Peter Bannas, Presenter: Nothing to Disclose

Christian R. Habermann MD, Abstract Co-Author: Nothing to Disclose

Caroline Jung, Abstract Co-Author: Nothing to Disclose

Harald Ittrich MD, Abstract Co-Author: Nothing to Disclose

Gerhard B. Adam MD, Abstract Co-Author: Nothing to Disclose

Andreas Koops MD, Abstract Co-Author: Nothing to Disclose

Due to artifacts of dental implants, staging of oral and oropharyngeal cancer by CT currently consists of primary axial and secondary tilted scans. Unfortunately, the complementary tilted scan cannot be applied with new and powerful, but untiltable MDCT scanners. Hence, we compared the relevance of axial and secondary tilted scans of head and neck CT in tumor staging.

Scans of a tiltable 64-row MDCT scanner of 53 patients with histologically proven oral or oropharyngeal cancer were evaluated. The number of artifact afflicted slices on axial scans due to dental implants was analyzed quantitatively and qualitatively on a 3-point-scale. Three blinded readers independently evaluated primary axial and secondary tilted scans and determined TN-stage. Results were compared to the histological reference.

Artifacts hampered image quality of the oral cavity in 39% and of the oropharynx in 37% of image slices, rendering 24% respectively 5% non-diagnostic. 39 of 53 tumors (74%) were detected on primary axial CT scans. Inspection of secondary tilted scans led to the detection of one more tumor (2%) and to an upstaging of tumors in seven patients (13%). N-stage was not altered by secondary tilted scans.

Tilted scans altered T-stage in 15% of our study population. This confirms the indispensability of secondary tilted scans for correct CT staging of oral and oropharyngeal cancer.

Artifact reducing sequences or relocation of the patient’s head for secondary images are needed when using new, but untiltable MDCT scanners for staging of oral and oropharyngeal cancer.

Bannas, P, Habermann, C, Jung, C, Ittrich, H, Adam, G, Koops, A, Diagnostic Accuracy of Untiltable MDCT Scanners in Patients with Oral and Oropharyngeal Cancer.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9011322.html