ACCELERATED HYPERFRACTIONATION RADIATION-THERAPY AFTER LUMPECTOMY ANDAXILLARY LYMPH-NODE DISSECTION IN PATIENTS WITH STAGE-I OR STAGE-II BREAST-CANCER - PILOT-STUDY

PURPOSE: To prospectively assess tolerance to accelerated hyperfractio nation radiation therapy in patients undergoing breast-conservation th erapy and to exclude, with 90% confidence, a 20% or greater risk of an acute toxic reaction of at least grade 3 (severe). MATERIALS AND METH ODS: Thirty-seven patients (aged 33-80 years) with evaluatable cases r eceived 48 Gy in twice-daily 1.6-Gy fractions to the breast and region al lymph nodes (if three or more lymph nodes were involved) and a boos t of 9.6 Gy in twice-daily 1.6-Gy fractions. Acute and late effects we re scored by using the Radiation Therapy Oncology Group and European O rganization for the Research and Treatment of Cancer radiation morbidi ty criteria. RESULTS: One patient developed a grade 3 acute skin toxic reaction and another grade 3 (continuous) acute edema. There have bee n no grade 4 (life-threatening)acute toxic reactions, local recurrence s, or cancer- or treatment-related deaths. CONCLUSION: This breast-con servation accelerated hyperfractionation radiation therapy schedule is tolerable. Additional follow-up is necessary to determine long-term m orbidity and cosmesis, and further study in a larger patient group is necessary to confirm efficacy.