Trends in PET Scan Usage for Imaging of Patients Diagnosed with Nonmetastatic Urologic Cancer

Introduction Positron emission tomography (PET) scanning is increasingly being used for imaging a variety of cancers, including urologic cancers. The precise utility of PET scanning for bladder cancer, prostate cancer, and renal cell carcinoma (RCC) is not yet well known. We examined the trends in PET scan usage for 3 cancers using a large population-based data set. Materials and Methods We analyzed all individuals identified with a diagnosis of nonmetastatic bladder cancer, prostate cancer, and RCC from the Surveillance, Epidemiology, and End Results-Medicare data set for 2004 to 2009 with follow-up data available to 2010. Logistic regression analysis and χ² and trend tests were performed to determine the predictors of performing PET scanning. Separate models were run for each of the cancer diagnoses. All analyses were performed using SAS, version 9.3, and P <.05 was considered significant. Results We identified 20,865, 70,414, and 7007 patients with a diagnosis of bladder cancer, prostate cancer, and RCC, respectively, from 2004 to 2009. PET scans had been performed for 3.60% of patients with bladder cancer, 1.09% of those with prostate cancer, and 5.32% of those with RCC. On regression analysis, a more recent year of diagnosis, younger age, and high stage or grade were predictors of PET scan usage for patients with bladder cancer and RCC. A higher Gleason score and higher D'Amico risk group predicted imaging with prostate cancer. Conclusion The usage of PET scanning for bladder cancer, prostate cancer, and RCC is increasing but still very selective. The selective use might be driven by a combination of reimbursement constraints and careful identification of the appropriate medical indication.