What Is Stereotactic Radiosurgery And How Is It Used ?
Despite its name, stereotactic radiosurgery is a non-surgical procedure that delivers precisely-targeted radiation at much higher doses than Cyber Knife while sparing healthy tissue organs nearby.
Stereotactic radiosurgery relies on several technologies:
- Three-dimensional imaging that determines the exact coordinates of the target within the body
- Systems to immobilize and carefully position the patient
- Highly focused gamma-ray or x-ray beams that converge on a tumor or abnormality radiation
- In some cases, image-guided radiation therapy (IGRT),which uses medical imaging to confirm the location of a tumor immediately before or during the delivery of radiation to further improve the precision and accuracy of the treatment
Stereotactic radiosurgery consists of a single treatment session. A rigid frame is attached to the head to ensure beam precision. Patients being fitted with a frame receive local anesthesia at stabilization sites. Radiosurgery patients should plan on being at the hospital for an entire day, arriving in the early morning and leaving early evening. The frame is removed prior to the patient’s discharge home.
Stereotactic radiotherapy consists of two or more treatment sessions. A treatment stabilization mask, contoured to the patient’s head and face, is used when multiple treatment sessions are required. This is a non-invasive procedure. Patients do not require any anesthetics for treatment planning or during treatment sessions. Radiotherapy patients are treated with lower fraction doses for shorter time periods per session over several weeks. Each treatment session lasts approximately 30-minutes.
The procedures generally cause only minor discomfort and patients usually experience minimal side effects. Patients typically are treated as outpatients and are required to have an escort home.
What Are The Risks ?
Side effects vary depending on the tumor type, total radiation dose, size of the fractions, length of therapy, and amount of healthy tissue in the target area. Some side effects are temporary and some are permanent. Generally, patients may experience fatigue, skin irritation around the target area, and hair loss.
On rare occasions, the radiation dose can cause a buildup of dead tumor tissue, called radiation necrosis, several weeks to months after treatment. Dead or necrotic tissue can become toxic to surrounding normal tissue, and swelling may occur. Brain swelling causes headaches, seizures and confusion. Treatment for radiation necrosis may include steroid medication, hyperbaric oxygen treatments or surgical removal.