People over 65 who are current or former heavy smokers may benefit from low-dose CT scans of the lungs to detect cancer, according to researchers from the National Cancer Institute.

Some experts have hesitated to recommend this type of lung cancer test because it has a high rate of false positives, ABC News reports. A positive test requires invasive follow-up tests to determine if the person has cancer.

Medicare is debating whether to pay for the scans, which cost $100 to $400, the article notes. A decision is expected in November.

The study found preventing one lung cancer death required screening 245 adults 65 and older, compared with 364 adults ages 55 to 64. Older participants had a false-positive rate of 28 percent, compared with 22 percent for middle-aged participants, the researchers report in the Annals of Internal Medicine.

“Until there is new and direct evidence to the contrary, it does not seem reasonable to exclude persons aged 65 to 74 years from access to screening,” Dr. Michael Gould of Kaiser Permanente Southern California, wrote in an editorial accompanying the study. Gould was not involved in the study.

In July 2013, a government panel recommended heavy smokers ages 55 to 80 receive annual screenings for lung cancer with low-dose CT scans. The U.S. Preventive Services Task Force based its recommendation on a large-scale clinical trial that found CT scans could reduce deaths by 16 percent in patients at the highest risk of lung cancer. Experts said the new policy could save 20,000 lives a year.

Smokers should get a yearly CT scan if they are between the ages of 55 to 80 and have smoked at least a pack a day for 30 years, even if they quit as long as 15 years ago, the task force said. The scans can detect lung cancer early enough for it to be effectively treated.