PET affects treatment in over a third of cancer cases

March 25, 2008

A study based on nearly 23,000 patients at 1200 U.S. healthcare facilities has found that FDG-PET or PET/CT led referring physicians to alter their opinion about the optimal treatment for about 37% of cancer patients.

A study based on nearly 23,000 patients at 1200 U.S. healthcare facilities has found that FDG-PET or PET/CT led referring physicians to alter their opinion about the optimal treatment for about 37% of cancer patients.

The results summarize the first-year experience of the National Oncology PET Registry, an effort that is measuring how numerous cancer-related PET applications that have conditional approval for Medicare payment influence patient management.

NOPR was organized in 2005 as a negotiated compromise between the Academy of Molecular Imaging and Medicare. AMI supported payment for more cancer-related PET indications beyond the nine procedures approved for Medicare beneficiaries up to that time. Medicare's administrator, the Centers for Medicare and Medicaid Services, responded with a Coverage with Evidence Development ruling that temporarily granted payment but required more research to determine PET's clinical influence.

The American College of Radiology Imaging Network acted as the research agency for the resulting patient registry. NOPR began compiling data on May 8, 2006, for FDG-PET procedures performed on patients with brain, cervical, ovarian, pancreatic, small cell lung, testicular, and other cancers not already covered by Medicare. Indications included staging, restaging, diagnosis of suspected recurrence, and therapy monitoring

Medicare paid for individual FDG-PET procedures only after confirmation that the referring physicians had completed and filed two web-based surveys with NOPR. One described the physician's management plan before FDG-PET was ordered, and the other covered PET's effect on decision making after its findings were known. About 86% of the studies were performed on a PET/CT scanner, with the remainder scanned on a dedicated PET platform.

Based on the first year of data collection, registry results reported in the March 24 Journal of Clinical Oncology show that PET has a substantial effect. Lead author Dr. Bruce Hillner, a professor of medicine at Virginia Commonwealth University, found that a major change in intended management occurred in 30.3% to 39.7% of the cases, depending on the indication.

The findings confirmed the results of numerous small clinical trials that evaluated the effect of PET on staging and restaging for various types of cancer, according to coauthor Dr. Anthony Shields, a professor of medicine and oncology at Wayne State University in Detroit.

"They all came pretty much to the same conclusion. PET will change the treatment plan from 30% to 40% of the time," he said.

Data from the NOPR also showed that referring physicians were three times more likely to shift from nontreatment to treatment after PET imaging than vice versa (28.3% versus 8.2%). PET was associated more frequently with upstaging than downstaging.

PET had a big effect on biopsy recommendations. Referring physicians were inclined to recommend biopsy for 15% of the cases before PET, but for only 3.8% after the PET results were appreciated.

Referring physician confidence in PET appeared to be high. Hillner and colleagues reported that a recommendation for some other form of imaging was the most popular strategy before PET. But afterward, the strategy shifted to either pursuing specific therapies or watchful waiting.

The results are powerful enough for CMS to raise its restrictions on payment for PET imaging for staging, restaging, and diagnosis of suspected recurrence, said coauthor Dr. R. Edward Coleman, director of nuclear medicine at Duke University Medical Center.

"Any study that changes management more than a third of the time is making a major impact on how these patients are being cared for. We think it does support our request for reimbusement," he said.

He expects an application will be submitted within a few days of the article's online publication March 24. The Academy for Molecular Imaging will file that application, Hillner said.

Data concerning the effect of PET as a therapy monitoring tool have been set aside for future analysis, he said.

"Except for breast cancer, PET hasn't really been used often to monitor therapy," Coleman said. "We have results for several thousand studies, but we thought that data deserved their own evaluation. It should be completed in a few weeks.

The future of NOPR is ultimately in the hands of CMS, Hillner said. Because of residual questions concerning value of PET for therapeutic monitoring, the registry is likely to continue for at least another year.

For more information from the Diagnostic Imaging archives:

PET alters management for one in three patients

NOPR paperwork bedevils payment for PET applications

Launch of registry aims to advance PET reimbursement