Effect of carbon nanoparticle suspension injection versus indocyanine green tracer in guiding lymph node dissection during radical gastrectomy (FUTURE-01): a randomized clinical trial

Background: Carbon nanoparticle suspension injection (CNSI) and indocyanine green (ICG) have both been applied intraoperatively to facilitate lymphatic mapping and postoperatively to sort lymph nodes (LNs) in gastric cancer patients. However, no study has compared the two tracers in gastric cancer patients. Materials and Methods: This prospective randomized controlled trial was conducted from January 2022 to March 2023. Patients with potentially resectable gastric cancer (cT1-4a N0/+ M0) were randomized to the CNSI or ICG group. Results: This study enrolled 96 patients. Ninety patients were in the modified intention-to-treat population, including 46 patients (32 males and 14 females; mean [SD] age, 57.4 [9.4] years) in the CNSI group and 44 patients (31 males and 13 females; mean [SD] age, 60.8 [8.8] years) in the ICG group. The mean (SD) number of retrieved LNs was 69.8 (21.9) and 53.6 (17.2) in the CNSI and ICG groups, respectively ( P <0.001). The mean (SD) number of retrieved micro-LNs was 19.9 (13.3) and 11.6 (9.9) in the CNSI and ICG groups, respectively ( P =0.001). The mean (SD) number of metastatic LNs was 8.1 (11.9) and 5.2 (9.2) in the CNSI and ICG groups, respectively ( P =0.19). Conclusions: Compared with ICG, CNSI can increase the number of LNs detected, especially micro-LNs. Both tracers have high diagnostic value for detecting metastatic LNs. CNSI-guided lymphography may be a superior method for improving the accuracy of LN dissection.