More bang for the buck? Lung CT screening brings opportunity to detect other diseases
Lung cancer screening using CT provides an opportunity to leverage image data to assess patients for multiple diseases of the chest, including cardiovascular disease, chronic obstructive pulmonary disease (COPD) and possibly, osteoporosis, according to an editorial published Oct. 10 in the Journal of the American Medical Association.

Onno M. Mets, MD, of the department of radiology at University Medical Center Utrecht, in the Netherlands, and colleagues noted that major organizations in the U.S. recommend lung cancer screening for patients who meet the National Lung Screening Trial (NLST) criteria. In addition, dozens of institutions have launched screening programs.

Mets and colleagues pointed out that low-dose non-contrast-enhanced chest CT images may contain significant findings beyond pulmonary nodules.

Previous studies have suggested that coronary calcium scoring using electrocardiography (ECG)-synchronized CT is an independent predictor of cardiovascular risk. Although lung cancer screening CT exams are not ECG-synchronized, they can demonstrate serious coronary heart disease. Appropriate treatment of these individuals can reduce cardiovascular morbidity and mortality. “Therefore, the information derived from chest CT screening might help provide more appropriate care for asymptomatic individuals with an increased risk profile,” wrote Mets et al.

COPD is typically diagnosed late in the course of the disease, when patients become symptomatic. Automated CT analysis tools enable quantification of various components of COPD, and screening CT may detect the disease in its early stages. Early detection of COPD and better characterization of the disease might inform development of more tailored treatment, according to the authors.

Finally, the editorialists noted lung cancer CT images contain data, specifically display of vertebral bodies from cervical 7 to lumbar 1/2, that may provide information about bone mineral density and incidental vertebral fractures. “This may allow for suggesting preventive measures in high-risk individuals before a debilitating fracture—with associated morbidity—occurs.”

Although these additional evaluations might result in a slight increase in the cost of screening CT, the model relies on readily available information.

Limitations of the strategy include the lack of quantification across scanners, protocols, evaluation techniques and software. The authors emphasized that a negative calcium score on a lung cancer screen would not exclude coronary calcium; instead, its presence indicates high cardiovascular risk. Finally, “the clinical utility of these approaches can only be estimated,” wrote Mets and colleagues.