Radiation therapy attempts to destroy tumor cells by using high-energy radiation focused onto the tumor to destroy the tumor cells' ability to function and replicate. Radiosurgery is a nonsurgical procedure that delivers a single high dose of precisely targeted radiation using highly focused gamma-ray or X-ray beams that converge on the specific area or areas of the brain where the tumor or other abnormality is located, minimizing the amount of radiation to healthy brain tissue. Equipment used to do radiosurgery varies in its radiation source; a gamma knife uses focused gamma rays, and a linear accelerator uses photons, while heavy-charged particle radiosurgery uses a proton beam. Tomotherapy is a type of radiotherapy in which radiation is delivered in a highly precise and individualized manner that minimizes radiation exposure to healthy tissue; it has also been used to treat brain cancer.
Edema is the swelling of tissues as a result of excess water accumulation. Peripheral edema occurs in the feet and legs. There are two types of edema, non-pitting edema and pitting edema. Causes of pitting edema is caused by systemic diseases (most commonly involving the heart, liver, and kidneys), and medications. Local conditions that cause edema are thrombophlebitis and varicose veins. Edema or swelling of the legs, feet, ankles, and face are common during pregnancy. Idiopathic edema is edema in which the cause is not known. Pitting edema is scored on pitting edema measurement scales. Edema is generally treated with medication.