DIAGNOSTIC YIELD OF 18F-FDG PET AFTER LUNG TRANSPLANTATION: A SINGLE-CENTER, RETROSPECTIVE COHORT STUDY.

BACKGROUND To investigate the diagnostic yield of F-fluorodeoxyglucose positron emission tomography (F-FDG PET) in lung transplant recipients. METHODS A single-center, retrospective cohort study including 234 F-FDG PET examinations in 199 lung transplant recipients. Indication for PET referral, F-FDG PET diagnosis/findings and final clinical diagnosis were classified into three groups: malignancy, infection/inflammation not otherwise specified (NOS); and chronic lung allograft dysfunction (CLAD) with restrictive allograft syndrome (RAS) phenotype. Sensitivity/specificity analysis was performed to determine accuracy of F-FDG PET in each group. RESULTS Sensitivity of F-FDG PET for malignancy was 91.4% (95% CI: 82.5-96.0%) and specificity was 82.3% (95% CI: 74.5-88.1%). Infection/inflammation NOS and RAS as indication for F-FDG PET comprised relatively small groups (14 and 31 cases, respectively). In addition, F-FDG PET revealed clinically relevant incidental findings in 15% of cases. CONCLUSIONS Referral for F-FDG PET after lung transplantation mainly occurred to confirm or rule out malignancy. In this specific setting, F-FDG PET has a high diagnostic yield. Accuracy of F-FDG PET for other indications is less clear, given small sample sizes. Clinically relevant diagnoses, unrelated to the primary indication for F-FDG PET, are found relatively often in this immunocompromised cohort.