Two hypofractionated schedules for early stage breast cancer: Comparative retrospective analysis for acute and late radiation induced dermatitis.

Purpose: To compare two hypofractionated radiation schedules in early breast cancer concerning skin toxicity. Methods: We retrospectively analyzed 80 patients (group A) versus 54 (group B) who underwent hypofractionated radiotherapy after breast conserving surgery. Group A received 42.75Gy in 15 fractions over 5 weeks (3 fractions/week) plus 8.55Gy boost to the tumor bed (3 fractions). Group B received 45.05Gy (5 fractions/week) and 7.95Gy boost (3 fractions). Multivariate logistic regression analysis (MVLRA) was conducted for relevant parameters regarding RTOG/EORTC skin toxicity. Results: Median follow up was 60 months. Median age was 75 years (group A) and 56 (group B). Mean values of radio-dermatitis were significantly higher in group A vs B until 3 months post RT (p<0.001 and p =0.002, respectively), while 6 months thereafter toxicity was regressed without any significant difference between groups. MVLRA showed a significant (p<0.001) odds ratio for age (2.36, 95%CI:1.11-3.75) and group A (1.31, 95%CI:1.12-1.49). Conclusion: Schedule B would be preferable in younger women in favor of toxicity. Schedule A could still be applied in elderly patients, unavailable attending daily schedules, with acceptable toxicity.