Rowena Yip MPH, Presenter: Nothing to Disclose

David F. Yankelevitz MD, Abstract Co-Author: Research Grant, AstraZeneca PLC Royalties, General Electric Company

Claudia I. Henschke MD, PhD, Abstract Co-Author: Nothing to Disclose

To determine the frequency of lung cancers with growth observed only in the short-axis dimension (width) and to examine their cell-type and nodule consistency distribution.

We reviewed 364 diagnosed cases of lung cancer in which the cancer was recommended for biopsy after demonstration of growth on low-dose screening CT scans. Lung nodule diameter was calculated using the maximum length and width measured on the same CT image just before diagnosis (LTime2, WTime2) and when it was first identified (LTime1, WTime1). Percentage change in both length and width was computed using the measurement at time 1 and 2: ∆L = (LTime2 -LTime1) / LTime1 x100%, ∆W = (WTime2 -WTime1) / WTime1 x100% Among these 364 cases, we determined how many had less than 10% growth in length (∆L < 10% ) while there was more than a 10% increase in width (∆W ≥ 10%). Cell-type and nodule consistency were also recorded.  

Among the 364 lung cancers, 40 (11%) only demonstrated an increase in the width. The cell-type of these 40 was: 29 (73%) adenocarcinoma, 5 (13%) squamous cell, 2 (5%) small cell and 4 (10%) other cell-types. Among the 40 cancers, 6(15%) manifested as a nonsolid nodule, 7 (18%) part-solid and 27 (68%) solid.

Average diameter (a bi-dimensional measurement) is useful in measuring nodule growth as it better reflects the actual volume growth of the nodule and is also an average of two measures rather than the single one-dimensional measure, length.

Use of average diameter, a bi-dimensional measure, as opposed to a uni-dimensional measure of length allows for growth to be ascertained when it is asymmetric and not increasing in length. Lung cancers do not grow uniformly and growth may manifest only as a change in width. The use of bi-dimensional measure can capture such asymmetric growth.  

Yip, R, Yankelevitz, D, Henschke, C, Lung Cancers Showing Growth in Only the Short-axis Dimension (width): The Advantage of using the Average Diameter.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045701.html