Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implants are specialized screws used to treat spinal tumors while improving cancer tracking. Carbon fiber is radiolucent, which means it doesn't create as much artifact in imaging as traditional spinal instrumentation. Carbon fiber implants are comparable to titanium implants in terms of stability and functional recovery.

Benefits of carbon fiber implants

• Improved radiation accuracy: If a tumor can’t be completely removed during surgery, the surgeon can place carbon fiber screws around the remaining tumor. When radiation therapy is given after the surgery, the beams can reach the tumor more accurately because of these implants. Carbon fiber also causes less deflection of the radiation beam than titanium.

• Clearer imaging: Doctors can evaluate the area of the tumor more easily with carbon fiber implants because they create fewer artifacts on an MRI scan than titanium. These artifacts, or shadows, make it harder to see the area where the tumor was taken from. These shadows can delay detection of regrowing tumors. With carbon fiber implants, doctors can see the area better during a scan, so they can catch tumor recurrences earlier.

“When we look at an MRI, we see the tissues very clearly if we’ve used carbon fiber implants,” explains neurosurgeon Miki Katzir, MD. “If we use titanium, we’ll see shadows or black discoloration of the picture because the titanium screw is a metal instrument. The MRI, which is a magnet, tries to go through those metal screws, and the radiation beams get scattered. This creates a big black hole around the screws, where you can't really see anything.”

Challenges of carbon fiber implants

Carbon fiber is more difficult to handle than the titanium implants that most surgeons are used to. If a hospital has carbon fiber implants and the surgeon has experience with that material, it has a lot of benefit for patients with spinal cancer. Studies have shown that after surgery there is no disadvantage of using carbon fiber compared to titanium.

“For surgeons, using carbon fiber versus titanium is like driving an automatic car versus a manual shift,” explains Dr. Katzir. “Both are good, but you must be comfortable with using this type of instrumentation. Carbon fiber feels different in your hand than titanium. If you're not used to it, carbon fiber can break if you mishandle it in surgery.”

What patients should know

For patients, the difference in the material isn’t noticeable. However, those with a carbon fiber implant may benefit from earlier detection of tumor recurrence and reduced side effects from the radiation. For example, if you're radiating very close to a vital organ and the radiation beam gets deflected because of the titanium screws, it can injure healthy tissues as well. 

“I found that there's approximately 30 percent more accuracy in radiation therapy with carbon fiber implants compared to titanium, which is quite a lot,” says Dr. Katzir. “This means that with a hundred percent of radiation beams, maybe 70 percent reaches the tumor.”

Cutting-edge robotic surgery

Dr. Katzir is the only surgeon in the state performing spinal cancer surgeries using the new Mazor X robot to place the carbon fiber screws. The robot helps the surgeon place the screws with sub-millimeter accuracy. 

“We create a plan for placing the implants and the robot guides me there and provides accurate positioning,” says Dr. Katzir. “This technology ensures that screws aren’t being placed where you can injure a blood vessel or a nerve, which is very important.”