F-DCFPyL PSMA PET/CT Tracheobronchial Uptake in Patients with Prostate Cancer: Incidence and Etiology.

We evaluated the incidence and potential etiology of tracheobronchial uptake in patients being evaluated by F-DCFPyL PET/CT for prostate cancer (PCa). The study included a consecutive 100 PCa patients referred for F-DCFPyL PET/CT. The PET/CT scans were retrospectively reviewed. The presence or absence of physiologic tracheobronchial uptake on PET/CT was recorded. To further evaluate tracheal prostate-specific membrane antigen (PSMA) expression, immunohistochemistry was performed on tracheal samples taken from 2 men who had surgical resection of lung cancer. Tracheal uptake was present in 31 of 100 patients (31%). When tracheal uptake was present, the SUV was significantly higher in the left main bronchus (mean, 2.7) than in the right (mean, 2.3) ( < 0.001). Histopathologic testing of tracheobronchial samples showed PSMA expression in bronchial submucosal glands. In PCa patients undergoing F-DCFPyL PET/CT, tracheobronchial uptake occurred in 31% of patients. This is attributed to normal physiologic PSMA expression in bronchial submucosal glands.