title: Measurement of head and neck paragangliomas: is volumetric analysis worth the effort? A method comparison study.
abstract: OBJECTIVE
  The aim of this study was to assess the reproducibility of different measurement methods and define the most workable technique for measuring head and neck paragangliomas, to determine the best method for evaluating tumour growth. The evaluation of tumour growth is vital for a 'wait-and-scan' policy, a management strategy that became increasingly important.
  
  
  METHODS
  Method comparison study.
  
  
  METHODS
  Thirty tumours, including carotid body, vagal body, jugulotympanic tumours and conglomerates of multiple tumours, were measured in duplicate, using linear dimensions, manual area tracing and an automated segmentation method.
  
  
  METHODS
  Reproducibility was assessed using the Bland-Altman method.
  
  
  RESULTS
  The smallest detectable difference using the linear dimension method was 11% for carotid body and 27% for vagal body tumours, compared with 17% and 20% for the manual area tracing method. Due to the irregular shape of paragangliomas in the temporal bone and conglomerates, the manual area tracing method showed better results in these tumours (26% and 8% versus 54% and 47%). The linear dimension method was significantly faster (median 4.27 versus 18.46 minutes, P < 0.001). The automatic segmentation method yielded smallest detectable differences between 39% and 75%, and although fast (2.19 ± 1.49 minutes), it failed technically.
  
  
  CONCLUSIONS
  Due to a relatively good reproducibility, fast and easy application, we found the linear dimension method to be the most pragmatic approach for evaluation of growth of carotid and vagal body paragangliomas. For jugulotympanic tumours, the preferred method is manual area tracing. However, volumetric changes of these tumours may be of less clinical importance than changes in relation to surrounding anatomical structures.
authors.affiliation: Department of Otolaryngology, Leiden University Medical Center, Leiden, the Netherlands. b.l.heesterman@lumc.nl.
authors.forename: B L
authors.initials: BL
authors.lastname: Heesterman
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: B M
authors.initials: BM
authors.lastname: Verbist
authors.affiliation: Department of Otolaryngology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: A G L
authors.initials: AG
authors.lastname: van der Mey
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Bayley
authors.affiliation: Department of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: E P M
authors.initials: EP
authors.lastname: Corssmit
authors.affiliation: Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: F J
authors.initials: FJ
authors.lastname: Hes
authors.affiliation: Department of Otolaryngology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Jansen
mesh_terms: D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D010235:Paraganglioma / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D047368:Tumor Burden