Background
Radiotherapy (RT) following conservation surgery for breast cancer has been proven to improve both local control and survival. Currently, the challenge is to minimise RT-induced side effects without losing efficacy. Conventional 2D RT breast plans can lead to substantial dose inhomogeneities, which may cause a worse cosmetic result. This is important to patients, as a poor cosmetic result can cause significant psychological morbidity. Planning studies have shown that breast dose homogeneity can be improved with 3D planning and intensity modulated radiotherapy (IMRT). However, there is very little evidence regarding the clinical benefit of IMRT for breast cancer. This unique NCRN-adopted randomised controlled trial will test the clinical benefit of IMRT for women with early breast cancer.