Hypofractionated Vs Conventional Fractionated Postmastectomy Radiotherapy for High Risk Breast Cancer

This trial is comparing a shorter (hypofractionated) radiation schedule to a longer conventional schedule after mastectomy for high-risk breast cancer, to see whether fewer sessions with higher doses work just as well with fewer long-term side effects. **You may be eligible if...** - You are a woman aged 18–75 with confirmed invasive breast cancer - You have had a mastectomy with removal of at least 10 lymph nodes - Your surgical margins are clear (cancer-free) - Your cancer meets high-risk criteria (e.g., young age, grade 3, lymph node involvement, hormone receptor-negative, or HER2-positive) - You did not receive chemotherapy before surgery (no neoadjuvant chemotherapy) **You may NOT be eligible if...** - You have had previous radiation to the chest wall or lymph node areas - You have another active cancer (other than minor skin cancers) - You have serious heart or lung disease - You have contraindications to radiation such as lupus or cirrhosis - Your cancer has spread to distant organs or to supraclavicular/internal mammary nodes Talk to your doctor to see if this trial is right for you.