Appropriateness and limitations of modified response evaluation criteria in solid tumors (mRECIST) in evaluating the efficacy of molecular-targeted therapy for patients with hepatocellular carcinoma

Modified Response Evaluation Criteria in Solid Tumors (mRECIST), which was proposed by Lencioni et al, is novel criteria used to evaluate the efficacy of molecular-targeted therapy (MTT) in patients with hepatocellular carcinoma by measuring the largest diameter of the enhanced area in the arterial phase of dynamic computed tomography. We have encountered several limitations of mRECIST. Here, we discussed these limitations and presented some impressive cases. One of the main limitations is whether we can regard the disappearance of arterial blood flow as a complete response. Moreover, several other limitations were noted as well. It is thought that mRECIST may be more useful than conventional RECIST in many cases. However, it should be recognized that mRECIST is not appropriate in all cases. We need to evaluate the clinical effects with medical images and tumor markers in clinical practice. (author)