Improving Accuracy, Reliability, and Efficiency of the RENAL Nephrometry Score With 3D Reconstructed Virtual Imaging

Abstract

Objective: To clarify the diagnostic performance of the three-dimensional reconstructed virtual image (3D-RVI) in evaluating RENAL nephrometry score (RENAL-NS).

Methods: This study included 130 patients who underwent preoperative contrast-enhanced computed tomography followed by partial nephrectomy for renal tumors suggestive of renal cell carcinoma. RENAL-NS was calculated prior to the surgery, and tumor resection was performed referring to the score. We retrospectively reviewed preoperative contrast-enhanced computed tomography images. We calculated the inter-observer variability of RENAL-NS using 3D-RVI vs two-dimensional (2D) imaging and compared the ability of RENAL-NS using 3D-RVI vs 2D imaging to predict the risk of opening of the urinary collecting system. We also compared the two modalities for the time required to evaluate RENAL-NS.

Results: RENAL-NS evaluated using 3D-RVI showed a higher inter-observer agreement compared to 2D-imaging (r_s = 0.85 vs r_s = 0.65). The "nearness to sinus" score was more strongly associated with the opening of the urinary collecting system when evaluated using 3D-RVI than 2D-imaging (AUC = 0.71 vs AUC = 0.57, P = .016). RENAL-NS using 2D-imaging required a significantly longer time compared to 3D-RVI (P = .036).

Conclusion: Using 3D-RVI improves the accuracy, reliability and efficiency of RENAL-NS evaluation in preoperative assessment and can play an important role in preoperative assessment and intraoperative navigation.