Acute Toxicity and Quality of Life of Hypofractionated Radiation Therapy for Breast Cancer

PURPOSE: To assess the acute toxicity and quality of life (QOL) of hypofractionation compared with conventional fractionation for whole breast irradiation (WBI) after breast-conserving surgery. METHODS AND MATERIALS: Women with node-negative breast cancer who had undergone breast-conserving surgery with clear margins were randomly assigned to conventional WBI of 5000 cGy in 25 fractions over 35 days or hypofractionated WBI of 4256 cGy in 16 fractions over 22 days. Acute skin toxicity and QOL were assessed at baseline and 2, 4, 6, and 8 weeks from the start of treatment for a subgroup of patients. QOL was assessed at baseline and 4 weeks posttreatment for all patients. In the acute toxicity substudy, repeated measures modeling was used to investigate treatment by time interactions over the 8-week period for acute toxicity and QOL mean change score. QOL mean change score from baseline to 4 weeks posttreatment was compared for all patients. RESULTS: In the acute toxicity substudy, 161 patients participated. In the main trial, 1152 patients participated. Acute skin toxicity was initially similar between groups but was less with hypofractionation compared with conventional fractionation toward the end of the 8-week period (P < .001). QOL at 6 weeks from the start of treatment was improved with hypofractionation for the skin side effects, breast side effects, fatigue, attractiveness, and convenience domains (all P < .05). In the main trial, hypofractionation resulted in improved overall QOL and QOL attributed to skin side effects, breast side effects, and attractiveness (all P < .01). CONCLUSIONS: Hypofractionated WBI compared with conventional WBI resulted in less acute toxicity and improved QOL. This further supports the benefits of hypofractionation.