October 14, 2019

Low-dose CT Scan for Lung Cancer Screening

By Jeffrey A. VandeSand, MD

 

Over the years, the use of low-dose CT (LDCT) scans has proven an effective method of screening for lung cancer, improving outcomes and reducing mortality for smokers. With evidence that only 15 percent of lung cancer cases are diagnosed at an early stage, an LDCT scan, a non-invasive method to detect abnormalities or nodules in the lungs, is currently the only recommended screening method for lung cancer.  

According to a study performed by the U.S. Department of Health and Human Services, patients receiving LDCT scans showed an overall reduction in mortality, with approximately five in 1,000 fewer total deaths compared to screening with chest X-ray. Crucial to the success of this screening protocol is the education provided by PCPs on risks, benefits and associated costs, often starting with smoking cessation counseling and a comprehensive overview of the screening process. 

When counseling patients, it’s important to advise them of the risks, including the cumulative nature of radiation exposure, the potential for false-positives, and overdiagnosis. While concerns over radiation exposure should be carefully considered, the potential for overdiagnosis and false positives has been largely mitigated by continued improvements to the algorithm used by radiologists. 

Regarding benefits, screening increases the likelihood that a cancerous nodule will be detected at an earlier stage, often allowing for less invasive treatments. The likelihood of curative treatment compared to a more progressive stage is also greater, and discovery of a nodule may serve as a “teachable moment” for reiterating the importance of smoking cessation.

Prior to screening, patients should check with their carrier about any copays, deductibles or associated fees. For most private insurers, the criteria for screening include those who have smoked the equivalent of at least one pack a day for 30 years or 2 packs a day for 15 years, are ages 55 to 80, and are currently smoking or have quit within the last 15 years. 

Qualified Medicare, Medicaid and privately insured patients within network should expect full coverage of this test as an annual screening exam. However, results necessitating follow-up exams in three or six months, or additional diagnostic testing, may require copays or additional charges. Medicare and Medicaid age guidelines differ from private insurers and only cover annual testing up to the age of 77.  

The United States Preventive Services Task Force (USPSTF) has issued a grade B recommendation for the screening, indicating a high certainty of moderate to substantial benefit. Applicable to approximately 8.7 million people in the U.S., this screening could help avoid as many as 12,000 lung cancer-associated deaths if implemented, according to the 2010 National Health Interview Survey. One in 320 high-risk patients screened will avoid death over five years, ​thereby reducing the cumulative​ risk by 20 percent. Again, as an LDCT scan is the only recommended screening test for lung cancer, primary care providers should be at the forefront of educating patients about its success and benefits.

Jeffrey A. VandeSand, MD, is a Board certified radiologist at TPMG Imaging and Breast Center in Williamsburg and Newport News. MyTPMG.com