Hypofractionated radiation therapy versus conventional radiation in they adjuvant setting of breast cancer; is there any difference in toxicity?

ABSTRACT

Recent studies of radiation toxicity in the treatment of breast cancer have shown that; the effects on normal tissues can constitute a significant health problem. One of these problems is skin toxicity. The aim of the current study is to compare the acute skin toxicity between two different fractionation schedules of adjuvant breast radiation the conventional radiation [CFR] versus hypofractionated radiation [HFR]. This is a prospective randomized study done in breast cancer patients referred for adjuvant radiation therapy. Radiation therapy was given in either one of two ways CFR [5000 cGy/ 25 fractions I 5 weeks; 200 cGy per fraction] or HFR [4005 cGy/15 fractions / 3 weeks; 267 cGy per fraction] Acute radiation reactions were graded according to the Radiation Therapy Oncology Group toxicity grading system [RTOG] [1]. A comparison was done between the incidence of these reactions and different variables as total radiation dose, type of surgery, number of surgically dissected nodes.etc. Seventy eight patients were accrued to the study, of whom 57.7% had breast conservative surgery [BCS], while 42.3% had modified radical mastectomy [MRM]. Patients who had received HFR represented 53.8%, while those who received CFR represented 46.2% of all patients. The majority of patients [64.1%] had grade 0/II radiation reaction, and 35.9% had grade III/IV reaction. On univariate analysis, there was a statistically significant difference between the two radiation arms regarding the incidence of radiation reaction, with higher incidence [52.8%] in CFR as compared to 21.4% in HFR [p 0.004], while the other variables [type of surgery, number of surgically removed nodes, etc] were not statistically significant. On multivariate analysis; the only factor of statistical significance regarding the incidence of radiation reaction was the radiation therapy schedule, with a higher incidence in CFR [p value 0.03]. There is a statistically less incidence of acute radiation reactions in hypofractionated arm as compared to conventional fractionated arm in the adjuvant radiation of breast cancer.