Impact of Unsuccessful Steroid Tapering on Survival in Patients Treated for Radiation Pneumonitis Following Definitive Radiation for Non-Small Cell Lung Cancer.

Objectives: Radiation pneumonitis (RP) presents a significant concern in the management of patients with locally advanced non-small cell lung cancer (NSCLC) undergoing definitive radiation therapy (RT). This study aims to investigate the clinical implication of unsuccessful steroid tapering due to rebound of respiratory symptoms in patients diagnosed with RP.

Materials and methods: This retrospective analysis included NSCLC patients treated with definitive RT between 2010 and 2020. Clinical data, steroid treatment outcome for RP, progression and survival data were collected. Patients were stratified based on RP diagnosis and successful or unsuccessful tapering of steroids due to rebound of respiratory symptoms. Survival was estimated using Kaplan-Meier and log-rank analyses. Univariate and multivariate Cox regression analyses were performed, P-values < .05 were considered significant.

Results: The cohort consisted of 273 patients. About 30.4% of patients (n = 83) developed RP. In the RP-group, 22.9% (n = 19) experienced unsuccessful tapering of steroid due to rebound of respiratory symptoms. Median progression-free survival (PFS) and overall survival (OS) in those patients were 9.0 months (95% CI 6.4-13.8) and 22.2 months (95% CI 17.0-34.9) respectively, significantly shorter than median PFS of 14.8 months (95% CI 5.9-36.3) and OS of 43.4 months (95% CI 27.9-71.2) in patients with successful tapering. A multivariate Cox regression with time-varying covariates confirmed the significantly higher risk of progression and death in those patients.

Conclusion: Patients with RP who experienced unsuccessful tapering of steroids due to rebound of respiratory symptoms had a significantly higher risk of progression and death compared to RP patients with successful tapering of steroids. More frequent surveillance may be considered in those patients.