Revolutionary Techniques in Neurosurgery:
A Q&A with Ravish Patwardhan, MD

Published Online: April 15, 2010 – 3:03:03 PM (CDT)
Ravish Patwardhan, MD, is the founder and director of the Comprehensive Neurosurgery Network (www.brainandspinecare.com), which “specializes in minimally invasive techniques for treating brain and spine problems.” Patwardhan has more than 12 years of experience in the neurosurgery industry and has published several peer reviewed studies on brain trauma, tumors, epilepsy, and spinal procedures. He is also a frequent speaker on the latest treatments and advances in brain and spinal surgeries.

What are the benefits of the Visualase laser probe technique, and do you believe it will become the standard for brain tumor eradication?

The best way to understand the Visualase laser system is to understand what it simplifies. Say a patient comes in with a brain tumor that is less than 2cm in diameter. While he or she is awake, a small area of the scalp is locally anesthetized, and a stab incision is made, with a small hole drilled in the precise trajectory to enter the middle of the tumor and run its length. The operating room portion ends here. The patient is transferred to the MRI suite, where the precise position is verified on MRI scan. Subsequently, the tumor is ablated in the MRI scanner, leaving a black hole where the tumor used to be. The probe is removed in the MRI scanner, and a previously placed stitch is tied, all while the patient is awake and responding, to ensure that no new problem has occurred. The entire procedure takes about an hour (5 minutes in the operating room and 45 minutes in the MRI suite).

The length of time of the procedure, avoidance of general anesthesia, shortened length of stay in the hospital (patients may go home the same day versus three days or more, following a typical craniotomy for tumor resection), reduced blood loss (a few drops), smaller incision size (stab incision), and subsequently less pain all result in a quicker recovery. Because this technology is so new, we’re learning more about it with each case. We learn about which tumors in which locations may or may not be amenable to treatment with laser ablation. Presently, though, laser ablation’s advantages appear to be its ability to treat deep brain tumors—which would destroy the brain if approached openly surgically—and to produce relatively instant results. This is opposed to waiting several weeks to see an MRI change for techniques like Gamma Knife.

Watching Tumors Die

Thursday, April 2, 2009
By Sarah Petrie

Above, from left: Kamran Ahrar, M.D., and R. Jason Stafford, Ph.D., discuss an upcoming spinal surgery that will use the Visualase technology. They’ll be able to watch the tumor fully die in near real time during the procedure. Depending on where the tumor is located, the patient may or may not be awake during the procedure.

History books show that surgeons began removing cancerous tumors as early as the second century. Zoom ahead to 2009, take away the scalpels, scars and side effects that typically accompany surgery, and trade them for a tiny laser beam that zaps cancer dead on the spot. It sounds like science fiction, but our researchers and clinicians are among the first in the nation to investigate a new procedure that does just this … and more.

“It’s called laser-induced thermal therapy, and the basic theory is that the laser heats the tumor to a certain temperature to kill it,” explains Jeffrey Weinberg, M.D., associate professor in Neurosurgery, who’s conducting a clinical trial to test the effectiveness of this procedure on patients with metastatic brain tumors.
How hot is too hot for a cancerous tumor? Sixty degrees Celsius, in most cases.

“The clinical trial targets patients with otherwise inoperable tumors or those for whom other treatments failed,” Weinberg says. “This is possible because tissues surrounding the tumor aren’t harmed or affected with this procedure — an advantage over other types of brain surgeries for cancer, including radiosurgery.”

Delivering laser energy using a device only millimeters in diameter, the procedure leaves a scar no bigger than your thumb. Plus, there should be no side effects for this less-invasive surgery, which takes only a few hours from start to finish. “The laser portion should only take a few minutes, and patients will experience no swelling and little pain,” Weinberg adds.

Other forms of what also is known as ablation therapy already are in practice, killing tumors using heat, cold or electricity. So what makes this particular procedure so revolutionary? The physician actually watches the tumor die in real time, according to Kamran Ahrar, M.D., associate professor in Interventional Radiology, who has performed the procedure on a few patients with bone and spinal tumors as part of a similar clinical trial.

Weinberg agrees this is the biggest advantage of this method over other forms of treatment. “Patients don’t have to wait weeks or months for tests to confirm if the entire tumor is gone, as is the case with most surgeries. Instead, using this technology, we can convert magnetic resonance imaging into a color picture that indicates the temperature of the tissue,” he says. “This allows us to know exactly when the tumor is hot enough to fully die.”

How does it work?

Houston-based company Visualase Inc., which sells the technology, approached M. D. Anderson in 2000 for help with developing the tool. “For this procedure to be successful, the doctors must know the precise location and distribution of temperature in the tumor and that’s where the physicists come in the picture,” explains R. Jason Stafford, Ph.D., assistant professor in Imaging Physics, and lead consultant on the Visualase technology development for M. D. Anderson.

In other words, a stereotactic navigation system, “like a GPS for your brain” as Weinberg puts it, pinpoints the exact location and size of the tumor. After the surgeon drills a hole and sends the specially designed fiber directly to the tumor, the laser is activated, thus heating the tumor. Doing it in the MRI allows clinicians to monitor temperatures within the tissue. “Temperature as well as predicted regions of complete treatment are color-coded on a screen, giving us the ability to adjust or retreat a certain area, as needed,” Stafford adds.

And at M. D. Anderson, this entire procedure can be performed in one room, unlike at other institutions that also are researching the procedure. We have a dedicated intra-operative MRI suite, which is safer for patients than moving them to different locations to complete the procedure.

Burning out brain tumors: new procedure shows promise

Posted: Apr 20, 2009 5:59 PM CDT Updated: Apr 28, 2009 11:51 AM CDT
By Carolyn Roy, KSLA News 12

SHREVEPORT, LA (KSLA) – A Shreveport neurosurgeon has taken brain surgery for the removal of tumors to a whole new level, finding a way to obliterate a tumors, with much less risk.  A Many, Louisiana woman was the first patient in the U.S. to have the procedure done.

Karen Mowad … has been through surgery, chemotherapy and radiation…, but when the cancer spread to her brain, she came to Dr. Ravish Patwardhan of the Comprehensive Neurosurgery Network.

The Shreveport neurosurgeon had to open her skull to remove that tumor.  It’s the kind of surgery that leaves a big scar and comes with serious risks and a longer recovery time.  But by the time another tumor appeared last fall, Dr. Patwardhan had a new tool to try: a laser probe, and he was looking for a patient willing to be the first.  “We offered her both options,” says Dr. Patwardhan. “We said, ‘Look, you’ll be the first one in, really, North America to have this tumor re-sected for a metastatic brain tumor.  If you’re interested in it, we can do this. It involves making a small opening and going in and burning it.”  The alternative was another open operation.  Mowad was in.

The procedure, marries the precision of navigation tools … with an MRI-guided laser probe developed by Visualase out of Houston. “What this does is you just have to make a hole that will take you to the middle of the tumor, burn the tumor and then the tumor will essentially evaporate.  It’s actually done in the MRI suite, so when the probe is confirmed to be in the correct position in the MRI suite what you do then is heat it and you can watch it directly on the MRI scanner what area is being heated using the program.  After that you can do another MRI scan, since the patient is already there to show the tumor is gone.  So you have instant gratification.”

The procedure leaves behind a small pinpoint incision, comparable to that size of the tip of a pencil.  Karen Mowad was able to stay awake through the procedure, and felt no significant discomfort.  In addition to avoiding the risks related to anesthesia, the laser ablation probe is thin and slides through the brain with much less disturbance.  It allows the surgeon to reach even deep tumors with far less risk, like the brain swelling that comes with conventional procedures.

“It’s so much simpler and easier on the patient than a conventional procedure,” says Dr. Patwardhan.   It’s also faster, and it appears to be just as effective, if not more so.  Mowad’s surgery came at the end of one week.  She was back at work by the beginning of the next.  (Please note Visualase is effective in ablating tumors. It is not a cure for cancer.) Six months later, there is still no sign of the tumor.  “The number of people who make it out one year with a metastatic brain tumor is very low,” explains Dr. Patwardhan.  “She’s actually functioning and working, which is incredible.”

“It’s because of a lot of what I’ve been through, you know, I want other people not to be afraid of this.”

Since Mowad became the first patient in North America to undergo the procedure, several others have followed.  For now, Dr. Patwardhan says they’re reserving the laser treatment for brain tumors as a last resort, as long as patients’ conditions meet certain criteria.  “It’s restricted for tumors where you can go into them, which are tumors that are not extraordinarily hard, but there are quite a few tumors that are amenable to this treatment, so that’s nice.”

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