The Journal of Laryngology & Otology

Main Article

Real-time computed tomography image update for endoscopic skull base surgery

B A Woodwortha1, A G Chiua1, N A Cohena1, D W Kennedya1, B W O'Malley Jra1 and J N Palmera1 c1

a1 Department of Otorhinolaryngology – Head and Neck Surgery, University of Pennsylvania Health System, Philadelphia, Pennsylvania, USA


Introduction: The development of computer-aided systems for endoscopic sinus surgery has enabled surgical navigation through diseased or surgically altered sinus anatomy with increased confidence. However, conventional computer-aided systems do not provide intra-operative updated computed tomography imaging. We describe the technical aspects of the xCAT™, a new intra-operative mobile volume computed tomography scanner.

Technical report: A patient with a malignant melanoma unwittingly removed at another hospital underwent surgery for removal of the lateral nasal wall and directed biopsies, in an attempt to identify the site of tumour origin. The procedure was performed with the GE InstaTrak 3500 PlusTM computer-aided system, updated with intra-operative computed tomography images. Intra-operative, updated images were integrated successfully into the InstaTrak system, and these images were consistent with the observed endoscopic anatomy.

Conclusion: The xCAT intra-operative mobile volume computed tomography scanner is a technological advancement that can assist the endoscopic sinus surgeon when performing complex rhinological and skull base procedures.

(Accepted May 29 2007)

(Online publication August 16 2007)


c1 Address for correspondence: Dr James N Palmer, Division of Rhinology, Dept of ORL:HNS, 3400 Spruce Street, Philadelphia, PA 19104, USA. Fax: (215) 614 0071 E-mail:


Dr J N Palmer takes responsibility for the integrity of the content of the paper.

Competing interests: Dr D W Kennedy acts as Consultant to Aventis, Novartis, Medtronic-Xomed and Schering Plough, as Speaker to Merck, and serves as Chair of the Xoran Academy, a research organisation funded by Xoran. His non-compensated position involves independent reviewing and awarding of research grants. Dr A G Chiu acts as Consultant to Medtronic and BrainLab, and as a member of the speaker's bureau for Sanofi-Aventis. Dr N A Cohen acts as Consultant to Medtronic. Dr J N Palmer acts as Consultant to Medtronic and General Electric, and as a member of the speaker's bureau for Ortho-McNeil and Sanofi-Aventis.