The predictors of lung injury during durvalumab maintenance therapy following concurrent chemoradiotherapy in unrescectable locally advanced non-small cell lung carcinoma

Objectives: Maintenance with durvalumab has become the standard treatment following concurrent chemoradiotherapy in patients with unresectable locally advanced non-small cell lung carcinoma (NSCLC). However, lung injuries, including immune-related adverse events (irAEs) and radiation pneumonitis, are concerning. This study retrospectively investigated the factors related to lung injury in patients receiving the PACIFIC regimen. Materials and Methods: Patients with unresectable locally advanced NSCLC who received durvalumab maintenance therapy following concurrent chemoradiotherapy at the Yokohama City University Medical Centre between July 2018 and March 2022 were included. Clinical background, volume of normal lung receiving 20 or 5 Gy or more (V20 or V5), planning target volume (PTV), and relative lung parenchyma volume in emphysematous lung receiving 20 or 5 Gy or more (RLPV20 or 5; V20 or V5 / 100- percentage of low-attenuation volume) were evaluated. Results: Performance status(PS), V20, V5, PTV, RLPV20, and RLPV5 were significantly higher in the lung injury group in the univariate analysis (PS: p = 0.0303, V5: p = 0.0115, V20: p = 0.0247, PTV: p = 0.0177, RLPV20: p = 0.0042, and RLPV5, p = 0.0030). Furthermore, RLPV20 was the most significant factor in the lung injury group in the multivariate analysis comprising PS, PTV, V20, and RLPV20. Conclusion: RLPV are useful in estimating the risk of lung inflammation. RLPV20 could be the most reliable risk factor for maintenance therapy with durvalumab following concurrent chemoradiotherapy in patients with unresectable locally advanced NSCLC.