External Beam Radiation Therapy
During external beam radiation therapy, a beam of radiation is directed through the skin to the cancer and the immediate surrounding area in order to destroy the main tumor and any nearby cancer cells. To minimize side effects, the treatments are typically given five days a week, Monday through Friday, for a number of weeks. This allows doctors to get enough radiation into the body to kill the cancer while giving healthy cells time each day to recover.

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INTENSITY MODULATED RADIATION THERAPY (IMRT)

IMRT is a specialized form of 3D-CRT that allows radiation to be more exactly shaped to fit the tumor. With IMRT, the radiation beam can be broken up into many "beamlets", and the intensity of each beamlet can be adjusted individually. Using IMRT, it may be possible to further limit the amount of radiation to healthy tissue near the tumor.
Above: A picture scanned breathing pattern of a patient to deliver a "gated" treatment that matches the patient's breathing pattern.