Can renal and bladder ultrasound replace CT urogram in patients investigated for microscopic hematuria?

Computed tomography urogram (CTU) is recommended when investigating patients with hematuria. We determine the incidence of urinary tract cancer and compare the diagnostic accuracy of CTU and renal and bladder ultrasound (RBUS) at identifying urinary tract cancer.

The DETECT I study (clinicaltrials.gov NCT02676180) is a prospective observational study recruiting patients ≥18 years following a presentation of macroscopic or microscopic haematuria at 40 hospitals. All patients had cystoscopy and upper tract imaging (CTU, RBUS or both).

3,556 patients with a median age of 68 years were recruited, of which 2166 had RBUS and 1692 had CTU in addition to cystoscopy. The incidence of bladder, renal and upper tract urothelial cancer (UTUC) were 11.0%, 1.4% and 0.8% respectively in macroscopic hematuria patients. Patients with microscopic hematuria had a 2.7%, 0.4% and 0% incidence of bladder, renal and UTUC respectively. The sensitivity and negative predictive value (NPV) of RBUS for the detection of renal cancer was 85.7% and 99.9% respectively but 14.3% and 99.7% for the detection of UTUC. RBUS was poor at identifying renal calculi. Sensitivity of RBUS was lower than CTU for the detection of bladder cancer (both <85%). Cystoscopy has a specificity and PPV of 98.3% and 83.9% respectively.

CTU can be safely replaced with RBUS in patients with microscopic hematuria. The incidence of UTUC is 0.8% in patients with macroscopic hematuria and CTU is recommended. Patients with suspected renal calculi will require non-contrast renal tract CT. Imaging cannot replace cystoscopy to diagnose bladder cancer.

The Journal of urology. 2018 Apr 24 [Epub ahead of print]

Wei Shen Tan, Rachael Sarpong, Pramit Khetrapal, Simon Rodney, Hugh Mostafid, Joanne Cresswell, James Hicks, Abhay Rane, Alastair Henderson, Dawn Watson, Jacob Cherian, Norman Williams, Chris Brew-Graves, Andrew Feber, John D Kelly, DETECT I trial collaborators

Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospital, London, UK. Electronic address: ., Surgical & Interventional Trials Unit, University College London, London, UK., Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospital, London, UK., Division of Surgery and Interventional Science, University College London, London, UK; UCL Cancer Institute, London, UK., Department of Urology, Royal Surrey County Hospital, Egerton Road, Guildford, Surrey GU2 7XX, UK., Department of Urology, James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK., Department of Urology, Western Sussex Hospitals NHS Foundation Trust, Worthing Hospital, Lyndhurst Road, Worthing, West Sussex, BN11 2DH, UK., Department of Urology, East Surrey Hospital, Canada Avenue, Redhill RH1 5RH, UK., Department of Urology, Maidstone Hospital, Hermitage Lane, Maidstone ME16 9QQ, UK., Department of Urology, The Pennine Acute Hospitals NHS Trust, North Manchester General Hospital, Delaunays Road, Crumpsall M8 5RB, UK., UCL Cancer Institute, London, UK.