Neurosurgeons Find New Advances in Brain Tumor Treatment

Newswise — Neurosurgeons today use amazingly sophisticated techniques and tools, especially in treating brain tumors. In attacking a tumor, neurosurgeons rely on computers, MRIs, and image-guidance technology to help them navigate through the complex terrain of the brain with greater precision. Treatment of brain tumors is a topic of interest during the First Annual Neurosurgery Awareness Week from May 1 to May 6 during the 72nd Annual Meeting of the American Association of Neurological Surgeon (AANS) in Orlando, Florida.

Brain tumors have long been difficult to treat. Because they occur at the control center for thought, emotion and physical function, neurosurgeons must be careful not to damage healthy brain tissue. Fortunately, the new sophisticated techniques and tools insure the safest and most complete removal of tumors. Tumors that were once inoperable, such as those in the brain stem or thalamus, are now often accessible, and many of these tumors can be removed without impairing neurological function.

Although brain tumors may be attacked in a number of ways, surgery is usually the first step for tumors that can be removed without damaging vital neurological functions. A tumor will recur if any tumor cells are left behind, so neurosurgeons attempt to remove the entire tumor if possible. Radiation therapy and chemotherapy may be used as secondary treatments for some tumors.

One of the most common advanced surgical tools used to treat tumors is a high-powered microscope. Microsurgery produces a magnified and illuminated view of the surgical field, making it easier to see and remove tumor tissue without disturbing healthy tissue. Image guidance, or stereotaxis, involves the use of MRI (magnetic resonance imaging) or computerized tomography (CT) scanning. A neurosurgeon in the operating room uses the latest computer technology to reformat data previously obtained from an MRI or CT scan. The result is a workable image of the brain tumor tissue.

An intraoperative MRI further aids a neurosurgeon. Because the brain "shifts" slightly during an operation, the real-time imaging allows for a more precise removal of the brain tumor.

Another high-tech tool of today's operating rooms is the laser, which destroys tumor cells with intense heat. Used in addition to or in place of scalpels, lasers can reach a tumor embedded deep within the brain.

Neurosurgeons continue to discover novel ways to identify and attack tumors. Photodynamic therapy involves injecting a photosensitizing drug into a vein or artery prior to surgery. During the operation, the tumor cells appear fluorescent, giving neurosurgeons a relatively easy target at which to aim the laser.

Neurosurgeons also have pioneered the use of stereotactic radiosurgery, which shoots high-dose radiation beams at the tumor. "Stereo" refers to three-dimensional, and stereotactic radiosurgery involves making an image map of the brain through an MRI or CT scan before delivering the radiation beams. There are two ways to deliver the radiation beams: through a large helmet or through a modified linear accelerator. In one technique, a sophisticated machine shoots many finely focused beams of radiation at the tumor. The patient wears a large helmet with holes that match the tumor's shape and through which the beams of energy pass. Alternatively, the radiation can be delivered through an adapted linear accelerator that delivers a beam of radiation to the tumor.

Neurosurgeons have made advances over the last decade in refining "molecular" techniques for treating tumors. These include gene therapy, in which engineered viruses deliver toxic agents into tumor cells or deliver genes that help impede the growth of the tumor cells. Another molecular technique is toxin therapy, which attacks the tumor cells.

The challenge of these therapies is to find effective ways for delivering the agents into the brain. One common method is convection-enhanced delivery, in which small agents are delivered to large regions of the brain. A significant new approach is the use of chemotherapy wafers, implanted directly into the cavity left behind after a tumor is removed.

Advances in the diagnosis and treatment of brain tumors are expected to continue in the next decade. Years ago, a diagnosis of brain tumor meant little hope for treatment and recovery. Today many brain tumors are treated successfully, and in the future increasingly refined and sophisticated techniques and tools are expected to allow a higher percentage of patients to recover and return to their normal lives. For more information about brain tumors, visit the public Web site of the American Association of Neurological Surgeons at http://www.NeurosurgeryToday.org.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 6,500 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system including the spinal column, spinal cord, brain and peripheral nerves.