Statement: Hypofractionated Simultaneous Integrated Boost Radiotherapy is used in  the secondary trial. but not the primary trial.
Primary_evidence: INTERVENTION 1:    Participants With Stage 0-III Breast Cancer   Women with Stage 0-III breast cancer, treated with breast conserving surgery or mastectomy and clear margins, will receive 15 doses of radiation over three weeks.   Hypofractionated Simultaneous Integrated Boost Radiotherapy: Participants will receive radiotherapy treatments to the whole breast or chest wall to a dose of 2.66 Gy per day x 15 fractions simultaneously with a boost treatment. The boost treatment will be given on the same days as the whole breast treatment. The lumpectomy cavity + scar (in lumpectomy patients) or chest wall scar (mastectomy patients) will receive 0.54 Gy per day x 15 fractions.
Secondary_evidence: INTERVENTION 1:    Arm I (Omega-3-fatty Acid)   Patients receive oral omega-3-fatty acid twice daily (BID) or three times daily (TID) for 24 weeks in the absence of disease progression or unacceptable toxicity INTERVENTION 2:    Arm II (Placebo)   Patients receive oral placebo BID or TID for 24 weeks in the absence of disease progression or unacceptable toxicity