title: Impact of combined (18)F-FDG PET/CT in head and neck tumours.
abstract: To compare the interobserver agreement and degree of confidence in anatomical localisation of lesions using 2-[fluorine-18]fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) and (18)F-FDG PET alone in patients with head and neck tumours. A prospective study of 24 patients (16 male, eight female, median age 59 years) with head and neck tumours was undertaken. (18)F-FDG PET/CT was performed for staging purposes. 2D images were acquired over the head and neck area using a GE Discovery LS PET/CT scanner. (18)F-FDG PET images were interpreted by three independent observers. The observers were asked to localise abnormal (18)F-FDG activity to an anatomical territory and score the degree of confidence in localisation on a scale from 1 to 3 (1=exact region unknown; 2=probable; 3=definite). For all (18)F-FDG-avid lesions, standardised uptake values (SUVs) were also calculated. After 3 weeks, the same exercise was carried out using (18)F-FDG PET/CT images, where CT and fused volume data were made available to observers. The degree of interobserver agreement was measured in both instances. A total of six primary lesions with abnormal (18)F-FDG uptake (SUV range 7.2-22) were identified on (18)F-FDG PET alone and on (18)F-FDG PET/CT. In all, 15 nonprimary tumour sites were identified with (18)F-FDG PET only (SUV range 4.5-11.7), while 17 were identified on (18)F-FDG PET/CT. Using (18)F-FDG PET only, correct localisation was documented in three of six primary lesions, while (18)F-FDG PET/CT correctly identified all primary sites. In nonprimary tumour sites, (18)F-FDG PET/CT improved the degree of confidence in anatomical localisation by 51%. Interobserver agreement in assigning primary and nonprimary lesions to anatomical territories was moderate using (18)F-FDG PET alone (kappa coefficients of 0.45 and 0.54, respectively), but almost perfect with (18)F-FDG PET/CT (kappa coefficients of 0.90 and 0.93, respectively). We conclude that (18)F-FDG PET/CT significantly increases interobserver agreement and confidence in disease localisation of (18)F-FDG-avid lesions in patients with head and neck cancers.
authors.affiliation: Institute of Nuclear Medicine, Middlesex Hospital, Mortimer Street, London W1N 3AA, UK.
authors.forename: R
authors.initials: R
authors.lastname: Syed
authors.forename: J B
authors.initials: JB
authors.lastname: Bomanji
authors.forename: N
authors.initials: N
authors.lastname: Nagabhushan
authors.forename: S
authors.initials: S
authors.lastname: Hughes
authors.forename: I
authors.initials: I
authors.lastname: Kayani
authors.forename: A
authors.initials: A
authors.lastname: Groves
authors.forename: S
authors.initials: S
authors.lastname: Gacinovic
authors.forename: N
authors.initials: N
authors.lastname: Hydes
authors.forename: D
authors.initials: D
authors.lastname: Visvikis
authors.forename: C
authors.initials: C
authors.lastname: Copland
authors.forename: P J
authors.initials: PJ
authors.lastname: Ell
mesh_terms: D000328:Adult; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18