Everything Changed
In July 1995, 25-year-old Chris LaVallee thought his life was right on track with a successful career as an investment banker and a wedding planned for the fall.

Then everything changed. He suddenly began experiencing frightening weekly episodes: his head would turn involuntarily to the right, his face would contort slightly, his right arm would stiffen, and he would be unable to speak.

He first thought that the symptoms were stress related, from his job and possibly his upcoming wedding; but when they began occurring almost daily, he sought out the advice of a neurologist. The diagnosis: seizures caused by a brain tumor in the left frontal lobe.

A Dangerous Place
LaVallee was put on anti-seizure medication, but his neurologist told him the best option was to have the tumor surgically removed. Adding to his worries, the tumor was in a dangerous spot, near his motor cortex, making the surgery extremely risky.

He consulted with some of the leading neurosurgeons in New York and learned everything he could about his condition. His search led him to Dr. Patrick J. Kelly, Chairman of the Department of Neurosurgery at New York University Medical Center. "Dr. Kelly's skills, experience, and innovation, combined with the technology and exemplary staff," said LaVallee, "made me decide to have the surgery done at NYU."

From Sailing to Stereotaxis
Dr. Kelly pioneered and continues to refine a highly sophisticated technique used in neurosurgery, computer-assisted volumetric stereotaxis. This system can precisely map the location of a brain tumor in a three-dimensional space.

Interestingly, the idea that led to the development of volumetric stereotaxis began with Dr. Kelly's experience as a sailor.

"At sea," says Dr. Kelly, "you have harbor maps that show you where the water ends and the land begins. In volumetric stereotactic surgery, you see exactly where the tumor has its boundaries in space and where normal brain tissue begins."

Ahead of its Time
Dr. Kelly's longtime goal of applying stereotactic methods to neurosurgery had to wait for today's powerful computers and high-resolution imaging systems like computed tomography (CT), magnetic resonance imaging (MRI), and digital angiography. By superimposing these perspectives, computer-assisted volumetric stereotaxis creates a single composite image of the anatomic, structural, and vascular details of the brain.

An even more recent development, magnetoencephalography (MEG), is a noninvasive technique that reveals the exact location of brain tissue responsible for crucial functions, such as movement and sensation. MEG maps real-time brain function by sensing the magnetic fields produced by the brain's electrical activity. This requires the most sensitive magnetic-field detection device in the world. NYU's MEG system, the only one on the East Coast, provides the surgeon with clear markers of critical areas to avoid on the way to the tumor.

No Margin
The goal of tumor surgery anywhere in the body is to "get the cancer out." When a surgeon excises a tumor from an organ like the breast, lung, kidney, or skin, the risk of recurrence is reduced by intentionally taking out "a margin of good tissue."

With brain tumors, this is not an option. Removing a margin of good brain tissue could result in severe neurological deficits with unacceptable reductions in quality of life.

Volumetric stereotactic technology is the best available tool for enabling a surgeon to "see" the all-important but elusive boundary between a tumor and a patient's brain.

Seeing the Unseeable
Radiographic and magnetic images are converted into a detailed 3-dimensional model of an individual patient's brain, by using a unique computer application called COMPASS, developed by Dr. Kelly and his colleagues.

COMPASS integrates enormous streams of data to create clear 3-D images of the tumor — positioned precisely within the surgical target area — and the associated vasculature, anatomical landmarks, and functional markers. A robotics-controlled stereotactic headframe, attached to the patient's skull with four pins, is used to ensure precision during the acquisition of the images, and during surgery.

Enhancing the Surgeon's Eyes
"During surgery," Dr. Kelly continues, "normal brain tissue and tumor often look alike to the eye, but having the volumetric stereotactic image before me extends my vision, letting me 'see' the entire tumor inside and out. Most important, it lets me know exactly where the tumor ends and the brain itself begins, allows me to remove the whole tumor and nothing but the tumor."

Virtual Reality
Throughout surgery, a "virtual reality" image of the brain is projected in front of the surgeon's eyes by a "heads-up" video display unit mounted on the operating microscope.

"What I see through the microscope," says Dr. Kelly, "is not only the actual surgical field itself, but also the computer-generated rendition of what actually is there and what's below the surface. I can see where I am and where I'm going."

"With this technology, you can also see and remove deep-seated tumors which might otherwise be considered inoperable."

Clinical and Economical Effectiveness

Using the stored 3-D image on a computer screen, the surgical procedure can be simulated beforehand, to identify the optimal approach. Before going into the operating room, the surgeon can decide where to open the skull, how large to make the craniotomy, and what essential tissue and blood vessels to avoid. Because the hole in the skull, the path to the tumor, and the excision are substantially smaller than in conventional neurosurgery, injury to the brain is further minimized.

Dr. Kelly and his colleagues have conducted a study of 1,165 patients at NYU Medical Center and Mayo Clinic who had computer-assisted stereotactic neurosurgery.

"We found that the tumors were completely removed in more than 90 percent of the cases," Dr. Kelly points out, "and the surgical mortality rate was less than one percent."

"Because of its precision, computer-assisted stereotactic surgery yields not only better clinical outcomes — such as minimizing neurological damage and increasing survival — but also achieves economic savings. The time patients spend in the operating room is reduced, sometimes by two or three hours. In addition, because of fewer postoperative complications and quicker recovery, patients are able to leave the hospital sooner. Also, they are less likely to have to return for additional surgery, because of the high success rate in the total removal of tumors."

Radiologists provide the CT, MRI, and angiographic images that form the core of the 3-D database.

The Center for Neuromagnetism of the Department of Physiology and Neuroscience uses magnetoencephalography to map functional areas of the brain.

The Stereotactic Lab Team assists in the precise placement of the headframe and operates the COMPASS computer system.

Neuroanesthesiologists are responsible for the administration of anesthesia, airway management, and hemodynamic and neurophysiologic monitoring during surgery.

Highly skilled nurses staff the operating suite and deliver care postoperatively in a dedicated neurosurgical unit.

Specialized social workers arrange for post-hospital services.

Neuro-oncologists, when indicated, plan and administer a course of individualized adjuvant medical therapy for patients with malignant tumors.

Neuropathologists use advanced techniques such as antibody assays to identify glial and neuronal antigens and tumors' proliferative capacity, which helps in the choice of adjuvant therapy.

"Dr. Kelly, Can I Just Get Married First?"

Volumetric stereotactic neurosurgery was Chris LaVallee's best hope to go on with life despite a tumor. With Dr. Kelly's approval, LaVallee briefly postponed surgery so that he could go ahead with some important immediate plans: his wedding and honeymoon.

Because the tumor was so close to the motor strip, LaVallee was told that paralysis was one of the risks of surgery. He will never forget the thrill of moving his fingers and wiggling his toes when he awoke from the anesthesia.

After surgery, specially trained ICU nurses monitored LaVallee closely for subtle neurological changes or complications, but none occurred. He went home three days later, and quickly returned to his demanding schedule.

Although LaVallee now returns to NYU for routine follow-up with MRI, after two years there has been no recurrence.

Suddenly, in August of 1995, Suzanne was struck by a seizure that terrified her mother, Sonja Mahle. Mrs. Mahle immediately rushed Suzanne to a local hospital, but that hospital's staff could find no problem and the two were sent home. A second seizure brought them back to the same ER and again they were falsely reassured, but this time Mrs. Mahle refused to leave.

Suzanne was examined by a neurologist who ordered an MRI and found an arteriovenous malformation (AVM). Eventually, they were referred to Dr. Kelly at NYU Medical Center. According to Suzanne's mom, Dr. Kelly was gentle, but honest. He told Suzanne that without surgery she would die.

With the stereotactic technology, Dr. Kelly knew exactly where the AVM was and could plan the route in great detail, enabling him to perform a craniotomy at precisely the right position and to use an opening substantially smaller than would have been necessary with conventional neurosurgery.

"The heads-up display unit showed me where the critical blood vessels were," Dr. Kelly said, "so I didn't have to look around. I went directly to the AVM in the central sulcus and removed it. Removal of a second AVM, four days later, was also successful."