Patient-Reported Outcome and Safety Between Preoperative and Postmastectomy Radiotherapy in DIEP Flap Reconstruction

This study compares two approaches to timing radiation therapy for breast cancer patients who need a mastectomy followed by breast reconstruction using their own tissue (called a DIEP flap): radiation before surgery (pre-operative) versus radiation after reconstruction (post-mastectomy). The goal is to find out which timing leads to better outcomes and quality of life. **You may be eligible if...** - You have invasive breast cancer confirmed by biopsy - Your cancer is at a stage that requires chemotherapy before surgery (neoadjuvant chemotherapy) and will also need radiation - You do not have cancer spread to distant organs - You are a suitable candidate for DIEP flap reconstruction at the time of mastectomy **You may NOT be eligible if...** - Your cancer worsened during neoadjuvant chemotherapy - You have a history of diabetes or heavy smoking (both can affect wound healing) - You are pregnant or breastfeeding - You are enrolled in another clinical trial that could affect outcomes Talk to your doctor to see if this trial is right for you.