Intraoperative near-infrared image-guided surgery for peritoneal carcinomatosis in a preclinical experimental model

Background: This study compared the quality of surgery performed under conventional light with near-infrared (NTR) image-guided surgery using a tumour-targeting probe and a portable clinical grade imaging device in a mouse model of peritoneal carcinomatosis. Methods: Peritoneal carcinomatosis was induced by injection of luciferase-positive tumour cells, leading. to the formation of small nodules in the peritoneal cavity. One day after intravenous injection of RAFT-c(RGDfK)(4)-Alexa Fluor 700 (R), a fluorescent tumour-targeting probe, the surgeon operated using the Fluobeam (R), a portable device that illuminated the mouse with NIR light and allowed NIR vision. The quality of the surgery was evaluated using bioluminescence, a highly sensitive method that detected the remaining tumour cells, and operating time was measured. Results: Under normal light, the surgeon detected and removed a mean(s.d.) of only 50.6(2.3) per cent of the nodules that were visible under NTR light. The duration of surgery was reduced from 19.5(3.3) min under normal light to 14.0(2.6) min when NIR light was used (P = 0.025). The sensitivity of the NIR system allowed the detection of nodules containing as few as 227 tumour cells. Conclusion: NI R image-guided surgery improved the quality of surgery for peritoneal carcinomatosis by doubling the number of nodules detected and significantly reducing the duration of surgery.