title: Tumor volume measurement error using computed tomography imaging in a phase II clinical trial in lung cancer.
abstract: To address the error introduced by computed tomography (CT) scanners when assessing volume and unidimensional measurement of solid tumors, we scanned a precision manufactured pocket phantom simultaneously with patients enrolled in a lung cancer clinical trial. Dedicated software quantified bias and random error in the [Formula: see text], and [Formula: see text] dimensions of a Teflon sphere and also quantified response evaluation criteria in solid tumors and volume measurements using both constant and adaptive thresholding. We found that underestimation bias was essentially the same for [Formula: see text], and [Formula: see text] dimensions using constant thresholding and had similar values for adaptive thresholding. The random error of these length measurements as measured by the standard deviation and coefficient of variation was 0.10 mm (0.65), 0.11 mm (0.71), and 0.59 mm (3.75) for constant thresholding and 0.08 mm (0.51), 0.09 mm (0.56), and 0.58 mm (3.68) for adaptive thresholding, respectively. For random error, however, [Formula: see text] lengths had at least a fivefold higher standard deviation and coefficient of variation than [Formula: see text] and [Formula: see text]. Observed [Formula: see text]-dimension error was especially high for some 8 and 16 slice CT models. Error in CT image formation, in particular, for models with low numbers of detector rows, may be large enough to be misinterpreted as representing either treatment response or disease progression.
authors.affiliation: Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, New York 10029, United States; Early Diagnosis and Treatment Research Foundation, PO Box 1609, New York, New York 10021-0044, United States.
authors.forename: Claudia I
authors.initials: CI
authors.lastname: Henschke
authors.affiliation: Icahn School of Medicine at Mount Sinai , One Gustave Levy Place, Box 1234, New York, New York 10029, United States.
authors.forename: David F
authors.initials: DF
authors.lastname: Yankelevitz
authors.affiliation: Icahn School of Medicine at Mount Sinai , One Gustave Levy Place, Box 1234, New York, New York 10029, United States.
authors.forename: Rowena
authors.initials: R
authors.lastname: Yip
authors.affiliation: Roche Products Limited (Pharmaceuticals) , Hexagon Place, 6 Falcon Way, Shire Park, Welwyn Garden City AL7 1TW, United Kingdom.
authors.forename: Venice
authors.initials: V
authors.lastname: Archer
authors.affiliation: F.Hoffmann-La Roche , Grenzacherstrasse 124, Basel 4070, Switzerland.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Zahlmann
authors.affiliation: Kitware Inc. , 28 Corporate Drive, Clifton Park, New York 12065, United States.
authors.forename: Karthik
authors.initials: K
authors.lastname: Krishnan
authors.affiliation: Kitware Inc. , 28 Corporate Drive, Clifton Park, New York 12065, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Helba
authors.affiliation: Accumetra LLC , 7 Corporate Drive, Clifton Park, New York 12065, United States.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Avila
keywords: calibration; computed tomography; measurement error; response evaluation criteria in solid tumors; volumetry