Occurrence frequency of unsuspected pneumothoraces in cancer patients undergoing PET/CT and 18F-FDG imaging

Objectives Pneumothorax, collection of air between the lung and the chest wall, is a serious condition that could be fatal if not treated. The incorporation of CT into PET has added another dimension to molecular imaging PE/CT by allowing it to identify pneumothoraces, otherwise impossible to recognize with PET alone. In this study, we investigate the frequency of occurrence of unsuspected pneumothoraces in patients undergoing PET/CT and 18F-FDG imaging for cancer evaluation.

Methods This research is based on 3084 body PET/CT and 18F-FDG scans performed on 2749 patients who were referred to our institution for their cancer evaluation. All CT scans (140 Kv; 114-209 mA) acquired for PET attenuation correction were evaluated for pneumothoraces using lung window.

Results Unsuspected pneumothoraces were observed in 3 out of 3084 (0.1%) scans of patients who underwent PET/CT and FDG imaging for diagnosis, staging or restaging.

Conclusions Although rare, unsuspected pneumothoraces can occur in cancer patients undergoing PET/CT and 18F-FDG imaging. Because pneumothoraces are life threatening situations, nuclear medicine technologists should be trained to recognize such dangerous conditions in order to advise the patients with pneumothoraces to go to the nearest emergency room or the appropriate service.