Correlation between preoperative ¹⁸F-FDG PET/CT findings and postoperative short-term prognosis in lung cancer patients with idiopathic interstitial pneumonia after lung resection

Background: The present study aimed to investigate the correlation between preoperative 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) PET/CT findings and short-term survival in lung cancer patients with idiopathic interstitial pneumonia (IIP). Methods: We retrospectively reviewed the data of 425 patients who underwent lung resection for non-small cell lung cancer without preoperative radiation therapy between November 2012 and October 2017. The maximum SUV (SUVmax) in the IIP area except the lung cancer site was measured in each patient. Results: Thirty-one of the 425 patients (7.3%) showed findings of IIP in chest CT. Five of the 31 patients (16.1%) developed acute exacerbation (AE) after lung resection (AE+ group). Twenty-six of the 31 patients (83.9%) did not develop AE (AE– group). In the AE+ group, ¹⁸F-FDG SUVmax in the IIP area was significantly higher (1.9 ± 0.6 vs. 2.7 ± 0.7, p = 0.02) compared with that in the AE− group. The receiver operating characteristic analysis identified an SUVmax threshold score of 2.55 (p = 0.02) for AE. There was no 90-day mortality in the patients with SUVmax < 2.55 (n = 25). On the other hand, the 90-day mortality rate in patients with SUVmax ≥ 2.55 (n = 6) was 33.3% (2 patients). Conclusions: ¹⁸F-FDG PET/CT may predict AE after lung resection and could be related to short-term survival in lung cancer patients with IIP. Further investigations are needed to improve the prognosis in patients with high SUVmax in the IIP area.