P2.05-09 FDG-PET for Predicting Acute Exacerbation of Interstitial Pneumonia After Lung Cancer Surgery

Abstract

Acute exacerbation of interstitial pneumonia (IP) is a critical complication after lung cancer resection. Although FDG-PET is commonly used for preoperative assessment of lung cancer, its role for predicting acute exacerbation of IP after lung cancer resection is unclear. We retrospectively analyzed data of lung cancer patients that underwent surgical resection at Gunma University Hospital between 2008 and 2016. We analyzed data from patients with IP based on computed tomography findings (IP group). As control, we also analyzed data in patients with no underlying lung disease (normal group) and with emphysema (emphysema group). Patients with sufficient FDG-PET data were selected and a final of 92 patients in the IP group, 21 patients in the normal group, and 20 patients in the emphysema group were enrolled in analysis. The FDG-PET values were measured at the aorta and the basal lung. Aorta values were used for reference and we calculated the basal/aorta ratio and analyzed correlation with preoperative factors, including acute exacerbation of IP and mortality. The basal/aorta ratio was significantly higher in the IP group when compared to normal and emphysema group (both p<0.01). The incidence of acute exacerbation of IP was 10.9%, and the sensitivity and specificity of basal/aorta value for predicting acute exacerbation of IP were 70.0% and 77.2%, respectively (cutoff of basal/aorta ratio at 0.833). Patients were further classified into high basal/aorta ratio group (n=35) and low basal/aorta ratio group (n=57). The incidence of acute exacerbation of IP was significantly higher in the high basal/aorta ratio group (p=0.035). We also compared the value of basal/aorta ratio in comparison to the existing IP acute exacerbation score. Patients were divided into low score (less than 10, n=64) and high score (higher or equal to 11, n=28). The sensitivity and specificity for predicting acute exacerbation of IP was 60.0% and 82.3%, respectively, and there was no significant difference between the high and low score groups (p=0.062). The basal/aorta ratio of FDG-PET values showed a significant correlation with the incidence of postoperative acute exacerbation of IP. Since FDG-PET is commonly used for preoperative assessment of lung cancer in Japan, it may be used not only for lung cancer staging but also for surgical indication in IP patients with lung cancer by preoperatively detecting patients at high risk for acute exacerbation.