External Beam Radiation Therapy to Control Proliferation of Cancer Cells
External beam radiation therapy is an important radiation tool that uses high-energy rays to slow down the rate of growth and proliferation of cancer cells. A focused beam of radiation is delivered from a machine outside the body.
A beam of high-energy x-rays is targeted at the tumor site. These high energy x-rays deposit their dose to the site of tumor to destroy cancer cells. External beam radiation therapy requires careful planning so that the surrounding normal tissues are spared. Radioactive sources are not placed inside the patient’s body.
However, this type of radiation treatment is not used for cancers that take up iodine as in case of thyroid cancers. Radioiodine therapy is a more effective treatment in such a case. It is generally used as part of the treatment for medullary thyroid cancer and anaplastic thyroid cancer. In other cases, where cancers do not take up iodine and has spread beyond the thyroid capsule, external beam radiation therapy helps to treat cancer or reduce the chance of disease from recurring after surgery. In case thyroid cancers do not respond to radioiodine therapy, external radiation therapy may be used to treat local neck recurrence that causes pain or other symptoms.
Some of the diseases that can be treated by external beam therapy are:
The main drawback of this treatment is that the radiation can destroy nearby healthy tissues if not done very carefully. Trouble swallowing, hoarseness and fatigue are the other possible side effects of external beam radiation therapy.