PhotoNodes Protocol: A Multicenter Prospective Study for the Assessment of Proper Lymphadenectomy in Minimally Invasive Gastric Cancer Surgery Using Intraoperative Photographs

Introduction: In gastric cancer surgery, an adequate D2 lymphadenectomy is associated with improved cancer-specific survival. The aim of this study was to test the reliability of a new score (PhotoNodes Score [PNS]) conceived to rate the quality of lymphadenectomy in minimally invasive gastrectomy. The primary outcome of the study was to assess the inter-observer agreement among the reviewers assigning the score. The secondary outcome was the association between PNS and survival. Methods: This is a multicentric observational prospective study enrolling patients undergoing minimally invasive gastrectomy for gastric cancer with D2 lymphadenectomy. A set of laparoscopic/robotic images will be collected from each patient. Based on each set of images, the quality of lymphadenectomy performed will be rated with the new PNS by three surgeons. Fleiss' Kappa measure of agreement will be used to study the rating agreement among examining surgeons. The PNS score will correlate with disease-free and overall survival. Conclusion: The spread of minimally invasive approaches in oncologic gastric surgery made the collection of intraoperative images easier; for this reason, we believe that PNS could represent a new and efficient tool to assess the quality of D2 lymphadenectomy in clinical practice. The PhotoNodes study was registered at ClinicalTrials.gov #NCT 06466902.