Radiation dose in CT-based active surveillance of small renal masses may be reduced by 75%. A retrospective exploratory multiobserver study
Active surveillance is increasingly utilized in managing small renal masses (SRM) regardless of patient age. The follow-up protocol most commonly used includes contrast-enhanced abdominal CT scanning. The cumulative radiation dose incurred in serial imaging as part of active surveillance is a concern. There is an unmet need for reducing radiation dose while preserving the accuracy and reproducibility needed in radiographic measurements such that small changes in renal mass size can be appreciated. Using a simulation technique, we investigated the accuracy and reproducibility of low-dose CT (75% dose reduction) compared to normal-dose CT to assess maximum axial renal tumor diameter. Open access CT datasets from the 2019 Kidney and Kidney Tumor Segmentation Challenge were used. We hypothesized that contrast-enhanced low-dose CT with a 75% reduction in radiation dose could be used interchangeably with contrast-enhanced normal-dose CT in terms of accuracy and reproducibility in determining the maximum diameter of SRMs. We found similar accuracy and reproducibility of low-dose versus normal-dose CT, which suggests these modalities can be used interchangeably for the assessment of maximal axial tumor diameter. The data deposited here consists of 2 CSV files with tumor diameter measurements completed by six observers evaluating 40 cases of low-dose CT and normal-dose CT, respectively. In addition, a PDF file is provided with key images of caliper placements for each case (n=40) and observer (n=6), as well as the tumor, CT, and patient details. The presented data may stimulate future research investigating low-dose CT for active surveillance of small renal masses.