Noncancerous chest CT features for predicting survival in stage I lung cancer

According to ARRS' American Journal of Roentgenology (AJR), noncancerous imaging markers on chest CT performed before stereotactic body radiation therapy (SBRT) improve survival prediction, compared with clinical features alone.

"In patients undergoing SBRT for stage I lung cancer," explained corresponding author and 2019 ARRS Scholar Florian J. Fintelmann, "higher coronary artery calcium (CAC) score, higher pulmonary artery (PA)-to-aorta ratio, and lower thoracic skeletal muscle index independently predicted worse overall survival."

Fintelmann and team's retrospective study included 282 patients (168 female, 114 male; median age, 75 years) with stage I lung cancer treated with SBRT between January 2009 and June 2017. To quantify CAC score and PA-to-aorta ratio, as well as emphysema and body composition, pretreatment chest CT was used. Associations of clinical and imaging features with overall were quantified using a multivariable Cox proportional hazards (PH) model.

For stage I lung cancer patients treated with SBRT, CAC score, PA-to-aorta ratio, and skeletal muscle index showed significant independent associations with overall survival. (p<.05). The model including clinical and imaging features demonstrated better discriminatory ability for 5-year overall survival than the model including clinical features alone (AUC 0.75 vs. 0.61, p<.01).

"The PA-to-aorta ratio, which is readily quantifiable with electronic calipers during routine image review, was the most important predictor of overall survival," the authors of this AJR article concluded.