Pulmonary fibrosis prevalence after adjuvant radiotherapy of Iranian patients with breast cancer: A single-center cross-sectional study

Aims: This study aims to investigate the incidence rate of pulmonary fibrosis as a late radiotherapy complication and identify the associated dosimetric and demographic factors using radiological findings between Iranian patients with breast cancer. Methods and Material: Breast cancer patients treated at the education hospital of Shohada-e Tajrish Hospital, Tehran, Iran, from 2017 to 2021 were considered. Patients have included for whom a secondary chest CT scan was available at least six months after radiotherapy. Dose-volume histogram (DVH) parameters of three-dimensional conformal radiotherapy (3D-CRT) treatment plans were exported. Demographic features and data on underlying lung diseases, diabetes, and smoking history were extracted. Results: A total of 250 patients were included in the study with a mean age of 46.1 7.5 yrs and a mean body mass index (BMI) of 24.5 +/- 4.2 kg/m(2). Pulmonary fibrosis was detected for sixty-two cases. A significant relationship was obtained between the ipsilateral lung DVH parameters of patients with pulmonary fibrosis (P value < 0.05). The V-5Gy, V-10Gy, V-13Gy, V-20Gy, V-30Gy, MLD, and D-Max for individuals with pulmonary fibrosis were significantly higher than those without this injury. Conclusions: Pulmonary fibrosis was distinguished for 25% of the breast cancer cases at least six months after adjuvant radiotherapy. A significant relationship between the DVH parameters, underlying lung disease, diabetes, radiotherapy fields (i.e., Breast + LN + SC or Breast/Chest-wall only), age, and BMI with the frequency of the ipsilateral pulmonary fibrosis was obtained. V-13Gy and V-30Gy of the ipsilateral lung may be the most predictor of pulmonary fibrosis incidence.