Study Comparing Whole Breast Radiotherapy With a Daily Versus a Weekly Tumor

All patients (with Stages 0-II breast cancer) will receive an accelerated three week regimen of prone whole breast radiotherapy. The study intends to test the hypothesis that a weekly boost to the tumor bed, delivered on Friday, before the weekend break, is as well tolerated as the daily boost during accelerated prone radiotherapy.

Arm 1 is a concomitant boost protocol over three weeks which has previously been evaluated in over 500 patients (NYU 03-30 and NYU 05-181) and has shown excellent tolerance, and results. Arm 2 evaluates a Weekend Boost Dose (WBD) regimen which may have a radiobiological advantage by counteracting tumor repopulation which can occur over the weekend break. At the time of registration in the study, patients will be randomized to either treatment arm and stratified according to pre or post-menopausal status and on previous chemotherapy received or not.