After lumpectomy, the usual course of radiation treats the whole breast and, if needed, nearby lymph node areas. The radiation beam comes from a linear accelerator, or linac. The radiation beam is a specialized X-ray, and it is painless. Each is brief. Treatment is delivered every day, five days a week, Monday through Friday. The full course of treatment is usually delivered over three to seven weeks, depending on findings during surgery.
Before beginning treatment, you will be scheduled for a planning session to map out the area of treatment. This procedure is called a simulation. Simulation involves having X-rays and/or a CT scan. Tiny tattoo-like marks made on your skin help the radiation therapist precisely position you for daily treatment.
Typically, radiation therapy is done with high energy X-rays, or photons. If needed, electrons may be used to treat the area where the lump was removed with a less penetrating, more focused beam.
Recent clinical trials suggest that whole breast radiation may be shortened by treating the tumor with higher daily doses over less time.
Additional research suggests women aged 70 or older with hormone receptor positive early-stage breast cancer benefit from radiation in terms of lowering their risk of getting breast cancer again in the treated breast but has not been shown to affect long-term survival. Discuss with your radiation oncologist whether treatment with radiation is necessary.