Predictive value of 18F-FDG PET/CT for acute exacerbation of interstitial lung disease in patients with lung cancer and interstitial lung disease treated with chemotherapy

Background We examined whether fluorine-18 2-fluoro-2-deoxy- d -glucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) performed before chemotherapy could predict the onset of acute exacerbation of interstitial lung disease (AE-ILD) in patients with lung cancer and ILD treated with chemotherapy. Methods Thirty-three patients with lung cancer and ILD who underwent 18 F-FDG PET/CT and were treated with chemotherapy at Kumamoto University Hospital between April 2006 and March 2018 were retrospectively analyzed. The maximum standardized uptake value (SUV max ) of interstitial lesions was measured to quantify the background ILD activity. A prediction model of AE-ILD was developed using logistic regression analyses for the SUV max , and receiver operating characteristic (ROC) curve analyses were conducted. Results Among the 33 patients, 7 experienced AE-ILD. The SUV max of contralateral interstitial lesions was significantly higher in patients with vs. without AE-ILD (median SUV max : 2.220 vs. 1.795, P = 0.025). Univariable logistic regression analyses showed that the SUV max of contralateral interstitial lesions trended towards being significantly associated with the onset of AE-ILD [odds ratio: 8.683, 95% confidence interval (CI) 0.88–85.83, P = 0.064]. The area under the ROC curve of the SUV max for predicting AE-ILD was 0.780 (95% CI 0.579–0.982, P = 0.025). The optimal cut-off value for SUV max was 2.005, with sensitivity and specificity values of 0.857 and 0.769, respectively. Conclusions The SUV max of contralateral interstitial lesions in 18 F-FDG PET/CT images might be useful for predicting the onset of AE-ILD in patients with lung cancer and ILD treated with chemotherapy.