Intraoperative Identification of Colonic Tumor Sites Using a Near-Infrared Fluorescence Endoscopic Imaging System and Indocyanine Green

This study aimed to investigate the feasibility of the PINPOINT® Endoscopic Fluorescence Imaging System (PINPOINT) for intraoperative identification of colonic tumor sites during laparoscopic colorectal surgery.

Eighty consecutive patients with colorectal cancer were prospectively enrolled. Preoperatively, 0.5 mL of indocyanine green (ICG; 2.5 mg/mL) was injected into the submucosal space only at the distal side of the tumor under colonoscopy. Intraoperatively, we identified the tumor site on a PINPOINT image in which near-infrared fluorescence was superimposed in pseudocolor on a white light image. We estimated the intraoperative visibility rate of the tumor site and safety of ICG injection and assessed the interobserver variability of visibility grade between 2 surgeons.

The intraoperative visibility rate of the tumor site was 93.8% (75/80). The visibility rate at an interval between injection and surgery of <7 days was significantly better than that at an interval of ≥10 days (p < 0.001). The kappa value between 2 observers was 0.827 (95% CI 0.635-1.019) with an agreement rate of 92.5%. There were no preoperative adverse reactions to ICG or intraoperative complications.

Using ICG with the PINPOINT for identifying colonic tumor sites was feasible without any adverse effects during laparoscopic colorectal surgery.