Hypofractionated Radiation Therapy for the Treatment of Breast Cancer: Experience of National Institute of Oncology, Rabat, Morocco

Abstract

Hypofraction at ed radiation therapy has proven effective on locoregional control and tolerance in the adjuvant treatment of breast cancer. The aim of this study is to compare the results of hypofractionated radiation therapy versus conventional radiation therapy in terms of local control and tolerance. It was a retrospective study of patients observations collected from January 2007 to December 2008 in Department of Radiation Therapy in Institut National d’Oncologie de Rabat. The treatment results were evaluated by the rate of locoregional recurrence, distant recurrence and research of late toxicities. Radiotherapy was delivered using the same technique in both groups, by gamma photons of cobalt 60 with an energy of 1.25 MeV. They were 2 groups: the first group treated with standard dose rate and the second group treated by hypofractionated radiation therapy. The mean age of the patients was 42.8 ± 6.9 years old in the standard group and 43.22 ± 7.2 years old in the hypofractionation group. We noted a predominance of infiltrating ductal carcinoma. The majority of patients were pT 2 , pN 0 and pN 1 . The majority of patients had radical surgery and chemotherapy with anthracyclines in both groups. We noted a statistically significant difference in the irradiation of chest wall between the standard (89.2%) and hypofractionated group (70.3%), with p = 0.043. The median duration of radiation therapy was statistically different in both groups: 39 days in the standard and 23 days in the hypofractionated group (p < 0.001). The local recurrences were statistically identical to 12 and 24 months (p = 0.999). Concerning toxicities, the frequency of adverse event was similar in both groups. Hypofractionated radiation therapy with a total dose of 42 Gy at 2.8 Gy per fraction in 5 fractions weekly is comparable to standard radiotherapy in terms of local control and tolerance and is therefore a very good alternative to standard treatment.