ICG-guided technique improves surgical time, accuracy of PLND

A technique involving an intracutaneous injection of indocyanine green (ICG) in the lower limbs and perineum followed by fluorescent laparoscopy was shown to be feasible for visualizing pelvic lymph nodes and guiding pelvic lymph node dissection (PLND) during radical cystectomy.¹

No patients experienced vascular or nerve injuries.

The findings, published in UroPrecision, showed that this approach reduced surgical times and improved the accuracy of PLND compared with standard methods.

"Integrating ICG and fluorescent imaging into bladder cancer surgery is a game-changer,” said senior author Xiaofeng Yeng in a news release on the findings.² “It is crucial for preventing cancer recurrence for unparalleled precision in locating and excising pelvic lymph nodes. Not only does this approach optimize the surgical process, but it also has the potential to enhance survival rates by ensuring more complete lymph node dissection. Our findings underscore the importance of ongoing innovation in surgical oncology to improve patient care."

For the study, the investigators first assessed the feasibility of ICG injection through the lower limbs and perineum in 54 patients who underwent radical cystectomy and PLND. Results confirmed that pelvic lymph nodes could be visualized at 1 hour following ICG injection.

The authors added, “In 15 patients, the image did not weaken significantly within 4.5 [hours] after injection, and sufficient time was given for surgical operation.”

No patients experienced vascular or nerve injuries.

The investigators then compared data between 44 patients in the perineal lower limb combined injection group and 11 patients who underwent radical cystectomy plus PLND without ICG injection, who served as a control group.

Overall, the average number of pelvic lymph nodes removed were not significantly different between the 2 groups. The average number was 11.52 ± 2.48 in the ICG injection arm and 10.54 ± 2.38 in the control arm (P = .25).

However, the ICG injection cohort did show an improvement in the accuracy of PLND and a reduction in operative times. In the injection arm, the accuracy of PLND was 93.41%, compared with 75.91% in the control arm (P = .01). Additionally, lymph node dissection took an average of 44.07 ± 4.72 minutes in the ICG injection cohort, compared with an average of 50.27 ± 5.18 minutes in the control cohort (P = .01).

The authors explained, “Improving the accuracy of lymph node removal can help reduce the unnecessary removal of fibrofatty tissue during PLND, effectively reducing operation time. The accuracy rate of lymph node removal in the group receiving lower limb and perineal injection of ICG was 93%, possibly due to some lymphatic vessels being contained within pathologically confirmed fibrofatty tissue.”

Although the authors indicate the promise of these findings, they also note several limitations of the current study, including a short follow-up time and a low specificity of ICG. Based on these shortcomings, they suggest that further research is needed on the long-term control effect of this approach, as well as further development of fluorescent probes with different tumor specificity.

Overall, they concluded, “This technique has far-reaching significance in standardizing PLND and studying the lymphatic metastasis pathway of tumor.”

References

1. Wei Y, Liu C, Cao X, et al. Fluorescence imaging-guided pelvic lymph node localization and resection of bladder cancer after intracutaneous injection of indocyanine green into the lower limbs and perineum. UroPrecision. 2024. doi:10.1002/uro2.70

2. Fluorescent guidance: A leap in bladder cancer surgery. News release. Chinese Academy of Sciences. January 20, 2025. Accessed January 21, 2025. https://www.newswise.com/articles/fluorescent-guidance-a-leap-in-bladder-cancer-surgery