Radiation Dermatitis and Pneumonitis in Patients Irradiated for Breast Cancer

Background/Aim: Adjuvant radiotherapy (RT) for breast cancer can be associated with acute dermatitis (ARD) and pneumonitis (RP). Prevalence and risk factors were characterized. Patients and Methods: This study included 489 breast cancer patients receiving adjuvant RT with conventional fractionation (CF) +/- sequential or simultaneous integrated boost, or hypo-fractionation +/- sequential boost. RT-regimen and 15 characteristics were investigated for grade >2 ARD and RP. Results: Prevalence of grade >2 ARD and RP was 25.3% and 2.5%, respectively. On univariate analyses, ARD was significantly associated with CF and radiation boost (p<0.0001), age <= 60 years (p=0.008), Ki-67 >15% (p=0.012), and systemic treatment (p=0.002). On multivariate analysis, RT-regimen (p<0.0001) and age (p=0.009) were associated with ARD. Chronic inflammatory disease was significantly associated with RP on univariate (p=0.007) and multivariate (p=0.016) analyses. Conclusion: Risk factors for grade >2 ARD and RP were determined that may help identify patients who require closer monitoring during and after RT.