A pilot study evaluating pulmonary nodule marking methods

Assessing the precision in the estimation of lesion dimensions is a prerequisite for the determination of growth rates and response to therapy both in clinical practice and research. An initial study was designed and performed to evaluate three different marking methods: uni-dimensional (maximum diameter of nodule in-axial plane), manual volumetric and a computer assisted mark-up (CAM) method. The CAM method has a good level of agreement with the manual method. Additionally, the CAM method is more repeatable than both the manual volumetric and uni-dimensional measures (CAM 95% Limits of Agreement (LoA):[-15.8, 21.2], manual 95% LoA [-23.4, 31.8], uni-dimensional 95% LoA [-43.8, 80.2]) so this study supports the expectation that more reproducible measurements can be made by using a computer assisted method compared to standard manual methods.