Cutting-Edge Techniques

Nothing evokes fear quite like the words brain tumor. That’s because any problem with the brain carries high stakes. Depending on its precise location, a tumor no larger than a pea may have the power to wreak havoc with hormones that regulate growth, blood pressure and fertility, or to impinge on nerves that enable us to hear, see, speak and even move. Likewise, a single ruptured or blocked blood vessel can rob us of movement, speech or even our lives.

Surgical treatment for tumors and other problems of the brain often carries serious risks as well. “In any surgery involving the brain, there is potential to damage vital structures,” says Nelson Oyesiku, M.D., Ph.D., FACS, professor of neurosurgery at Emory University School of Medicine.

Surgically removing a tumor or repairing a ruptured aneurysm, for example, may jeopardize the nerves that control blinking, swallowing or other critical functions, leaving patients and their families wondering if the cure is worse than the disease.

Increasingly, however, scientists are finding better, safer and often more effective ways to treat tumors and other problems with this all-important organ. In many cases, the most cutting-edge treatments require no cutting. Procedures that involve highly focused radio waves, catheters snaked from the groin to the brain, or drugs injected directly into the site of the clots are sparing many people the pain and potential complications of surgery – and even their lives. In other instances, doctors are finding new uses for surgery or better ways to perform more traditional procedures with less damage to surrounding tissues.

In an age of health care that has come to recognize the value of specialization and regionalization, Georgia medical centers are becoming known in the Southeast and throughout the United States as leaders in many areas of neurosurgery – from the treatment of pituitary tumors and aneurysm repair to surgery to stop epileptic seizures.

Here are some of the areas of expertise and exciting technologies available now – and on the horizon – that hold promise for people throughout Georgia and those who travel to the state’s medical centers to receive treatment for complex neurological problems. Perhaps some will even help lessen the fear that surrounds the words brain tumor.

Operating Without A Knife

One of the most exciting techniques in brain surgery today, stereotactic radiosurgery has made its way into larger medical centers statewide. As the name implies, radiosurgery involves using radio waves to replace the knife.

The technique has been used successfully to treat a number of problems in the brain, including arteriovenous malformations (AVMs), areas of tangled, weakened blood vessels that are prone to rupture and bleed into the brain, and, most notably, brain tumors.

“Because tumors can be close to vital structures of the brain such as the carotid artery that supplies blood to the brain and the optic nerve that supplies vision to the eye, surgical treatment is challenging,” says Dr. Oyesiku, one of the world’s foremost experts on tumors of the pituitary gland. The pituitary, a small oval gland located at the base of the brain, produces hormones that control other glands and influences many body functions, including growth, blood pressure and sexual development.

“Radiosurgery basically allows you to send many low energy beams into a target in the brain such as a tumor. While, individually, the beams are not strong enough to cause damage, where they meet, where they are focused, they have a high-energy radiation that allows you to destroy the tumor.”

The biological effect – the ability to destroy abnormal tissue such as tumors – is greatly enhanced with radiosurgery because the doctor can target a dose of radiation to a precise area requiring treatment, while sparing the tissues around it. In fact, the treatment system offered at Emory is so precise that it can target an area within 0.4 of a millimeter, similar to the width of a pencil line drawn on a piece of paper.

The system comes equipped with a robotic medical linear accelerator, which rotates around the patient to deliver radiation treatments at any angle, and a device to shape the radiation beam to match the tumor’s three-dimensional shape.

Although Emory is the first medical center in the world to offer a system with that degree of precision (the next best machine targets within 0.75 of a millimeter), at least three other centers, including the Medical College of Georgia (MCG) in Augusta and Atlanta’s Piedmont Hospital, offer stereotactic radiosurgery, using a system called the Gamma Knife. The results are essentially the same – highly focused beams of radiation that obliterate a tumor while subjecting surrounding tissue to radiation comparable to that of a chest X-ray.

While traditional surgery for some problems – such as acoustic neuromas (tumors that grow on the auditory-vestibular nerve) – carries a complication rate in the range of 20 to 25 percent, the risk of complications with the Gamma Knife is closer to one or two percent, says Mark Lee, M.D., Ph.D., professor and chair of the department of neurosurgery at Medical College of Georgia.

One drawback with Gamma Knife and radiosurgery in general is that it is only effective for tumors that can be seen and have clear borders. Sometimes malignant tumors put out tentacles that move throughout the brain, Dr. Lee says. Radiosurgery may destroy the original tumor but not the outgrowths.

Nevertheless, Dr. Lee says, the Gamma Knife is “an excellent way to take care of a lot of tumors. The patient can be treated in the morning, go home that afternoon and return to work the next day.”

Blocking Ballooning Blood Vessels

Aside from brain tumors, aneurysms – balloon-like swellings in blood vessels that can burst, leaking blood into surrounding tissues – are among the most common and potentially deadly problems that affect the brain.

Typically, half of the people who have ruptured brain aneurysms die before they reach the hospital, says Dan Barrow, M.D., chairman of the department of neurosurgery at Emory, which treats more ruptured aneurysms than any other U.S. medical center. For those who survive a rupture – or those who’ve had aneurysms diagnosed before they ruptured – treatment has involved locating the aneurysm, going into the brain surgically and sealing off the affected vessel with clips made for this purpose.

For many people today, however, there’s a kinder, gentler way to seal off these bulging blood vessels – a procedure called cardiovascular coiling. Performed at a handful of Georgia medical centers, coiling involves making a small incision in the groin where a catheter is fed into the blood vessel that has the aneurysm. The doctor then snakes the catheter up to the aneurysm and uses it to place a bunch of small platinum coils to fill the aneurysm.

“Once the aneurysm is filled with the coils, it no longer has blood flowing through it so it can’t rupture [or re-rupture],” says MCG’s Dr. Lee, who is using coiling “aggressively.” The best news: Coiling is an outpatient procedure. Some patients with an unruptured aneurysm have the procedure and are back at work a couple of days later.

Stopping Seizures For Good

As many as 1 percent of Americans have epilepsy, a condition in which nerve cells in the brain fire electrical impulses in large bursts of activity and at a rate up to four times higher than normal, causing seizures. Nearly half are unable to adequately control their seizures with medication. Some experience multiple daily seizures, which leave them unable to drive, hold a job, have a family or even leave home. For those people, new surgical procedures offer hope.

When the abnormally firing cells are found to be isolated to one part of the brain, doctors can now identify and surgically remove that section of the brain and stop the seizures, while interfering little, if any, with normal brain function. In fact, the biggest problem with the surgery is that the people most likely to get it are those who have had seizures for so long that they already have greatly diminished quality of life.

A new multicenter study is examining the role of the surgery in people who’ve had seizures less than two years – to see if it has a more substantial benefit on their social, economic and psychological function, says Robert Gross, M.D., Ph.D., assistant professor and director of functional and epilepsy surgery at Emory, one of the study centers.

Dr. Lee is a firm believer that the earlier the surgery is performed the better – that’s why MCG has chosen to focus largely on epilepsy surgery for children. In fact, the center ranks among the top five nationally in volume of pediatric epilepsy surgery.

“[In adults who had had epilepsy for years] we were able to stop their seizures, but we weren’t really able to change their lives,” Dr. Lee says. “Because they had gone their whole lives with epilepsy, a lot of them had never finished school, they still lived with their parents and never developed social skills.”

While the procedure is invasive – it involves implanting electrodes in the brain to identify the seizures’ source and then surgery to remove the responsible area – its benefits are immeasurable for families desperate to get help for their kids.

“You have a kid who has 20 seizures a day who can’t go to school, whose family can’t take vacations, who acts like a zombie because of all of the medications and compare that with a kid who has no seizures, goes to school and takes no medications. It’s a huge change,” Dr. Lee says.

“When I see this – when we have a successful outcome – I just feel like this is why I do what I do.”

Tumors Under The Microscope

Just being noncancerous doesn’t make a tumor benign. Even nonmalignant tumors can compress key blood vessels and wrap around nerves, threatening or at least altering your life.

“If you are able to remove those types of tumors completely it is a curative operation,” says James Robinson, M.D., chief of neurosurgery and medical director for the Gamma Knife at Piedmont Hospital in Atlanta.

Thanks to microsurgical techniques – the ability to perform surgery under a microscope – the precise and delicate surgery to remove such tumors is often possible. But it’s never easy, particularly if the tumor is located deep within the brain and hard to access.

Recent advances in treating these tumors include those designed to gain better access. “Sometimes this involves removing bones of the face and putting them back once the surgery is completed,” Dr. Robinson says. Or it may involve using endoscopic techniques (similar to those that became popular for knee surgery in the 1980s and for a host of other medical procedures in more recent years) whereby small masses can be removed through a hole drilled in the skull.

Direct Drug Delivery

After heart attacks and cancer, strokes – the death of brain cells caused by a blockage in an artery that supplies the brain – are the leading cause of death in the United States.

If people are fortunate enough to make it to the hospital in time, a drug called tissue plasminogen activator (tPA), given intravenously, may help dissolve the blockage and allow blood flow to resume. But the window of opportunity is small, and the drug carries the risk of unwanted bleeding.

For some people, a new way of administering these drugs – directly into the blocked artery at the site of the clot – may both make the procedure more effective and help reduce bleeding risk.

Using a method similar to heart angioplasty, doctors thread a catheter through the large artery in the groin, and move it through the vessel up to the site of the clot in the brain to administer a single dose of clot-busting tPA.

“Certainly, there is still a slight risk of a hemorrhage, but because you are infusing a much smaller dose right at the site of the clot, you tend to get a better overall effect than putting a higher dose into a vein and having it go all over the body,” says Cargill Alleyne, M.D., associate professor of neurosurgery and director of the cerebrovascular service at MCG, one of a few specialized centers, including Emory, that does the procedure. The new method of administration also opens the window of opportunity for stroke treatment a bit wider ? from three hours for intravenous tPA to six hours for the interarterial version.

Dr. Alleyne adds that for patients whose clots don’t respond to interarterial therapy alone, adding intravenous drug is an option.

Understanding Tumors

In addition to providing cutting-edge treatment for brain tumors now, Emory is also at the forefront of research into the understanding of and better treatments for hard-to-treat tumors in the future.

Led by Dr. Oyesiku, Emory researchers recently received a $1.6 million National Institutes of Health grant to study the most common type of pituitary tumors. These tumors can be either functional ? meaning they cause excess hormone production – or nonfunctional – meaning they inhibit hormone production. While the former is undesirable, the latter can prove fatal by lowering blood pressure or upsetting electrolyte balance, Dr. Oyesiku says.

Although most nonfunctional tumors have required treatment with surgery and radiation, Dr. Oyesiku and his colleagues are trying to find ways to avoid invasive treatments and, when appropriate, treat tumors medically.

Using sophisticated imaging techniques, researchers have identified a molecule on the tumors that allows them to use other injected molecules called radioactive tracers to take pictures not only of the tumors themselves but of the individual tumor cells – all without surgery. “The tumor cells can tell you which type of tumor you’re dealing with and more importantly whether that tumor can be treated medically,” says Dr. Oyesiku says. “We can take a picture before we ever perform surgery or do a biopsy to determine whether the tumor will likely respond to medication or whether the patient will need surgery.”

Understanding the tumor’s specific nature will also help doctors select the best medication for it or to develop newer, more effective medications. Dr. Oyesiku says he’s working with the biotechnology industry now to design specific types of drugs. But for now, he says, new drugs may still be a number of years away.

Stimulating The Brain

When areas of the brain are either underactive or overactive, the result can be problems as diverse as Parkinson’s disease and depression. A growing body of research shows that manipulating those areas with an electrical current can help relieve many problems.

Using what’s known as functional neurosurgery, doctors can alter brain function either by specifically and purposely damaging overactive parts of the brain, or more recently, by electrically stimulating parts of the brain that they want to become more active, Dr. Barrow says. The procedure involves running electrodes through a small hole in the skull, placing them into very specific parts of the brain, and then hooking them up to an internalized power source, similar to a pacemaker.

While the procedure is approved for tremors and Parkinson’s disease, Emory doctors have recently used it for Tourette’s syndrome, a genetic disorder characterized by the presence of tics or repetitive movements that are difficult or impossible to control. “We had one patient who could not sit in a room and look at a corner without an uncontrollable urge to get up and ram his head in the wall as hard as he could,” Dr. Barrow says. “He had cuts and injuries to his head and brain and had to wear a helmet. After surgery, the problem was completely eliminated.”

Potentially functional neurosurgery could be used for all types of psychiatric disorders, Dr. Barrow says. It has been used experimentally for depression and obsessive-compulsive behavior. Animal research suggests it may also be useful for controlling morbid obesity.

Better Brain Pictures

When a tumor is treated with surgery and or/radiation, scar tissue-like changes to the surrounding area can closely resemble that of tumor growth. Traditionally when imaging scans such as MRI or CT showed such changes in brain tissue, doctors often went back into the brain to biopsy the questionable tissue. But new technology allows doctors to get a closer look at the qualities of brain tissue, often eliminating the need for invasive tests.

“This technology – MR spectroscopy – allows us to actually get a chemical profile of the brain tissue,” says Jay Cinnamon, M.D., a neuroradiologist and director of 3D imaging at Quantum Radiology Northwest in Atlanta, a private radiology practice contracted to provide services to Kennestone Hospital, Cobb Hospital and Paulding Hospital.

“As it turns out, the post-therapy changes have a different chemical spectrum from tumors – tumor cells make certain chemicals and post-therapy changes make other chemicals. Once we can interrogate the brain on a chemical level, we can distinguish between these two types of tissue without having to do a biopsy.”

Other new imaging technology – which, in some cases, involves the melding of different technologies – is allowing doctors to diagnose aneurysms in the brain with the quick and relatively safe injection of dye into a vein in the arm. It’s also helping determine precisely which parts of a brain abnormality are metabolically active – that is, having the characteristics of a growing tumor. Knowing that, doctors can remove that part of the abnormality with the potential to cause harm while minimizing the risk of unnecessary cutting.

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