External beam radiation

is usually used after a lumpectomy as part of breast conservation therapy. It can be administered as partial breast radiation (only a portion of the breast receives treatment) or whole breast radiation. It can also be used in the operating room just after the lumpectomy which allows one-day therapy. In some cases it is recommended after mastectomy in more advanced stages of the cancer.

Brachytherapy

places radioactive material inside your body using tubes or catheters placed inside the breast tissue.

Most common side-Effects observed with External Beam Radiation Therapy