Prevalence and characteristics of symptomatic pneumonitis after radiotherapy of patients with locally advanced lung cancer

Background/Aim: Radiotherapy of locally advanced lung cancer often requires high doses potentially leading to pneumonitis. This study evaluated the rate of symptomatic pneumonitis and characteristics in these patients. Patients and Methods: This study included 278 patients irradiated for locally advanced lung cancer between 2016 and 2019. In patients experiencing symptomatic pneumonitis, patient and treatment characteristics were analyzed. Results: Pneumonitis was diagnosed in 21 patients (7.6%) after a median of 9 (1-23) weeks. Ipsilateral lungs received mean doses >13 Gy in 21 (100%) and >20 Gy in 15 patients (71.4%). Seventeen patients (81.0%) received chemotherapy and/or immunotherapy, 12 (57.1%) had significant cardiovascular disease (all 21 patients had risk factors), 11 (52.4%) were heavy smokers (≥40 pack years), 7 (33.3%) were aged ≥74 years, 5 (23.8%) had chronic inflammatory disease and 4 (19.0%) had previous tumors. Conclusion: Overall pneumonitis rate was 7.6%. Frequent characteristics included high mean lung doses, systemic treatment, cardiovascular disease (and risk factors), heavy smoking, older age, chronic inflammatory disease and history of a previous tumor.