External Beam Treatment Using Conventional Therapy
Radiation therapy (RT) is a type of cancer treatment that uses high energy x-rays or particles to kill cancer cells. Radiation kills cancer cells by destroying the genetic material that controls how cells divide and grow. There are two main types of radiation therapy; external beam radiation and brachytherapy.
External beam radiation therapy (EBRT) remains one of the primary treatment modalities for patients with localized or locally advanced prostate cancer. During external beam radiation therapy (EBRT), beams of radiation are generated with a machine called a linear accelerator, these beams are directed through the skin to the cancer and the immediate surrounding areas to destroy tumors and any nearby cancer cells. In order to minimize side effects, treatments are typically given five days a week, for a number of weeks. The process of dividing a dose of radiation into multiple "fractions" is called fractionation. Fractionation allows enough radiation to get into the body to kill the cancer while giving healthy cells time to recover. There are several specific types of external beam radiation therapy used for specific types of cancer.
Three-Dimensional Conformal Radiation Therapy (3-D CRT or conventional therapy) is a type of external radiation therapy treatment that shapes the radiation beams to match the shape of the tumor while minimizing dose to surrounding healthy tissue. Conventional Therapy is used to confine the radiation dose to the planning target volume. The name conformal is derived from the technique of shaping the radiation beams to conform to the shape of the tumor.