Fig. 7
From: Imaging biomarkers for evaluating tumor response: RECIST and beyond
Application of Choi criteria in the gastrointestinal stromal tumor (GIST) after targeted therapy with imatinib. A 49-year-old man was diagnosed with GIST. A Pretreatment CE axial CT scan shows an 88-mm-sized enhancing tumor (arrow) arising from the stomach. The measured CT number on the region of interest (ROI) is 36.1 Hounsfield units (HU). B After targeted therapy with imatinib, posttreatment CE CT scan shows no significantly decreased in tumor size (87 mm in diameter) (arrow) but markedly decreased attenuation (22.6 HU, 37 % reduction), suggesting tumor response according to Choi criteria