Pulmonary F-18 FDG uptake of non-tumor area in lung cancer patients to provide risk stratification in postoperative acute exacerbation of interstitial lung disease.

Abstract

e13165 Background: The incidence of lung cancer in patients with idiopathic pulmonary fibrosis (IPF) is higher than the general population. In IPF patients with lung cancer, postoperative acute exacerbation (AE) is considered a fatal comorbidity. This study aimed to investigate whether FDG-PET/CT can be used to assess the risk of postoperative AE of IPF and severe respiratory adverse events (SRAE),which are defined as grade 3a or more severe respiratory complications such as AE, bacterial pneumonia, empyema, and bronchial fistula based upon Clavian-Dindo classification. Methods: We identified 822 patients with lung cancer who had preoperative FDG-PET/CT and subsequent pulmonary resection from July 2012 to July 2018. We reviewed the patients’ clinical records and transferredthe preoperative FDG-PET/CT images of each patient to SynapseVincent system (Fujifilm Corporation, Tokyo, Japan) for measuring SUV value of the lung.Inevery case, both SUVmax of main tumor (tumor-SUVmax) and non-lung tumor part (NLT-SUVmax) were measured. Univariate and multivariate analyses were performed for exploring significant parameters associated with AE and SRAE. Results: The cohort in this study consisted of 460 men and 362 women (mean age 67.9 ± 10.1 years; range 23–87). SRAE was observed in 35 (4.2%) patients including those with AE (n = 16, 1.9%). NLT-SUVmax and presence of IPF on CT were the independent predictive factors for both AE and SRAE. The receiver operating characteristic (ROC) area under the curve (AUC) of significant factors associated with AE and SRAE was measured, and cut-off levels on ROC curves for significant parameters associated with AE and SRAE were 1.69 and 1.55, respectively. The risk rates for the incidence of AE and SRAE according to NLT-SUVmax and chest CT findings were 19.0 % and 30.2% of the patients with positive IPF on CT and NLT-SUV max ≥1.69. Conclusions: NLT-SUVmax was the independent predictor of the incidence of AE and SRAE for patients who underwent pulmonary resection. FDG/PET-CT can be used in routine clinical practice to identify high-risk individuals for AE who require careful and intensive observation after pulmonary resection and that can facilitate clinical decision-making.