[Radiological evaluation on the efficacy of neoadjuvant therapy for gastrointestinal tumors]

Neoadjuvant therapy can benefit the patients with locally advanced tumors of the gastrointestinal tract through the increase of the likelihood of radical resection. Radiology is the common modalities to evaluate the efficacy of neoadjuvant therapy, which plays an important role in the achievement of the individualized tumor treatment. Radiological modalities in the evaluation of response mainly include CT, MRI, and PET. RECIST is the commonly used criteria internationally in the response evaluation of solid tumors, the value of which is however limited in gastrointestinal tumor due to no measurable target lesion in most circumstances. To overcome the above disadvantage, recent researches have been mainly focusing on functional imaging. There have been primary exciting results in the study of PET and DWI, which have the potential to provide new approaches for the response evaluation of gastrointestinal tumors. The stability of the performance of various radiological modalities depends on the normalization and standardization of the process, through which the reproducibility and comparability between the pre- and post-treatment imaging data is guaranteed.