ABBR: RT, XRT The use of energy from man-made ionizing radiation or from the radioactive decay of atomic nuclei to destroy diseased tissues, esp. cancers.
SYN: SEE: radiotherapy

PATIENT CARE
The radiotherapy must be directed only at the diseased tissue. The patient's body is precisely measured and marked (“tattooed”), and cradles are designed to hold the patient in a precise position for each treatment. Systemic adverse effects of radiation therapy include weakness, fatigue, anorexia, nausea, vomiting, and anemia. These may subside with antiemetics, steroids, frequent small meals, fluid maintenance, and added rest and are seldom severe enough to require discontinuation of treatment although dosage adjustment may be required. Local adverse effects of radiation depend on the organ system affected. For example, radiation of the breast may sometimes result in esophagitis or pneumonitis; cranial radiation may cause hair loss; radiation treatment of head and neck cancers may cause dry mouth (for which good oral hygiene or artificial saliva may be helpful). Because radiation may affect bone marrow, patients require frequent measurement of complete blood counts. Radiation also requires special skin care, and the patient should use a hypoallergenic moisturizer (Biafine, Radiacare Gel, and Aquaphor are popular brands). Many nurses and patients prefer using natural aloe (from the leaf of an aloe plant, split open to apply the gel from inside) or bottled aloe. Usually the radiation therapist will recommend that the skin be free of any such preparations at treatment time.