A Study of Diffusing Alpha Radiation Therapy for Patients With Breast Carcinoma in Frail or Elderly Patients.

This trial tests a radiation treatment called Alpha DaRT (diffusing alpha radiation therapy), where small radioactive seeds are placed directly inside a breast tumor, for elderly or frail patients who cannot have standard surgery. **You may be eligible if...** - You have an invasive breast tumor confirmed by biopsy, no larger than 4 centimeters - You are a woman aged 65 or older, or younger if you are not fit for standard surgery - You are not a candidate for standard surgery or prefer not to have it - You have only one tumor in the treatment area - Your general health is reasonable (ECOG score 3 or below) - Your blood counts and organ function are adequate **You may NOT be eligible if...** - Your tumor has grown into the skin - You have inflammatory breast cancer - You have had radiation to the same breast area in the last 6 months - You are taking immunosuppressants or high-dose steroids (other than inhalers) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.