Indocyanine Green Improves Lymph Node Harvesting in Gastric Cancer Patients

By Marilynn Larkin

March 09, 2020

NEW YORK (Reuters Health) - In patients with gastric cancer who undergo D2 lymphadenectomy, indocyanine green (ICG) helps surgeons harvest more lymph nodes than conventional dissection and reduces the number of nodes that should have been excised, but weren't, a phase-3 trial reveals.

Drs. Chao-hui Zheng and Chang-Ming Huang of Fujian Medical University Union Hospital in China randomized 266 patients (mean age, about 59; two-thirds men) to ICG tracer-guided or conventional laparoscopic gastrectomy.

As reported in JAMA Surgery, the mean number of lymph nodes retrieved in the ICG group was significantly more than in the non-ICG group (mean, 50.5 vs. 42.0, respectively).

Similarly, significantly more perigastric and extraperigastric lymph nodes were retrieved in the ICG group, and the mean total number of lymph nodes retrieved with ICG within the scope of the entire procedure was also significantly higher than without ICG (mean, 49.6 vs. 41.7).

Further, the ICG group's lymph node noncompliance rate was significantly lower than in the non-ICG group: 31.8% vs. 57.4%.

Additional analyses showed that the number of metastatic lymph nodes in each station in the ICG group was not significantly higher than in the non-ICG group, regardless of the resection method. And an analysis of the relationship between the fluorescence lymph nodes and metastatic lymph nodes retrieved in the ICG group indicated that the diagnostic sensitivity and specificity of fluorescence and metastatic lymph nodes were 56.3% and 46.1%, respectively

Notably, no significant between-group differences were found during the postoperative recovery process in the incidence of complications (15.5% vs. 16.3%) or their severity within 30 days after surgery.

"This is a very important study that shows the usefulness of ICG for patients with gastric cancer," Dr. Marco Giuseppe Patti of the University of North Carolina at Chapel Hill, coauthor of a related editorial, told Reuters Health by email. "The technique is very simple and safe and allows the retrieval of a larger number of lymph nodes. We feel that is even more important for us surgeons in the Western world, as we operate on very few patients with gastric cancer as compared to surgeons in the East."

"In addition, our patients are often overweight with large amounts of intra-peritoneal fat, which makes the dissection more cumbersome and lengthy," he noted. "Presently, we feel that infrared fluorescent imaging should be used in any patient with cancer."

Dr. Amit Bhatt, director of Cleveland Clinic's Endoluminal Surgery Center in Ohio, commented in an email to Reuters Health, "While there has been interest in the use of ICG tracer with near-infrared fluorescent imaging in gastric cancer for some time, previous studies focused on sentinel node identification or small patient populations. The strengths of the study are the high volume of gastric cancer surgeries involved, and the robust design of the study."

"Moving forward," he said, "the two main questions that remain are: 1) Is the long-term survival between these two groups different; and 2) Are these findings translatable to lower surgical volume centers like those in the West where gastric cancer surgery is less common."

"Despite these questions," he added, "the use of ICG is simple and should be considered in patients undergoing gastrectomy for gastric cancer."

Drs. Chao-hui Zheng and Chang-Ming Huang did not respond to requests for comment.

SOURCE: JAMA Surgery, online February 26, 2020.