Whether you’re a current smoker or former smoker, worried about symptoms of lung cancer, or simply trying to understand annual screenings for your overall health, you may wonder whether a lung cancer screening program is right for you.
Everything in health care has risks and benefits. We want to help you make an informed decision that is right for you and your health needs.
This article will review the difference between a standard and low-dose CT chest scan, ionizing radiation, risk factors for lung disease, and how to determine which screening test is right for you.
What Is a Low-Dose CT (LDCT) Scan?
An LDCT, or low-dose Computed Tomography (CT) scan, is a recommended screening procedure for adults at high risk of lung cancer.
Low-dose CT scans use a similar technology to regular CT scans but emit much less ionizing radiation. The amount of exposure to radiation during an LDCT scan is generally considered safe and is FDA regulated and approved.
Difference Between a Standard CT scan and a Low-Does CT scan (LDCT)
Both regular CT scans and low-dose CT scans produce high-quality images that allow for early detection of lung cancer.
Radiation exposure is the most significant difference.
A low-dose CT screening uses much less ionizing radiation than a regular CT. A standard chest CT scan exposes you to about 7mSv of ionizing radiation. In contrast, a low-dose CT lung cancer screening exposes you to about 2mSv of ionizing radiation.
What Is Ionizing Radiation? Is It Safe?
Unlike MRI scans, CT scans work through a combination of X-rays and computer processing to produce pictures of your body’s tissues and organs.
X-rays are a form of ionizing radiation, which is potentially harmful.
Ionizing radiation is a type of energy that removes electrons from the atoms and molecules making up living tissues.
While ezra’s LDCT is safe, it does expose you to this radiation, which is associated with a slight increase in cancer risk. However, the knowledge gathered from the screening dramatically outweighs the risks of not having it, especially if lung cancer is discovered.
The exact amount of radiation you’ll receive depends on the specific radiation used and the amount of radiation your body absorbs. This means each person’s radiation exposure depends on the particular protocol used and an individual’s body composition and size.
Absorbed dose describes how much radiation is absorbed by a tissue or organ.
Equivalent dose weighs the type of radiation with the absorbed radiation dose in an organ or tissue.
Effective dose relates to the overall long-term risk of cancer induction and depends heavily on the organ being treated.
To put your risk into context, let’s look at some numbers.
How Does a CT scan Compare to Other Radiation Exposures?
As humans, we’re all exposed to radiation daily. We call this background radiation.
Background radiation comes from environmental factors like cosmic rays, radon, rocks, and soil. Your exposure to additional radiation depends on where you live, what you eat, and what you do for work.
We measure our exposure to radiation in millisieverts (mSv).
Here are some expected exposure levels:
- The average American is exposed to 3mSv of background radiation per year, according to the National Cancer Institute.
- Radiation exposure can increase 1.5mSv per year for those living at high altitudes like Colorado and New Mexico.
- Those in the armed forces are typically exposed to an additional 1mSv per year.
- On average, flight attendants and pilots are exposed to an additional 3mSv per year
- Astronauts can be exposed to up to 150mSv of radiation, while on the International Space Station
- A standard chest CT scan exposes you to a typical effective dose of 7mSv.
- A LDCT for lung cancer screening exposes you to approximately 1.5mSv — 3mSv of ionizing radiation, according to the American College of Radiology.
Calculate your average background radiation if you live in the US by going to the Environmental Protection Agency’s website.
So, while an LDCT screening does expose you to radiation, it’s lower than a standard chest CT scan and well within acceptable safety limits.
Can a CT scan Increase My Risk of Developing Cancer?
This is where assessing your attitudes on the risks and benefits of a procedure is extremely important.
A CT scan may slightly increase your risk of developing cancer. However, if you are at risk for developing lung cancer, a CT scan helps with early detection, which can be lifesaving.
If you’d like to estimate how your cancer risk may increase, visit xrayrisk.com, select Chest CT (Low Dose Screening), and enter your age and gender.
Should I Get a Low-Dose CT (LDCT)?
You should consider an LDCT if you are concerned about lung cancer.
Like an ezra Full-Body MRI, an ezra LDCT is a proactive test for asymptomatic individuals.
You should consider an ezra LDCT if you are over 30 and/or meet the following:
- Have a 20 pack-year or more smoking history, and
- Smoke now or have quit smoking within the past 15 years, and
- Are between 50 and 80 years old
While booking an ezra screening doesn’t require a physician’s referral, if you’d like, you can discuss this further with your ezra health care provider or your primary care provider.
A pack-year is a year when someone smokes an average of one pack of cigarettes per day. For example, a person is considered a 10-pack-year if they smoke one pack a day for 10 years or two packs a day for five years.
You should NOT get an ezra chest LDCT if you:
- Have a history of significant pulmonary symptoms and/or other conditions such as
- Current or chronic cough
- Lung cancer
- History of radiation treatment to the chest
Why Can’t I Just Get an MRI?
The lungs present some unique challenges.
The first has to do with signal intensity.
When assessing MRI images, radiologists refer to the shade of gray representing tissues or fluids with the word “intensity.” Lungs exhibit a low signal intensity, showing up as black on MRI scans. Because lungs are so dark, it’s difficult to discern lesions and nodules.
CT scans produce high-quality images that allow radiologists to visualize lesions and lung nodules and better understand your lung health.
The second relates to motion.
MRI scans are affected by the motion of the lungs. Breathing can blur MRI images, making them even more challenging to read and interpret.
CT scans, on the other hand, are much faster. This is particularly important for patients who have trouble holding their breath.
To ensure high-quality results, ezra forgoes chest MRI and recommends LDCT instead.
What Are the Benefits and Risks of a Chest LDCT?
The most significant benefit to getting a chest LDCT is information gathering.
If you are at risk of developing lung cancer, getting an LDCT is the best way to get information about your lung health.
Cancer discovered during screening is usually in the early stages of the disease. This early detection allows patients more time to do additional testing and make informed decisions about their cancer treatment. If surgery is advised, procedures on early-stage cancer are generally less-invasive. They require less lung tissue removal than cancers that are more progressed.
Other benefits include
- High-quality images which allow for early detection and treatment of lung cancer.
- Fast imagining time, preventing blurry images and making the test doable for patients who have difficulty holding their breath.
- Painless, noninvasive, and does not require contrast material.
- Safe to undergo with electronic or metal implants.
- No immediate side effects.
- LDCT scans leave no radiation in your body once the scan is complete.
- Radiation exposure may slightly increase your cancer risk.
- A potential risk of any screening procedure is a false-positive result followed by additional diagnostic work, such as a biopsy. A large-scale clinical trial found the false-positive rate for LDCT to be approximately 27%.
- Screening procedures can also result in a false negative, meaning something cancerous was not picked up during the scan. The best way to increase detection accuracy is through follow-up scans.
Because of the high sensitivity and low risk, LDCT is the gold standard for preventive lung cancer screening.
How Does ezra Use LDCT?
Lung cancer is the second most common cancer and the leading cause of cancer death in the US in 2020, according to the U.S. Preventive Services Task Force (USPSTF).
Ezra offers low-dose CT scans as an add-on scan to the standard ezra Full-Body MRI. The MRI does not include the chest (lungs, heart, ETC.).
If you are concerned about your lung health, fit the eligibility criteria mentioned above, and are comfortable with the risks involved, adding an LDCT could be right for you. Screenings provide a look into your overall health and help with the early detection of potential cancer and other abnormalities.
If you’d like to add an LDCT when you book your ezra Full-Body MRI screening, click “Add LDCT” in your medical questionnaire.
If not, click “Decline LDCT.”