Opportunistic Detection of Early-Stage Lung Cancer on CAC Score CT

“Calcium score screening is widely recognized as an effective tool to stratify cardiovascular disease,” said Syed Muhammad Awais Bukhari, MD, research fellow at University Hospitals (UH) in Cleveland. “Given that cardiovascular disease and lung cancer share several common risk factors, many lung cancers could be detected in asymptomatic patients undergoing CSSCT exams.” 

According to Dr. Bukhari, lung nodules may be missed due to the common practice of using small field-of-view (FOV) reconstructions. While the small FOV provides better resolution and image quality for calculating the coronary artery calcium (CAC) score, a full FOV provides a wider view of the chest, lungs and rib cage where incidental findings such as lung nodules may be observed.

However, Dr. Bukhari said current major guidelines lack specific recommendations whether full FOV images should be routinely reconstructed for the CSSCT exam. "Reading CSSCT exams in small FOV results in missed diagnoses of lung nodules which might have the potential to progress to lung cancer in later stages," he said. 

Catching Cancers Before They Progress

In his study, Dr. Bukhari and his team explored the prevalence of incidental lung cancers opportunistically identified on CSSCT and the impact of using the FOV on the detection of nodules.

“In 2017, UH, began offering a no-cost CSSCT screening, which has generated a significant amount of data on our diverse patient population, especially women, African Americans, and low-income individuals,” he said. 

Between 2005 and 2023, 149,573 individuals underwent CSSCT at UH. Cross-referencing these patients with patient EMRs and the hospital’s cancer registry revealed that 914 (0.6%) were diagnosed with lung cancer at some point in the study period.

Of those 914, a suspicious lung nodule or mass was first detected by CSSCT in 216 (23.7%) cases. Of those cases, 202 (59.4%) were primary lung malignancies, while 16 were secondary lung malignancies. CSSCT initially detected 66.8% of the lung cancers that occurred in the study group.

A FOV data analysis revealed that 52 of the 202 (26%) primary lung malignancies would have been missed if only small FOV reconstructions were used.

"Most of these cased were detected at Stage 1 or earlier (59.4%) allowing patients to be treated before the cancer progressed," Dr. Bukhari noted.

“Our study demonstrates the utility of CSSCT for the opportunistic detection of early lung cancer, which is typically diagnosed at late stages after it has spread to nearby tissues or distant organs,” Dr. Bukhari said. “Early detection is crucial, as survival rates are significantly higher when lung cancer is diagnosed early.”

“If you incorporate the practice of reviewing the full FOV reconstruction of CSSCT scan, it will increase the chances of lung cancer detection,” he concluded. “Reviewing both the small and full FOV should be a prevalent and wide practice.”