What is Stereotactic Radiosurgery?

Stereotactic radiosurgery, also known as stereotactic radiotherapy (SRT), is a minimally invasive treatment for many tumors, abnormalities and functional disorders of the brain, head or upper neck. Although called radiosurgery, the procedure does not require a surgical incision. We call it surgery because stereotactic radiosurgery can have the same precision and result as open surgery, but with the advantages of a minimally invasive procedure.

With minimally invasive stereotactic radiosurgery, it is not necessary to open the skull to treat tumors or lesions in the brain. Stereotactic radiosurgery is also a good alternative to whole brain radiation therapy, as radiation exposure is limited to the treatment site while other areas of the head and neck are not affected.

In performing stereotactic radiosurgery, physicians use sophisticated technology to direct powerful, beams of ionizing radiation to the tumor or abnormality. Because the radiation is so precisely focused, nearby healthy tissues and other structures are unharmed. Since no incision is required, the procedure is virtually painless. Patients return home the same day and can resume normal activities right away.

The three types of stereotactic radiosurgery are:

• cobalt-60 based (photon)
• particle beam (proton)
• linear accelerator-based (linac)

What conditions are treated with stereotactic radiosurgery?

Stereotactic radiosurgery can treat:

• metastatic brain tumors (tumors originally arising outside of the brain, such as lung cancer or breast cancer)
• benign (non-cancerous) brain tumors, such as acoustic neuromas, meningiomas and pituitary tumors
• malignant (cancerous) brain tumors
• arteriovenous malformations (a disorder of the blood vessels)
• trigeminal neuraligia
• certain seizure disorders

Stereotactic radiosurgery is an excellent option for patients who are not good candidates for traditional open surgery, including patients whose tumor or lesion is:

• inaccessible through open surgery
• located very close to arteries, nerves and other important structures in the head and neck

How does stereotactic radiosurgery work?

As with other forms of radiation treatment, stereotactic radiosurgery does not remove the tumor or lesion. Rather, the radiation breaks the DNA in tumor cells so they are unable to reproduce. As a result, the targeted lesion is converted to dead scar tissue and often becomes smaller over time.

With stereotactic radiosurgery, trained neurosurgeons, radiation oncologists and other experts use 3-D computer-aided planning to map out the procedure according to each patient's condition. Based on the computer mapping, they apply complex technology to very accurately deliver radiation to the treatment site.

Shrinkage of the tumor or lesion can take anywhere from a few months to a few years, depending on the normal growth rate of the abnormality. Fast-growing lesions, like malignant or metastatic tumors, tend to shrink more quickly than benign tumors and blood vessel defects.