Current Status of Imaging Assessment of Cancer Response to Immunotherapy

Immune checkpoint inhibitors have already been the promising novel treatment of cancer therapy. The response pattern of immunotherapy is different from that of traditional cytotoxic therapies and may present delayed response, pseudoprogression or hyperprogression. Traditional RECIST is difficult to identify new treatment response patterns, thus underestimating the efficacy of immunotherapy. Therefore, a series of criteria for evaluating the efficacy of immunotherapy, such as iRECIST, emerged. This paper reviews the recent progress and application of imaging methods in the evaluation criteria of immunotherapy efficacy.