BACKGROUND: Immune checkpoint inhibitors (ICIs) have become a standard treatment method for lung cancer in recent years. While they improve survival, they are associated with adverse effects affecting the safety of patients and their subsequent treatment. This study aimed to assess checkpoint inhibitor pneumonitis (CIP) in lung cancer patients receiving ICIs prior to chest radiotherapy (chest-RT). MATERIALS AND METHODS: Between October 2018 and September 2024, 52 lung cancer patients who received ICIs before chest-RT were enrolled in the hospital. Clinical characteristics, treatment details, incidence of CIP, prognosis, and hypersensitive C-reactive protein (hsCRP) levels were collected. Associations between clinical characteristics, treatment, hsCRP, and CIP were analyzed. RESULTS: Among patients treated with ICIs before chest-RT, 21.2% (11/52) developed CIP. Compared with patients without CIP, those with CIP had higher proportions of T4 stage (54.5% vs. 31.7%), N3 stage (45.5% vs. 26.8%), and stage IIIc-IV disease (45.5% vs. 22.0%) although these differences are not statistically significant. The impact of treatment on CIP was significant for the percent volume of lung receiving ≥ 20 Gy (V20, < 28% vs. ≥ 28%), P = 0.042. Among 11 patients with CIP, two patients died from CIP and three were unable to complete radiotherapy due to toxicity. The mean value of the highest hsCRP in patients with CIP were 79.3 mg/L (25.6-195.5 mg/L), and pretreatment mean values of hsCRP for these patients were 5.7 mg/L (0.5-11.9 mg/L), compared to the hightest hsCRP 23.8 mg/L (0.9-190.3 mg/L) in patients without CIP. CONCLUSIONS: Lung cancer patients receiving ICIs prior to chest-RT have a relatively high incidence of CIP, particularly those with high V20. Monitoring hsCRP, a simple and cost-effective biomarker, may allow clinicians to detect CIP early and intervene promptly.
Fu et al. (Thu,) studied this question.