Radiation Therapy (definition of)

Nuclear radiation, in the form of radiation therapy, is a common and usually effective cancer treatment. Such therapy may employ x-rays, electron beams, or gamma rays. Radiation therapy basically uses a controlled form of nuclear fallout in high doses to destroy malignant cells at the DNA level, effectively sterilizing them and rendering them unable to reproduce.

Because healthy cells are also damaged in the process, the radiation must be tightly targeted. For this reason, a simulation, or "dress rehearsal carried out prior to the actual procedure. During the simulation, the oncologist and nuclear medicine technician confer as to where and how treatment should be applied.

There are two basic delivery methods: brachytherapy is an invasive method by which a delivery device is inserted directly into or near the tumor, which releases radiation over the course of several days or weeks. Teletherapy involves a focused beam of radiation that is used to bombard the cancerous cells from outside of the body; this treatment is performed five or six times a week over a 30 to 60-day period.

For mesothelioma patients, radiation is often used together with chemotherapy or may be used after surgery designed to remove as much of the asbestos cancer as possible.