75 yr. old female, diagnosed with Parotid Adenocarcinoma metastasis to the lung. Figure A demonstrates the longest diameters of three lung nodules (one per row) at four time points (one per column), consistent with known history of metastatic disease. These TRAC (Tumor Response Assessment by Criteria) measurements are performed by technologists in the Stanford Radiology 3D and Quantitative Imaging Lab using sophisticated software. The TRAC Report graph shown in Figure B demonstrates the measurements made as a function of time.  The oncologist utilizes this report as an empirical measure to evaluate therapy success according to the response criteria in use.