Supplementary Material for: Acute Radiological Abnormalities after Bronchial Thermoplasty: A Prospective Cohort Trial

Background: Bronchial thermoplasty (BT) is a novel treatment for severe asthma based on radiofrequency energy delivery to the larger airways. Although impressive radiological abnormalities have been reported, the incidence, pattern, and behavior over time of acute radiological abnormalities following BT are not well established. Objective: To assess the incidence pattern and behavior over time of acute radiological abnormalities following BT. Methods: This is a prospective, observational imaging study of severe asthma patients participating in the TASMA trial. Imaging of the lung (chest X-ray and/or computed tomography [CT]) was performed routinely before and directly after BT, within 6 weeks and at 6 months' follow-up. Results: Thirty-four chest X-rays were performed within <5 h following 34 BT procedures in 12 patients. In 91% of cases, radiological abnormalities were seen, designated as peribronchial consolidations (97%) and/or atelectasis (29%). Ultra-low-dose (ULD) chest CTs were performed following 16 BT procedures showing abnormalities in all. Four different radiological patterns were identified: peribronchial consolidations with surrounding ground glass opacities (94%), atelectasis (38%), partial bronchial occlusions (63%), and bronchial dilatations (19%). No bronchoscopic intervention was needed. At 6 months' follow-up, in a single patient, high-resolution chest CT showed a focal bronchiectasis in a single airway. Conclusions: There is a high incidence of acute radiological abnormalities after BT. Four distinct radiological patterns can be identified on ULD chest CT, which resolve without clinical impact in virtually all cases.