Hypofractionation versus conventional fractionation radiotherapy after conservative treatment of breast cancer: early skin reactions and cosmetic results.

PURPOSE To compare in a prospective trial the acute skin reaction and late cosmetic effects of normal fractionation versus hypofractionation radiotherapy after breast conserving surgery. PATIENTS AND METHODS Thirty patients with T 1-2N0M0 breast cancer who underwent breast conserving surgery (BCS) were included in the study. Half of the patients received whole breast irradiation, consisting of 50 Gy/25f/5w+boost 10Gy/5f/1w to tumor bed (group A). The other half received 42.5Gy/16f/22 days (group B). The two groups were comparable otherwise. Early skin reaction and late cosmetic results were graded according to RTOG guidelines. RESULTS The study showed no statistical significant difference between the two treatment groups as regards acute skin reactions and cosmetic appearance. However, the maximum skin reaction occurred 2 weeks earlier for patients within group B (3rd week) compared to group A (5th week). Apart from breast volume, there was no significant correlation between any of the patients or tumor factors and the incidence of acute skin reactions in either group of patients. Patients with large breast volume >1100cc had a higher rate and a longer duration of maximum skin reaction in group A (4 weeks versus 2 weeks in patients with small breast volume </= 1100cc), while in group B, all patients had a maximum duration of 4.5 weeks. This difference was not statistically significant. After median follow-up of 22 months, again there was no difference between the two groups as regard the cosmetic outcome. Lumpectomy volume and lumpectomy/breast volume ratio (regardless of the tumor volume) were the only factors that significantly affected the cosmetic appearance. CONCLUSIONS Preliminary results support the use of a shorter fractionation schedule of 42.5Gy/16f/22 days in patients with breast conserving surgery. The study is still going on to study the late effects on a larger number of patients for final evaluation of this regimen.