Tumor-Lymph Node Mapping

The purpose of this study is to assess the feasibility and safety of ICG-guided intraoperative lymphography for detecting sentinel lymph nodes (SLN) in pediatric patients with solid tumors who require retroperitoneal lymph node dissection/sampling. This trial is a single-site cross-sectional study. The injection of ICG directly into lymphatics draining the primary tumor will take place at the time of operation after the patient is under anesthesia.

Inclusion Criteria: * Any pediatric patient (under the age of 18 years) being treated at the University of Rochester Medical Center, Department of Surgery. * Diagnosed with pediatric solid tumor * Scheduled to undergo lymph node sampling as part of their clinical management. Exclusion Criteria: * Subjects with a history of iodide allergies. * Inability or unwillingness of research participant or parent/legal guardian to give written informed consent. * Currently pregnant. * Infants under 650 grams. * Patients with extensive prior surgery at the primary site or nodal basin expected to affect the lymphatic drainage.