The last thing lung cancer patients want to hear is that their cancer is back following remission. If they must deal with a second bout of the disease, early detection is key for increasing survival rates and improving quality of life.

A new study suggests that one approach used by hospitals to catch cancer’s return is being overused, and isn't helping patients survive longer. The findings, published in the Journal of the National Cancer Institute by a multi-institutional research team, detailed how survivors of lung cancer often underwent a sort of imaging called PET scanning as the primary method of monitoring their condition, as opposed to other cheaper scans, like Magnetic Resonance Imaging (MRI).

PET scans are one of the few imaging systems for which the Medicare system imposes limits — currently, regulation allows for three follow-up PET scans per person. Though this guideline limits use of the scans for Medicare patients, the scans may be utilized in excess for patients with other types of insurance, or on patients despite Medicare not covering the costs of additional scans.

PET scans allow doctors to see cells that are more active, including cancer cells, inside the body, and earlier than through other types of scans. Many cancer patients receive PET scans as a diagnostic tool to determine how advanced the cancer is and how it responds to treatment. For these reasons, many hospitals are choosing to use them for follow-up care as well as diagnostics, despite a lack of evidence that they actually improve survival rates, according to researchers from the University of Michigan Medical School and Dartmouth-Hitchcock.

The team found widespread use of PET scans when they examined Medicare data for more than 100,000 lung and esophageal cancer patients —more than 22 percent of lung cancer patients and 31 percent of the esophageal cancer patients had at least one PET scan to look for a reoccurrence of cancer during their follow-up period. The PET scans were used first before a CT scan or other type of imaging.

Individual hospitals varied widely in how they utilized PET technology for cancer patients. Regardless of how often hospitals used the scan, the result was the same — patients who went to a high PET-use hospital (a hospital in the highest fifth for PET use) for their lung cancer follow-up were just as likely to survive two years as their counterparts at a low PET-use hospital (a hospital in the lowest fifth for PET use).

“PET scanning is a great technology and very effective, but using it in this way doesn’t seem to make any difference for these cancers that have a relatively poor prognosis,” said Dr. Mark Healy, a surgical resident and research fellow at the U-M Department of Surgery and member of the Center for Health Outcomes & Policy, in a press release. “The appropriate use of PET scanning in follow-up care for lung and esophageal cancer is after findings on lower-cost imaging options.”

Healy said that better coordination between radiologists and physicians directly in charge of patient care could improve appropriate use of PET scans in hospitals. The researchers hope their findings will aid all kinds of medical providers in understanding the best use of PET scanning in cancer care.

“Following evidence-based guidelines for clinical follow-up is the way to go. Don’t order PET in asymptomatic patients,” Healy said. “And for patients, if you are not having symptoms and you’re doing well, there’s no reason to seek out this scan.”

Source: Healy M, Yin H, Reddy R, Wong S. Use of positron emission tomography to detect recurrence and associations with survival in patients with lung and esophageal cancers. Journal of the National Cancer Institute. 2016.