Accelerated hyperfractionation radiation therapy after lumpectomy and axillary lymph node dissection in patients with stage I or II breast cancer: Pilot study

PURPOSE: To prospectively assess tolerance to accelerated hyperfractionation radiation therapy in patients undergoing breast- conservation therapy and to exclude, with 90% confidence, a 20% or greater risk of an acute toxic reaction of at least grade 3 (severe). MATERIALS AND METHODS: Thirty-seven patients (aged 33-80 years) with evaluatable cases received 48 Gy in twice-daily 1.6-Gy fractions to the breast and regional lymph nodes (if three or more lymph nodes were involved) and a boost of 9.6 Gy in twice-daily 1.6-Gy fractions. Acute and late effects were scored by using the Radiation Therapy Oncology Group and European Organization for the Research and Treatment of Cancer radiation morbidity criteria. RESULTS: One patient developed a grade 3 acute skin toxic reaction and another grade 3 (continuous) acute edema. There have been no grade 4 (life-threatening) acute toxic reactions, local recurrences, or cancer- or treatment-related deaths. CONCLUSION: This breast-conservation accelerated hyperfractionation radiation therapy schedule is tolerable. Additional follow-up is necessary to determine long-term morbidity and cosmesis, and further study in a larger patient group is necessary to confirm efficacy.