Medicare coverage: PET proponents win some, lose some
The PET community again feels frustration after presenting what it believes is sufficient evidence for Medicare reimbursement and then waiting -- sometimes years -- before the Centers for Medicare and Medicaid Services denies its requests.
Last week, the government announced coverage of FDG-PET for one thyroid cancer indication and for myocardial perfusion imaging using nitrogen-13 ammonia. But it closed the door on three other thyroid indications, soft-tissue sarcomas, and Alzheimer?s disease.
?CMS is tremendously micromanaging the process,? said Dr. Barry A. Siegel, director of nuclear medicine at Mallinckrodt Institute of Radiology. ?I don?t understand why the government is torturing PET on an indication-by-indication, disease-by-disease basis.?
Siegel questioned why the government is paying for diagnostic tests or treatments in patients with suspected or proven severe acute respiratory syndrome (SARS) when there?s no evidence that anything works for this new disease.
?How do we know the technologies we?ve been using for garden-variety pneumonia work for dealing with SARS? Why is that any different from PET?? he said.
Thyroid consideration has been languishing for years. PET proponents have been pressuring CMS to devise a way to review rare cancers that do not have a plethora of peer-reviewed evidence. Thyroid cancer and soft-tissue sarcoma each constitute less than 1% of all human malignant tumors. Because of the overall small sample sizes and poor study quality, CMS also considered outside experts whose support tipped the scales in favor of coverage for the one thyroid cancer indication. The date that approval begins has not been set, and soft-tissue sarcoma did not enjoy the same endorsement.
The American Thyroid Association had requested FDG-PET coverage for four indications. CMS granted approval for one: Restaging of previously treated follicular cell origin thyroid cancer with an elevated or rising serum thyroglobulin (greater than 10 ng/mL) and a negative iodine-131 whole-body scan.
CMS denied two indications: · Initial staging of postsurgical thyroid cancer of cell types known to concentrate I-131 poorly, such as Hürthle cell and variants of papillary cancer · Restaging of previously treated thyroid cancer of medullary cell origin with an 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. 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.
Using available studies, CMS found: · FDG-PET does not surpass biopsy, the gold standard, for initial diagnosis of soft-tissue sarcomas. · FDG-PET does not surpass biopsy for distinguishing low-grade malignant tumors from benign lesions or high-grade tumors from low-grade tumors. · Insufficient evidence exists to support the clinical utility of FDG-PET for detecting metastases, for evaluating tumor response to preoperative chemo- or radiation therapy, and for diagnosing locoregional recurrence.
?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??
The government did approve the use of N-13 ammonia PET for the evaluation of myocardial perfusion imaging. Whether at rest alone or with stress, the PET scan is performed only in place of or following an inconclusive SPECT exam. In 1995, CMS 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 last year.)
Support for N-13 ammonia came from the American Society of Nuclear Cardiology and the American College of Cardiology, as well as from other outside experts. CMS also considered that N-13 ammonia, like FDG, is made in cyclotrons. Therefore, communities or hospitals with access to cyclotrons can utilize PET technology in the evaluation of coronary artery disease without having to invest in the generator technology required for Rb-82. CMS will continue to cover Rb-82 PET so hospitals that currently have access to generators can continue avoid additional capital investment.
Finally, CMS denied coverage for FDG-PET in Alzheimer?s disease -- for a second time. Position letters received by CMS reflect a divide. While the Society of Nuclear Medicine and the National Electrical Manufacturers Association support FDG-PET as a reimbursable indication for AD, the American College of Radiology and the Alzheimer?s Association do not.
A randomized control trial would be the strongest support of clinical benefit, but such evidence does not exist. CMS also found insufficient evidence that a positive PET scan improves treatment to patients with dementia or those with mild cognitive impairment, or asymptomatic patients with a family history of AD. Compared with current evaluative methods, including clinical diagnosis and conventional MR, a positive PET scan does not significantly alter patient management, according to CMS.
Dr. Daniel Silverman and colleagues from the University of California, Los Angeles submitted a study that described a decision model comparing outcomes from two approaches. The first strategy used the standard clinical evaluation recommended by the American Academy of Neurology (AAN). The second approach incorporated FDG-PET to test for the presence of a pattern of regional metabolism characteristic of AD.
The authors concluded that use of FDG-PET for evaluating early dementia in the elderly would increase diagnostic accuracy by decreasing rates of false-negative and false-positive diagnoses of AD compared with the AAN-recommended strategy. This strategy would also reduce the need for nursing home care and unnecessary drug therapy.
CMS will design a demonstration to evaluate the appropriate role of PET in 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.
