Radiation Doses for Lung Cancer Screenings Vary

A study published in JAMA Internal Medicine found that many facilities exceed the recommended radiation dose when performing CT scans for lung cancer. The study also found that facilities following protocols set by a radiologist or an internal medical physicist contained lower doses.

“If CT scans are performed with higher radiation dose than recommended, this will limit the margin of benefit of lung cancer screening,” Joshua Demb, PhD, MPH, a postdoctoral scholar from the Moores Cancer Center at the University of California, San Diego, told Healio Primary Care. “While the risk of radiation-induced cancer from CT is in general lower than the benefit conferred from finding lung cancer early through low-dose lung cancer screening, the risks of radiation-induced cancer rises when doses rise.”

Data for this study was collected from U.S.-based institutions that are included in the University of California, San Francisco clinic registry.

Researchers used mean volume CT dose index (CTDIvol) to measure average radiation dose and mean effective dose to determine possible future cancer risk from radiation doses received in the scan.

The study included 12,529 patients with a median age of 65 years who had lung cancer screening CT scans at 72 institutions. The various institutions had a 21% median CTDIvol and 65% had median effective doses above those recommended in the American College of Radiology guidelines.

Locations that only allowed lead radiologists to decide the amount of radiation per scan had a higher mean CTDIvol (mean dose difference = 44%; 95% CI, 19-69) and higher mean effective dose (mean dose difference = 27%; 95% CI, 5-50).

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