Efficacy of nebulized acetylcysteine for relieving symptoms and reducing usage of expectorants in patients with radiation pneumonitis

BACKGROUND: Radiation pneumonitis is one of the most harmful and clinically significant complications of radiotherapy. This study investigated the benefits of nebulized acetylcysteine for lung cancer patients diagnosed with radiation pneumonitis after radiotherapy. METHODS: We prospectively enrolled and followed 25 patients with radiation pneumonitis who used nebulized acetylcysteine three times a day for 12 weeks. We also reviewed the medical records of 106 control patients who had undergone radiotherapy for lung cancer but had not used acetylcysteine. We evaluated the effects of nebulized acetylcysteine by comparing visits 1 and 4 among nebulizer users and by comparing the acetylcysteine group with the control group. RESULTS: Twenty‐five acetylcysteine group patients and 101 control group patients were included in the analyses. The mean patient‐rated severity score associated with sputum production decreased in the acetylcysteine group between visits 1 and 4 (from 1.10 to 0.95; P = 0.08). None of the patients used additional expectorant agents after using nebulized acetylcysteine and critical adverse events were not reported. The acetylcysteine group had a shorter mean duration of expectorant use among patients whose radiation pneumonitis required steroid therapy and covered > 10% of a single lung field on computed tomography (37.2 vs. 78.1 days, respectively; P = 0.07). CONCLUSIONS: The beneficial effects of nebulized acetylcysteine for patients with radiation pneumonitis included relieving sputum severity and minimizing expectorant use, especially in severe cases. Further investigation is required to clarify and expand on the benefits of nebulized acetylcysteine for patients with radiation pneumonitis.