Radiation is highly effective at killing any residual tumour cells that may be left behind after surgery. However, it can have some deleterious effects on the normal tissue around an implant. Compared to a non-radiated breast, radiated breast will have more capsular contracture (tight and thickened scar tissue) around the breast implant. The normal tissue around the implant can undergo shrinkage. In addition, the normal pectoralis muscle in front of the implant can be tight and have less muscle excursion.