CT Lung Screening and Follow-up Protocol

Research published in this month’s American Journal of Roentgenology reported excellent results on a protocol for working up patients with nodules found in CT lung screening. Ever since the National Lung Screening Trial showed a 20% mortality reduction among high-risk patients screened for the disease, criticism has been vocalized due to the potentially large number of false-positive results following diagnostic imaging investigations. Though the possibility of finding cancer outweighs the risk of false positives, the researchers argued that false-positive results could potentially increase the risks and costs of screening, diminishing the benefit of early cancer detection.

This study, which required participants without a history of cancer to have smoked a minimum of 10 pack-years, concluded with positive results. According to the research, the algorithm produced low false-positive rates, and could make the establishment of large-scale CT screening programs more feasible.

Follow-up CT protocols in lung cancer screening – once a finding is discovered and needs to be evaluated over time or even just routinely on a schedule – is one area ripe for ultra low-dose CT technique. With this technique, we really can see doses reduced by 40 – 80% among these applications! Accepting higher noise in images, very low-dose kVp (in the 80-100 range), and aggressive application of iterative reconstruction techniques can produce diagnostic CT results at breathtakingly low doses.