Presented by: Mario Basulto-Martinez MD, MSc
Western University Schulich School of Medicine and Dentistry, Division of Urology

Introduction

Patients with urinary stone disease (USD) are often exposed to repeated computed tomography (CT) scans. While CT is the most accurate imaging for USD allowing a comprehensive evaluation, it is also associate with ionizing radiation. The low-dose CT scan protocols reduce this exposure and must be adopt whenever possible. We aimed to audit doses from CT scans performed for USD in London, Ontario.

Materials

The CT records for the 3 University affiliated hospitals in London, Ontario were audited and those non-enhanced performed for USD were identified. The total dose was calculated from every study performed in January every other year from 2011 – 2021. The dose was compared between sites. The Kruskal-Wallis test with Bonferroni correction was utilized for comparison between sites.

Results

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A total of 663 CT scans were audited; n=152, n=154, and n=357 at Victoria Hospital (VH), University Hospital (UH), and St. Joseph’s Health Care (SJHC), respectively. The overall median dose was significantly different between VH: 10.6 (6.5 – 15.8) mSv, UH: 6.6 (5.0 – 11.1) mSv, and SJHC: 3.9 (3.4 – 7.4) mSv, p<0.001. The CT dose trends from 2011 – 2021 are presented in Figure 1.

Conclusion

Low-dose CT scans for USD must be preferred whenever feasible. This audit study demonstrated that SJHC, the center where endourologists are based, had lower CT scan dose of more than half compared to the other centers. This may be explained by more awareness of radiation exposure and acquaintance with low-dose protocols. Reducing radiation exposure in patients with USD is paramount.

Funding

None

Lead Authors

Cameron Dawson, MD
Western University Schulich School of Medicine and Dentistry, Department of Medical Imaging, London Health Sciences Centre

Co-Authors

Eduardo Gonzalez-Cuenca, MD, MSc
Western University Schulich School of Medicine and Dentistry, Division of Urology

Justin Amann, MD
Department of Diagnostic Imaging, Schulich School of Medicine and Dentistry, Western University

Jennifer Bjazevic, MD, MSc
Western University

Hassan Razvi, MD
Western University, Schulich School of Medicine and Dentistry, Division of Urology