Clinically unrecognized pulmonary aspiration during gastrointestinal endoscopy with sedation: A potential pitfall interfering the performance of 18F-FDG PET for cancer screening

PurposeWe found several cases with unexpected pulmonary abnormalities on the 18F-FDG PET scan after the gastrointestinal endoscopy with sedation during a compact health check-up course, interfering the interpretations of 18F-FDG PET scan for cancer screening. The current studies aimed to analyze the incidence and the clinical relevance of this pulmonary finding.Materials and methodsFrom June to December 2009, 127 subjects undergoing the sequential gastrointestinal endoscopy with sedation and 18F-FDG PET scan within 48 h as part of routine health check-up were retrospectively enrolled in this study. The incidence of abnormal pulmonary findings and their SUVmax of FDG were calculated and correlated with the clinical manifestations.ResultsFive subjects had abnormal 18F-FDG PET findings but pulmonary symptoms were only found in 2. The SUVmax did not seem to reflect the severity of pulmonary symptoms or the need of intervention. Although the incidence of unrecognized pulmonary aspiration featuring inflammation detected by the 18F-FDG PET scan was high (3.94%, 5/127), the incidence of events needed intervention remained low (0.79%, 1/127), similar to those previously reported literatures.ConclusionsAlthough higher incidence of pulmonary aspiration in this study, it probably reflects the better sensitivity of 18F-FDG PET for inflammation. The low incidence of clinical events needed intervention may still reflect the safety of sedation used for gastrointestinal endoscopy. Proper arrangement of the sequential examinations if subjects need both gastrointestinal endoscopy with sedation and 18F-FDG PET is important to reduce the interference degrading the performance of 18F-FDG PET in cancer screening, diagnosis or staging.