Value of 18F-FDG PET/CT for predicting postoperative acute exacerbation in idiopathic pulmonary fibrosis

Abstract

Introduction: acute exacerbation (AEx) is the most lethal postoperative complication in idiopathic pulmonary fibrosis (IPF); however, predicting factors are not well defined. Aims: to investigate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for predicting postoperative AEx in IPF Methods: We retrospectively analyzed 48 IPF patients (mean age: 67.8 years, male: 90%) who underwent 18F-FDG PET/CT for for cancer evaluation and performed thoracic surgery at Asan Medical Center, Seoul, South Korea. Standardized uptake value (SUV) was measured in fibrotic area and lesion-to-liver SUV ratio (SUVR) was also obtained. Results: Among 48 patients, 44 underwent surgery for lung cancer and 4 for lung biopsy. Within 30 days after surgery, AEx and death occurred in 6 (12.5%) and 7 (14.6%) patients, respectively. SUV (3.1±0.8 vs. 2.4±0.6, p=0.026) and SUVR (1.7±0.5 vs. 1.3±0.4, p=0.005) were significantly higher in patients with AEx compared to those without. SUV (odds ratio [OR], 3.709; p=0.041) and SUVR (OR, 20.592; p=0.017) were also predicting factors for AEx by univariate logistic analysis; however, any other factors including baseline lung function were not. On receiver operating characteristics curve analysis, SUV (area under the curve [AUC], 0.754; the best cut-off value, 2.44; p=0.010) and SUVR were significant predictors for AEx (AUC, 0.806; cut -off value, 1.35; p=0.007). Conclusions: Our findings suggest that 18F-FDG PET/CT may be useful to predict AE after operation in patients with IPF and SUVR seems to be superior to SUV