Intraoperative Volume CT Demonstrates Appeal, but Questions Remain

ORLANDO – Intraoperative volume CT is showing promise as a tool to help with complex endoscopic sinonasal and skull base procedures. However, it is not needed in every case, and researchers are trying to define just when it is most appropriate to use.

Using it judiciously is the key at this point in time, according to Pete Batra, MD, a rhinologist and Section Head of Nasal and Sinus Disorders at the Cleveland Clinic. As of yet, there are no guidelines for its use, and few centers have the device on hand.

We really have to carefully weigh the risks and the benefits of this technology, and we need to accrue additional data to refine the indications, Dr. Batra told ENT Today in an interview.

CT scans are done on patients with complex disease prior to surgery to use as a map during image-guided surgery (IGS). But what happens is, as you use image guidance and you go through a long case, you’re manipulating the anatomy. By doing that, the image guidance becomes less accurate as time goes on, Dr. Batra said. That is why the idea of something such as intraoperative volume CT scanning is appealing, especially in cases where there is uncertainty as to whether the surgical goal has been met, or uncertainty because of altered anatomy.

At the recent annual Combined Otolaryngology Spring Meeting, Dr. Batra described findings from a study using intraoperative volume CT in patients who underwent endoscopic sinonasal and skull base procedures.

Intraoperative Volume CT Study

The study was a retrospective chart review of patients with complex disease and who underwent intraoperative volume CT. The study included a total of 25 patients who were treated at the Cleveland Clinic Head and Neck Institute between May and July 2007. The scanning was done with the portable xCAT (Xoran Technologies) in the operating room.

Patients ranged in age from 20 to 80 years (mean, 56.8 years), and 16 were male. A total of 12 (48%) patients had chronic rhinosinusitis, either with or without polyposis; 6 (24%) had mucoceles; 5 (20%) had neoplasms; one patient (4%) was treated for meningoencephalocele; and one had sphenoid fibrous dysplasia.

In 76% of the patients, volume CT scanning was performed during surgery to help the surgeon view altered anatomy after paranasal sinus dissection. In 24% it was done to confirm complete tumor removal, and in 24% to verify the accuracy of a frontal stent position.