PET scans serve role in altering cancer patients treatment plan
Physicians participating in the National Oncologic PET Registry (NOPR) reported changing the treatment plan for 43.1 percent of their patients undergoing cancer treatment as the result of information gained from a PET scan, according to a study published online Nov. 17 in Cancer.

The researchers said that major changes physicians made in the intended management of their cancer patients as a result of the PET scan included: changing to another chemotherapy agent; changing the mode of therapy; or changing the current dose or duration of therapy.  

Currently, PET imaging is not considered the standard of care for monitoring the effects of cancer therapy and, therefore, is not paid for by most insurance companies, according to the authors. However, under Medicare’s NOPR program launched in May 2006, the agency began paying for PET (and PET/CT) scans for the purpose of cancer treatment monitoring.  

The NOPR investigators examined 8,240 patients who had 10,497 treatment-monitoring PET scans performed at 946 imaging centers to monitor chemotherapy alone (82 percent of scans), radiation therapy alone (6 percent of scans) or combined chemo-radiation therapy (12 percent of scans).  

The authors reported the treating physicians altered their patients’ intended care by switching to another chemotherapy agent as a result of approximately 26.5 percent of the PET scans performed and were prompted to adjust the dose or duration of treatment as a result of approximately16.5 percent of the scans performed.

Overall, the treating physician judged the patient’s prognosis as a result of the PET scan was better or improved for 42.1 percent of scans, unchanged for 31.5 percent of scans, and worse for 26.4 percent of scans, the researchers said.  

“The referring physician’s assessment of prognosis in light of the PET findings was associated strongly with changes in the management,” said the study’s lead author Bruce Hillner, MD, professor in the department of internal medicine at Virginia Commonwealth University in Richmond. “We also learned that these modifications occur predominantly after scans in which PET demonstrates more extensive disease than what was anticipated.”

Co-author Barry Siegel, MD, chief of the nuclear medicine division at Washington University’s Mallinckrodt Institute of Radiology in St. Louis, said that “using PET to monitor cancer treatment appears to have broad benefit as we found that the change in a patient’s intended treatment didn’t significantly differ for those patients whose scans indicated local and regional disease versus those with metastatic disease.”