1. New York University Department of Radiation Oncology Prospective Randomized Trial of Prone Accelerated Intensity Modulated Whole Breast Radiation Therapy with a Daily Versus Weekly Boost to the Tumor Bed: 3-Year Results B.T. Cooper 1, G.F. Formenti-Ujlaki 1, S.M. Shin 1, M. Fenton-Kerimian 1, D. Roses 2, A. Guth 2, G. Jozsef 1, J.K. Dewyngaert 1 and S.C. Formenti 1 1 Department of Radiation Oncology, 2 Department of Surgery, New York University School of Medicine and Langone Medical Center, New York, New York

2. New York University Department of Radiation Oncology 400 pts Cosmesis data available in 70% of patients Median f/u 40 months Provider and patient reported cosmesis were recorded based on the LENT/SOMA criteria.

3. New York University Department of Radiation Oncology More patients reporting good or excellent cosmesis in Arm 2 that approached significance (80% vs 88%; p = 0.08) P = 0.08 P = 0.25

4. New York University Department of Radiation Oncology There was no statistical difference in 3 year recurrence free survival between the two arms (98% vs 97%; log-rank p = 0.7) One local and two distant recurrences in Arm 1 Three local and one distant recurrences in Arm 2 P = 0.7