PET affects treatment in over one-third of cancer cases

A study based on nearly 23,000 patients at 1,178 US healthcare facilities has found that FDG-PET or PET/CT led referring physicians to alter their opinion about the optimal treatment for 36.5% of cancer patients.

The results summarize the first-year experience of the National Oncologic PET Registry (NOPR), 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 (AMI) and the Centers for Medicare & Medicaid Services (CMS).

AMI supported payment for more cancer-related PET indications beyond the nine procedures already approved for Medicare beneficiaries. CMS 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.

What the registry showed

Based on the first year of data collection, registry results, reported online in the Journal of Clinical Oncology on March 24, 2008, show that PET has a substantial effect. Lead author Bruce Hillner, MD, of Virginia Commonwealth University, found that a major change in intended management occurred in 30.3% to 39.7% of 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 Anthony Shields, MD, of Wayne State University.

“They all came pretty much to the same conclusion. PET will change the treatment plan from 30% to 40% of the time,” Dr. Shields 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% vs 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. Dr. Hillner 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 R. Edward Coleman, MD, director of nuclear medicine, 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 reimbursement,” he said.