Image classification of immune checkpoint inhibitor–related pneumonia in lung cancer patients

Immune checkpoint inhibitor-related pneumonia (ICIP) is an independent risk factor for immunotherapy-related death.To evaluate the ICIP, dynamic observation of computed tomography (CT) images of lung cancer patients with ICIP was conducted to study the relationship between the occurrence of ICIP and clinical information.CT images and clinical information of lung cancer patients (n = 76) from two hospitals who received immune checkpoint inhibitor (ICI) treatment were collected. A total of 49 cases were enrolled after screening according to the inclusion and exclusion criteria. We performed statistical analysis on the imaging features and clinical information.Analysis of imaging characteristics revealed two types of ICIP: the limited-onset type and diffuse-onset type. The median onset time of limited-onset ICIP was significantly earlier than that of diffuse-onset ICIP (1.5 months vs. 2.8 months; p = 0.045). Statistical analysis based on differences within the group showed that the clinical ICIP grade and immunotherapy response rate of limited-onset cases were statistically significant (p = 0.003) and the imaging/clinical ICIP grade and the outcome of ICIP were statistically significant (p = 0.031/0.007). The immunotherapy strategy of diffuse-onset cases and the response rate of immunotherapy were statistically significant (p = 0.016).This study suggests that pre-existing lung lesions can be one of the possible predisposing factors for ICIP and describes the development of ICIP through continuous imaging. Our findings indicate pre-existing lung lesions as a referential monitoring target for the onset and progression of ICIP for clinical practice.