Feds expand MR and PET coverage in some cases but deny others

Expansion falls short of advocates' hopes

Reimbursement typically lags behind the march of imaging technology. But slowly, some would say grudgingly, Medicare and Medicaid have begun to catch up.

As April drew to a close, the Centers for Medicare and Medicaid Services expanded coverage for both PET and MR. On April 21, CMS announced coverage for MR angiography would be expanded to assess abdominal and pelvic vascular disease. Several days earlier, the agency announced expanded coverage of FDG-based imaging for a type of thyroid cancer and the use of nitrogen-13 ammonia for myocardial perfusion imaging.

CMS has also decided specifically to evaluate the appropriate role of PET in assessing patients suspected of having Alzheimer's disease. It will convene an expert panel with the National Institutes of Health to explore the value of PET for diagnosing the dementia, as well as conduct a special demonstration project to assess the modality's value for this application.

Terry Douglass, Ph.D., chairman and CEO of CTI Molecular Imaging, said the news regarding expanded PET coverage was better than expected.

"The positive decision on thyroid cancer took place much faster than we had anticipated," he said. "Additionally, (efforts regarding Alzheimer's disease) could expedite the creation of more specific coverage criteria for PET and is evidence of the continued progress to gain Medicare approval for this indication."

The expanded coverage for MR angiography has wide-ranging implications for vendors of contrast media whose products are used off-label for this purpose. Expanded reimbursement could lead to increasing use of this technique and, consequently, the extracellular agents that fuel it.

It could also prove a future boon for the adoption of MR blood pool agents now in development. Epix Medical expects to submit a new drug application to the agency later this year for its experimental contrast agent, MS-325. Clinical data supporting the NDA will address vascular disease in the aortoiliac, pedal, and renal arteries. Other companies are developing similar agents.

CMS currently covers abdominal and pelvic MRA only when the wall of the aorta is damaged. Dispensing with this restriction and allowing reimbursement for x-ray cardiac cath in addition to MRA, when clinically warranted, may indicate a growing appreciation for the value of MR angiography. But it has not come soon enough for some.

"There is a decade's worth of published data showing the benefits of renal MRA," said Dr. Jeffrey C. Weinreb, chief of MRI at Yale University.

Many patients with suspected renal artery stenosis have compromised renal function and should be getting MRA rather than CTA or catheter angiography, according to Weinreb. Part of the frustration of radiologists who practice body MR is that they've continued to do renal MRA despite the lack of reimbursement.

"You could not justify subjecting these patients to injections of iodinated contrast when we knew we had a test that gave the answer without it," Weinreb said.

The frustration for PET advocates is just as palpable. Although CMS expanded coverage to include one thyroid indication, it voted down three others, as well as coverage for soft-tissue sarcomas and Alzheimer's disease.

"I don't understand why the government is torturing PET on an indication-by-indication, disease-by-disease basis," said Dr. Barry A. Siegel, director of nuclear medicine at Mallinckrodt Institute of Radiology.

Wins have come only with great perseverance. The decision to cover N-13 ammonia PET for myocardial perfusion imaging came eight years after the government approved PET for myocardial perfusion using rubidium-82. Both Rb-82 and N-13 ammonia PET are currently combined with FDG-PET to provide the matching analysis between perfusion and viability. (FDG-PET for myocardial viability was approved only last year.)

The American Thyroid Association had requested FDG-PET coverage for four thyroid indications. CMS granted coverage to restage previously treated follicular cell origin thyroid cancer with elevated or rising serum thyroglobulin (greater than 10 ng/mL) and a negative iodine-131 whole-body scan. It denied two others: initial staging of postsurgical thyroid cancer of cell types known to concentrate I-131 poorly and restaging of previously treated thyroid cancer of medullary cell origin with elevated serum calcitonin and negative standard imaging tests. A fourth indication-to identify patients with metastatic thyroid cancer at highest risk for death within three years-was not even considered. CMS said the test is for informational purposes only and not for changing patient management.

The agency denied coverage for soft-tissue sarcoma because current techniques have good diagnostic capabilities, and PET does not improve patient outcomes, according to CMS. Up to 20% of patients presenting with soft-tissue sarcomas will already have metastatic disease, most commonly in the lung. Treatment options depend on the grade and size of the tumor and the presence of metastases.

But Siegel contends that PET should be given greater latitude because of the extraordinary track record this modality has with other cancers.

"It is eminently clear that in many cancers FDG-PET changes patient management, improves overall diagnostic ability, improves staging accuracy, and allows us to better assess the presence of residual, recurrent, or metastatic disease," Siegel said. "Do we really have to prove that PET works for each and every individual cancer and have this process go on forever-and ultimately be left with some cancers for which we will never be able to prove effectiveness because the numbers are too small?"

A major challenge is proving the effectiveness of PET in managing patients with diseases that affect a relatively small number of people, he said. Thyroid cancer and soft-tissue sarcoma each constitute less than 1% of all human malignant tumors. PET proponents have not yet been able to convince CMS to devise an effective way to review rare cancers that may lack peer-reviewed evidence of PET's clinical benefit.

CMS denied coverage for FDG-PET in evaluating Alzheimer's disease in the second go-round for this indication. The agency did agree to design a demonstration project to evaluate the appropriate role of PET in assessing patients with suspected dementia. The agency will work with the National Institutes of Health to convene a multidisciplinary expert meeting with geriatricians, neurologists, radiologists, PET experts, and patient advocates.

Expansion of CMS coverage may be agonizingly slow, but it is happening and more diseases, including Alzheimer's, will be covered in the future.

"We expected that gaining reimbursement approval for Alzheimer's disease would take some time," Douglass said. "But we remain confident that CMS will provide coverage of PET in appraising Alzheimer's disease, as published clinical studies show a 93% diagnostic accuracy in these patients."