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

Abstract

ABSTRACT 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/m2. 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 V5Gy, V10Gy, V13Gy, V20Gy, V30Gy, MLD, and DMax 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. V13Gy and V30Gy of the ipsilateral lung may be the most predictor of pulmonary fibrosis incidence.