Therapeutic radiology (also called radiation oncology) is the treatment of cancer and other diseases with radiation. High energy x-rays are used to kill the cancer cells by preventing them from multiplying. Therapeutic radiology may be used to cure or control cancer, or to alleviate some of the symptoms associated with cancer.
The level of radiation will be determined by the radiation oncologist based on the type of cancer, location of the tumor, and sensitivity of the surrounding tissue. Although each hospital may have specific protocols in place, generally, radiation oncology procedures follow this process:
To help set up the actual treatment, the treatment team first "maps" out the position the patient will be in for each treatment with the aid of molds, headrests, or other devices. Sometimes the area on the body to be treated will be marked to ensure the radiation will be given in the exact area. In addition, special shields may be made to help focus the radiation and protect surrounding tissue.
Once the simulation has taken place, the radiation oncologist will determine the exact type of treatment.
Examples of types of radiation therapy used to destroy cancerous tissue include:
- External Beam Therapy
- Intensity Modulated Radiation Therapy (IMRT)
Brachytherapy is radiation treatment inside the patient, as close to the cancer as possible. The radiation is delivered inside the body with isotopes (chemical elements) such as wires, seeds, or rods.
Brachytherapy is often used in the treatment of cervical, uterine, vaginal, or rectal cancer, as well as eye and certain head and neck cancers. However, the therapy may also used to treat many other cancers.
There are two types of brachytherapy:
Containers that hold radioactive sources are put in or near the tumor through body cavities such as the vagina, uterus, or windpipe.
The radioactive sources alone are put into the tumor and may stay in the patient permanently.
General anesthesia may be used during the insertion of brachytherapy sources.
Sometimes brachytherapy is done in combination with external beam therapy to help destroy the main mass of tumor cells.