Incidence and risk factors of pneumonia in patients with thoracic tumors receiving radiotherapy combined with immunotherapy
10.3760/cma.j.cn113030-20241025-00412
- VernacularTitle:胸部肿瘤放疗联合免疫治疗的肺炎发生率及影响因素
- Author:
Wenjie ZHANG
1
;
Jing WANG
1
;
Wei SHI
1
;
Hu QIU
1
;
Yongshun CHEN
1
Author Information
1. 武汉大学人民医院肿瘤中心，武汉 430060
- Publication Type:Journal Article
- Keywords:
Radiotherapy;
Immunotherapy;
Pneumonia;
Combination treatment;
Risk factors
- From:
Chinese Journal of Radiation Oncology
2025;34(9):914-920
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the incidence and risk factors of pneumonia in patients with thoracic cancer treated with immunotherapy combined with radiotherapy (RT).Methods:The clinic data of 265 patients with thoracic cancer who received RT and at least 2 cycles of immunotherapy at Renmin Hospital of Wuhan University between January 2020 and January 2024 were retrospectively analyzed. Patients were divided into 2 groups according to treatment sequence: 100 patients with sequential immunotherapy after RT, 165 patients with RT after immunotherapy, including sequential RT after immunotherapy (119 cases) and concurrent RT with immunotherapy (46 cases). The occurrence and grading of treatment-related pneumonia were determined by clinical symptoms, signs, and chest CT findings. The relationship between interval time window of different treatment methods and pneumonia was analyzed by Pearson correlation analysis. χ2 test was used for univariate analysis of risk factors, and logistic regression for multivariate analysis. Results:In the sequential immunotherapy after RT group, the incidence of pneumonia was 12.0% (12/100), with grade ≥2 pneumonia in 4.0% (4/100). The interval time between RT and immunotherapy, has a strong negative correlation with pneumonia incidence and grade ≥2 pneumonia incidence ( r=-0.88, -0.79; both P<0.001). When immunotherapy was initiated ≥7 weeks after RT, the incidence of pneumonia significantly decreased to 5% ( P=0.020), with no grade ≥2 cases. In the immunotherapy followed by sequential / concurrent RT cohort, the incidence of pneumonia was significantly higher in the concurrent subgroup compared with the sequential subgroup [65% (30/46) vs. 44.5% (53/119), P=0.027], and the comparison of the incidence of grade ≥2 pneumonia was the same [33% (15/46) vs. 14.3% (17/119), P=0.014]. The interval time window of RT after immunotherapy was strongly negatively correlated with the incidence of pneumonia and grade ≥2 pneumonia ( r=-0.77, -0.83; both P<0.001). When RT was initiated ≥4 weeks after immunotherapy, the incidence of pneumonia significantly decreased ( P<0.001). Pneumonia incidence differed significantly across RT target sites (intrapulmonary vs. extrapulmonary), total dose (<60 Gy vs. ≥ 60 Gy), and fractionation regimen (conventional vs. hypofractionation) ( P < 0.001, = 0.008, = 0.031), but was not associated with age, gender, smoking history, type of immune checkpoint inhibitor (anti-programmed death-1 vs. anti-programmed death ligand-1), or the number of prior immunotherapy cycles (all P > 0.05). Multivariate analysis identified RT within the lung and interval time of RT after immunotherapy ≤ 4 weeks as independent risk factors for the incidence of pneumonia (both P < 0.001). Conclusions:The interval window between RT and immunotherapy is a critical determinant of pneumonia incidence. Delaying immunotherapy for more than 7 weeks after RT, or delaying RT for more than 4 weeks after immunotherapy, can significantly reduce the risk of radiation-related pneumonia.
