Researchers in the Department of Radiation Oncology at the University of North Carolina Hospitals found that almost one-third of low-risk and almost one-half of intermediate-risk prostate cancer patients received a staging bone scan. That’s surprising because these patients had almost no chance of having metastatic disease. A metastatic work-up for patients with low- and intermediate-risk cancer, which costs Medicare $11.3 million, is unlikely to yield useful clinical information. Of these low- and intermediate-risk patients, 21% had subsequent x-rays, 7% had a CT scan, and 3% underwent an MRI scan.
On the other hand, writes Ronald C. Chen, MD, MPH, and associates, bone scans were only used in 62% of high-risk patients. This is in contrast to published guidelines, which recommend staging scans for this population. Among high-risk patients who received a bone scan, 14% were diagnosed with metastatic disease. These findings were published in the International Journal of Radiation Oncology
The researchers write that physicians should be “judicious when ordering tests and procedures to spare patients from unnecessary procedures and to help curb rising health care costs.” Those patients with apparent low- and intermediate-risk prostate cancer “almost never have metastatic disease at the time of diagnosis, the positive predictive value of a bone scan is low, and the risk of false-positive results is high.” Despite the low yield in clinically useful data, bone imaging studies are frequently performed on these patients.
Overall, bone scans for all patients costs Medicare $19.3 million annually, including $9.3 million for low- and intermediate-risk patients. An additional $2 million is spent annually on downstream imaging after a bone scan for low- and intermediate-risk patients.
Patients were drawn from the Surveillance, Epidemiology, and End Results (SEER) Medicare database. The authors note that patients younger than 65 years of age were not included. However, because the median age for diagnosis of prostate cancer is 67 years of age, this disease and its associated costs are highly relevant to Medicare.
The authors conclude that the results demonstrate “a pervasive lack of adherence to guidelines, and a common overuse and underuse of this test in prostate cancer.”
Percent of Patients Receiving Scans