title: Impact of Acquisition Method and Region of Interest Placement on Inter-observer Agreement and Measurement of Tumor Response to Targeted Therapy Using Dynamic Contrast-Enhanced Ultrasound.
abstract: This study evaluated the impact of different acquisition methods, user-directed region of interest placement and post-processing steps on the quantification of dynamic contrast-enhanced ultrasound measurements of blood volume in 29 patients with renal cancer, pre- and post-treatment. Specifically, we compared tumor quantification using multiple planes versus a single plane, breathhold versus free breathing and large region of interest versus a region targeting the area of highest vascularity. Performance was evaluated using area under the receiver operating characteristic curves to identify the method that best predicts progression-free survival. The intra-class correlation coefficient was also used to investigate how the same parameters affect inter-observer agreement. Of the different methods used to quantify blood volume in this study, the combination that had the highest level of inter-observer agreement (intra-class correlation coefficient = 0.8-0.97) and was the best predictor of progression-free survival was the change in blood volume measured (area under receiver operating characteristic curve = 0.77, p = 0.04) by a multiplane average, acquired during quiet breathing, quantified using a region of interest that encompassed the entire tumor.
authors.affiliation: Division of Abdominal Imaging, Department of Medical Imaging, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada. Electronic address: Mostafa.atri@uhn.ca.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Atri
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: John M
authors.initials: JM
authors.lastname: Hudson
authors.affiliation: Division of Abdominal Imaging, Department of Medical Imaging, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Sinaei
authors.affiliation: Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: Ross
authors.initials: R
authors.lastname: Williams
authors.affiliation: Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Laurent
authors.initials: L
authors.lastname: Milot
authors.affiliation: Division of Abdominal Imaging, Department of Medical Imaging, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
authors.forename: Hadas
authors.initials: H
authors.lastname: Moshonov
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Burns
authors.affiliation: Medical Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario, Canada.
authors.forename: Georg A
authors.initials: GA
authors.lastname: Bjarnason
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D003287:Contrast Media; D018572:Disease-Free Survival; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007211:Indoles / Q000627:therapeutic use; D007680:Kidney Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy / Q000379:methods; D009389:Neovascularization, Pathologic / Q000150:complications / Q000000981:diagnostic imaging* / Q000517:prevention & control; D015588:Observer Variation; D056888:Patient Positioning; D011758:Pyrroles / Q000627:therapeutic use; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077210:Sunitinib; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
chemical_list: D020533:Angiogenesis Inhibitors; D003287:Contrast Media; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib
keywords: Inter-observer agreement; Treatment evaluation; Tumor blood flow; Ultrasound contrast