RENAL nephrometry scoring system in bilateral Wilms tumor: predictive application

Area of Science:

• Pediatric Oncology
• Nephrology
• Surgical Oncology

Background:

• Bilateral Wilms tumor (BWT) presents unique surgical challenges.
• Accurate assessment of tumor characteristics is crucial for treatment planning.

Purpose of the Study:

• To evaluate the applicability of the RENAL nephrometry scoring system in characterizing bilateral Wilms tumors.
• To correlate tumor complexity with surgical management and patient outcomes.

Main Methods:

• Retrospective review of 29 patients with BWT (53 kidney units) from 2010-2022.
• Independent assessment of tumor complexity using the RENAL score by blinded reviewers.
• Comparison of tumor characteristics with surgical interventions (nephron-sparing surgery vs. radical nephrectomy) and outcomes.

Main Results:

• Most BWTs were high-complexity (60.4%), with a significant proportion having multiple lesions (26.4%).
• Nephron-sparing surgery (NSS) was performed in 79.2% of kidney units, with lower complexity tumors favoring NSS.
• Kidney autotransplantation was utilized for higher-complexity tumors undergoing NSS.

Conclusions:

• The RENAL score effectively describes BWT anatomical complexity.
• While complexity did not correlate with prognosis in this cohort, it informed surgical approach selection.
• NSS is feasible for low-complexity BWT, and kidney autotransplantation offers a solution for complex cases, though refined scoring is needed for multifocal disease and tumor thrombus.