Last December, Medicare announced that it would begin covering positron emission tomography scanning to diagnose, stage, and restage six specific cancerslymphoma, melanoma, and lung, colorectal, esophageal, and head and neck cancers (see News, Feb. 7, p. 177).
Later this month, the issue of whether this technology could be useful in breast cancer diagnosis and staging will come to the table. The group charged with answering this question is a panel of the Medicare Coverage Advisory Committee.
In November 1998, Health and Human Services Secretary Donna Shalala established the committee as an impartial advisory body charged with advising the Health Care Financing Administration on the evidence to back covering new technologies under Medicare. The committees inception occurred just as the political conflict over the future of Medicare became heated. Additionally, physician leaders of the nascent health care quality movement were articulating a new message that stressed bolstering wider use of effective health care, discarding ineffective treatments, and questioning inappropriate use and overuse of treatments.
The committees charge is a "massive undertaking," said Sean Tunis, M.D., HCFA liaison to the committee. In its first year and a half, MCACs executive committee has been consumed with establishing guidelines for operation, and only a handful of new technologies have been reviewed by MCAC panels.
"Ideally, MCAC would operate as a sort of scientific courtroom where everyone would hear all the evidence and attempt to render some reasonable judgment," Tunis said.
Application to Oncology
In oncology, Tunis said, "we are trying to look broadly at the framework of diagnostic testing. . . . In discussions, it has often come down to, to what extent the sensitivity and specificity of imaging tests provides sufficient grounds for coverage or alters patient management or outcomes. . . . It raises the whole philosophy of what standard of evidence to hold a new imaging technology to, what clinical value does an added test make in clinical treatments."
When the committee considers the benefit of an imaging test for detecting recurrence, the rules are somewhat different because there are so few randomized trials, explained Harold C. Sox Jr., M.D., chair of MCACs executive committee, and professor of medicine at Dartmouth-Hitchcock Medical Center in Lebanon, N.H. Thus, "you have to focus on whether the test changes patient management."
|
MCAC is organized into six panels based on broad review areas: drugs, biologics, and therapeutics; laboratory and diagnostic services; medical and surgical procedures; diagnostic imaging; medical devices and prosthetics; and durable medical equipment. Each MCAC panel consists of 15 voting members, a chair, consumer representative, and one industry representative. The Diagnostic Imaging Panel will examine PET scans for breast cancer in the June 19 meeting.
No matter how MCAC weighs in on a technology, its conclusions are strictly "advisory." HCFA will use other information to make their final coverage decision.
Reviewing PET Scans
When the MCAC panel evaluated whether PET scans alter the management of colorectal cancer last year, it reviewed the technologys purported ability to "take advantage of cancer cells somewhat different glucose metabolism to be able to identify a collection of cancer cells," noted Sox. Also, the panel examined PETs contrast capability compared with computed tomography scanning to see if it enhanced differentiation between malignant and nonmalignant tissue.
"The basic purpose was to see whether PET adds something, particularly whether it changes the probability of detecting recurrence over CT scan, and whether it changes it enough so that it changes the clinical management and patient outcomes for patients undergoing the test," Sox said.
A key question in considering PET for colorectal cancer recurrence was "whether a negative imaging test conferred a low enough probability to not call something normal when it was cancer," said Sox. "Studies revealed that patients with a negative test would have a 1 in 12 chance of a recurrence. In this particular instance, the evidence suggests that PET is a reasonable thing to do."
By contrast, using PET for diagnosing dementia was given a thumbs-down by the panel. "Studies were of such poor quality that the committee recommended against covering PET for this use," Sox said. While proponents of the technology argued that it can differentiate the pattern of blood flow to the brain to discriminate between patients with dementia and control patients, the studies had serious methodological flaws," he added.
MCAC Process
MCAC relies heavily on reports generated by Agency for Healthcare Research and Qualitysupported evidence-based practice centers, particularly those generated by the Blue Cross/Blue Shield Technology Evaluation Center, Chicago.
Typically, HCFA requests that MCAC evaluate common, costly items that are either being disseminated rapidly for use in treatment of Medicare beneficiaries or for which the precise benefit is uncertain.
Peter C. Albertsen, M.D., who participates in Blue Cross/Blue Shield technology assessment reviews, praised the process. "The good thing about the Committee is that it works to elevate the standards by which new technologies are evaluated. However, like everything else, the evidence is sometimes strong, but other times, it is paper thin." Albertsen is professor and chair of urology at the University of Connecticut Health Science Center in Farmington.
One aspect of the process that Albertsen admires is the "attempt to balance evidence and claims so you are not demanding evidence for 20-plus years when a new technology improves quality of life and efficacy."
That said, Albertsen was quick to acknowledge that MCACs scientific reviews are far from isolated from the political process. "Ultimately, it comes down to what payers like HCFA and private insurers decide to cover. There is not only a scientific debate, but a political/social debate as well."
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |