title: Semi-automatic cone beam CT segmentation of in vivo pre-clinical subcutaneous tumours provides an efficient non-invasive alternative for tumour volume measurements.
abstract: OBJECTIVE
  To evaluate the feasibility and accuracy of using cone beam CT (CBCT) scans obtained in radiation studies using the small-animal radiation research platform to perform semi-automatic tumour segmentation of pre-clinical tumour volumes.
  
  
  METHODS
  Volume measurements were evaluated for different anatomical tumour sites, the flank, thigh and dorsum of the hind foot, for a variety of tumour cell lines. The estimated tumour volumes from CBCT and manual calliper measurements using different volume equations were compared with the "gold standard", measured by weighing the tumours following euthanasia and tumour resection. The correlation between tumour volumes estimated with the different methods, compared with the gold standard, was estimated by the Spearman's rank correlation coefficient, root-mean-square deviation and the coefficient of determination.
  
  
  RESULTS
  The semi-automatic CBCT volume segmentation performed favourably compared with manual calliper measures for flank tumours ≤2 cm(3) and thigh tumours ≤1 cm(3). For tumours >2 cm(3) or foot tumours, the CBCT method was not able to accurately segment the tumour volumes and manual calliper measures were superior.
  
  
  CONCLUSIONS
  We demonstrated that tumour volumes of flank and thigh tumours, obtained as a part of radiation studies using image-guided small-animal irradiators, can be estimated more efficiently and accurately using semi-automatic segmentation from CBCT scans.
  
  
  CONCLUSIONS
  This is the first study evaluating tumour volume assessment of pre-clinical subcutaneous tumours in different anatomical sites using on-board CBCT imaging. We also compared the accuracy of the CBCT method to manual calliper measures, using various volume calculation equations.
authors.affiliation: 1 Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: N P
authors.initials: NP
authors.lastname: Brodin
authors.forename: J
authors.initials: J
authors.lastname: Tang
authors.forename: K
authors.initials: K
authors.lastname: Skalina
authors.forename: T J
authors.initials: TJ
authors.lastname: Quinn
authors.forename: I
authors.initials: I
authors.lastname: Basu
authors.forename: C
authors.initials: C
authors.lastname: Guha
authors.forename: W A
authors.initials: WA
authors.lastname: Tomé
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D054893:Cone-Beam Computed Tomography; D004195:Disease Models, Animal; D005240:Feasibility Studies; D051379:Mice; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D011857:Radiographic Image Interpretation, Computer-Assisted; D047368:Tumor Burden
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