A Comparison Study of Radiotherapy Toxicity between Conventional and Hypofractionated Whole Breast Radiotherapy

Abstract

The aim is to compare the acute skin toxicity between two different fractionation schedules of adjuvant whole breast radiotherapy, conventional fractionation radiotherapy and hypofractionated radiotherapy. This is a prospective study of breast cancer patients referred for adjuvant radiation therapy. Radiation therapy was given either as conventional fractionation radiotherapy (5000 cGy/ 25 fractions / 5 weeks) or hypofractionated radiotherapy (4005 cGy/15 fractions / 3 weeks). Acute RT toxicity was evaluated using the Radiation Therapy Oncology Group toxicity grading system; the incidence of radiation therapy toxicity was compared. Seventy-eight patients were accrued in the study, 58% had breast conservative surgery and 42% had modified radical mastectomy. 54% were treated with hypofractionated radiotherapy and 46% with conventional fractionation radiotherapy, while 64% had Grade 0-II radiation therapy toxicity and 36% had Grade III-IV toxicity. On univariate analysis, the incidence of radiation therapy toxicity was (52.8%) in conventional fractionation radiotherapy group as compared to 21.4% in hypofractionated radiotherapy group (p = 0.004); other variables were not statistically significant. On multivariate analysis radiotherapy fractionation was the only factor of statistical significance regarding the incidence of radiation reaction (p = 0.03). This study showed fewer incidences of acute radiation reactions in hypofractionated arm as compared to conventional fractionated arm in the adjuvant whole breast radiotherapy.