Fluorescence-guided lymphadenectomy in gastric cancer: a prospective western series.

Background: Indocyanine green (ICG) has been recently introduced in clinical practice as a fluorescent tracer. Lymphadenectomy is particularly challenging in gastric cancer surgery, owing to the complex anatomical drainage.

Aim: The primary outcomes of this study were the feasibility and usefulness of ICG-guided lymphadenectomy in gastric cancer surgery, considering both the success rate and improved understanding of the surgical anatomy of nodal basins. The secondary outcome was the diagnostic ability of ICG to predict the presence of nodal metastases.

Patients And Methods: We conducted a single-center prospective trial comprising 13 patients with gastric cancer. ICG was injected the afternoon prior to surgery or intraoperatively via the submucosal or subserosal route. Standard lymphadenectomy was performed in all patients, according to patient age and tumor stage, as usual, but after standard lymphadenectomy the residual ICG + nodes were harvested and analyzed. Each nodal station and each dissected node was recorded and classified as ICG + or ICG- (both in vivo and back table evaluation was utilized for classification). After pathological analysis, each nodal station and each dissected node was recorded as metastatic or nonmetastatic (E&E staining).

Results: The feasibility rate was 84.6% (11/13). The mean number of dissected lymph nodes per patient was 37.9. Focusing on the 11 patients in whom ICG-guided nodal navigation was successfully performed, 81 lymph node stations were removed, for a total of 417 lymph nodes. Sixty-six stations (81.48%), comprising a total of 336 lymph nodes, exhibited fluorescence. No IC- node was metastatic; all 54 metastatic nodes were ICG + . A total of 282 ICG + nodes were nonmetastatic. In two cases, some nodes outside D2 areas were harvested, being ICG + (1 case of metastatic node).

Conclusions: Fluorescence lymphography-guided lymphadenectomy is a promising new technique that combines a high feasibility rate with considerable ease of use. Regarding its diagnostic value, the key finding from this prospective series is that no metastatic nodes were found outside fluorescent lymph node stations. Further studies are needed to investigate whether this technique can help surgeons performing standard lymphadenectomy and selecting cases for D2 + lymphadenectomy.