Frameless Stereotactic Radiosurgery

Stereotactic radiosurgery isn't really surgery at all, but a form of radiation treatment that uses precisely targeted doses of radiation to treat a specific area within the brain or spine while avoiding radiation exposure or damage to adjacent normal tissues. Indications for stereotactic radiosurgery include brain and spinal tumors, arteriovenous malformations and Tic Douloureaux.

The size of the tumor or malformation is a limiting factor for radiosurgery, with conventional surgery usually more effective in treating lesions greater than 2.5 cm in diameter.

To avoid injury to surrounding tissue, radiation is delivered from several points simultaneously, such that no one beam is damaging to the tissue through which it must pass, but the convergence of multiple beams is sufficient to destroy the tumor or lesion.

The Accuray Cyberknife system at University Hospital has two major advantages over conventional radiosurgery systems, such as the gamma knife. Treatment with the Cyberknife does not require the patient's head to be placed in a stereotactic frame (as is required in traditional treatments, such as the gamma knife), and the Cyberknife has the ability to treat both brain and spine lesions.

Because the Accuray Cyberknife operates on a three-dimensional moving arm, it allows the surgeon to access areas such as the brain stem, where traditional stereotactic radiosurgery tools may be ineffective.

The time required for this procedure is generally from one to two hours, and success is often achieved with only a single, outpatient treatment.

A Patient's Story:

Jay Chapman, a 54-year old University of Tennessee Hospital employee, experienced a partial loss of hearing in one ear in association with ringing (tinnitus) in the same ear. Hearing tests confirmed a neurosensory hearing loss on the right side, and an MRI confirmed a small (5 mm) growth consistent with an acoustic neuroma.

In March of 2005, Jay underwent stereotactic radiosurgery using the Cyberknife at University Hospital . Given the non-invasive nature of the procedure, he was able to continue working while having outpatient treatment.

Three months after treatment, Jay reports that the tinnitus has resolved and a post-treatment hearing test documented improvement in his hearing.