Radiological Evaluation of the Response of Abdominal Tumors to Targeted Therapy: Current Status and Prospect

Targeted therapy is an important component of the individualized precision medical treatment for abdominal tumors. It is especially effective in the treatment of gastrointestinal stromal tumors, which is regarded as "a model of modern anti-cancer therapy". Radiology is the common method to evaluate the response of abdominal tumors to targeted therapy. The morphological bias is demonstrated in response evaluation criteria in solid tumors (RECIST) because of the diverse change of post-treatment tumor tissue. The problem of enlarged tumor caused by necrosis and cystic degeneration was resolved by combination of Choi, mChoi, size and morphology(SACT), morphology, attenuation, size and structure(MASS), and CT values. The new technologies of positron emission tomography (PET), diffusion-weighted imaging (DWI), dynamic contrast enhanced magneticresonance imaging(DCE-MRI) and monochromatic CT, and a series of functional imaging parameters including standard uptake value (SUV), apparent diffusion coefficient (ADC), K^trans value and iodine concentration, provide potential surrogate for the prediction and early evaluation of tumors to targeted therapy. Texture analysis technique in radiology can further explore the radiological information, to provide rich quantitative parameters for response evaluation. The radiologists should strengthen the communication with clinicians and initiate cooperative research through multi-disciplinary team (MDT) patterns, actively explore new parameters and criteria to further improve the response prediction and evaluation of targeted therapy for abdominal tumors.