HEAD AND NECK
Improved detection rates and treatment planning of head and neck
cancer using dual-layer spectral CT
Fabian K. Lohöfer
Georgios A. Kaissis
Frances L. Köster
Peter B. Noel
Ernst J. Rummeny
Rickmer F. Braren
Received: 21 February 2018 /Revised: 17 April 2018 /Accepted: 20 April 2018
European Society of Radiology 2018
Purpose The aim of this study was to evaluate the advantages of dual-layer spectral CT (DLSCT) in detection and staging of head
and neck cancer (HNC) as well as the imaging of tumour margins and infiltration depth compared to conventional contrast
enhanced CT (CECT).
Materials and methods Thirty-nine patients with a proven diagnosis of HNC were examined with a DLSCT scanner and
retrospectively analysed. An age-matched healthy control group of the same size was used. Images were acquired in the venous
phase. Virtual monoenergetic 40keV-equivalent (MonoE40) images were compared to CECT-images. Diagnostic confidence for
tumour identification and margin detection was rated independently by four experienced observers. The steepness of the
Hounsfield unit (HU)-increase at the tumour margin was analysed. External carotid artery branch image reconstructions were
performed and their contrast compared to conventional arterial phase imaging. Means were compared using a Student’st-test.
ANOVA was used for multiple comparisons.
Results MonoE40 images were superior to CECT-images in tumour detection and margin delineation. MonoE40 showed signif-
icantly higher attenuation differences between tumour and healthy tissue compared to CECT-images (p < 0.001). The HU-increase
at the boundary of the tumour was significantly steeper in MonoE40 images compared to CECT-images (p < 0.001). Iodine uptake
in the tumour was significantly higher compared to healthy tissue (p <0.001).MonoE40 compared to conventional images allowed
visualisation of external carotid artery branches from the venous phase in a higher number of cases (87% vs. 67%).
Conclusion DLSCT enables improved detection of primary and recurrent head and neck cancer and quantification of tumour
iodine uptake. Improved contrast of MonoE40 compared to conventional reconstructions enables higher diagnostic confidence
concerning tumour margin detection and vessel identification.
• Sensitivity concerning tumour detection are higher using dual-layer spectral-CT than conventional CT.
• Lesion to background contrast in DLSCT is significantly higher than in CECT.
• DLSCT provides sufficient contrast for evaluation of external carotid artery branches.
Keywords Tomography , spiral computed
Head and neck neoplasms
Carotid artery , external
Fabian K. Lohöfer and Georgios A. Kaissis contributed equally to this
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s00330-018-5511-2) contains supplementary
material, which is available to authorized users.
* Rickmer F. Braren
Institute for diagnostic and interventional Radiology, Klinikum rechts
der Isar der Technischen Universität München, Ismaninger Straße 22,
D-81675 München, Germany
Department of Oral and Maxillofacial Surgery, Klinikum rechts der
Isar der Technischen Universität München, Ismaninger Straße 22,
D-81675 München, Germany
Department of Oral and Maxillofacial Surgery, Charité
Universitätsmedizin Berlin, Augustenburger Platz 1,
D-13353 Berlin, Germany