Nephrometry Scoring Systems for Nephron Sparing Surgery in Children

The surgical decision to attempt nephron-sparing surgery (NSS) in children with renal tumors can be difficult. In adults, nephrometric tools are used for decision-making. More than 90% of low-complexity tumors are eligible for NSS, and high-complexity tumors often require total nephrectomy. We retrospectively applied those nephrometric tools [Radius, Exophytic, Nearness to the sinus or collecting system, Anterior/posterior, Location relative to polar lines (RENAL), Preoperative Aspects and Dimensions Used for an Anatomical classification (PADUA), and Renal Tumor Invasion Index (RTII) scoring systems] to the preoperative imaging of children operated for renal tumors in our institution from 2015 to 2019 and correlated them with the type of surgery. The scores were assessed by 2 independent surgeons and 1 radiologist. Forty-four tumors were removed, including 16 NSS, 38 after neo-adjuvant chemotherapy, and 6 upfront surgeries, in 30 children. More than 50% of patients in the low and medium-risk population for RENAL, PADUA, and RTII scores, and similar to 15% in the high-complexity categories underwent NSS. Tumors removed through NSS were significantly less complex according to each score. Interobserver reliability was good for 3 scores. The application of the RENAL, PADUA, and RTII was able to accurately classify most of the pediatric tumors, according to their complexity. These scores could help increase the indications of NSS in renal tumor surgery.