Imageology evaluation for therapeutic effect of targeted therapy to gastrointestinal stromal tumor        ZHANG Xiao-peng, TANG Lei. Department of Medical Imaging, Peking University School of Oncolgy, Beijing 100142, China
Corresponding author: ZHANG Xiao-peng, E-mail: zxp@bjcancer.org
Abstract    Imageology is the primary method to evaluate the therapeutic effect of targeted therapy to gastrointestinal stromal tumor (GIST). CT and MRI can conveniently and objectively reflect the post-therapy alterations of GIST, which are the most prevailing modalities in clinical practices. The responder lesions of GIST post therapy mainly display hemorrhage, necrosis, cystic degeneration and mucinous degeneration at early stage, usually accompanied by insignificantly volume reduction, even enlarged lesions, which restrict the application of RECIST morphological criteria. It recently proposed Choi criteria which included CT value, and EORTC/ISG/AGITG criteria which based on large sample follow-up patients in Europe, has renewed radiology evaluating conceptions of GIST. PET and diffusion-weighted magnetic resonance imaging (DW-MRI) can detect the therapeutic response at earlier stage. The quantificated apparent values significantly decreased post one week of initial therapies, which can be potential modalities in the evaluation and prediction of GIST therapeutic effect.