Restrict Lung Cancer Screening CT To Highest-Risk People? The National Lung Screening Trial showed that 3 annual low-dose chest CT scans in people with heavy smoking histories (30+ pack-years) saved lives, reducing the risk of death from lung cancer by a relative 20% compared to screening with annual chest X-rays. With 160,000 lung cancer deaths in the U.S. each year, widespread CT screening could theoretically