The Incidence Rate of Radiation Pneumonitis Observed in Patients Treated with Thoracic Radiotherapy and Concurrent First-Generation EGFR-TKIs, Second-Generation EGFR-TKIs or Third-Generation EGFR-TKIs in Advanced Lung Adenocarcinoma.

The main aim of this study was to evaluate the incidence rate of radiation pneumonitis (RP) in advanced lung adenocarcinoma treated with first-generation, second-generation, or third-generation EGFR-TKIs combined with thoracic radiotherapy. We retrospectively evaluated advanced lung adenocarcinoma patients simultaneously treated with first-generation EGFR-TKIs, second-generation, or third-generation EGFR-TKIs and thoracic radiotherapy between January 2015 to December 2021 at Shandong Cancer Hospital and Institute. The clinical grades of RP were evaluated according to the pneumonitis of Common Toxicity Criteria (CTC) 5.0 Grading System, and the imaging grading of RP was evaluated using the pulmonary fibrosis of CTC 5.0 Grading System. Consecutive 100 patients who were treated with first-generation EGFR-TKIs were enrolled, 20 patients were treated with second-generation EGFR-TKIs and 50 patients who received third-generation EGFR-TKIs (10:2:5 matched with patients and tumor characteristics), and all three groups were concurrent with thoracic radiotherapy. In terms of overall incidence of RP, first-generation group versus second-generation group versus third-generation group of clinical grades were 2.083 vs 2.389 vs 1.935, and their imaging grades were 1.753 vs 1.895 vs 1.524. The incidence of the imaging grading of grade greater than or equal to 3 RP in three groups were 22% vs 15% vs 4%, and the clinical grades of grade greater than or equal to 3 RP in three groups were 28% vs 55% vs 20%. Other details can be referred to in the Table. Patients treated with third-generation EGFR-TKIs combined with thoracic radiotherapy achieved minimum probability of RP. In contrast, the second-generation EGFR-TKIs concomitant thoracic radiotherapy are the most likely to happen RP. The clinical grades and imaging grades were not completely same in RP. [ABSTRACT FROM AUTHOR]