Intraoperative Volume CT Demonstrates Appeal, but Questions Remain

Use of the CT scan led to further surgical intervention in 24% of the patients, which is significant, Dr. Batra said. Two patients underwent additional ethmoid surgery, two patients had additional tumor removal, one had additional bone removal during frontal sinus surgery, and in one case a frontal stent was repositioned more optimally.

If, in a quarter of your patients, you are improving outcome, it seems to suggest this could be a very important technology, he said. However, further study with larger numbers of patients need to be done to confirm its utility and help better define which patients to use it on. At his own institution, Dr. Batra said plans are under way to do prospective studies to further investigate use of the technology.

Pros and Cons of Intraoperative Volume CT

Pros and cons must be carefully weighed when considering use of this technology.

On the pro side, intraoperative volume CT can help with navigation after anatomy has been altered during surgery, and help surgeons confirm that they have reached their surgical objective. On the downside, the technology is costly, and there are risks associated with exposing patients to additional radiation.

Doing a scan during surgery does not take much time. In fact, the entire process takes no more than five to 10 minutes, Dr. Batra said. The actual scan acquisition takes about 40 seconds, so overall it causes very little disruption in the procedure.

When the scan is being performed, only essential personnel should be present in the operating room, and they are shielded behind the machine, he said. All nonessential personnel should be asked to leave the OR at the time of the scan acquisition.

As for patient safety, the amount of radiation use is only about a tenth of what is used prior to surgery in standard image-guided CT, he said. The device used for this study is relatively small and can be stored in the operating suite. The dimensions are 32 inches by 47 inches by 60 inches.

Use of other intraoperative scanning devices for otolaryngologic procedures has been reported in the literature, Dr. Batra said. One is fluoroscopic CT. The main reported limitations of that technology are that it involves a larger piece of equipment, and a radiology technician is needed to operate the C-arm.

Some studies have reported the use of intraoperative MRI. An advantage of this technique is that does not expose patients to further radiation, but the device creates distortion in many types of nearby video monitors, he said.