Stereotactic Radiation Therapy (SRT)
A type of external radiation therapy that uses special equipment to position the patient and precisely delivers radiation to a tumor. The total dose of radiation is divided into several smaller doses given over several days. Stereotactic radiation therapy is used to treat brain tumors and other brain disorders. It is also being studied in the treatment of other types of cancer, such as lung cancer. Also called stereotactic external-beam radiation therapy and stereotaxic radiation therapy.
Stereotactic Radiosurgery (SRS)
Stereotactic radiosurgery is the use of focused, high-energy beams to treat small tumors with well-defined edges in the brain and central nervous system. It may be an option if surgery is too risky due to your age or other health problems or if the tumor cannot safely be reached with surgery. Gamma Knife is a type of stereotactic radiosurgery.
You will be placed in a head frame or some other device to make sure you do not move during treatment. In stereotactic radiosurgery, many small beams of radiation are aimed at the tumor from different directions. Each beam has very little effect on the tissue it passes through, but a precisely targeted dose of radiation is delivered to the site where all the beams come together.
Stereotactic Body Radiation Therapy (SBRT)
Stereotactic body radiation therapy is similar to stereotactic radiosurgery, but it is used for small, isolated tumors outside the brain and spinal cord, often in the liver or lung. It may be an option when you cannot have surgery due to age, health problems, or the location of the tumor.
As in stereotactic radiosurgery, stereotactic body radiation therapy uses special equipment to hold you still during treatment. It delivers a highly precise beam to a limited area.
External Beam Radiation Therapy for Cancer was originally published by the National Cancer Institute.