title: Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe.
abstract: OBJECTIVE
  In cervical radiotherapy, it is essential that the uterine position is correctly determined prior to treatment delivery. The aim of this study was to evaluate an autoscan ultrasound (A-US) probe, a motorized transducer creating three-dimensional (3D) images by sweeping, by comparing it with a conventional ultrasound (C-US) probe, where manual scanning is required to acquire 3D images.
  
  
  METHODS
  Nine healthy volunteers were scanned by seven operators, using the Clarity(®) system (Elekta, Stockholm, Sweden). In total, 72 scans, 36 scans from the C-US and 36 scans from the A-US probes, were acquired. Two observers delineated the uterine structure, using the software-assisted segmentation in the Clarity workstation. The data of uterine volume, uterine centre of mass (COM) and maximum uterine lengths, in three orthogonal directions, were analyzed.
  
  
  RESULTS
  In 53% of the C-US scans, the whole uterus was captured, compared with 89% using the A-US. F-test on 36 scans demonstrated statistically significant differences in interobserver COM standard deviation (SD) when comparing the C-US with the A-US probe for the inferior-superior (p < 0.006), left-right (p < 0.012) and anteroposterior directions (p < 0.001). The median of the interobserver COM distance (Euclidean distance for 36 scans) was reduced from 8.5 (C-US) to 6.0 mm (A-US). An F-test on the 36 scans showed strong significant differences (p < 0.001) in the SD of the Euclidean interobserver distance when comparing the C-US with the A-US scans. The average Dice coefficient when comparing the two observers was 0.67 (C-US) and 0.75 (A-US). The predictive interval demonstrated better interobserver delineation concordance using the A-US probe.
  
  
  CONCLUSIONS
  The A-US probe imaging might be a better choice of image-guided radiotherapy system for correcting for daily uterine positional changes in cervical radiotherapy.
  
  
  CONCLUSIONS
  Using a novel A-US probe might reduce the uncertainty in interoperator variability during ultrasound scanning.
authors.affiliation: 1 Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.|2 Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark.|3 Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark.
authors.forename: Mariwan
authors.initials: M
authors.lastname: Baker
authors.affiliation: 4 Elekta Ltd., Montréal, QC, Canada.
authors.forename: David T
authors.initials: DT
authors.lastname: Cooper
authors.affiliation: 1 Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Claus F
authors.initials: CF
authors.lastname: Behrens
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D061089:Radiotherapy, Image-Guided; D012984:Software; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D014599:Uterus / Q000000981:diagnostic imaging*