BACKGROUND AND PURPOSE: Breast irradiation after lumpectomy is an integral component of breast-conserving therapy (BCT). As the prognosis is general good following BCT, late morbidity and cosmesis are important. The present study compares two different radiation schedules with respect to these two endpoints. PATIENTS AND METHODS: 129 breast cancer patients (pT1-2 pN0-1 cM0) were irradiated between 09/1992 and 08/1994 with either a 22-day fractionation schedule (2.5 Gy to 55 Gy, 4x/week, n = 65) or with a conventional fractionation schedule (28 days, 2.0 Gy to 55 Gy, 5x/week, n = 64), both without additional boost. The equivalent dose of 2-Gy fractions (EQD2) was 55 Gy and 62 Gy, respectively. Late toxicity, assessed according to the LENT-SOMA criteria, and cosmetic outcome, graded on a 5-point scale, were evaluated after a median of 86 months (range 72-94 months) in tumor-free breast cancer patients. RESULTS: LENT-SOMA grade 2/3 toxicity (2.5 Gy vs. 2.0 Gy): breast pain (18% vs. 11%; p = 0.3), fibrosis (57% vs. 16%; p <0.001), telangiectasia (22% vs. 3%; p = 0.002), atrophy (31% vs. 3%; p <0.001). Medication to breast pain was taken by 8% versus 9% of patients. Cosmesis was very good/good/acceptable in 75% versus 93% (2.5 Gy vs. 2.0 Gy; p = 0.006). CONCLUSION: Late morbidity was significantly frequent and cosmesis was significantly worse after hypofractionated radiotherapy (2.5 Gy to 55 Gy). However, morbidity was not associated with major implications on daily life.
