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

Background: Acute exacerbation (AE) of interstitial pneumonia disease (ILD) in lung cancer (LC) patients with ILD could be one of the lethal adverse effect related to chemotherapy. The purpose of this study was to determine if the result of 18F-FDG PET/CT before chemotherapy could predict onset of chemotherapy-related AE-ILD in LC patients with ILD. Methods: Between April 2006 and March 2018, 33 patients with LC and ILD performed 18F-FDG PET/CT and treated with chemotherapy in Kumamoto University Hospital. The SUVmax of interstitial lesion was measured to quantify the background ILD activity. A prediction model chemotherapy-related AE of ILD was developed using a logistic regression and ROC curve analysis. Results: Among 33 patients, 7 experienced AE of ILD (AE group) and 26 did not (non-AE group), the SUVmax of contralateral interstitial lesion in AE group was significantly higher than that in non-AE group (median SUVmax 2.22 vs. 1.80, P = 0.041). An univariable logistic regression analysis showed that the SUVmax of contralateral interstitial lesion had potential to be associated with chemotherapy-related AE of ILD (odds ratio, 8.683; 95% confidence interval [CI], 0.88–85.83; P = 0.064). The AUC of the SUVmax for predicting chemotherapy-related AE of ILD was 0.780 (95% CI: 0.579-0.982, P = 0.025). The optimal cut-off value for SUVmax was 2.005. Sensitivity and specificity value for this cut-off point were 0.857 and 0.769, respectively. Conclusions: The SUVmax of contralateral interstitial lesion in 18F-FDG PET/CT might be useful to predict chemotherapy-related AE of ILD in LC with ILD.