Response to: "timing of administration of indocyanine green for fluorescence-guided surgery in pancreatic cancer: response to Shirakawa et al.".

This is the response article to correspondence article received for our published article in BMC surgery titled "A prospective single-center protocol for using near-infrared fluorescence imaging with indocyanine green during staging laparoscopy to detect small metastasis from pancreatic cancer". Peter L. Labib, MBChB pointed out the necessity to administer indocyanine green intravenously in separate timing for detection of metastasis in liver and peritoneum. Preoperative injection is suitable to detect hepatic metastasis and intraoperative injection is reported to be well suited to detect peritoneal metastasis. However, we could not find the usefulness of intraoperative injection of indocyanine green for detecting peritoneal metastasis in cases with staging laparoscopy prior to this study. We employed this study protocol with only preoperative injection of indocyanine green to simplify the procedure with consideration of probably more frequent cases of hepatic metastasis that is difficult to detect with white-light imaging than those of peritoneal metastasis.