Purpose:
Our aim is to investigate the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in assessing atherosclerosis (AS) risk in lung cancer patients compared to patients with other types of cancer.
Methods:
This prospective study enrolled 60 cancer patients (30 lung cancer and 30 non-lung cancer) who were referred for 18F-FDG PET/CT. The aortic average max standardized uptake value (avgSUVmax) was calculated by drawing ROIs on the entire aorta (ascending, arch, descending thoracic and abdominal aorta till iliac bifurcation). The maximum target-to-blood pool ratio (TBRmax) is calculated by dividing aortic avgSUVmax by the regional blood pool average mean standardized uptake value (avgSUVmean) of superior vena cava (SVC), and inferior vena cava (IVC).
TBRmax was the primary outcome variable that was compared between the two cancer cohorts. Also MVA (multivariate analysis) was performed for factors that showed significance in UVA (univariate analysis) including sex and smoking.
Results:
All aortic segments of lung cancer patients apart from the ascending aorta showed significantly higher TBRmax: the aortic arch (P = 0.001), the descending thoracic aorta (P = 0.006), the abdominal aorta (P = 0.001), and the ascending aorta (P = 0.972).
The lung cancer cohort has a higher proportion of men and smokers. MVA analysis of TBRmax of different aortic segments in respect to cancer type, sex and smoking status showed that for arch & abdominal aorta the highest odd ratio goes to lung cancer not male sex or smoking status, which indicate that lung cancer has the highest contribution in increased TBRmax, though the absolute p value did not reach typical significant level of 0.05.
Conclusions:
TBRmax of the majority of aorta segments tend to increase in lung cancer patients compared to non-lung patients independent of other known atherosclerotic risk factors; this may signify a higher burden of inflammatory plaques.