Multicenter Analysis of RENAL, mRENAL, and (MC)2 Scoring Systems as Predictors of Outcomes after Percutaneous Cryoablation of Renal Cell Carcinoma

Abstract

Purpose

To compare the performance of the RENAL, mRENAL, and (MC)² scores in predicting outcomes after cryoablation of renal cell carcinoma.

Materials and Methods

Retrospective chart review was performed for patients who underwent cryoablation within a hospital system between 2018 and 2023. A total of 103 cryoablation procedures in 103 patients were included. Medical history, demographic information, preprocedural imaging, tumor characteristics, periprocedural hospital course, postprocedural adverse events, and follow-up imaging results were reviewed. Each tumor was assigned a RENAL, mRENAL, and (MC)² score and categorized into a low, medium, or high group for each scoring system.

Results

Twenty-one patients (20.5%) developed Society of Interventional Radiology (SIR) graded adverse events. Severe adverse events occurred in 9 patients (8.7%). High RENAL (P = .003), mRENAL (P = .047), and (MC)² (P = .004) scores were associated with a significant increase in the risk of severe postprocedural adverse events. All 3 scoring systems were equivalent in their ability to predict severe adverse events. Higher RENAL (P = .018 and P = .019) and mRENAL (P = .007 and P = .005) but not (MC)² scores were associated with increased likelihood of unplanned hospital admission and longer hospital length of stay (LOS). RENAL, mRENAL, and (MC)² scores were not significantly associated with primary technique effectiveness.

Conclusions

The RENAL, mRENAL, and (MC)² scores performed equally in predicting severe adverse events after cryoablation. The RENAL and mRENAL scores predicted postprocedural hospital admission and hospital LOS more effectively than (MC)². The scoring systems were not predictive of primary technique effectiveness despite a trend toward lower effectiveness in tumors with higher scores.