Abstract:

Objective  To prospectively observe the incidence of radiation dermatitis (RD) on the chest wall of patients underwent postmastectomy radiotherapy (PMRT) and analyze risk factors relevant to the incidence of RD. Methods  The prospective cohort analysis was performed for 786 female patients with stage Ⅱ-Ⅲ breast cancer who underwent PMRT. The skin of chest wall was observed and assessed weekly from the beginning of PMRT. The primary endpoint was 90 days after PMRT and the secondary endpoint was the incidence of Grade 1-3 RD symptoms defined by CTCAE v4.03. Results  The accumulative incidence of RD within 90 d after PMRT was 30.2% (n=237) and 184 of them developed RD during PMRT and 53 of them developed RD after PMRT. Multivariate analysis indicated that diabetes, obesity, and the use of skin bolus were correlated with the incidence of RD. Conclusion   Diabetes, obesity, and the use of skin bolus are risk factors of RD on the chest wall of patients underwent PMRT. Especially diabetes and the use of skin bolus significantly correlate with the incidence of grade 2-3 RD. Evaluation of relevant risk factors and carefully considering about the use of skin bolus before determining the radiotherapy plan are helpful for reducing the risk of developing RD of patients underwent PMRT.

Key words: radiation dermatitis, post-mastectomy radiotherapy, risk factor