Diagnostic Accuracy of Dual-Energy CT for Evaluation of Renal Masses: Systematic Review and Meta-Analysis

OBJECTIVE. The purpose of this study is to determine the diagnostic accuracy of dual-energy CT (DECT) using quantitative iodine concentration in patients with renal masses using histopathologic analysis or follow-up imaging as the reference standard. The secondary objective is to compare the accuracy of DECT (using iodine concentration) to that of conventional CT (using Hounsfield unit measurements). MATERIALS AND METHODS. We searched the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases for studies evaluating the accuracy of DECT for renal mass characterization (1947-2018). To be included, studies had to evaluate quantitative iodine concentrations in human patients with indeterminate renal masses. Risk of bias and applicability were assessed using quality assessment of diagnostic accuracy studies-2. A bivariate random-effects model was used to determine pooled sensitivity and specificity. Variability was assessed by subgroup analyses (DECT technique and risk of bias) and metaregression using test type and threshold applied as covariates. RESULTS. Of 201 studies identified, five were included (367 patients). Pooled sensitivity and specificity for DECT were 96.6% (95% CI, 85.9-99.3%) and 95.1% (95% CI, 90.7-97.5%), respectively. Metaregression evaluating the influence of the test type (DECT vs conventional CT) did not identify differences in accuracy (p = 0.06). No differences in accuracy based on risk of bias or DECT technique were identified. Limitations include the small number of studies, most of which were at risk of bias. CONCLUSION. DECT with iodine quantification shows sensitivity and specificity greater than 95% for evaluation of renal masses and may be an alternative to conventional CT for assessment of renal masses. Larger scale trials are needed to corroborate our findings.