External beam radiation therapy (EBT) is a state of the art targeted delivery technique for radiation therapy. Using computer imaging to plan the procedure, the patient can expect precision in the aiming of the high energy electromagnetic beam. Therefore, the cancerous tissue will be given a high dosage of radiation while surrounding healthy tissue will be spared. This will reduce radiation side effects. EBT can be used as an alternative to surgery when it is too risky to perform. Consequently, EBT is desirable for breast cancer, uterine and cervical cancer, lung cancer, head and neck cancer, prostate cancer and even brain tumors. External beam radiation can also be used in unison with chemotherapy to ensure the cancerous tissue is wiped out.