CMS coverage decision favors dedicated PET scanners

The worst fears of owners and vendors of coincidence cameras were confirmed on June 29, when the Centers for Medicare and Medicaid Services (CMS) formally restricted reimbursement to selected types of nuclear medicine devices.

Expanded PET applications that were approved Dec. 15, 2000, and took effect on July 1 are being reimbursed only if examinations are done on high-performance dedicated full- and partial-ring systems, according to the June 29 memorandum explaining the decision. Gamma cameras modified to allow coincidence detection are specifically excluded.

The newly covered indications allow for the diagnosis, staging, and restaging of lung, colorectal, lymphoma, melanoma, esophageal, and head and neck cancers (exclusive of those involving the brain or thyroid).

Imaging done with coincidence cameras will be reimbursed for conditions approved by CMS (formerly the Health Care Financing Administration) prior to last December. These are narrow indications, however, such as the diagnosis of single pulmonary nodules or recurrent colon cancer indicated by a rising carcinoembryonic antigen level. And there are caveats even to these exceptions: The crystal must be at least 5/8-inch thick, techniques must be in place to minimize or correct for scatter, detectors must be digital, and the processors must support iterative reconstruction.

CMS personnel appear, however, to be keeping an open mind. The agency might revise its policy if PET advocates can prove that gamma cameras are at least equivalent to dedicated PET systems using ring detectors or that they provide diagnostic information that adds to data provided by conventional imaging. PET proponents have until Dec. 31, 2002, to make their case.

The decision directly affects only Medicare recipients, but the implications are broad. Third-party payers tend to follow Medicare policy in developing their own coverage decisions (SCAN April 25, 2001). Opponents of the CMS decision argue that the policy sets a dangerous precedent. This is the first instance in which Medicare policy makers have disallowed coverage depending on performance specifications associated with different types of devices cleared by the FDA for the same purpose. Critics argue that CMS is interfering in the practice of medicine.

“It is a very dangerous policy for medical imaging to have CMS say what instruments you can use to do your imaging. That domain is reserved for the FDA,” said Dr. Robert E. Henkin, acting chair of radiology at Loyola University.

CMS policy does not ban reimbursement depending on the product specifications of other modalities. CT, MRI, and ultrasound use low- to high-end scanners. The range of quality is similar to the cost; yet all are covered equally by CMS.

Dr. Sean Tunis, director of the coverage and analysis group at CMS, said that the comparison with high- and low-end CT and MR scanners is valid.

“If you upgrade an ultrasound scanner to do CT, does it then become a CT scanner?” he said. “A gamma camera is a nuclear medicine scanner that has been upgraded to perform coincidence imaging. Does that make it a PET scanner?”

Some physicians worry that CMS has been asking the wrong questions. Positron imaging, they note, is not the only example of Medicare trying to fine-tune medical practice. CMS allows additional payment to healthcare providers who use digital instead of film-based mammography systems. The distinction is made even though the FDA bases its decisions on whether clinical data demonstrate digital systems perform as well as-not better than-analog units. This approach raises serious questions about the roles of the CMS and the FDA.

“Is CMS saying that in addition to the FDA, we now have to get device approval from them as well?” Phelps said.

The answer may be yes. Tunis said that CMS makes its decision on the basis of evidence indicating clinical utility; the FDA does not.

“Proponents of a technology need only prove to the FDA that it is safe and does what it promises to do-in this case, detect positrons,” Tunis said. “Whether it’s clinically useful to detect positrons takes actual clinical studies that examine specific areas such as, for example, the restaging of colorectal cancer.”

He disagrees that CMS should follow any other approach. Some detractors allege, however, that CMS has veered from its tried-and-true course by basing coverage decisions on product specifications. In doing so, it has raised the standard of clinical proof higher for PET than for other modalities.

“Yes, the process has changed, but I don’t think the bar has been raised,” Tunis said. “We’ve adopted an evidence-based framework that says we’ll look at proof of clinical utility. It agitates me when people say we were easier on CT and MRI than on PET. The level of the bar has been made clearer for everybody to see.”