Fig. 1

Example of evaluating percentile change in tumor size and density. Pre-treatment and post-treatment CT scans showing shrinkage of hepatic metastases from a pancreatic neuroendocrine tumor in one’s fifties, the percentile change of tumor size was (8.0–11.9)/11.9 × 100% = −33% (a). In another lesion in the same patient, the hepatic metastases appeared more heterogeneous, with high vascularization prior to treatment. Sunitinib induced a large area of tumor hypodensity, suggesting tumor necrosis, the percentile change of tumor attenuation was (108–121)/121 × 100% = −11% (b). In patients with more than one target lesion, the sum of the longest diameters/density of each target lesion in each patient was computed