.0 +/- 3.9% of the total tumor burden after neoadjuvant chemotherapy. Fluorescence-guided surgery with Angiostamp800 and Bevacizumab-IRDye 800CW increased the total tumor burden resection to 88.7 +/- 4.3%, whereas ICG did not improve surgery at all. Bevacizumab-IRDye 800CW and Angiostamp800 better detect ovarian tumors and metastases than the clinically used fluorescent tracer ICG, and can help surgeons completely remove tumors, especially after surgery neoadjuvant chemotherapy.