Radiotherapy in Breast Cancer

Radiotherapy or radiation therapy is a fundamental part of the multidisciplinary management of breast cancer. It is a treatment that utilizes high-energy X-rays, protons, or other unstable particles, in which hyperproliferative cells, such as cancer cells are affected more and therefore more susceptible to radiotherapy compared to normal cells. When treating early-stage breast cancer, radiotherapy can often be given before, during, or after surgery, in order to shrink tumors or to eradicate cancer cells. Postoperative radiation allows to destroy any cancer cells that may remain after surgery and lowers the risk of recurrence. Radiotherapy can also be used in cases of unresectable or metastatic breast cancers where surgery is no longer a viable option. The modality used, such as external beam therapy, brachytherapy, intraoperative therapy, and the dosage used, varies depending on the treatment plan. The dose of radiation given is split into fractions, usually given daily, over a few days or weeks, depending on the choice of radiotherapy. A combination of chemotherapy or immunotherapy with radiotherapy is recommended for the progressive stages of breast cancer. This chapter dwells on different types of radiotherapy, methods of administration, evolution, benefits, and adverse effects of radiotherapy in breast cancer.