Application of Indocyanine Green Tracer in D2 Lymphadenectomy of Locally Advanced Gastric Cancer

Gastric cancer is a frequent neoplasm in the world, presenting more than one million new cases and around 768,000 deaths in the data registered in 2020. Among the therapeutic options for gastric cancer, surgery is an essential pillar for its treatment. Gastric cancer surgery consists of gastric resection with negative margins and radical lymphadenectomy in patients without distant metastases. It has been demonstrated over the years that radical lymphadenectomy in gastric cancer allows for adequate staging and improved long-term survival.

In order to perform a correct staging using the TNM system, it is necessary to resect at least 15 lymph nodes in the radical lymphadenectomy. For radical lymphadenectomy staging, the Japanese Gastric Cancer Association defined and subdivided nodal stations. Three types of lymphadenectomy are described according to oncologic gastric resections (D1, D1+ and D2), with D2 lymphadenectomy being the standard of treatment for locally advanced gastric tumors. Performing an insufficient or inadequate lymphadenectomy has been shown to negatively impact survival after gastrectomy in such a cohort.

The development of technology based on fluorescence guided by indocyanine green could improve the technique and results of D2 lymphadenectomy in patients with gastric cancer. There is evidence that the application of ICG in D2 lymphadenectomy increases the number of resected nodes, however, studies of higher scientific quality (randomized clinical trials) are needed. Furthermore, most studies in this field have focused on Eastern countries (Japan, Korea and China), where the percentage of early tumors and chemotherapy treatment is different from Western centers.

Therefore, we propose a multicenter randomized clinical trial aimed at evaluating whether the application of ICG-guided fluorescence-based technology in D2 lymphadenectomy of locally advanced gastric cancer increases the number of resected nodes, improves the oncologic quality of the lymphadenectomy, and thus may increase overall survival and disease-free survival at 2 and 5 years postoperatively.

Objective:

- Mean total number of nodes/ nodal ratio (number of positive nodes divided by the number of total nodes).

Secondary objective:

* Overall Survival and disease- free survival at 2 and 5 years.
* Number of metastatic nodes
* Complications measured with the Comprehensive Complication Index (CCI)
* Intraoperative bleeding volume
* Surgical time (minutes)
* Days of hospitalization (days) Randomized clinical trial 1:1. The patient will be included once the perioperative chemotherapy treatment is completed. The investigator at each center will explain the study, and if the patient consents to participate, he/she will sign the informed consent form (IC). After which, the investigator of each center will contact the principal investigator of the University Hospital of Navarra (HUN), who will perform the randomization and communicate the result by email to the participating center.

Requirements for participating centers:

* Esophagogastric Surgery Unit with a volume of 20 patients with gastric neoplasia operated on in one year.
* Use the 4k Rubina Tower of the Karl Storz brand.

Inclusion criteria:

* \< 85 years
* T1/T4a, N+, M0 in the preoperative study.
* PS 0-1
* ASA I-III
* Laparoscopic surgery

Exclusion criteria:

* Previous gastric abdominal surgery
* DSE
* Cognitive impairment
* Allergic to iodine
* Synchronous neoplasm
* Stroke in the last 6 months
* Angina or AMI in the last 6 months
* Plastic lymphitis
* Open surgery

ICG administration: For ICG administration, a gastroscopy must be performed by the Digestive Service of each center, with sedation 24 hours before surgery. For this, the lesion is located by gastroscopy, after which it is injected in 4 quadrants in the submucosa, with a total volume of 2 ml.

To prepare the ICG, 0.5 ml (containing 0.625 mg of ICG) is dissolved in 1.25 mg/dl of sterile water.

Eligibility Criteria:
Inclusion Criteria:

* T2-T4a, N+, M0 on preoperative study
* PS 0-1
* ASA I-III
* Laparoscopic surgery

Exclusion Criteria:

* - Previous gastric abdominal surgery
* DSE
* Cognitive impairment
* Allergic to iodine
* Synchronous neoplasm
* Stroke in the last 6 months
* Angina or AMI in the last 6 months
* Plastic lymphitis
* Open surgery