Contemporary trends in imaging test utilization for prostate cancer staging: data from the cancer of the prostate strategic urologic research endeavor.

PURPOSE: Previous investigators have reported widespread overuse of imaging tests for staging clinically localized prostate cancer. In this study imaging test utilization rates were analyzed in a contemporary group of patients, and clinical and demographic predictors of testing were identified.
MATERIALS AND METHODS: Data were abstracted from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a longitudinal registry of men with various stages of prostate cancer. A total of 4,966 men met study inclusion criteria of available treatment and staging data. The rates of computerized tomography, magnetic resonance imaging and bone scans performed between the dates of diagnosis and primary treatment were analyzed in patients at 3 levels of clinical risk based on serum prostate specific antigen, Gleason sum and T stage. Time trends in test utilization were analyzed by linear regression. Contemporary rates were compared with those identified in a previous analysis of an earlier CaPSURE cohort. Demographic and clinical predictors of utilization were identified using generalized linear model analysis.
RESULTS: Since June 1997, the overall use of staging tests has decreased 63%, 25.9% and 11.4% in patients at low, intermediate and high risk, respectively. The most precipitous decrease was noted for bone scan but the use of cross-sectional imaging also decreased in all groups. Utilization rates were lower in 2001 than in any other year studied in CaPSURE.
CONCLUSIONS: The rates of testing decreased significantly in all risk groups. However, in the absence of established clinical practice guidelines many patients at low and intermediate risk continue to undergo unnecessary testing, while a growing number of those at high risk are proceeding to treatment without previous imaging.