title: A Bland-Altman analysis of the bias between computed tomography and ultrasound prostate volume measurements.
abstract: This study assesses the agreement between computed tomography (CT) measurements of prostate volume and those obtained by ultrasound (US), a well-established non-invasive technique. Twenty-six patients aged between 58 and 74 years were evaluated for prostate seed implant therapy using both CT and US measurements. The level of agreement between these 2 methods, which were strongly correlated (R2 = 0.828; p < 0.0001), was determined through Bland-Altman analysis. The mean prostate volume (+/- one standard deviation) of the sample was 31.8 +/- 10.5 cc for the CT method and 27.0 +/- 8.2 cc for the US method. The prostate volumes obtained by CT were, on average, 17% larger than the corresponding volumes determined by US. The average bias between the 2 imaging methods is 4.80 cc or 15%, which is significantly larger than the clinically acceptable margin of 10%.
authors.affiliation: Department of Radiation Oncology, St. Vincent Hospital, Green Bay, WI 54301, USA. agloi@stvgb.org
authors.forename: Aime
authors.initials: A
authors.lastname: Gloi
authors.forename: Stephen
authors.initials: S
authors.lastname: McCourt
authors.forename: Corrie
authors.initials: C
authors.lastname: Zuge
authors.forename: AnnDrea
authors.initials: A
authors.lastname: Goettler
authors.forename: Sally
authors.initials: S
authors.lastname: Schlise
authors.forename: Greg
authors.initials: G
authors.lastname: Cooley
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000368:Aged; D016477:Artifacts; D001918:Brachytherapy / Q000379:methods; D003287:Contrast Media; D003627:Data Interpretation, Statistical; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011467:Prostate / Q000000981:diagnostic imaging; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D012107:Research Design; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography / Q000379:methods
chemical_list: D003287:Contrast Media; D007457:Iodine Radioisotopes