The use of medical imaging during spine surgery has increased in recent years. These image guidance systems are used in a wide range of back surgeries, from scoliosis surgery to tumor surgery to degenerative disc surgeries.
Imaging systems help surgeons work more safely. It enables them to place surgical instruments in the spine more precisely. This is especially important during minimally invasive procedures where imaging provides the best view of the spine and surrounding tissues.
However, imaging tools like fluoroscopy (X-ray “movies”) and CT scans both expose patients and health care staff to ionizing radiation. This carries some health risks
, including an increased chance of developing cancer later in life. These risks are higher with larger doses of radiation and also with more frequent imaging scans.
“Repetitive radiation exposure comes with a range of negative consequences that both patients and surgeons want to avoid,” says Dr. Eric Freeman
, medical director and founder Redefine Healthcare, an orthopedic pain and spine center with locations in New Jersey.
Most patients have a lower risk of overexposure to radiation, compared to surgeons and other operating room staff.
“Unless a patient is undergoing procedures on a daily basis, the risk to the patient is minimal,” says Dr. Kaliq Chang, a spine and neck interventional pain management specialist with Atlantic Spine Center in New York and New Jersey. “More concerning is the risk to the surgeons.”
Each time medical imaging is used during surgery, surgeons and other medical staff are exposed to radiation. Over time, this can add up. One study
estimated that spine surgeons can receive their lifetime limit of radiation within the first 10 years of their career.
Chang says there are two ways to reduce patient and surgeon radiation exposure during spinal surgery. “There are ways to reduce the number of shots taken during the procedure, depending on the skill of the radiation technologist or the proceduralist,” says Chang. “There also is the possibility of using low-resolution images when appropriate to reduce the amount of radiation used per shot.”
Over the past decade, a number of image guidance systems have been developed that reduce the amount of radiation that patients are exposed during surgery. The images produced by some of these low-dose systems, though, have not been that clear. This makes it more difficult for surgeons to place instruments in the spine.
To overcome these limitations, scientists have developed ways of using computers to process the medical images to give them better sharpness, clarity, and contrast. This is similar to the technology used to improve the images taken with a camera or even a smartphone. This provides surgeons with a clearer image, but still reduces radiation exposure in the operating room
High-quality images with low-dose radiation
One of these devices is the LessRay platform
developed by San Diego-based NuVasive, Inc. This platform merges low-dose radiation fluoroscopy images with a previous high-quality image to produce an enhanced image with higher quality than the typical low-dose image. The merging is done by a computer and occurs in real time.
The software can also reduce the number of images needed during surgery, which can further decrease the radiation exposure. This lower radiation exposure is backed up by two recent studies.
In one study
, surgeons used the LessRay system while performing minimally-invasive spinal fusion in the lower back (lumbar). While using this platform, surgeons and other medical staff in the room were exposed to 62 percent to 84 percent less radiation during surgery, compared to standard fluoroscopy.
In a later study
, 11 patients underwent lumbar spinal fusion while surgeons used the LessRay system. Another 21 patients underwent the same procedure, but surgeons used standard-dose fluoroscopy. The total doses of radiation emitted by the LessRay platform were 69 percent to 81 percent less than with standard fluoroscopy.
Neither study measured patients’ radiation exposure directly. But less radiation emitted by the imaging device should translate into less exposure for the patient.
The NuVasive platform has other features that can make it easier for surgeons to see the spine and surrounding tissues. This includes an improved ability to stitch together images of different parts of the spine.
Platforms like NuVasive’s LessRay can help reduce radiation exposures in the operating room while ensuring that surgeons have access to high-quality images to aid during surgery. They are likely to continue to play an important role in reducing the health risks of medical imaging during spine surgery.
“It’s no surprise that a technology that can reduce radiation exposure for both patients and surgeons, without sacrificing the integrity of the images, is something all surgeons can appreciate,” says Freeman.
Updated: July 23, 2020