title: Quantitative multiparametric MRI in uveal melanoma: increased tumor permeability may predict monosomy 3.
abstract: BACKGROUND
  Uveal melanoma is a rare intraocular tumor with heterogeneous biological behavior, and additional noninvasive markers that may predict outcome are needed. Diffusion- and perfusion-weighted imaging may prove useful but have previously been limited in their ability to evaluate ocular tumors. Our purpose was to show the feasibility and potential value of a multiparametric (mp-) MRI protocol employing state of the art diffusion- and perfusion-weighted imaging techniques.
  
  
  METHODS
  Sixteen patients with uveal melanoma were imaged with mp-MRI. Multishot readout-segmented echoplanar diffusion-weighted imaging, quantitative dynamic contrast-enhanced (DCE) MR perfusion imaging, and anatomic sequences were obtained. Regions of interest (ROIs) were drawn around tumors for calculation of apparent diffusion coefficient (ADC) and perfusion metrics (K (trans) , v e , k ep , and v p ). A generalized linear fit model was used to compare various MRI values with the American Joint Commission on Cancer (AJCC) tumor group and monosomy 3 status with significance set at P < 0.05.
  
  
  RESULTS
  mp-MRI was performed successfully in all cases. MRI tumor height (mean [standard deviation]) was 6.5 mm (3.0). ROI volume was 278 mm(3) (222). ADC was 1.07 (0.27) × 10-3 mm(2)/s. DCE metrics were K (trans) 0.085/min (0.063), v e 0.060 (0.052), k ep 1.20/min (0.32), and v p 1.48 % (0.82). Patients with >33 % monosomy 3 had higher K (trans) and higher v e values than those with disomy 3 or ≤33 % monosomy (P < 0.01). There were no significant differences between ADC (P = 0.07), k ep (P = 0.37), and v p with respect to monosomy 3.
  
  
  CONCLUSIONS
  mp-MRI for ocular tumor imaging using multishot EPI DWI and quantitative DCE perfusion is technically feasible. mp-MRI may help predict monosomy 3 in uveal melanoma.
authors.affiliation: Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, Ste B265, Los Angeles, CA, 90095, USA.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Kamrava
authors.forename: Ali R
authors.initials: AR
authors.lastname: Sepahdari
authors.forename: Kevin
authors.initials: K
authors.lastname: Leu
authors.forename: Pin-Chieh
authors.initials: PC
authors.lastname: Wang
authors.forename: Kristofer
authors.initials: K
authors.lastname: Roberts
authors.forename: D Jeffrey
authors.initials: DJ
authors.lastname: Demanes
authors.forename: Tara
authors.initials: T
authors.lastname: McCannel
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Ellingson
mesh_terms: D000328:Adult; D000368:Aged; D000782:Aneuploidy; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008545:Melanoma / Q000235:genetics* / Q000473:pathology*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010539:Permeability; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D014604:Uveal Neoplasms / Q000235:genetics* / Q000473:pathology*; D000098943:Uveal Melanoma