Should radiation dose from CT scans be a factor in patient care? Yes

Abstract

The challenge for clinicians is to apply aggregate data from studies ofupwards of 25,000 people to the patient. Applying epidemiologic data to the patient requires expertise and judgment, a classic challenge in health care. In screening large numbers of people with LDCT scan, small increases in risk from cumulative radiation may result in large numbers of avoidable cancer, because of the millions of people who meet eligibility criteria for LDCT scan screening. 4,7 The major risk factors for lung cancer are smoking intensity and duration, family history of lung cancer, advancing age, and the presence of COPD. 18,19 Despite these efforts at defining risks and benefits of screening, the data are not sufficiently practical to use in clinical care. Risks of lung cancer associated with ionizing radiation need to be addressed with care, since screening tests are conducted on people without symptoms and without apparent disease and in whom cancer may never develop. The NLST demonstrated that 320 people need to be screened annually for 3 years to prevent one lung cancer death. 20 How does a clinician advise their patient regarding LDCT scanning? As always, effective communication about benefits and risks is paramount. Advise patients that the NLST showed that one ofevery four to five people who undergo testing will have a positive test and that one of 25 patients with positive test results will have lung cancer. For those who do not meet the NLST criteria, it is unclear whether LDCT will reduce mortality from lung cancer. What is perfectly clear, however, is that cigarette smoking is associated with accelerated decline in lung function, COPD, and lung cancer. Efforts aimed at improved rates of cigarette-smoking cessation will have the most impact in reducing mortality from lung cancer.