VolCT - Group 1B

Current Goals & Status:

• Question: What is the minimum detectable level of change in patient datasets under a “No Change” condition?
  • AIMS: For patient datasets acquired over a very short time interval (“no change” condition”) investigate variance in measuring change in volume, diameter and bi-directional diameters of lesions
  • Investigate inter-observer variability in each task
  • Investigate Intra-observer variability in each task

• • Methods - Materials
    • Image Data from MSK Coffee Break Experiment
    • 32 NSCLC patients, imaged twice on same scanner over period < 15 minutes
    • Thin slice (1.25 mm thick) image data
    • Selected one lesion per patient
    • no outcome data
    • Publicly Available on NCIA

• • Methods - Readings
    • 5 readers
    • Read CT at timepoint 1, CT at timepoint 2 and repeat either CT timepoint 1 or timeoint 2 to assess intra-reader variability
  • Methods - Measurements
    • Measure Single Longest Diameter, manually (SLD)
    • Measure Longest Diameter and Perpendicular Diameter; take product to obtain Product of Diameters (POD)
    • Contour Full Boundary of lesion with semiautomated tool; calculate volume (Vol)
    • Extract other measures as well (SLD from POD measureement; SLD from VOl and POD from Vol).
  • The Order of Readers, Lesions and Measurement Methods were Randomized (Measurements done in Blocks of 10)

• • Analyses
    • Pooled Analysis across readers and lesions; Percent Difference between Scan 1 and Scan 2 for each measurement method
    • Subgroup Analyses: (a) Based on Measureable/Non-Measureable lesions identified by Mike O'Neal of CoreLabs; (b) Difficult, Moderate and Easy as Identified by Mike McNitt-Gray

• Related Profile: Lung Vol Quantification - Measurement Activity

• Vol-CT - 1B Group Call Summaries

• QIBA CT Volumetrics,Group 1B:(Patient Image Datasets), 4.19.2011 - Dr. McNitt-Gray

• Proposed Group 1B Questions & Datases (2009-02-10) -- Feedback Welcome -- Dr. McNitt-Gray
• ACRIN 6678 Quality Control Parameters for CT Scan Tumor Volumetric Measurements

• Conference Paper on Reproducibility and Accuracy of Uni- and Bi-Dimensional Tumor Measurements from MRI and CT Volumes, which looks at RECIST, WHO and Volume measurements.

• Naming Convention for the QIBA Group 1B Experiment

• Exp 1B Coffee Break Descriptive Statistics - Oct 4, 2010