External beam accelerated partial breast irradiation versus whole breast irradiation after breast conserving surgery in women with ductal carcinoma in situ and node-negative breast cancer (RAPID): a randomised controlled trial

Background Whole breast irradiation delivered once per day over 3–5 weeks after breast conserving surgery reduces local recurrence with good cosmetic results. Accelerated partial breast irradiation (APBI) delivered over 1 week to the tumour bed was developed to provide a more convenient treatment. In this trial, we investigated if external beam APBI was non-inferior to whole breast irradiation. Methods We did this multicentre, randomised,...