Can Renal and Bladder Ultrasound Replace Computerized Tomography Urogram in Patients Investigated for Microscopic Hematuria?

Abstract

PURPOSE: Computerized tomography urogram is recommended when investigating patients with hematuria. We determined the incidence of urinary tract cancer and compared the diagnostic accuracy of computerized tomography urogram to that of renal and bladder ultrasound for identifying urinary tract cancer. MATERIALS AND METHODS: The DETECT (Detecting Bladder Cancer Using the UroMark Test) I study is a prospective observational study recruiting patients 18 years old or older following presentation with macroscopic or microscopic hematuria at a total of 40 hospitals. All patients underwent cystoscopy and upper tract imaging comprising computerized tomography urogram and/or renal and bladder ultrasound. RESULTS: A total of 3,556 patients with a median age of 68 years were recruited in this study, of whom 2,166 underwent renal and bladder ultrasound, and 1,692 underwent computerized tomography urogram in addition to cystoscopy. The incidence of bladder, renal and upper tract urothelial cancer was 11.0%, 1.4% and 0.8%, respectively, in macroscopic hematuria cases. Patients with microscopic hematuria had a 2.7%, 0.4% and 0% incidence of bladder, renal and upper tract urothelial cancer, respectively. The sensitivity and negative predictive value of renal and bladder ultrasound to detect renal cancer were 85.7% and 99.9% but they were 14.3% and 99.7%, respectively, to detect upper tract urothelial cancer. Renal and bladder ultrasound was poor at identifying renal calculi. Renal and bladder ultrasound sensitivity was lower than that of computerized tomography urogram to detect bladder cancer (each less than 85%). Cystoscopy had 98.3% specificity and 83.9% positive predictive value. CONCLUSIONS: Computerized tomography urogram can be safely replaced by renal and bladder ultrasound in patients who have microscopic hematuria. The incidence of upper tract urothelial cancer is 0.8% in patients with macroscopic hematuria and computerized tomography urogram is recommended. Patients with suspected renal calculi require noncontrast renal tract computerized tomography. Imaging cannot replace cystoscopy to diagnose bladder cancer.