Swedish Initiative Results in Significant Reduction in Inappropriate Prostate Cancer Imaging
A number of initiatives have been implemented to encourage reduction of inappropriate use of imaging to stage incident prostate cancer. Since 2000, the National Prostate Cancer Register (NPCR) of Sweden has led an effort to decrease national rates of inappropriate prostate cancer imaging by disseminating utilization data along with the latest imaging guidelines to urologists in Sweden. As reported in Journal of the National Cancer Institute by Danil V. Makarov, MD, of the U.S. Department of Veterans Affairs, and colleagues, this effort has resulted in a large and significant reduction of inappropriate imaging in patients with low-risk prostate cancer and a small but still significant reduction in those with high-risk cancer.
Study Details
The investigators performed a retrospective cohort study among men diagnosed with prostate cancer from the NPCR from 1998 to 2009. Imaging use over time was stratified by clinical risk categories of low, intermediate, and high and by geographic region.
Among 99,879 men diagnosed with prostate cancer between 1998 and 2009, 36,414 (36%) underwent imaging within 6 months of diagnosis. Those undergoing imaging were younger (P < .001) and had higher-risk features (clinical stage, prostate-specific antigen, and Gleason score) at presentation (all P < .001). Patients with high-risk disease accounted for 70% of men undergoing imaging and 36% of those not undergoing imaging. In a random sample of 500 patients with detailed data, 88% had one or more bone scans, with 75% having bone scans alone; 6% of patients had MRI alone and 2% had CT scans alone. There was wide regional variation in imaging use, but imaging use significantly decreased over time in all regions.
Reduced Imaging Rates in All Risk Groups
Overall use of imaging decreased from a high of 58% among men diagnosed in 1998 to a low of 23% among men diagnosed in 2008 (P <.001), with the decline over time being significant within each risk category (P < .001 for each). At each time point, imaging use was greater among men with high-risk prostate cancer than among those with intermediate-risk disease and greater among the latter than among those with low-risk disease. Among men with low-risk cancer, the proportion undergoing imaging decreased from 45% in 1998 to a low of 3% in 2008 and 2009 (P < .001). The proportion of men with high-risk cancer undergoing imaging decreased from 63% to 43% in 2008 and 47% in 2009 (P < .001).
The investigators concluded: “A Swedish effort to provide data on prostate cancer imaging use and imaging guidelines to clinicians was associated with a reduction in inappropriate imaging over a 10-year period, as well as slightly decreased appropriate imaging in high-risk patients. These results may inform current efforts to promote guideline-concordant imaging in the United States and internationally.”
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