Based on a study in the April 28 issue of the Journal of the American Medical Association, the use of diagnostic imaging studies in cancer patients covered by Medicare is growing--with the use of PET imaging most significantly increasing--and costs for this patient population are growing at twice the rate of the overall costs of cancer care. However, while imaging costs are increasing, as of 2006 these costs still made up less than 6 percent of the overall healthcare costs for cancer patients, the study's lead author Michaela A. Dinan, BS, said in an interview.

"They are increasing faster, but are still a relatively small portion of overeall healthcare costs for cancer patients," said Dinan, who is from the Duke Clinical Research Institute in Durham, N.C.  

Dinan and colleagues examined the use and costs of imaging and how these changes may relate to the cost of cancer care. The authors noted that while types and costs of imaging, including costly new imaging modalities among Medicare beneficiaries with cancer have not been examined previously, “we did expect to see imaging utilization increase over study period, because we knew that over the years Medicare had changed reimbursements for different imaging modalities as they became available,” said Dinan.
 
Utilizing a nationally representative 5 percent sample of claims from the Centers for Medicare & Medicaid Services, the researchers included 100,954 new cases of breast cancer, colorectal cancer, leu­kemia, lung cancer, non-Hodgkin lymphoma and prostate cancer diagnosed between 1999 and 2006 using eight various imaging technologies. 
 
The authors found that while two-year costs per patient increased annually at a rate of 2 to 5 percent, the cost of imaging climbed 5 to 10 percent per patient. Most noteworthy, was the number of PET scans per beneficiary, experiencing an average growth rate of 36-53 percent annually. “PET increased the fastest, but that is in the context that Medicare did not reimburse for most PET scans at the beginning of the study period,” Dinan said.
 
In addition, the use of conventional radiographs decreased or stayed the same in each cancer subgroup while remaining the most heavily used imaging modality for all diagnoses, at an average of 4.3 to 12.2 procedures per patient, wrote the authors.

Dinan attributed this to the fact that most patients are already given this exam, and have been since the beginning of the study so there was not a great deal of room for growth.  “Whereas with PET scans,” she explained, “very few patients were receiving them and by the end of the study, a large proportion of people--specifically half of the lung cancer and lymphoma Medicare beneficiaries--were receiving a PET scan.”
 
The authors also noted increases occurring in the use of bone density scans, up from 6 percent to 20 percent; echocardiograms, 5 percent to 7 percent; MRI, 4 percent to 11 percent; and ultrasound, 0.7 percent to 7.4 percent. CT usage increased 4 percent to 7 percent with the exception of the lymphoma patient population.  
 
The authors wrote that it is unclear whether the rapid increase in use of advanced imaging is a result of advanced technologies, better outcomes, or a shift to new revenue sources after the enactment of the Medicare Prescription Drug, Improvement and Modernization Act, Yet,  Dinan said that the results "indicate as newer technologies become available, that’s where we are seeing the majority of the increase.”
 
Citing the limitations to the research, Dinan said that it is possible that the number or the costs of imaging for specific patients may have been undercounted because the study relied on claims data and physicians may or may not have filed all imaging studies for reimbursement. In addition, she noted that analysis included imaging studies performed for any reason among patients with the recent diagnosis of cancer.  
 
Given the rapid increases of PET scans and other advanced imaging modalities, Dinan believes that this is something that should continue to be monitored. “Medicare beneficiaries will be important to continue to look at and reassess, because of constantly changing reimbursement policies and as new technologies become more advanced,” she concluded.