Low-Dose Lung Cancer Screening: Take Care of Your Lungs

Syed Hassaan Ali
21 minutes ago
3 min read

By Bridget Fox

What is lung cancer screening?

Low-dose computed tomography (LDCT) is an imaging technique used to view the structures and organs in the body while using a low dose of radiation (2). This scan is used for lung cancer screening because it can show any abnormal features in the lungs, such as masses that may be cancerous. The CDC describes the process as a short scan that takes only a few minutes, where you lie down on a table while a machine uses a small amount of radiation to create a detailed picture of your lungs (2). This is not painful and should not trigger claustrophobia, as you move through the donut-shaped machine.

Due to the slight amount of radiation exposure, which is less than 100 millisieverts, this should only be done annually (2, 3). The radiation can cause cells in your body to release free electrons, which will react with other cells to cause mutations. Over time, your body is able to correct most of the mutated DNA in the cells, however, some mutations can persist and lead to cancer. Recent studies have shown that the cumulative dose of radiation from 10-20 scans (up to 200 millisieverts) increased risk for cancer (4). By having this scan annually, your body has more time to repair itself and reduce the risk of side effects from the radiation exposure(3).

Who qualifies?

You do not need to have symptoms to qualify for the screening. The goal is to detect lung cancer early, when it is easier to treat. In order to qualify for lung cancer screening, it is recommended by the US Preventive Service Task Force that the patient is:

Between 50 to 80 years old.
Has a 20 pack-year smoking history.
Who is actively smoking or has quit within the past 15 years (5).

To calculate your pack-year history, multiply the number of packs smoked per day by the amount of years you smoked. For example, smoking an average of 20 cigarettes per day is equal to one pack per day. If you smoked one pack a day for 20 years, you would have a 20 pack-year smoking history. If you are unsure about your pack-year history, online pack-year calculators can be helpful tools.

Does it work?

Lung cancer screening is an efficient way to monitor patients who are at high risk of having lung cancer. A study conducted by the National Lung Screening Trial Research Team found that the patients who underwent chest x-rays three times a year were 20% more likely to die than patients who received low-dose CT scans three times a year (6). There are alternatives to low-dose lung cancer scans, like sputum cytology, which is a lab test that tests for abnormal cells in mucus, and chest roentgenography, which is an x-ray that gives a 2D view of the chest. However, these methods did not significantly reduce lung cancer mortality/death from lung cancer compared to low-dose CT scan (7).

Lung cancer is a serious disease, but early detection is key to survival. In high risk populations, it is estimated that lung cancer screening could prevent 80% of lung cancer deaths (8). If you are interested in lung cancer screening or would like to know whether you qualify, speak with your primary care provider or pulmonologist. They can provide information about the screening programs and can order a low-dose computed tomography (LDCT) scan.

References

Living Image Wellness. CT lung cancer screening [Internet image]. Living Image Wellness; 2025 [cited 2026 Apr 21]. Available from: https://livingimagewellness.com/wp-content/uploads/2025/04/ct-lung-cancer-screening.jpg (Source for CT scan figure)
Centers for Disease Control and Prevention. Screening for lung cancer [Internet]. Centers for Disease Control and Prevention; 2024 [cited 2026 Apr 21]. Available from: https://www.cdc.gov/cancer/lung/basic_info/screening.htm
Bach PB, Mirkin JN, Oliver TK, Azzoli CG, Berry DA, Brawley OW, et al. Benefits and harms of CT screening for lung cancer: a systematic review. Chest. 2012;141(2):435–444.
Smith-Bindman R, Miglioretti DL, Johnson E, Lee C, Feigelson HS, Flynn M, et al. Risk of cancer from CT scans and other sources of low-dose radiation: a critical appraisal of methodologic quality. Prehosp Disaster Med. 2012;27(3):284–290.
Siegel RL, Miller KD, Wagle NS, Jemal A. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17–48.
Aberle DR, Adams AM, Berg CD, Black WC, Clapp JD, Fagerstrom RM, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409.
de Koning HJ, Meza R, Plevritis SK, ten Haaf K, Munshi VN, Jeon J, et al. Benefits and harms of computed tomography lung cancer screening strategies: a comparative modeling study for the U.S. Preventive Services Task Force. Ann Intern Med. 2014;160(5):311–320.
Claudia I. Henschke, David F. Yankelevitz, Daniel M. Libby, Mark W. Pasmantier, James P. Smith, Otis W. Miettinen, et al. Survival of patients with stage I lung cancer detected on CT screening. N Engl J Med. 2006;355(17):1763–1771.

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