Elsevier

Urology

Volume 133, November 2019, Pages 40-45
Urology

Ambulatory, Office-based, and Geriatric Urology
Evaluation of the Risks and Benefits of Computed Tomography Urography for Assessment of Gross Hematuria

https://doi.org/10.1016/j.urology.2019.04.055Get rights and content

Abstract

Objective

To model the risk of radiation-induced malignancy from computed tomography urography (CTU) in evaluation of gross hematuria and contrast this with the benefits of urinary tract cancer detection when compared to renal ultrasound.

Methods

A PUBMED-based literature search was performed to identify model inputs. Estimates of radiation-induced malignancy rates were obtained from the Biological Effects of Ionizing Radiation VII report with dose extrapolation using the linear no-threshold model.

Results

Male gender and age over 50 years were associated with a relative risk of upper tract malignancy of 2.04 and 2.95, respectively. The risk of upper tract malignancy missed by renal ultrasound ranged from 0.055% in females under 50 to 0.51% in males over 50. Risk of CTU-induced malignancy with associated loss of life expectancy ranged from 0.25% and 0.027 years in females under 50 to 0.08% and 0.0054 years in males over 50. For CTU to be superior to renal ultrasound, an undiagnosed upper tract malignancy would have to carry a loss of life expectancy of 49.2 years in females under 50, 13.4 years in males under 50, 2.6 years in females over 50, and 1.1 years in males over 50.

Conclusion

In low-risk patients, CTU for evaluation of gross hematuria may carry a significant risk of radiation-induced secondary malignancy relative to the diagnostic benefit offered over renal ultrasound

Section snippets

Identification of Model Inputs

A PUBMED-based literature review was performed to identify model inputs. These included age and gender distribution of gross hematuria patients, detection rates of upper tract malignancy in gross hematuria patients,3, 4, 8 sensitivity of renal ultrasound for upper tract malignancy detection,4,9, 10, 11 CTU radiation dose,12 and the loss of life expectancy (LLE) from a radiation-induced malignancy.13 The age and gender of patients with upper tract malignancy was used to calculate the relative

RESULTS

Model inputs and sources are summarized in Table 1. Three prospective series of gross hematuria patients were identified with pooled analysis consisting of 3671 patients. Prevalence of upper tract urothelial carcinoma and renal cell carcinoma was 0.63% and 1.20%, respectively. The age and gender distribution of gross hematuria patients was identified, of whom 72.7% were male and 72.5% were over age 50. Male gender and age over 50 years were associated with a relative risk of upper tract

DISCUSSION

This study demonstrates that the risk of malignancy related to CTU radiation is significant compared to the diagnostic benefit offered over renal ultrasound in patients with gross hematuria. This is most pronounced in younger or female patients, who have lower rates of upper tract malignancy and higher risk of radiation-induced malignancy. For CTU to be superior to renal ultrasound in the evaluation of gross hematuria, an undiagnosed upper tract malignancy would have to carry a LLE of greater

CONCLUSION

Based on current radiation risk models, CTU for the evaluation of gross hematuria may be associated with a small but significant risk of radiation-induced secondary malignancy. In low-risk patients, renal ultrasound should be considered as an alternative modality.

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    • Cited by (6)

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