The growth rate among non-radiologists who own or lease PET equipment was far higher than radiologists between 2002 and 2007, according to a study published in the March issue of the Journal of the American College of Radiology.

The data for the study was collected utilizing the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2002 through 2007.

"Although a large percentage of PET scans in private offices are done by radiologists (45.4 percent in 2007), the growth rate among nonradiologists was far higher (737 percent) than radiologists (259 percent) between 2002 and 2007 " and private-office PET market share for nonradiologists rose from 13 percent in 2002 to 24 percent in 2007, according to Rajan Agarwal, MD and colleagues at the department of radiology, University of Pennsylvania Health System in Philadelphia.

“Five specialty groups accounted for 95 percent of all nonradiologist PET volume in 2007: internal medicine subspecialties (28,324 studies in 2007), medical oncology (14,320 studies), cardiology (13,724 studies), radiation oncology (9,563 studies), and primary care (2,398 studies)," said Agarwal.

Agarwal and colleagues suggest that the overall rapid growth in PET imaging is likely secondary to the fact that PET is a relatively novel technology that has compelling clinical indications, can replace less sensitive and specific diagnostic tests, and has significant research applications.

“One of the well-known factors contributing to rising imaging costs is self-referral among non-radiologist physicians which has been shown to result in unnecessary utilization of imaging. This has made imaging one focus of concern as policymakers and third party payers look to cut health care costs,” said Agarwal.

An additional contributing factor could be technical reimbursements for PET scans. “Favorable technical-component reimbursements increase the profitability of scans performed on privately owned scanners, providing further incentive to nonradiologists to purchase PET scanners,” added Agarwal.

The investigators noted that the study had certain limitations. First, there was no way to distinguish between PET scans done on units owned by nonradiologist physicians and those leased by them from imaging centers that may in turn be owned by radiologists or companies. Second, how many physicians were actually involved in owning or leasing the units could not be determined. Third, in some cases, the nonradiologist physician who ordered a PET scan may not be the same physician who owns or leases the scanner. Last, there was no way to determine the appropriateness of the PET scans done by nonradiologist physicians who self-referred to units they owned or leased, noted Agarwal and colleagues.