Things you should know about lung cancer screening

Q1. What is lung cancer CT screening?

Lung cancer screening uses low-dose computed tomography (LDCT) i.e. a CT scan with a low dose of radiation, to find lung nodules, some of which may be cancer. People who take part in screening can lower their chances of dying from lung cancer.

In general, lung cancer screening is not a single test but a process that must be done correctly under the direction of your doctor(s).

Q2. Who is eligible for screening?

Lung cancer screening is not appropriate for everybody. You qualify for screening if you:

  • are between 55 and 80 years old,
  • have smoked within the last 15 years, and
  • have smoked 30 pack-years or more,

according to the United States Preventive Services Task Force. A pack-year is used to describe how many cigarettes you have smoked in your lifetime, with a pack equal to 20 cigarettes. If you have smoked a pack a day for the last 30 years, or two packs a day for the last 15 years, you have 30 pack-years. Click here to calculate how many pack years you have.

Note: As of February 2015, high-risk individuals insured by Medicare will have screening covered up through the age 77.

Q3. What happens at the screening?

The following description is adapted from the American College of Radiology:

For a low-dose CT screening, you will lie flat on the exam table. Pillows and straps may be used for comfort, to help you maintain the correct position and to help you remain still during the exam. You will usually be asked to hold your arms over your head. Next, the table will move through the scanner to the correct starting position for the scans. Then, while you hold your breath for 5 to 10 seconds, the table will move through the machine as the actual CT scan is done.

Q4. What happens after my first screening?

If a lung nodule is found on your CT scan, your doctor may recommend a follow-up CT scan, usually 6 months later to check that the nodule has not grown. In the unlikely case that the nodule does grow or may present a worry, your doctor may recommend further testing using a PET scan or a biopsy (taking out a small piece of the nodule).

However, since more than 95% of lung nodules found are not cancer, you may only need to go back in one year as with other annual health checks to continue the process of screening. Remember, lung cancer screening is not a single test: it is a process that must be done correctly under the direction of your doctor(s).

Q5. How much radiation will I be exposed to from the CT scan for lung cancer screening?

CT scanning for lung cancer screening uses up to 90% less radiation than a conventional chest CT scan. The approximate effective radiation dose is 1.5 millisievert (mSv), which is equal to about 6 months of "normal" background radiation and has very low risk. In fact, no correlation has been found between background radiation and cancer risk. The additional risk of developing fatal lung cancer from one adult exam is low enough that it is difficult to measure, with the estimated chances being between 1 in 100,000 and 1 in 10,000. For more information on exposure to radiation, you may want to visit here or here.

Q6. Where can I get screened?

You should only be screened at an accredited facility. You can find one close to you by going here.