The Harms of Hematuria Workup: Modeling the Risk-Benefit of Using Split-Bolus CT Urography to Reduce Radiation Exposure in a Theoretical Cohort

Abstract:Purpose:CT urography (CTU) is used to evaluate patients with gross (GH) or microscopic hematuria (MH). CTU is a high radiation dose scan and thus confers higher risk of secondary malignancy. A CTU “Split-Bolus” (SB) protocol reduces radiation exposure; however, it may reduce sensitivity. This study uses a theoretical cohort of patients with hematuria to model the risk of missing malignancies against the benefit of averting secondary malignancies.Materials and Methods:The prevalence of renal cell carcinoma (RCC) and upper tract urothelial carcinoma (UTUC) in hematuria patients was calculated by pooled analysis of cohort studies, which, in conjunction with SB sensitivity, allows the estimation of missed malignancies. The number of secondary malignancies prevented was calculated from lifetime attributable risk estimates. Sensitivity analyses were run to determine the minimum sensitivity required for net population benefit.Results:Estimates of SB-CTU sensitivity range from 80-100% (mean 95.2%). At th...