Intraparenchymal Indocyanine Green Use Improves Nodal Yield During Minimally Invasive Tumor Nephrectomy in Children

Introduction: Correctly identifying positive lymph nodes associated with pediatric renal tumors is key to guiding management. Recommended targets for lymph node sampling are commonly missed during tumor nephrectomy, particularly if minimally invasive surgery (MIS) is performed. Indocyanine green (ICG) is used for lymph node mapping in adult oncology with excellent efficacy and safety profile. Materials and Methods: A prospective study was undertaken at a single-quaternary-level pediatric surgery center. All patients undergoing MIS radical or partial nephrectomy for renal tumors 2016-2023 were included. Patients managed from 2020 onwards received intra-parenchymal ICG prior to lymph node sampling. Main Results: Twenty-five patients underwent MIS nephrectomy at mean age 2 years 10 months. Eighteen patients were pre-ICG and 7 received ICG. ICG administration successfully demonstrated fluorescent nodes in all patients. Median number of nodes sampled was three pre-ICG and seven with ICG (P = 0.009). Forty-six nodes were sampled across 7 ICG patients-33 fluorescent, 10 non-fluorescent, and 3 identified histologically. Three nodes overall contained active disease, two pre-ICG and one fluorescent node with ICG. Neither operative time (180 pre-ICG versus 161 minutes ICG, P = 0.7) nor length of stay (72 versus 84 hours, P = 0.3) were significantly affected by ICG administration. There were no adverse events associated with ICG use. Conclusions: ICG is safe and effective at identifying nodes in MIS resection of pediatric renal tumors with the potential to increase the number of nodes sampled. Further research is needed, specifically a randomized control trial with extended follow-up.