Diagnostic Performance of Multiparametric Clear Cell Likelihood Score for Characterization of Subcentimeter Solid Renal Lesions: A Multi-institutional Study.

Abstract

Rationale and objectives: Early characterization of subcentimeter (≤1cm) renal lesions is crucial for effective clinical management. This study aims to validate the diagnostic performance of the multiparametric MRI (mpMRI) clear cell likelihood score (ccLS) category in diagnosing subcentimeter clear cell renal cell carcinoma (ccRCC).

Materials and methods: This retrospective study included consecutive patients with subcentimeter solid renal masses who underwent mpMRI between September 2009 and September 2022 at three hospitals. Two urological radiologists independently scored each lesion using the ccLS algorithm. Diagnostic accuracy was calculated using contingency tables, and the distribution of ccRCC by ccLS was tabulated. Interobserver agreement was evaluated with the Cohen κ statistic.

Results: 50 patients (mean age: 52 years±13, 24 men) with 51 subcentimeter lesions were included. Of the 51 lesions [mean size: 9 mm±1 (range, 6-10 mm)], 23 (45%) were benign, and 20 (39%) were ccRCC. The sensitivity, specificity, and positive predictive value for diagnosing ccRCC when ccLS was 4 or higher were 75% (95% CI: 60, 86), 84% (95% CI: 73, 91), and 75% (95% CI: 60, 86), respectively. The negative predictive value of a ccLS of 2 or lower was 96% (95% CI: 81, 99). The percentages of ccRCC were 8% (1/12), 0% (0/14), 25% (9/36), 81% (17/21), and 69% (13/19) for ccLSs of 1-5, respectively. The interobserver agreement was moderate (κ=0.48; 95% CI: 0.32, 0.63).

Conclusion: Subcentimeter solid renal lesions can be qualitatively assessed by mpMRI. The mpMRI ccLS category demonstrated acceptable accuracy in diagnosing subcentimeter ccRCC.

Data availability statement: Data generated or analyzed during the study are available from the corresponding author by request.