title: Assessment of fully-automated atlas-based segmentation of novel oral mucosal surface organ-at-risk.
abstract: Current oral mucositis normal tissue complication probability models, based on the dose distribution to the oral cavity volume, have suboptimal predictive power. Improving the delineation of the oral mucosa is likely to improve these models, but is resource intensive. We developed and evaluated fully-automated atlas-based segmentation (ABS) of a novel delineation technique for the oral mucosal surfaces.
  
  
  
  An atlas of mucosal surface contours (MSC) consisting of 46 patients was developed. It was applied to an independent test cohort of 10 patients for whom manual segmentation of MSC structures, by three different clinicians, and conventional outlining of oral cavity contours (OCC), by an additional clinician, were also performed. Geometric comparisons were made using the dice similarity coefficient (DSC), validation index (VI) and Hausdorff distance (HD). Dosimetric comparisons were carried out using dose-volume histograms.
  
  
  
  The median difference, in the DSC and HD, between automated-manual comparisons and manual-manual comparisons were small and non-significant (-0.024; p=0.33 and -0.5; p=0.88, respectively). The median VI was 0.086. The maximum normalised volume difference between automated and manual MSC structures across all of the dose levels, averaged over the test cohort, was 8%. This difference reached approximately 28% when comparing automated MSC and OCC structures.
  
  
  
  Fully-automated ABS of MSC is suitable for use in radiotherapy dose-response modelling.
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK. Electronic address: jamie.dean@icr.ac.uk.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Dean
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Liam C
authors.initials: LC
authors.lastname: Welsh
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Dualta
authors.initials: D
authors.lastname: McQuaid
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Kee H
authors.initials: KH
authors.lastname: Wong
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Aleksic
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Dunne
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Islam
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Anushka
authors.initials: A
authors.lastname: Patel
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Patel
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Imran
authors.initials: I
authors.lastname: Petkar
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Iain
authors.initials: I
authors.lastname: Phillips
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Jackie
authors.initials: J
authors.lastname: Sham
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.
authors.forename: Kate L
authors.initials: KL
authors.lastname: Newbold
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.
authors.forename: Shreerang A
authors.initials: SA
authors.lastname: Bhide
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Harrington
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Gulliford
authors.affiliation: The Royal Marsden NHS Foundation Trust, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Nutting
mesh_terms: D001271:Atlases as Topic; D004307:Dose-Response Relationship, Radiation; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D009061:Mouth Mucosa / Q000528:radiation effects*; D058958:Organs at Risk; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage
keywords: Atlas-based segmentation; Contouring; Delineation; OAR; Oral cavity; Oral mucosa