Pulmonary artery enlargement on routine staging 18F-fluodeoxyglucose positron emission tomography/CT for lung and oesophageal cancer

Objective: Pulmonary hypertension (PH) is an underdiagnosed condition associated with poor survival and increased post-operative mortality in lung cancer. CT-based parameters of pulmonary artery enlargement are strong predictors of PH. We used these parameters to investigate pulmonary artery enlargement in lung and oesophageal cancer. Methods: Consecutive patients with lung cancer (n = 100) or oesophageal cancer (n = 100) undergoing staging 18F-fluodeoxyglucose PET/CT were retrospectively identified. The transverse diameter of the main pulmonary artery (mPA) and ascending aorta, and the pulmonary artery-to-ascending aorta (PA:A) ratio were obtained. Abnormal values were defined following the Framingham Heart Study cohort. Results: Lung cancer patients had a significantly increased mPA diameter compared to the oesophageal cancer patients (males: 27.29 ± 0.39 vs. 25.88 ± 0.24 mm, females: 26.10 ± 0.28 vs. 24.45 ± 0.18 mm). Similarly, a significantly increased proportion of these patients had an abnormal mPA diameter (males: 35.1% vs 12.5%, females: 32.6% vs 10.7%). Lung cancer patients also had a significantly higher PA:A ratio (males: 0.83 ± 0.01 vs. 0.79 ± 0.008, females: 0.85 ± 0.01 vs. 0.79 ± 0.009), with a larger proportion having an abnormal PA:A ratio (males: 24.6% vs 11.1%, females: 27.9% vs 14.3%). Conclusion: Simple measurements of mPA diameter and PA:A ratio reveal that lung cancer patients exhibit increased rates of pulmonary artery enlargement compared to oesophageal cancer patients. Advances in knowledge: This study demonstrates there is an increased prevalence of pulmonary enlargement in lung cancer, easily detected on routine staging scans, holding implications for further work-up and risk stratification.