At UCSF, patient given single-dose radiation for breast cancer As if a breast cancer diagnosis isn't difficult enough, sometimes the treatment can disrupt the patient's quality of life for weeks. But there's a new way of delivering therapy to breast cancer patients who are over 50 and have a tumor that's three centimeters or smaller that has not spread to the lymph nodes. It takes just about a half hour, is less invasive, and a new study shows the therapy is just as effective as traditional treatment.